Production & Supply Chain
Everything About Hydrogen Podcast: Improving PEM Efficiency
Jan 2023
Publication
On this episode of EAH we sat down with Alejandro Oyarce Barnett Chief Technology Officer and Co-Founder at Hystar. Hystar is a technology-focused company specializing in PEM electrolysers for hydrogen production using renewable energy. The company got its start as a spin-off from SINTEF one of Europe’s largest independent research organizations and has raised private funding so the company can focus on production of its high-efficiency PEM units and keep pace with demand for hydrogen generation capacity. Hystar announced on January 11 2023 that the company has closed a Series B funding round of USD 26mn to rapidly scale-up to full commercial operations with an automated GW-capacity production line by 2025. Alejandro joined us to discuss in more detail the origins of Hystar its technology and the mission at the core of the company.
The podcast can be found on their website.
The podcast can be found on their website.
Exploring Machine Learning Approaches for Biohydrogen Production through Dark Fermentation in Wastewater
Jul 2025
Publication
The global dependence on fossil fuels continues to contribute to greenhouse gas emissions driving the search for cleaner energy alternatives like biohydrogen. Dark fermentation has emerged as a promising method for sustainable hydrogen production while simultaneously treating wastewater. However optimizing biohydrogen yields remains challenging due to the complexity of biological interactions and environmental factors. Machine learning (ML) offers a data-driven approach to predict and enhance hydrogen production efficiency. In this review recent studies employing ML techniques are systematically analyzed to evaluate their role in modeling and optimizing biohydrogen generation through dark fermentation. This review examines various ML models including artificial neural networks support vector machines decision trees and gradient boosting techniques for their effectiveness in optimizing fermentation conditions. Unlike traditional models like Monod kinetics the anaerobic digestion model no.1 (ADM1) and response surface methodology (RSM) which are limited by fixed input ranges results indicate that ML models outperform traditional statistical methods with CatBoost achieving an R2 of 0.98 and SVM reaching 0.988. Key influencing factors include chemical oxygen demand nickel concentration and butyrate levels. Furthermore the review also highlights methodological gaps prioritization of lifecycle assessments and cost-benefit analyses and also provides insights into the future integration of ML with experimental workflows. While ML-driven optimization has significantly improved hydrogen yields further research is required to refine models expand datasets and improve scalability for industrial applications.
Biogas Reforming as a Sustainable Solution for Hydrogen Production: Comparative Environmental Metrics with Steam-methane Reforming and Water Electrolysis in the Portuguese Context
Apr 2024
Publication
This study delves into the dynamics of hydrogen production with a specific focus on biogas reforming (BGSMR) for hydrogen generation. It compares the environmental impact of this solution with hydrogen production from natural gas-steam reforming (NGSMR) and commercial electrolysis in the Portuguese context. Various metrics including carbon footprint water depletion energy utilization and waste valorization are employed for a comprehensive comparison. The assessment explores the impact of operational parameters and different off-gas combustion scenarios incorporating water recycling practices. Due to challenges in obtaining detailed data on the actual reforming process the study relies on process simulation techniques primarily using DWSIM. Commercially available data for water electrolysers were used for comparison. In the context of decarbonizing power systems hydrogen from water electrolysis emerges as a competitive option only in a scenario where the power system is 100% reliant on renewable sources particularly with respect to the carbon footprint metric. Biogas systems characterized by near-zero carbon emissions stand out as a favourable option from the near future to the long run. This research contributes valuable insights into the dynamics of hydrogen production shedding light on environmentally viable alternatives across a range of power system scenarios.
Influence of Renewable Energy Power Fluctuations on Water Electrolysis for Green Hydrogen Production
Nov 2022
Publication
The development of renewable energy technologies is essential to achieve carbon neutrality. Hydrogen can be stably stored and transported in large quantities to maximize power utilization. Detailed understanding of the characteristics and operating methods of water electrolysis technologies in which naturally intermittent fluctuating power is used directly is required for green hydrogen production because fluctuating power-driven water electrolysis processes significantly differ from industrial water electrolysis processes driven by steady grid power. Thus it is necessary to overcome several issues related to the direct use of fluctuating power. This article reviews the characteristics of fluctuating power and its generation as well as the current status and issues related to the operation conditions water electrolyzer configuration system requirements stack/catalyst durability and degradation mechanisms under the direct use of fluctuating power sources. It also provides an accelerated degradation test protocol method for fair catalyst performance comparison and share of effective design directions. Finally it discusses potential challenges and recommendations for further improvements in water electrolyzer components and systems suitable for practical use suggesting that a breakthrough could be realized toward the achievement of a sustainable hydrogen-based society.
Decarbonization in Ammonia Production, New Technological Methods in Industrial Scale Ammonia Production and Critical Evaluations
Oct 2021
Publication
With the synthesis of ammonia with chemical methods global carbon emission is the biggest threat to global warming. However the dependence of the agricultural industry on ammonia production brings with it various research studies in order to minimize the carbon emission that occurs with the ammonia synthesis process. In order to completely eliminate the carbon emissions from ammonia production both the hydrogen and the energy needed for the operation of the process must be obtained from renewable sources. Thus hydrogen can be produced commercially in a variety of ways. Many processes are discussed to accompany the Haber Bosch process in ammonia production as potential competitors. In addition to parameters such as temperature and pressure various plasma catalysts are being studied to accelerate the ammonia production reaction. In this study various alternative processes for the capture storage and complete removal of carbon gas released during the current ammonia production are evaluated and the current conditions related to the applicability of these processes are discussed. In addition it has been discussed under which conditions it is possible to produce larger capacities as needed in the processes studied in order to reduce carbon gas emissions during ammonia production in order to provide raw material source for fertilizer production and energy sector. However if the hydrogen gas required for ammonia production is produced using a solid oxide electrolysis cell the reduction in the energy requirement of the process and in this case the reduction of energy costs shows that it will play an important role in determining the method to be used for ammonia production. In addition it is predicted that working at lower temperature (<400 °C) and pressure (<10 bar) values in existing ammonia production technologies despite increasing possible energy costs will significantly reduce process operating costs.
Thermochemical Looping Technologies for Clean Hydrogen Production – Current Status and Recent Advances
Nov 2022
Publication
This review critically analyses various aspects of the most promising thermochemical cycles for clean hydrogen production. While the current hydrogen market heavily relies on fossil-fuel-based platforms the thermochemical water-splitting systems based on the reduction-oxidation (redox) looping reactions have a significant potential to significantly contribute to the sustainable production of green hydrogen at scale. However compared to the water electrolysis techniques the thermochemical cycles suffer from a low technology readiness level (TRL) which retards the commercial implementation of these technologies. This review mainly focuses on identifying the capability of the state-of-the-art thermochemical cycles to deploy large-scale hydrogen production plants and their techno-economic performance. This study also analyzed the potential integration of the hybrid looping systems with the solar and nuclear reactor designs which are evidenced to be more cost-effective than the electrochemical water-splitting methods but it excludes fossil-based thermochemical processes such as gasification steam methane reforming and pyrolysis. Further investigation is still required to address the technical issues associated with implementing the hybrid thermochemical cycles in order to bring them to the market for sustainable hydrogen production.
Bioanode as a Limiting Factor to Biocathode Performance in Microbial Electrolysis Cells
Mar 2017
Publication
The bioanode is important for a microbial electrolysis cell (MEC) and its robustness to maintain its catalytic activity affects the performance of the whole system. Bioanodes enriched at a potential of +0.2 V (vs. standard hydrogen electrode) were able to sustain their oxidation activity when the anode potential was varied from -0.3 up to +1.0 V. Chronoamperometric test revealed that the bioanode produced peak current density of 0.36 A/m2 and 0.37 A/m2 at applied potential 0 and +0.6 V respectively. Meanwhile hydrogen production at the biocathode was proportional to the applied potential in the range from -0.5 to -1.0 V. The highest production rate was 7.4 L H2/(m2 cathode area)/day at -1.0 V cathode potential. A limited current output at the bioanode could halt the biocathode capability to generate hydrogen. Therefore maximum applied potential that can be applied to the biocathode was calculated as -0.84 V without overloading the bioanode.
Pathways to Hydrogen as an Energy Carrier
Feb 2007
Publication
When hydrogen is used as an alternative energy carrier it is very important to understand the pathway from the primary energy source to the final use of the carrier. This involves for example the understanding of greenhouse gas emissions associated with the production of hydrogen and throughout the lifecycle of a given utilization pathway as well as various energy or exergy1 efficiencies and aspects involved. This paper which is based on a talk given at the Royal Society in London assesses and reviews the various production pathways for hydrogen with emphasis on emissions energy use and energy efficiency. The paper also views some aspects of the breaking of the water molecule and examines some new emerging physical evidence which could pave the way to a new and more feasible pathway.
Link to document download on Royal Society Website
Link to document download on Royal Society Website
Dynamic System Modeling of Thermally-integrated Concentrated PV-electrolysis
Feb 2021
Publication
Understanding the dynamic response of a solar fuel processing system utilizing concentrated solar radiation and made of a thermally-integrated photovoltaic (PV) and water electrolyzer (EC) is important for the design development and implementation of this technology. A detailed dynamic non-linear process model is introduced for the fundamental system components (i.e. PV EC pump etc.) in order to investigate the coupled system behavior and performance synergy notably arising from the thermal integration. The nominal hydrogen production power is ∼2 kW at a hydrogen system efficiency of 16–21% considering a high performance triple junction III-V PV module and a proton exchange membrane EC. The device operating point relative to the maximum power point of the PV was shown to have a differing influence on the system performance when subject to temperature changes. The non-linear coupled behavior was characterised in response to step changes in water flowrate and solar irradiance and hysteresis of the current-voltage operating point was demonstrated. Whilst the system responds thermally to changes in operating conditions in the range of 0.5–2 min which leads to advantageously short start-up times a number of control challenges are identified such as the impact of pump failure electrical PV-EC disconnection and the potentially damaging accentuated temperature rise at lower water flowrates. Finally the simulation of co-generation of heat and hydrogen for various operating conditions demonstrates the significant potential for system efficiency enhancements and the required development of control strategies for demand matching is discussed.
Pyrolysis-catalytic Steam Reforming of Agricultural Biomass Wastes and Biomass Components for Production of Hydrogen/syngas
Oct 2018
Publication
The pyrolysis-catalytic steam reforming of six agricultural biomass waste samples as well as the three main components of biomass was investigated in a two stage fixed bed reactor. Pyrolysis of the biomass took place in the first stage followed by catalytic steam reforming of the evolved pyrolysis gases in the second stage catalytic reactor. The waste biomass samples were rice husk coconut shell sugarcane bagasse palm kernel shell cotton stalk and wheat straw and the biomass components were cellulose hemicellulose (xylan) and lignin. The catalyst used for steam reforming was a 10 wt.% nickel-based alumina catalyst (NiAl2O3). In addition the thermal decomposition characteristics of the biomass wastes and biomass components were also determined using thermogravimetric analysis (TGA). The TGA results showed distinct peaks for the individual biomass components which were also evident in the biomass waste samples reflecting the existence of the main biomass components in the biomass wastes. The results for the two-stage pyrolysis-catalytic steam reforming showed that introduction of steam and catalyst into the pyrolysis-catalytic steam reforming process significantly increased gas yield and syngas production notably hydrogen. For instance hydrogen composition increased from 6.62 to 25.35 mmol g 1 by introducing steam and catalyst into the pyrolysis-catalytic steam reforming of palm kernel shell. Lignin produced the most hydrogen compared to cellulose and hemicellulose at 25.25 mmol g 1. The highest residual char production was observed with lignin which produced about 45 wt.% char more than twice that of cellulose and hemicellulose.
Significantly Enhanced Electrocatalytic Activity of Copper for Hydrogen Evolution Reaction Through Femtosecond Laser Blackening
Jan 2021
Publication
In this work we report on the creation of a black copper via femtosecond laser processing and its application as a novel electrode material. We show that the black copper exhibits an excellent electrocatalytic activity for hydrogen evolution reaction (HER) in alkaline solution. The laser processing results in a unique microstructure: microparticles covered by finer nanoparticles on top. Electrochemical measurements demonstrate that the kinetics of the HER is significantly accelerated after bare copper is treated and turned black. At −0.325 V (v.s. RHE) in 1 M KOH aqueous solution the calculated area-specific charge transfer resistance of the electrode decreases sharply from 159 Ω cm2 for the untreated copper to 1 Ω cm2 for the black copper. The electrochemical surface area of the black copper is measured to be only 2.4 times that of the untreated copper and therefore the significantly enhanced electrocatalytic activity of the black copper for HER is mostly a result of its unique microstructure that favors the formation and enrichment of protons on the surface of copper. This work provides a new strategy for developing high-efficient electrodes for hydrogen generation.
Multi-Tubular Reactor for Hydrogen Production CFD Thermal Design and Experimental Testing
Jan 2019
Publication
This study presents the Computational Fluid Dynamics (CFD) thermal design and experimental tests results for a multi-tubular solar reactor for hydrogen production based on the ferrite thermochemical cycle in a pilot plant in the Plataforma Solar de Almería (PSA). The methodology followed for the solar reactor design is described as well as the experimental tests carried out during the testing campaign and characterization of the reactor. The CFD model developed for the thermal design of the solar reactor has been validated against the experimental measurements with a temperature error ranging from 1% to around 10% depending on the location within the reactor. The thermal balance in the reactor (cavity and tubes) has been also solved by the CFD model showing a 7.9% thermal efficiency of the reactor. CFD results also show the percentage of reacting media inside the tubes which achieve the required temperature for the endothermic reaction process with 90% of the ferrite pellets inside the tubes above the required temperature of 900 °C. The multi-tubular solar reactor designed with aid of CFD modelling and simulations has been built and operated successfully
Production of H2-rich Syngas from Excavated Landfill Waste through Steam Co-gasification with Biochar
Jun 2020
Publication
Gasification of excavated landfill waste is one of the promising options to improve the added-value chain during remediation of problematic old landfill sites. Steam gasification is considered as a favorable route to convert landfill waste into H2-rich syngas. Co-gasification of such a poor quality landfill waste with biochar or biomass would be beneficial to enhance the H2 concentration in the syngas as well as to improve the gasification performance. In this work steam co-gasification of landfill waste with biochar or biomass was carried out in a lab-scale reactor. The effect of the fuel blending ratio was investigated by varying the auxiliary fuel content in the range of 15e35 wt%. Moreover co-gasification tests were carried out at temperatures between 800 and 1000°C. The results indicate that adding either biomass or biochar enhances the H2 yield where the latter accounts for the syngas with the highest H2 concentration. At 800°C the addition of 35 wt% biochar can enhance the H2 concentration from 38 to 54 vol% and lowering the tar yield from 0.050 to 0.014 g/g-fuel-daf. No apparent synergetic effect was observed in the case of biomass co-gasification which might cause by the high Si content of landfill waste. In contrast the H2 production increases non-linearly with the biochar share in the fuel which indicates that a significant synergetic effect occurs during co-gasification due to the reforming of tar over biochar. Increasing the temperature of biochar co-gasification from 800 to 1000°C elevates the H2 concentration but decreases the H2/CO ratio and increases the tar yield. Furthermore the addition of biochar also enhances the gasification efficiency as indicated by increased values of the energy yield ratio.
Efficient Hydrogen Production with CO2 Capture Using Gas Switching Reforming
Jul 2019
Publication
Hydrogen is a promising carbon-neutral energy carrier for a future decarbonized energy sector. This work presents process simulation studies of the gas switching reforming (GSR) process for hydrogen production with integrated CO2 capture (GSR-H2 process) at a minimal energy penalty. Like the conventional steam methane reforming (SMR) process GSR combusts the off-gas fuel from the pressure swing adsorption unit to supply heat to the endothermic reforming reactions. However GSR completes this combustion using the chemical looping combustion mechanism to achieve fuel combustion with CO2 separation. For this reason the GSR-H2 plant incurred an energy penalty of only 3.8 %-points relative to the conventional SMR process with 96% CO2 capture. Further studies showed that the efficiency penalty is reduced to 0.3 %-points by including additional thermal mass in the reactor to maintain a higher reforming temperature thereby facilitating a lower steam to carbon ratio. GSR reactors are standalone bubbling fluidized beds that will be relatively easy to scale up and operate under pressurized conditions and the rest of the process layout uses commercially available technologies. The ability to produce clean hydrogen with no energy penalty combined with this inherent scalability makes the GSR-H2 plant a promising candidate for further research.
Opportunities and Challenges for Thermally Driven Hydrogen Production Using Reverse Electrodialysis System
Jul 2019
Publication
Ongoing and emerging renewable energy technologies mainly produce electric energy and intermittent power. As the energy economy relies on banking energy there is a rising need for chemically stored energy. We propose heat driven reverse electrodialysis (RED) technology with ammonium bicarbonate (AmB) as salt for producing hydrogen. The study provides the authors’ perspective on the commercial feasibility of AmB RED for low grade waste heat (333 K–413 K) to electricity conversion system. This is to our best of knowledge the only existing study to evaluate levelized cost of energy of a RED system for hydrogen production. The economic assessment includes a parametric study and a scenario analysis of AmB RED system for hydrogen production. The impact of various parameters including membrane cost membrane lifetime cost of heating inter-membrane distance and residence time are studied. The results from the economic study suggests RED system with membrane cost less than 2.86 €/m2 membrane life more than 7 years and a production rate of 1.19 mol/m2/h or more are necessary for RED to be economically competitive with the current renewable technologies for hydrogen production. Further salt solubility residence time and inter-membrane distance were found to have impact on levelized cost of hydrogen LCH. In the present state use of ammonium bicarbonate in RED system for hydrogen production is uneconomical. This may be attributed to high membrane cost low (0.72 mol/m2/h) hydrogen production rate and large (1281436 m2) membrane area requirements. There are three scenarios presented the present scenario market scenario and future scenario. From the scenario analysis it is clear that membrane cost and membrane life in present scenario controls the levelized cost of hydrogen. In market scenario and future scenario the hydrogen production rate (which depends on membrane properties inter-membrane distance etc.) the cost of regeneration system and the cost of heating controls the levelized cost of hydrogen. For a thermally driven RED system to be economically feasible the membrane cost not more than 20 €/m2; hydrogen production rate of 3.7 mol/m2/h or higher and cost of heating not more than 0.03 €/kWh for low grade waste heat to hydrogen production.
Pathways to Low-cost Clean Hydrogen Production with Gas Switching Reforming
Feb 2020
Publication
Gas switching reforming (GSR) is a promising technology for natural gas reforming with inherent CO2 capture. Like conventional steam methane reforming (SMR) GSR can be integrated with CO2 -gas shift and pressure swing adsorption units for pure hydrogen production. The resulting GSR-H2 process concept was techno-economically assessed in this study. Results showed that GSR-H2 can achieve 96% CO2 capture at a CO2 avoidance cost of 15 $/ton (including CO2 transport and storage). Most components of the GSR-H2 process are proven technologies but long-term oxygen carrier stability presents an important technical uncertainty that can adversely affect competitiveness when the material lifetime drops below one year. Relative to the SMR benchmark GSR-H2 replaces some fuel consumption with electricity consumption making it more suitable to regions with higher natural gas prices and lower electricity prices. Some minor alterations to the process configuration can adjust the balance between fuel and electricity consumption to match local market conditions. The most attractive commercialization pathway for the GSR-H2 technology is initial construction without CO2 capture followed by simple retrofitting for CO2 capture when CO2 taxes rise and CO2 transport and storage infrastructure becomes available. These features make the GSR-H2 technology robust to almost any future energy market scenario.
Dynamic Simulation of Different Transport Options of Renewable Hydrogen to a Refinery in a Coupled Energy System Approach
Sep 2018
Publication
Three alternative transport options for hydrogen generated from excess renewable power to a refinery of different scales are compared to the reference case by means of hydrogen production cost overall efficiency and CO2 emissions. The hydrogen is transported by a) the natural gas grid and reclaimed by the existing steam reformer b) an own pipeline and c) hydrogen trailers. The analysis is applied to the city of Hamburg Germany for two scenarios of installed renewable energy capacities. The annual course of excess renewable power is modelled in a coupled system approach and the replaceable hydrogen mass flow rate is determined using measurement data from an existing refinery. Dynamic simulations are performed using an open-source Modelica® library. It is found that in all three alternative hydrogen supply chains CO2 emissions can be reduced and costs are increased compared to the reference case. Transporting hydrogen via the natural gas grid is the least efficient but achieves the highest emission reduction and is the most economical alternative for small to medium amounts of hydrogen. Using a hydrogen pipeline is the most efficient option and slightly cheaper for large amounts than employing the natural gas grid. Transporting hydrogen by trailers is not economical for single consumers and realizes the lowest CO2 reductions.
Hydrogen Production by Steam Reforming of DME in a Large Scale CFB Reactor. Part I: Computational Model and Predictions
Oct 2015
Publication
This study presents a computational fluid dynamic (CFD) study of Dimethyl Ether steam reforming (DME-SR) in a large scale Circulating Fluidized Bed (CFB) reactor. The CFD model is based on Eulerian–Eulerian dispersed flow and solved using commercial software (ANSYS FLUENT). The DME-SR reactions scheme and kinetics in the presence of a bifunctional catalyst of CuO/ZnO/Al2O3+ZSM-5 were incorporated in the model using in-house developed user-defined function. The model was validated by comparing the predictions with experimental data from the literature. The results revealed for the first time detailed CFB reactor hydrodynamics gas residence time temperature distribution and product gas composition at a selected operating condition of 300 °C and steam to DME mass ratio of 3 (molar ratio of 7.62). The spatial variation in the gas species concentrations suggests the existence of three distinct reaction zones but limited temperature variations. The DME conversion and hydrogen yield were found to be 87% and 59% respectively resulting in a product gas consisting of 72 mol% hydrogen. In part II of this study the model presented here will be used to optimize the reactor design and study the effect of operating conditions on the reactor performance and products.
A Perspective on Hydrogen Investment, Deployment and Cost Competitiveness
Feb 2021
Publication
Deployment and investments in hydrogen have accelerated rapidly in response to government commitments to deep decarbonisation establishing hydrogen as a key component in the energy transition.
To help guide regulators decision-makers and investors the Hydrogen Council collaborated with McKinsey & Company to release the report ‘Hydrogen Insights 2021: A Perspective on Hydrogen Investment Deployment and Cost Competitiveness’. The report offers a comprehensive perspective on market deployment around the world investment momentum as well as implications on cost competitiveness of hydrogen solutions.
The document can be downloaded from their website
To help guide regulators decision-makers and investors the Hydrogen Council collaborated with McKinsey & Company to release the report ‘Hydrogen Insights 2021: A Perspective on Hydrogen Investment Deployment and Cost Competitiveness’. The report offers a comprehensive perspective on market deployment around the world investment momentum as well as implications on cost competitiveness of hydrogen solutions.
The document can be downloaded from their website
Asymmetric Solvation of the Zinc Dimer Cation Revealed by Infrared Multiple Photon Dissociation Spectroscopy of Zn2+(H2O)n (n = 1–20)
Jun 2021
Publication
Investigating metal-ion solvation—in particular the fundamental binding interactions—enhances the understanding of many processes including hydrogen production via catalysis at metal centers and metal corrosion. Infrared spectra of the hydrated zinc dimer (Zn2+(H2O)n; n = 1–20) were measured in the O–H stretching region using infrared multiple photon dissociation (IRMPD) spectroscopy. These spectra were then compared with those calculated by using density functional theory. For all cluster sizes calculated structures adopting asymmetric solvation to one Zn atom in the dimer were found to lie lower in energy than structures adopting symmetric solvation to both Zn atoms. Combining experiment and theory the spectra show that water molecules preferentially bind to one Zn atom adopting water binding motifs similar to the Zn+(H2O)n complexes studied previously. A lower coordination number of 2 was observed for Zn2+(H2O)3 evident from the highly red-shifted band in the hydrogen bonding region. Photodissociation leading to loss of a neutral Zn atom was observed only for n = 3 attributed to a particularly low calculated Zn binding energy for this cluster size.
Parametric Study of Pt/C-Catalysed Hydrothermal Decarboxylation of Butyric Acid as a Potential Route for Biopropane Production
Jun 2021
Publication
Sustainable fuel-range hydrocarbons can be produced via the catalytic decarboxylation of biomass-derived carboxylic acids without the need for hydrogen addition. In this present study 5 wt% platinum on carbon (Pt/C) has been found to be an effective catalyst for hydrothermally decarboxylating butyric acid in order to produce mainly propane and carbon dioxide. However optimisation of the reaction conditions is required to minimise secondary reactions and increase hydrocarbon selectivity towards propane. To do this reactions using the catalyst with varying parameters such as reaction temperatures residence times feedstock loading and bulk catalyst loading were carried out in a batch reactor. The highest yield of propane obtained was 47 wt% (close to the theoretical decarboxylation yield of 50 wt% on butyric acid basis) corresponding to a 96% hydrocarbon selectivity towards propane. The results showed that the optimum parameters to produce the highest yield of propane from the range investigated were 0.5 g butyric acid (0.57 M aqueous solution) 1.0 g Pt/C (50 mg Pt content) at 300 °C for 1 h. The reusability of the catalyst was also investigated which showed little or no loss of catalytic activity after four cycles. This work has shown that Pt/C is a suitable and potentially hydrothermally stable heterogeneous catalyst for making biopropane a major component of bioLPG from aqueous butyric acid solutions which can be sourced from bio-derived feedstocks via acetone-butanol-ethanol (ABE) fermentation.
Hydrogen Generation from Wood Chip and Biochar by Combined Continuous Pyrolysis and Hydrothermal Gasification
Jun 2021
Publication
Hydrothermal gasification (HTG) experiments were carried out to extract hydrogen from biomass. Although extensive research has been conducted on hydrogen production with HTG limited research exists on the use of biochar as a raw material. In this study woodland residues (wood chip) and biochar from wood-chip pyrolysis were used in HTG treatment to generate hydrogen. This research investigated the effect of temperature (300–425 °C) and biomass/water (0.5–10) ratio on gas composition. A higher temperature promoted hydrogen production because the water–gas shift reaction and steam-reforming reaction were promoted with an increase in temperature. The methane concentration was related positively to temperature because of the methanation and hydrogenation reactions. A lower biomass/water ratio promoted hydrogen production but suppressed carbon-monoxide production. Most reactions that produce hydrogen consume water but water also affects the water–gas shift reaction balance which decreases the carbon-monoxide concentration. By focusing on the practical application of HTG we attempted biochar treatment by pyrolysis (temperature of heating part: 700 °C) and syngas was obtained from hydrothermal treatment above 425 °C.
Progress and Prospects of Hydrogen Production: Opportunities and challenges
Jan 2021
Publication
This study presents an overview of the current status of hydrogen production in relation to the global requirement for energy and resources. Subsequently it symmetrically outlines the advantages and disadvantages of various production routes including fossil fuel/biomass conversion water electrolysis microbial fermentation and photocatalysis (PC) in terms of their technologies economy energy consumption and costs. Considering the characteristics of hydrogen energy and the current infrastructure issues it highlights that onsite production is indispensable and convenient for some special occasions. Finally it briefly summarizes the current industrialization situation and presents future development and research directions such as theoretical research strengthening renewable raw material development process coupling and sustainable energy use.
Metal‐Supported Biochar Catalysts for Sustainable Biorefinery, Electrocatalysis and Energy Storage Applications: A Review
Feb 2022
Publication
Biochar (BCH) is a carbon‐based bio‐material produced from thermochemical conversion of biomass. Several activation or functionalization methods are usually used to improve physicochemical and functional properties of BCHs. In the context of green and sustainable future development activated and functionalized biochars with abundant surface functional groups and large surface area can act as effective catalysts or catalyst supports for chemical transformation of a range of bioproducts in biorefineries. Above the well‐known BCH applications their use as adsorbents to remove pollutants are the mostly discussed although their potential as catalysts or catalyst supports for advanced (electro)catalytic processes has not been comprehensively explored. In this review the production/activation/functionalization of metal‐supported biochar (M‐BCH) are scrutinized giving special emphasis to the metal‐functionalized biochar‐based (electro)catalysts as promising catalysts for bioenergy and bioproducts production. Their performance in the fields of biorefinery processes and energy storage and conversion as electrode materials for oxygen and hydrogen evolutions oxygen reduction and supercapacitors are also reviewed and discussed.
Estimation of Hydrogen Production using Wind Energy in Algeria
Aug 2015
Publication
In response to problems involved in the current crisis of petrol in Algeria with the decrease in the price of the oil barrel the rate of growth in domestic electricity demand and with an associated acceleration of global warming as a result of significantly increased greenhouse gas (GHG) emissions renewable energy seems today as a clean and strategic substitution for the next decades. However the greatest obstacles which face electric energy comes from renewable energy systems are often referred to the intermittency of these sources as well as storage and transport problems the need for their conversion into a versatile energy carrier in its use storable transportable and environmentally acceptable are required. Among all the candidates answering these criteria hydrogen presents the best answer. In the present work particular attention is paid to the production of hydrogen from wind energy. The new wind map of Algeria shows that the highest potential wind power was found in Adrar Hassi-R'Mel and Tindouf regions. The data obtained from these locations have been analyzed using Weibull probability distribution function. The wind energy produced in these locations is exploited for hydrogen production through water electrolysis. The objective of this paper is to realize a technological platform allowing the evaluation of emergent technologies of hydrogen production from wind energy using four wind energy conversion systems of 600 1250 1500 and 2000 kW rated capacity. The feasibility study shows that using wind energy in the selected sites is a promising solution. It is shown that the turbine " De Wind D7" is sufficient to supply the electricity and hydrogen with a least cost and a height capacity factor. The minimum cost of hydrogen production of 1.214 $/kgH2 is obtained in Adrar.
Conceptual Design of Pyrolytic Oil Upgrading Process Enhanced by Membrane-Integrated Hydrogen Production System
May 2019
Publication
Hydrotreatment is an efficient method for pyrolytic oil upgrading; however the trade-off between the operational cost on hydrogen consumption and process profit remains the major challenge for the process designs. In this study an integrated process of steam methane reforming and pyrolytic oil hydrotreating with gas separation system was proposed conceptually. The integrated process utilized steam methane reformer to produce raw syngas without further water–gas-shifting; with the aid of a membrane unit the hydrogen concentration in the syngas was adjusted which substituted the water–gas-shift reactor and improved the performance of hydrotreater on both conversion and hydrogen consumption. A simulation framework for unit operations was developed for process designs through which the dissipated flow in the packed-bed reactor along with membrane gas separation unit were modelled and calculated in the commercial process simulator. The evaluation results showed that the proposed process could achieve 63.7% conversion with 2.0 wt% hydrogen consumption; the evaluations of economics showed that the proposed process could achieve 70% higher net profit compared to the conventional plant indicating the potentials of the integrated pyrolytic oil upgrading process.
End of Life of Fuel Cells and Hydrogen Products: From Technologies to Strategies
Feb 2019
Publication
End-of-Life (EoL) technologies and strategies are needed to support the deployment of fuel cells and hydrogen (FCH) products. This article explores current and novel EoL technologies to recover valuable materials from the stacks of proton exchange membrane fuel cells and water electrolysers alkaline water electrolysers and solid oxide fuel cells. Current EoL technologies are mainly based on hydrometallurgical and pyro-hydrometallurgical methods for the recovery of noble metals while novel methods attempt to recover additional materials through efficient safe and cost-competitive pathways. Strengths weaknesses opportunities and threats of the reviewed EoL technologies are identified under techno-economic environmental and regulatory aspects. Beyond technologies strategies for the EoL of FCH stacks are defined mainly based on the role of manufacturers and recovery centres in the short- mid- and long-term. In this regard a dual role manufacturer/recovery centre would characterise long-term scenarios within a potential context of a well-established hydrogen economy.
Compact Heat Integrated Reactor System of Steam Reformer, Shift Reactor and Combustor for Hydrogen Production from Ethanol
Jun 2020
Publication
A compact heat integrated reactor system (CHIRS) of a steam reformer a water gas shift reactor and a combustor were designed for stationary hydrogen production from ethanol. Different reactor integration concepts were firstly studied using Aspen Plus. The sequential steam reformer and shift reactor (SRSR) was considered as a conventional system. The efficiency of the SRSR could be improved by more than 12% by splitting water addition to the shift reactor (SRSR-WS). Two compact heat integrated reactor systems (CHIRS) were proposed and simulated by using COMSOL Multiphysics software. Although the overall efficiency of the CHIRS was quite a bit lower than the SRSR-WS the compact systems were properly designed for portable use. CHIRS (I) design combining the reactors in a radial direction was large in reactor volume and provided poor temperature control. As a result the ethanol steam reforming and water gas shift reactions were suppressed leading to lower hydrogen selectivity. On the other hand CHIRS (II) design combining the process in a vertical direction provided better temperature control. The reactions performed efficiently resulting in higher hydrogen selectivity. Therefore the high performance CHIRS (II) design is recommended as a suitable stationary system for hydrogen production from ethanol.
Economic Viability and Environmental Efficiency Analysis of Hydrogen Production Processes for the Decarbonization of Energy Systems
Aug 2019
Publication
The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen if produced efficiently can play a pivotal role in decarbonizing the global energy systems. Therefore this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA) with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria including capital cost feedstock cost O&M cost hydrogen production and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally slack-based DEA computed the efficiency of alternatives. Among the 11 three alternatives (wind electrolysis PV electrolysis and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.
Promotion Effect of Proton-conducting Oxide BaZr0.1Ce0.7Y0.2O3−δ on the Catalytic Activity of Ni Towards Ammonia Synthesis from Hydrogen and Nitrogen
Aug 2018
Publication
In this report for the first time it has been observed that proton-conducting oxide BaZr0.1Ce0.7Y0.2O3−δ (BZCY) has significant promotion effect on the catalytic activity of Ni towards ammonia synthesis from hydrogen and nitrogen. Renewable hydrogen can be used for ammonia synthesis to save CO2 emission. By investigating the operating parameters of the reaction the optimal conditions for this catalyst were identified. It was found that at 620 °C with a total flow rate of 200 mL min−1 and a H2/N2 mol ratio of 3 an activity of approximately 250 μmol g−1 h−1 can be achieved. This is ten times larger than that for the unpromoted Ni catalyst under the same conditions although the stability of both catalysts in the presence of steam was not good. The specific activity of Ni supported on proton-conducting oxide BZCY is approximately 72 times higher than that of Ni supported on non-proton conductor MgO-CeO2. These promotion effects were suspected to be due to the proton conducting nature of the support. Therefore it is proposed that the use of proton conducting support materials with highly active ammonia synthesis catalysts such as Ru and Fe will provide improved activity of at lower temperatures.
Hydrogen Production and Subsequent Adsorption/Desorption Process within a Modified Unitized Regenerative Fuel Cell
Apr 2019
Publication
For sustainable and incremental growth mankind is adopting renewable sources of energy along with storage systems. Storing surplus renewable energy in the form of hydrogen is a viable solution to meet continuous energy demands. In this paper the concept of electrochemical hydrogen storage in a solid multi-walled carbon nanotube (MWCNT) electrode integrated in a modified unitized regenerative fuel cell (URFC) is investigated. The method of solid electrode fabrication from MWCNT powder and egg white as an organic binder is disclosed. The electrochemical testing of a modified URFC with an integrated MWCNT-based hydrogen storage electrode is performed and reported. Galvanostatic charging and discharging was carried out and results analyzed to ascertain the electrochemical hydrogen storage capacity of the fabricated electrode. The electrochemical hydrogen storage capacity of the porous MWCNT electrode is found to be 2.47 wt% which is comparable with commercially available AB5-based hydrogen storage canisters. The obtained results prove the technical feasibility of a modified URFC with an integrated MWCNT-based hydrogen storage electrode which is the first of its kind. This is surelya step forward towards building a sustainable energy economy
The Role of Effectiveness Factor on the Modeling of Methanol Steam Reforming Over CuO/ZnO/Al2O3 Catalyst in a Multi-tubular Reactor
Jan 2022
Publication
A pseudo-homogeneous model for the methanol steam reforming process was developed based on reaction kinetics over a CuO/ZnO/Al2O3 catalyst and non-adiabatic heat and mass transfer performances in a co-current packed-bed reactor. A Thiele modulus method and an intraparticle distribution method were applied for predicting the effectiveness factors for main reactions and providing insights into the diffusion-reaction process in a cylindrical catalyst pellet. The results of both methods are validated and show good agreements with the experimental data but the intraparticle distribution method provides better predictions. Results indicate that increases in catalyst size and bulk fluid temperature amplify the impact of intraparticle diffusion limitations showing a decrease in effectiveness factors. To satisfy the requirements of a high temperature polymer electrolyte membrane fuel cell stack the optimized operating conditions which bring the methanol and CO concentrations to less than 1% vol in the reformate stream are determined based on the simulation results.
Progress in Catalytic Hydrogen Production from Formic Acid over Supported Metal Complexes
Mar 2021
Publication
Formic acid is a liquid organic hydrogen carrier giving hydrogen on demand using catalysts. Metal complexes are known to be used as efficient catalysts for the hydrogen production from formic acid decomposition. Their performance could be better than those of supported catalysts with metal nanoparticles. However difficulties to separate metal complexes from the reaction mixture limit their industrial applications. This problem can be resolved by supporting metal complexes on the surface of different supports which may additionally provide some surface sites for the formic acid activation. The review analyzes the literature on the application of supported metal complexes in the hydrogen production from formic acid. It shows that the catalytic activity of some stable Ru and Ir supported metal complexes may exceed the activity of homogeneous metal complexes used for deposition. Non-noble metal-based complexes containing Fe demonstrated sufficiently high performance in the reaction; however they can be poisoned by water present in formic acid. The proposed review could be useful for development of novel catalysts for the hydrogen production.
A Study on the Characteristics of Academic Topics Related to Renewable Energy Using the Structural Topic Modelling and the Weak Signal Concept
Mar 2021
Publication
It is important to examine in detail how the distribution of academic research topics related to renewable energy is structured and which topics are likely to receive new attention in the future in order for scientists to contribute to the development of renewable energy. This study uses an advanced probabilistic topic modeling to statistically examine the temporal changes of renewable energy topics by using academic abstracts from 2010–2019 and explores the properties of the topics from the perspective of future signs such as weak signals. As a result in strong signals methods for optimally integrating renewable energy into the power grid are paid great attention. In weak signals interest in large-capacity energy storage systems such as hydrogen supercapacitors and compressed air energy storage showed a high rate of increase. In not-strong-but-well-known signals comprehensive topics have been included such as renewable energy potential barriers and policies. The approach of this study is applicable not only to renewable energy but also to other subjects.
A Review on Recent Progress in the Integrated Green Hydrogen Production Processes
Feb 2022
Publication
The thermochemical water‐splitting method is a promising technology for efficiently con verting renewable thermal energy sources into green hydrogen. This technique is primarily based on recirculating an active material capable of experiencing multiple reduction‐oxidation (redox) steps through an integrated cycle to convert water into separate streams of hydrogen and oxygen. The thermochemical cycles are divided into two main categories according to their operating temperatures namely low‐temperature cycles (<1100 °C) and high‐temperature cycles (<1100 °C). The copper chlorine cycle offers relatively higher efficiency and lower costs for hydrogen production among the low‐temperature processes. In contrast the zinc oxide and ferrite cycles show great potential for developing large‐scale high‐temperature cycles. Although several challenges such as energy storage capacity durability cost‐effectiveness etc. should be addressed before scaling up these technologies into commercial plants for hydrogen production. This review critically examines various aspects of the most promising thermochemical water‐splitting cycles with a particular focus on their capabilities to produce green hydrogen with high performance redox pairs stability and the technology maturity and readiness for commercial use.
Dual Z-scheme Charge Transfer in TiO2–Ag–Cu2O Composite for Enhanced Photocatalytic Hydrogen Generation
Apr 2015
Publication
Photocatalytic hydrogen generation is one of the most promising solutions to convert solar power into green chemical energy. In this work a multi-component TiO2–Ag–Cu2O composite was obtained through simple impregnation-calcination of Cu2O and subsequent photodeposition of Ag onto electrospun TiO2 nanotubes. The resulting TiO2–Ag–Cu2O photocatalyst exhibits excellent photocatalytic H2 evolution activity due to the synergetic effect of Ag and Cu2O on electrospun TiO2nanotubes. A dual Z-scheme charge transfer pathway for photocatalytic reactions over TiO2–Ag–Cu2O composite was proposed and discussed. This work provides a prototype for designing Z-scheme photocatalyst with Ag as an electron mediator.
Scenario-Based Techno-Economic Analysis of Steam Methane Reforming Process for Hydrogen Production
Jun 2021
Publication
Steam methane reforming (SMR) process is regarded as a viable option to satisfy the growing demand for hydrogen mainly because of its capability for the mass production of hydrogen and the maturity of the technology. In this study an economically optimal process configuration of SMR is proposed by investigating six scenarios with different design and operating conditions including CO2 emission permits and CO2 capture and sale. Of the six scenarios the process configuration involving CO2 capture and sale is the most economical with an H2 production cost of $1.80/kg-H2. A wide range of economic analyses is performed to identify the tradeoffs and cost drivers of the SMR process in the economically optimal scenario. Depending on the CO2 selling price and the CO2 capture cost the economic feasibility of the SMR-based H2 production process can be further improved.
Nickel Sulfides Supported by Carbon Spheres as Efficient Catalysts for Hydrogen Evolution Reaction
Jun 2021
Publication
Ni3S2 and NiS supported on carbon spheres are successfully synthesized by a facile hydrothermal method. And then a series of physical characterizations included XRD (X-ray diffraction) EDS (energy dispersive spectroscopy) FESEM (field emission scanning electron microscopy) and XPS (X-ray photo-electron spectroscopy) were used to analyze the samples. XRD was used to confirm that NiNi3S2 S2 and NiS were successfully fabricated. FESEM indicated that Ni3S2 and NiS disperse well on carbon spheres. Electrochemical tests showed that nickel sulfides supported by carbon spheres exhibited excellent hydrogen evolution performance. The excellent catalytic activity is attributed to the synergistic effect of carbon spheres and transition metal sulfides of which the carbon spheres act to enhance the electrical conductivity and the dispersion of Ni3S2 and NiS thus providing more active sites for the hydrogen evolution reaction.
Shining the Light on Clean Hydrogen
Jun 2021
Publication
Clean hydrogen:
- What's driving the excitement?
- Will hydrogen stay on the main stage of the energy transition?
- What is the market for clean hydrogen today?
Carbons Formed in Methane Thermal and Thermocatalytic Decomposition Processes: Properties and Applications
Jun 2021
Publication
The hydrogen economy will play a key role in future energy systems. Several thermal and catalytic methods for hydrogen production have been presented. In this review methane thermocatalytic and thermal decomposition into hydrogen gas and solid carbon are considered. These processes known as the thermal decomposition of methane (TDM) and thermocatalytic decomposition (TCD) of methane respectively appear to have the greatest potential for hydrogen production. In particular the focus is on the different types and properties of carbons formed during the decomposition processes. The applications for carbons are also investigated.
Advances in Reforming and Partial Oxidation of Hydrocarbons for Hydrogen Production and Fuel Cell Applications
May 2019
Publication
One of the most attractive routes for the production of hydrogen or syngas for use in fuel cell applications is the reforming and partial oxidation of hydrocarbons. The use of hydrocarbons in high temperature fuel cells is achieved through either external or internal reforming. Reforming and partial oxidation catalysis to convert hydrocarbons to hydrogen rich syngas plays an important role in fuel processing technology. The current research in the area of reforming and partial oxidation of methane methanol and ethanol includes catalysts for reforming and oxidation methods of catalyst synthesis and the effective utilization of fuel for both external and internal reforming processes. In this paper the recent progress in these areas of research is reviewed along with the reforming of liquid hydrocarbons from this an overview of the current best performing catalysts for the reforming and partial oxidizing of hydrocarbons for hydrogen production is summarized.
The ‘Green’ Ni-UGSO Catalyst for Hydrogen Production under Various Reforming Regimes
Jun 2021
Publication
A new spinelized Ni catalyst (Ni-UGSO) using Ni(NO3)2·6H2O as the Ni precursor was prepared according to a less material intensive protocol. The support of this catalyst is a negative-value mining residue UpGraded Slag Oxide (UGSO) produced from a TiO2 slag production unit. Applied to dry reforming of methane (DRM) at atmospheric pressure T = 810 °C space velocity of 3400 mL/(h·g) and molar CO2/CH4 = 1.2 Ni-UGSO gives a stable over 168 h time-on-stream methane conversion of 92%. In this DRM reaction optimization study: (1) the best performance is obtained with the 10–13 wt% Ni load; (2) the Ni-UGSO catalysts obtained from two different batches of UGSO demonstrated equivalent performances despite their slight differences in composition; (3) the sulfur-poisoning resistance study shows that at up to 5.5 ppm no Ni-UGSO deactivation is observed. In steam reforming of methane (SRM) Ni-UGSO was tested at 900 °C and a molar ratio of H2O/CH4 = 1.7. In this experimental range CH4 conversion rapidly reached 98% and remained stable over 168 h time-on-stream (TOS). The same stability is observed for H2 and CO yields at around 92% and 91% respectively while H2/CO was close to 3. In mixed (dry and steam) methane reforming using a ratio of H2O/CH4 = 0.15 and CO2/CH4 = 0.97 for 74 h and three reaction temperature levels (828 °C 847 °C and 896 °C) CH4 conversion remains stable; 80% at 828 °C (26 h) 85% at 847 °C (24 h) and 95% at 896 °C (24 h). All gaseous streams have been analyzed by gas chromatography. Both fresh and used catalysts are analyzed by scanning electron microscopy-electron dispersive X-ray spectroscopy (SEM-EDXS) X-ray diffraction (XRD) and thermogravimetric analysis (TGA) coupled with mass spectroscopy (MS) and BET Specific surface. In the reducing environment of reforming such catalytic activity is mainly attributed to (a) alloys such as FeNi FeNi3 and Fe3Ni2 (reduction of NiFe2O4 FeNiAlO4) and (b) to the solid solution NiO-MgO. The latter is characterized by a molecular distribution of the catalytically active Ni phase while offering an environment that prevents C deposition due to its alkalinity.
The Global Status of CCS 2020: Vital to Achieve Net Zero
Dec 2020
Publication
The Global Status of CCS Report 2020 demonstrates the vital role of carbon capture and storage technologies (CCS) in reducing emissions to net-zero by 2050 as well as documenting the current status and important milestones for the technology over the past 12 months.<br/>The report provides detailed information on and analyses of the global CCS facility pipeline international policy perspectives CO2 storage and the CCS legal and regulatory environment.<br/>In addition four regional updates provide further detail about CCS progress across the Americas Europe Asia Pacific and the Gulf Cooperation Council States and a Technology section provides updates on key innovations and applications of CCS.
Power-to-fuels Via Solid-oxide Electrolyzer: Operating Window and Techno-economics
May 2019
Publication
Power-to-fuel systems via solid-oxide electrolysis are promising for storing excess renewable electricity by efficient electrolysis of steam (or co-electrolysis of steam and CO2) into hydrogen (or syngas) which can be further converted into synthetic fuels with plant-wise thermal integration. Electrolysis stack performance and durability determine the system design performance and long-term operating strategy; thus solid-oxide electrolyzer based power-to-fuels were investigated from the stack to system levels. At the stack level the data from a 6000-h stack testing under laboratory isothermal conditions were used to calibrate a quasi-2D model which enables to predict practical isothermal stack performance with reasonable accuracy. Feasible stack operating windows meeting various design specifications (e.g. specific syngas composition) were further generated to support the selection of operating points. At the system level with the chosen similar stack operating points various power-to-fuel systems including power-to-hydrogen power-to-methane power-to-methanol (dimethyl ether) and power-to-gasoline were compared techno-economically considering system-level heat integration. Several operating strategies of the stack were compared to address the increase in stack temperature due to degradation. The modeling results show that the system efficiency for producing H2 methane methanol/dimethyl ether and gasoline decreases sequentially from 94% (power-to-H2) to 64% (power-to-gasoline) based on a higher heating value. Co-electrolysis which allows better heat integration can improve the efficiency of the systems with less exothermic fuel-synthesis processes (e.g. methanol/dimethyl ether) but offers limited advantages for power-to-methane and power-to-gasoline systems. In a likely future scenario where the growing amount of electricity from renewable sources results in increasing periods of a negative electricity price solid oxide electrolyser based power-to-fuel systems are highly suitable for levelling the price fluctuations in an economic way.
Interfacial Confinement of Ni-V2O3 in Molten Salts for Enhanced Electrocatalytic Hydrogen Evolution
Apr 2020
Publication
Implementation of non-precious electrocatalysts is key-enabling for water electrolysis to relieve challenges in energy and environmental sustainability. Self-supporting Ni-V2O3.electrodes consisting of nanostrip-like V2O3.perpendicularly anchored on Ni meshes are herein constructed via the electrochemical reduction of soluble NaVO3 in molten salts for enhanced electrocatalytic hydrogen evolution. Such a special configuration in morphology and composition creates a well confined interface between Ni and V2O3. Experimental and Density-Functional-Theory results confirm that the synergy between Ni and V2O3.accelerates the dissociation of H2O for forming hydrogen intermediates and enhances the combination of H* for generating H2.
Hybrid Hydrogen PEM Fuel Cell and Batteries Without DC–DC Converter
Sep 2013
Publication
Concerns about greenhouse gases as well as the price and security of oil supply have acted as a spur to sustainable automobile development. The hydrogen fuel cells electric vehicle (HFCEV) is generally recognised by leading automobile manufacturers and scientists as one of the optimum technologies for long-term future low carbon vehicle. In a typical HFCEV power train a DC–DC converter is required to balance the voltage difference between the fuel cells (FCs) stack and batteries. However research shows that a considerable amount of energy generated by the hydrogen FCs stack is deplete during this conversion process as heat. This experiment aims to improve the power train efficiency by eliminating the DC–DC converter by finding the best combination of FC stack and batteries matching the size and capacity of the electrical components.
Hydrogen Production by Steam Reforming of Ethanol on Rh-Pt Catalysts: Influence of CeO2, ZrO2, and La2O3 as Supports
Nov 2015
Publication
CeO2- ZrO2- and La2O3-supported Rh-Pt catalysts were tested to assess their ability to catalyze the steam reforming of ethanol (SRE) for H2 production. SRE activity tests were performed using EtOH:H2O:N2 (molar ratio 1:3:51) at a gaseous space velocity of 70600 h−1 between 400 and 700 °C at atmospheric pressure. The SRE stability of the catalysts was tested at 700 °C for 27 h time on stream under the same conditions. RhPt/CeO2 which showed the best performance in the stability test also produced the highest H2 yield above 600 °C followed by RhPt/La2O3 and RhPt/ZrO2. The fresh and aged catalysts were characterized by TEM XPS and TGA. The higher H2 selectivity of RhPt/CeO2 was ascribed to the formation of small (~5 nm) and stable particles probably consistent of Rh-Pt alloys with a Pt surface enrichment. Both metals were oxidized and acted as an almost constant active phase during the stability test owing to strong metal-support interactions as well as the superior oxygen mobility of the support. The TGA results confirmed the absence of carbonaceous residues in all the aged catalysts.
The Role of Hydrogen in Achieving Net Zero: Parliamentary Inquiry
Mar 2021
Publication
A key component of the Government's recently announced ‘Ten Point Plan for a Green Industrial Revolution’ is 'Driving the Growth of Low Carbon Hydrogen'. The plan outlined a range of measures to support the development and adoption of hydrogen including a £240 million 'Net Zero Hydrogen Fund'. Noting this and the further £81 million allocated for hydrogen heating trials in the 2020 Spending Review the House of Commons Science and Technology Committee is today launching a new inquiry into the role of hydrogen in achieving Net Zero.
Following recommendations from the Committee on Climate Change that the Government develop a strategy for hydrogen use and should aim for largescale hydrogen trials to begin in the early 2020s the Committee seeks to ensure that the Government's intended plan will be suitable and effective. The Committee will also assess the infrastructure required for hydrogen as a Net Zero fuel and examine progress made so far internationally to determine the viability of hydrogen as a significant contributor to achieving Net Zero.
All documents are in the Supplements tab above.
Following recommendations from the Committee on Climate Change that the Government develop a strategy for hydrogen use and should aim for largescale hydrogen trials to begin in the early 2020s the Committee seeks to ensure that the Government's intended plan will be suitable and effective. The Committee will also assess the infrastructure required for hydrogen as a Net Zero fuel and examine progress made so far internationally to determine the viability of hydrogen as a significant contributor to achieving Net Zero.
All documents are in the Supplements tab above.
Resource Assessment for Hydrogen Production
Jul 2020
Publication
This analysis was conducted in support of the U.S. Department of Energy's H2@Scale initiative and this report examines the resources required to meet demand for an additional 10 million metric tonnes (MMT) of hydrogen in 2040. The technical potential of hydrogen production from fossil nuclear and renewable energy resources is presented. Updated maps describe the geographical distribution of hydrogen production potential from renewable energy resources. The results conclude that the technical resource availability of domestic energy resources is sufficient to meet an additional 10 MMT of hydrogen demand in 2040 without placing significant pressure on existing resources. While this level of hydrogen demand could result in a significant increase in renewable energy consumption in particular the technical potential of each resource is estimated to be sufficient to meet the demand. Future research to enable the large-scale integration of hydrogen in the U.S. energy and other sectors will include analyzing the geographic distribution of resources in relation to hydrogen demand for a variety of applications. Additional techno-economic analysis is also needed to understand the economic potential of hydrogen in other industries beyond transportation; such analysis is currently being undertaken by a multi-lab project initiated by DOE in 2016. Finally information from techno-economic analyses should be used to continually update and inform R&D targets for energy production hydrogen production and hydrogen utilization technologies.
Numerical Analysis of VPSA Technology Retrofitted to Steam Reforming Hydrogen Plants to Capture CO2 and Produce Blue H2
Feb 2022
Publication
The increasing demand for energy and commodities has led to escalating greenhouse gas emissions the chief of which is represented by carbon dioxide (CO2). Blue hydrogen (H2) a lowcarbon hydrogen produced from natural gas with carbon capture technologies applied has been suggested as a possible alternative to fossil fuels in processes with hard-to-abate emission sources including refining chemical petrochemical and transport sectors. Due to the recent international directives aimed to combat climate change even existing hydrogen plants should be retrofitted with carbon capture units. To optimize the process economics of such retrofit it has been proposed to remove CO2 from the pressure swing adsorption (PSA) tail gas to exploit the relatively high CO2 concentration. This study aimed to design and numerically investigate a vacuum pressure swing adsorption (VPSA) process capable of capturing CO2 from the PSA tail gas of an industrial steam methane reforming (SMR)-based hydrogen plant using NaX zeolite adsorbent. The effect of operating conditions such as purge-to-feed ratio and desorption pressure were evaluated in relation to CO2 purity CO2 recovery bed productivity and specific energy consumption. We found that conventional cycle configurations namely a 2-bed 4-step Skarstrom cycle and a 2-bed 6-step modified Skarstrom cycle with pressure equalization were able to concentrate CO2 to a purity greater than 95% with a CO2 recovery of around 77% and 90% respectively. Therefore the latter configuration could serve as an efficient process to decarbonize existing hydrogen plants and produce blue H2.
A Comprehensive Review of Microbial Electrolysis Cells (MEC) Reactor Designs and Configurations for Sustainable Hydrogen Gas Production
Nov 2015
Publication
Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles. A cutting edge technology called a microbial electrolysis cell (MEC) can achieve sustainable and clean hydrogen production from a wide range of renewable biomass and wastewaters. Enhancing the hydrogen production rate and lowering the energy input are the main challenges of MEC technology. MEC reactor design is one of the crucial factors which directly influence on hydrogen and current production rate in MECs. The rector design is also a key factor to upscaling. Traditional MEC designs incorporated membranes but it was recently shown that membrane-free designs can lead to both high hydrogen recoveries and production rates. Since then multiple studies have developed reactors that operate without membranes. This review provides a brief overview of recent advances in research on scalable MEC reactor design and configurations.
Techno-economic Analysis of Hydrogen Production from PV Plants
Jan 2022
Publication
Hydrogen production through electrolysis from renewable sources is expected to play an important role to achieve the reduction targets of carbon dioxide emissions set for the next decades. Electrolysers can use the renewable energy surplus to produce green hydrogen and contribute to making the electrical grid more stable. Hydrogen can be used as medium-long term energy storage converted into other fuels or used as feedstock in industry thus contributing to decarbonise hard-to-abate-sectors. However due to the intermittent and variable nature of solar and wind power the direct coupling of electrolysers with renewables may lead to high production fluctuations and frequent shutdowns. As a consequence accelerated electrolyser degradation and safety issues related to low load operation may arise. In this study simulations of hydrogen production with an electrolyser fed by a PV system are performed in Matlab for a reference year. The effect of PV power fluctuations on the electrolyser operation and production is investigated. The impact of the electrolyser size for a fixed nominal power of the PV plant is also analysed from both energetic and economic points of view.
Recent Advances in High-Temperature Steam Electrolysis with Solid Oxide Electrolysers for Green Hydrogen Production
Apr 2023
Publication
Hydrogen is known to be the carbon-neutral alternative energy carrier with the highest energy density. Currently more than 95% of hydrogen production technologies rely on fossil fuels resulting in greenhouse gas emissions. Water electrolysis is one of the most widely used technologies for hydrogen generation. Nuclear power a renewable energy source can provide the heat needed for the process of steam electrolysis for clean hydrogen production. This review paper analyses the recent progress in hydrogen generation via high-temperature steam electrolysis through solid oxide electrolysis cells using nuclear thermal energy. Protons and oxygen-ions conducting solid oxide electrolysis processes are discussed in this paper. The scope of this review report covers a broad range including the recent advances in material development for each component (i.e. hydrogen electrode oxygen electrode electrolyte interconnect and sealant) degradation mechanisms and countermeasures to mitigate them.
Techno-Economic Analysis of Flare Gas to Hydrogen: A Lean and Green Sustainability Approach
Jul 2025
Publication
The increasing demand for hydrogen has made it a promising alternative for decarbonizing industries and reducing CO2 emissions. Although mainly produced through the gray pathway the integration of carbon capture and storage (CCS) reduces the CO2 emissions. This study presents a sustainability method that uses flare gas for hydrogen production through steam methane reforming (SMR) with CCS supported by a techno-economic analysis. Data Envelopment Analysis (DEA) was used to evaluate the oil company’s efficiency and inverse DEA/sensitivity analysis identified maximum flare gas reduction which was modeled in Aspen HYSYS V14. Subsequently an economic evaluation was performed to determine the levelized cost of hydrogen (LCOH) and the cost–benefit ratio (CBR) for Nigeria. The CBR results were 2.15 (payback of 4.11 years with carbon credit) and 1.96 (payback of 4.55 years without carbon credit) indicating strong economic feasibility. These findings promote a practical approach for waste reduction aiding Nigeria’s transition to a circular low-carbon economy and demonstrate a positive relationship between lean and green strategies in the petroleum sector.
Hydrogen Production Using Advanced Reactors by Steam Methane Reforming: A Review
Apr 2023
Publication
The present review focuses on the current progress on harnessing the potential of hydrogen production by Methane Steam Reforming (MSR). First based on the prominent literature in last few years the overall research efforts of hydrogen production using different feed stocks like ethanol ammonia glycerol methanol and methane is presented. The presented data is based on reactor type reactor operating conditions catalyst used and yield of hydrogen to provide a general overview. Then the most widely used process [steam methane reforming (SMR)/ methane steam reforming (MSR)] are discussed. Major advanced reactors the membrane reactors Sorption Enhanced methane steam reforming reactors and micro-reactors are evaluated. The evaluation has been done based on parameters like residence time surface area scale-up coke formation conversion space velocity and yield of hydrogen. The kinetic models available in recently published literature for each of these reactors have been presented with the rate constants and other parameters. The mechanism of coke formation and the rate expressions for the same have also been presented. While membrane reactors and sorption enhanced reactors have lot of advantages in terms of process intensification scale-up to industrial scale is still a challenge due to factors like membrane stability and fouling (in membrane reactors) decrease in yield with increasing WHSV (in case of Sorption Enhanced Reactors). Micro-reactors pose a higher potential in terms of higher yield and very low residence time in seconds though the volumes might be substantially lower than present industrial scale conventional reactors.
Climate Change Impacts on Gaseous Hydrogen (H2) Potential Produced by Photovoltaic Electrolysis for Stand-Alone or Grid Applications in Europe
Dec 2022
Publication
The EU’s hydrogen strategy consists of studying the potential for renewable hydrogen to help decarbonize the EU in a cost-effective way. Today hydrogen accounts for less than 2% of Europe’s energy consumption. It is primarily used to produce chemical products. However 96% of this hydrogen production is through natural gas leading to significant amounts of CO2 emissions. In this paper we investigated PV electrolysis H2 gas (noted H2(g)) production for mapping this resource at Europe’s scale. The Cordex/Copernicus RCPs scenarios allow for evaluating the impact of climate changes on the H2 -produced mass and the equivalent energy according to both extreme RCPs scenarios. New linear regressions are investigated to study the great dependence in H2(g) produced masses (kg·yr−1 ) and equivalent energies (MWh·yr−1 ) for European countries. Computational scenarios are investigated from a reference year (2005) to the end of the century (2100) by steps of 5 years. According to RCPs 2.6 (favorable)/8.5 (extreme) 31.7% and 77.4% of Europe’s area presents a decrease of H2(g)-produced masses between 2005 and 2100. For the unfavorable scenario (8.5) only a few regions located in the northeast of France Germany Austria Romania Bulgaria and Greece present a positive balance in H2(g) production for supplying remote houses or smart grids in electricity and heat energy.
Review—Identifying Critical Gaps for Polymer Electrolyte Water Electrolysis Development
Feb 2017
Publication
Although polymer electrolyte water electrolyzers (PEWEs) have been used in small-scale (kW to tens of kW range) applications for several decades PEWE technology for hydrogen production in energy applications (power-to-gas power-to-fuel etc.) requires significant improvements in the technology to address the challenges associated with cost performance and durability. Systems with power of hundreds of kW or even MWs corresponding to hydrogen production rates of around 10 to 20 kg/h have started to appear in the past 5 years. The thin (∼0.2 mm) polymer electrolyte in the PEWE with low ohmic resistance compared to the alkaline cell with liquid electrolyte allows operation at high current densities of 1–3 A/cm2 and high differential pressure. This article after an introductory overview of the operating principles of PEWE and state-of-the-art discusses the state of understanding of key phenomena determining and limiting performance durability and commercial readiness identifies important ‘gaps’ in understanding and essential development needs to bring PEWE science & engineering forward to prosper in the energy market as one of its future backbone technologies. For this to be successful science engineering and process development as well as business and market development need to go hand in hand.
Process Reconfiguration and Intensification: An Emerging Opportunity Enabling Efficient Carbon Capture and Low-cost Blue Hydrogen Production
Mar 2023
Publication
Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources requiring additional CO2 capture to decarbonize which energy intense and costly. In a recent Green Energy & Environment paper Cheng and Di et al. proposed a novel integration process referred to as SECLRHC to generate high-purity H2 by in-situ separation of H2 and CO without using any additional separation unit. Theoretically the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process and thus attaining high-purity hydrogen of ∼99% as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive as long as a suitable CCS measure can be integrated into the industrial manufacturing process.
Water Consumption from Electrolytic Hydrogen in a Carbon-neutral US Energy System
Feb 2023
Publication
Hydrogen is an energy carrier with potential applications in decarbonizing difficult-to-electrify energy and industrial systems. The environmental profile of hydrogen varies substantially with its inputs. Water consumption is a particular issue of interest as decisions are made about capital and other investments that will affect the scale and scope of hydrogen use. This study focuses on electrolytic hydrogen due to its path to greenhouse gas neutrality and irreducible water demand (though other pathways might be more water intensive). Specifically it evaluates life cycle consumptive freshwater intensity of electrolytic hydrogen in the United States at volumes associated with 12 scenarios for a deeply decarbonized 2050 US energy system from two modeling efforts for which both electricity fuel mix and electrolytic hydrogen production were projected (America’s Zero Carbon Action Plan and Net Zero America) in addition to volumes for a stylized energy storage project (500 MW hydrogen-fired turbine). Freshwater requirements for hydrogen could be large. Under a central estimate for 2050 US electrolytic hydrogen production electrolytic freshwater demand for process and feedstock inputs alone (i.e. excluding water for electricity) would be about 7.5% of total 2014 US freshwater consumption for energy (1 billion cubic meters/year 109 m3 /y; [0.2% 15%] across scenarios for 2050 electrolytic hydrogen production of [0.3 18] exajoules EJ). Including water associated with production of input electricity doubles this central estimate to 15% (2 × 109 m3 /y; [1% 23%] across scenarios). Turbines using electrolytic hydrogen are estimated to be about as freshwater intensive as a coal or nuclear plant assuming decarbonized low-water electricity inputs. Although a decarbonized energy system is projected to require less water for resource capture and electricity conversion than the current fossil-dominated energy system additional conversion processes supporting decarbonization like electrolysis could offset water savings.
Energy Recovery from Wastewater in Mexico: A Systematic Review
Feb 2023
Publication
The usage of fossil fuels to generate energy and the lack of wastewater treatment in Mexico are two issues that can be addressed at the same time while developing wastewater treatment technologies that incorporate energy recovery in their process train. We carried out a systematic review based on the PRISMA methodology to identify and review studies regarding energy recovery using wastewater as a substrate in Mexico. Peer-reviewed papers were identified through Scopus Web of Knowledge and Google Scholar using a timeframe of 22 years that represented from 2000 to 2022. After applying the selection criteria we identified 31 studies to be included in the final review starting from 2007. The kind of energy product type of technology used substrate wastewater amount of energy produced and main parameters for the operation of the technology were extracted from the papers. The results show that methane is the most researched energy recovery product from wastewater followed by hydrogen and electricity and the technology used to archive it is an up-flow anaerobic sludge bed (UASB) reactor to produce methane and hydrogen. In addition microbial fuel cells (MFCs) were preferred to produce electricity. According to our data more energy per kgCOD removed could be obtained with methane-recovering technologies in the Mexican peer-reviewed studies compared with hydrogen recovery and electricity production.
Contribution to Net Zero Emissions of Integrating Hydrogen Production in Wastewater Treatment Plants
Jul 2023
Publication
The reliability of renewable hydrogen supply for off-take applications is critical to the future sustainable energy economy. Integrated water electrolysis can be deployed at distributed municipal wastewater treatment plants (WWTP) creating opportunity for reduction in carbon emissions through direct and indirect use of the electrolysis output. A novel energy shifting process where the co-produced oxygen is compressed and stored to enhance the utilisation of intermittent renewable electricity is analysed. The hydrogen produced can be used in local fuel cell electric buses to replace incumbent diesel buses for public transport. However quantifying the extent of carbon emission reduction of this conceptual integrated system is key. In this study the integration of hydrogen production at a case study WWTP of 26000 EP capacity and using the hydrogen in buses was compared with two conventional systems: the base case of a WWTP with grid electricity consumption offset by solar PV and the community’s independent use of diesel buses for transport and the non-integrated configuration with hydrogen produced at the bus refuelling location operated independently of the WWTP. The system response was analysed using a Microsoft Excel simulation model with hourly time steps over a 12-month time frame. The model included a control scheme for the reliable supply of hydrogen for public transport and oxygen to the WWTP and considered expected reductions in carbon intensity of the national grid level of solar PV curtailment electrolyser efficiency and size of the solar PV system. Results showed that by 2031 when Australia’s national electricity is forecast to achieve a carbon intensity of less than 0.186 kg CO2-e/kWh integrating water electrolysis at a municipal WWTP for producing hydrogen for use in local hydrogen buses produced less carbon emissions than continuing to use diesel buses and offsetting emissions by exporting renewable electricity to the grid. By 2034 an annual reduction of 390 t–CO2–e is expected after changing to the integrated configuration. Considering electrolyser efficiency improvements and curtailment of renewable electricity the reduction increases to 872.8 t–CO2–e.
A Techno-Economic Study for Off-Grid Green Hydrogen Production Plants: The Case of Chile
Jul 2023
Publication
In this study we present a pre-feasibility analysis that examines the viability of implementing autonomous green hydrogen production plants in two strategic regions of Chile. With abundant renewable energy resources and growing interest in decarbonization in Chile this study aims to provide a comprehensive financial analysis from the perspective of project initiators. The assessment includes determining the optimal sizing of an alkaline electrolyzer stack seawater desalination system and solar and wind renewable energy farms and the focus is on conducting a comprehensive financial analysis from the perspective of project initiators to assess project profitability using key economic indicators such as net present value (NPV). The analyses involve determining appropriate sizing of an alkaline electrolyzer stack a seawater desalination system and solar and wind renewable energy farms. Assuming a base case production of 1 kiloton per year of hydrogen the capital expenditures (CAPEX) and operating expenses (OPEX) are determined. Then the manufacturing and production costs per kilogram of green hydrogen are calculated resulting in values of USD 3.53 kg−1 (utilizing wind energy) and USD 5.29 kg−1 (utilizing photovoltaic solar energy). Cash flows are established by adjusting the sale price of hydrogen to achieve a minimum expected return on investment of 4% per year yielding minimum prices of USD 7.84 kg−1 (with wind energy) and USD 11.10 kg−1 (with photovoltaic solar energy). Additionally a sensitivity analysis is conducted to assess the impact of variations in investment and operational costs. This research provides valuable insights into the financial feasibility of green hydrogen production in Chile contributing to understanding renewable energy-based hydrogen projects and their potential economic benefits. These results can provide a reference for future investment decisions and the global development of green hydrogen production plants.
Can Methane Pyrolysis Based Hydrogen Production Lead to the Decarbonisation of Iron and Steel Industry?
Mar 2021
Publication
Decarbonisation of the iron and steel industry would require the use of innovative low-carbon production technologies. Use of 100% hydrogen in a shaft furnace (SF) to reduce iron ore has the potential to reduce emissions from iron and steel production significantly. In this work results from the techno-economic assessment of a H2-SF connected to an electric arc furnace(EAF) for steel production are presented under two scenarios. In the first scenario H2 is produced from molten metal methane pyrolysis in an electrically heated liquid metal bubble column reactor. Grid connected low-temperature alkaline electrolyser was considered for H2 production in the second scenario. In both cases 59.25 kgH2 was required for the production of one ton of liquid steel (tls). The specific energy consumption (SEC) for the methane pyrolysis based system was found to be 5.16 MWh/tls. The system used 1.51 MWh/tls of electricity and required 263 kg/tls of methane corresponding to an energy consumption of 3.65 MWh/tls. The water electrolysis based system consumed 3.96 MWh/tls of electricity at an electrolyser efficiency of 50 KWh/kgH2. Both systems have direct emissions of 129.4 kgCO2/tls. The indirect emissions are dependent on the source of natural gas pellet making process and the grid-emission factor. Indirect emissions for the electrolysis based system could be negligible if the electricity is generated from renewable energy sources. The levellized cost of production(LCOP) was found to be $631 and $669 respectively at a discount rate of 8% for a plant-life of 20 years. The LCOP of a natural gas reforming based direct reduction steelmaking plant of operating under similar conditions was found to be $414. Uncertainty analysis was conducted for the NPV and IRR values.
Technical Performance and Environmental Assessment of an Ionic Liquid-based CCS Process for Hydrogen Production
Apr 2023
Publication
Hydrogen (H2) production combined with carbon capture and storage (CCS) is anticipated to be an important technology contributing to reduce the carbon footprint of current fossil-based H2 production systems. This work addresses for the first time the techno-environmental assessment of a CCS process based on the ionic liquid [Bmim][Acetate] for H2 production by steam methane reforming (SMR) and the comparison to conventional amine-based systems. Two different SMR plants using MDEA or [Bmim][Acetate] for CO2 capture were rigorously modelled using Aspen Plus to compute material and energy needs and emissions. Literature and simulation results were then used to perform a life cycle impact assessment (LCIA) of these processes based on the ReCiPe model. Solvent synthesis CCS process and hydrogen production stages were considered for the cradle-to-gate analysis. Results showed that although [Bmim][Acetate] is a priori more harmful to the environment than amines (in a kg-to-kg comparison) LCIAs carried out for both CCS processes showed from 5 to 17 % lower environmental impacts values for all estimated categories when using [Bmim][Acetate] due to a 9.4 % more energy-efficient performance than MDEA which also reduced a 17.4 % the total utility cost. Indeed if a typical amine loss rate of 1.6 kg/tCO2 is assumed the values of the environmental impacts increase up to 14 % for the IL-based CCS plant but still maintaining its favorable results over MDEA. As consequence the SMR plant with the IL-based CCS system exhibited 3–20 % lower values for most of the studied impact categories. These results contribute to shed some light on evaluating the sustainability of ILs with respect to conventional solvents for CO2 capture and to guide the synthesis of new more sustainable ILs but also they would be used to compare the environmental burdens from the synthesis and process performance of other promising ILs for CO2 capture that are not environmentally assed yet.
Additive Manufacturing for Proton Exchange Membrane (PEM) Hydrogen Technologies: Merits, Challenges, and Prospects
Jul 2023
Publication
With the growing demand for green technologies hydrogen energy devices such as Proton Exchange Membrane (PEM) fuel cells and water electrolysers have received accelerated developments. However the materials and manufacturing cost of these technologies are still relatively expensive which impedes their widespread commercialization. Additive Manufacturing (AM) commonly termed 3D Printing (3DP) with its advanced capabilities could be a potential pathway to solve the fabrication challenges of PEM parts. Herein in this paper the research studies on the novel AM fabrication methods of PEM components are thoroughly reviewed and analysed. The key performance properties such as corrosion and hydrogen embrittlement resistance of the additively manufactured materials in the PEM working environment are discussed to emphasise their reliability for the PEM systems. Additionally the major challenges and required future developments of AM technologies to unlock their full potential for PEM fabrication are identified. This paper provides insights from the latest research developments on the significance of advanced manufacturing technologies in developing sustainable energy systems to address the global energy challenges and climate change effects.
Massive Green Hydrogen Production Using Solar and Wind Energy: Comparison between Europe and the Middle East
Jul 2023
Publication
This comparative study examines the potential for green hydrogen production in Europe and the Middle East leveraging 3MWp solar and wind power plants. Experimental weather data from 2022 inform the selection of two representative cities namely Krakow Poland (Europe) and Diyala Iraq (Middle East). These cities are chosen as industrial–residential zones representing the respective regions’ characteristics. The research optimizes an alkaline water electrolyzer capacity in juxtaposition with the aforementioned power plants to maximize the green hydrogen output. Economic and environmental factors integral to green hydrogen production are assessed to identify the region offering the most advantageous conditions. The analysis reveals that the Middle East holds superior potential for green hydrogen production compared to Europe attributed to a higher prevalence of solar and wind resources coupled with reduced land and labor costs. Hydrogen production costs in Europe are found to range between USD 9.88 and USD 14.31 per kilogram in contrast to the Middle East where costs span from USD 6.54 to USD 12.66 per kilogram. Consequently the Middle East emerges as a more feasible region for green hydrogen production with the potential to curtail emissions enhance air quality and bolster energy security. The research findings highlight the advantages of the Middle East industrial–residential zone ‘Diyala’ and Europe industrial–residential zone ‘Krakow’ in terms of their potential for green hydrogen production.
Research Progress of Hydrogen Production Technology and Related Catalysts by Electrolysis of Water
Jun 2023
Publication
As a clean and renewable energy source for sustainable development hydrogen energy has gained a lot of attention from the general public and researchers. Hydrogen production by electrolysis of water is the most important approach to producing hydrogen and it is also the main way to realize carbon neutrality. In this paper the main technologies of hydrogen production by electrolysis of water are discussed in detail; their characteristics advantages and disadvantages are analyzed; and the selection criteria and design criteria of catalysts are presented. The catalysts used in various hydrogen production technologies and their characteristics are emphatically expounded aiming at optimizing the existing catalyst system and developing new high-performance high-stability and low-cost catalysts. Finally the problems and solutions in the practical design of catalysts are discussed and explored.
Comparative Exergy and Environmental Assessment of the Residual Biomass Gasification Routes for Hydrogen and Ammonia Production
Jul 2023
Publication
The need to reduce the dependency of chemicals on fossil fuels has recently motivated the adoption of renewable energies in those sectors. In addition due to a growing population the treatment and disposition of residual biomass from agricultural processes such as sugar cane and orange bagasse or even from human waste such as sewage sludge will be a challenge for the next generation. These residual biomasses can be an attractive alternative for the production of environmentally friendly fuels and make the economy more circular and efficient. However these raw materials have been hitherto widely used as fuel for boilers or disposed of in sanitary landfills losing their capacity to generate other by-products in addition to contributing to the emissions of gases that promote global warming. For this reason this work analyzes and optimizes the biomass-based routes of biochemical production (namely hydrogen and ammonia) using the gasification of residual biomasses. Moreover the capture of biogenic CO2 aims to reduce the environmental burden leading to negative emissions in the overall energy system. In this context the chemical plants were designed modeled and simulated using Aspen plus™ software. The energy integration and optimization were performed using the OSMOSE Lua Platform. The exergy destruction exergy efficiency and general balance of the CO2 emissions were evaluated. As a result the irreversibility generated by the gasification unit has a relevant influence on the exergy efficiency of the entire plant. On the other hand an overall negative emission balance of −5.95 kgCO2/kgH2 in the hydrogen production route and −1.615 kgCO2/kgNH3 in the ammonia production route can be achieved thus removing from the atmosphere 0.901 tCO2/tbiomass and 1.096 tCO2/tbiomass respectively.
Techno-Economic Assessment of a Full-Chain Hydrogen Production by Offshore Wind Power
May 2024
Publication
Offshore wind power stands out as a promising renewable energy source offering substantial potential for achieving low carbon emissions and enhancing energy security. Despite its potential the expansion of offshore wind power faces considerable constraints in offshore power transmission. Hydrogen production derived from offshore wind power emerges as an efficient solution to overcome these limitations and effectively transport energy. This study systematically devises diverse hydrogen energy supply chains tailored to the demands of the transportation and chemical industries meticulously assessing the levelized cost of hydrogen (LCOH). Our findings reveal that the most cost-efficient means of transporting hydrogen to the mainland is through pipelines particularly when the baseline distance is 50 km and the baseline electricity price is 0.05 USD/kWh. Notably delivering hydrogen directly to the port via pipelines for chemical industries proves considerably more economical than distributing it to hydrogen refueling stations with a minimal cost of 3.6 USD/kg. Additionally we assessed the levelized cost of hydrogen (LCOH) for supply chains that transmit electricity to ports via submarine cables before hydrogen production and subsequent distribution to chemical plants. In comparison to offshore hydrogen production routes these routes exhibit higher costs and reduced competitiveness. Finally a sensitivity analysis was undertaken to scrutinize the impact of delivery distance and electricity prices on LCOH. The outcomes underscore the acute sensitivity of LCOH to power prices highlighting the potential for substantial reductions in hydrogen prices through concerted efforts to lower electricity costs.
Evaluation of Surplus Hydroelectricity Potential in Nepal until 2040 and its Use for Hydrogen Production Via Electrolysis
May 2023
Publication
The abundant hydro resources in Nepal have resulted in the generation of electricity almost exclusively from hydropower plants. Several hydropower plants are also currently under construction. There is no doubt that the surplus electricity will be significantly high in the coming years. Given the previous trend in electricity consumption it will be a challenge to maximize the use of surplus electricity. In this work the potential solutions to maximize the use of this surplus electricity have been analysed. Three approached are proposed: (i) increasing domestic electricity consumption by shifting the other energy use sectors to electricity (ii) cross-border export of electricity and (iii) conversion of electricity to hydrogen via electrolysis. The current state of energy demand and supply patterns in the country are presented. Future monthly demand forecasts and surplus electricity projections have been made. The hydrogen that can be produced with the surplus electricity via electrolysis is determined and an economic assessment is carried out for the produced hydrogen. The analysis of levelized cost of hydrogen (LCOH) under different scenarios resulted values ranging from 3.8 €/kg to 4.5 €/kg.
Emerging Trends and Challenges in Pink Hydrogen Research
May 2024
Publication
Pink hydrogen is the name given to the technological variant of hydrogen generation from nuclear energy. This technology aims to address the environmental challenges associated with conventional hydrogen production positioning itself as a more sustainable and eco-efficient alternative while offering a viable alternative to nuclear power as a source of electricity generation. The present research analyzes the landscape of pink hydrogen research an innovative strand of renewable energy research. The methodology included a comprehensive search of scientific databases which revealed a steady increase in the number of publications in recent years. This increase suggests a growing interest in and recognition of the importance of pink hydrogen in the transition to cleaner and more sustainable energy sources. The results reflect the immaturity of this technology where there is no single international strategy and where there is some diversity of research topic areas as well as a small number of relevant topics. It is estimated that the future development of Gen IV nuclear reactors as well as Small Modular Reactor (SMR) designs will also favor the implementation of pink hydrogen.
System-Level Offshore Wind Energy and Hydrogen Generation Availability and Operations and Maintenance Costs
May 2024
Publication
With the current trends of wind energy already playing a major part in the Scottish energy supply the capacity of wind farms is predicted to grow exponentially and reach further depths offshore. However a key challenge that presents itself is the integration of large producing assets into the current UK grid. One potential solution to this is green hydrogen production which is being heavily researched in industry with many concepts being investigated for large-scale purposes. However the operations and maintenance (O&M) costs and availability of green hydrogen systems need to be quantified to ensure economical and technical viability which is sparse in the available literature. The study presented in this paper investigated the availability and O&M costs of coupled wind–hydrogen systems by attempting to quantify the failure rates repair times repair costs and number of technicians required for key green hydrogen components. This study also utilised an O&M model created by the University of Strathclyde which uses Monte Carlo Markov chain simulations to produce the O&M outputs. A number of assumptions were made throughout the study in relation to the O&M model inputs and the baseline availability for the coupled wind–hydrogen system was 85.24%. Whilst the wind turbine still contributed a major part to the downtime seen in the simulations the combined hydrogen system also contributed a significant amount a total of 37% which could have been due to the technology readiness levels of some the components included in the hydrogen system.
A Green Route for Hydrogen Producton from Alkaline Thermal Treatment (ATT) of Biomass with Carbon Storage
Apr 2023
Publication
Hydrogen a green energy carrier is one of the most promising energy sources. However,it is currently mainly produced from depleting fossil fuels with high carbon emissions which has serious negative effects on the economy and environment. To address this issue sustainable hydrogen production from bio-energy with carbon capture and storage (HyBECCS) is an ideal technology to reduce global carbon emissions while meeting energy demand. This review presents an overview of the latest progress in alkaline thermal treatment (ATT) of biomass for hydrogen production with carbon storage especially focusing on the technical characteristics and related challenges from an industrial application perspective. Additionally the roles of alkali and catalyst in the ATT process are critically discussed and several aspects that have great influences on the ATT process such as biomass types reaction parameters and reactors are expounded. Finally the potential solutions to the general challenges and obstacles to the future industrial-scale application of ATT of biomass for hydrogen production are proposed.
Highly Efficient Solar Hydrogen Production through the Use of Bifacial Photovoltaics and Membrane Electrolysis
Jul 2020
Publication
T The large-scale implementation of solar hydrogen production requires an optimal combination of photovoltaic systems with suitably-designed electrochemical cells possibly avoiding power electronics for DC-DC conversion to decrease costs. Here a stable solar-driven water splitting system is presented obtained through the direct connection of a state-of-the-art proton exchange membrane (PEM) electrolyzer to a bifacial silicon hetero junction (SHJ) solar module of three cells in series with total area of 730 cm2 . The bifaciality of the solar module has been optimized through modeling in terms of the number of cells module height and inclination. During outdoor operation in the standard monofacial configuration the system is able to produce 3.7 gr of H2 h 1 m 2 with an irradiation of 1000 W m 2 and a solar-to-hydrogen efficiency (STH) of 11.55%. The same system operating in bifacial mode gives rise to a higher H2 flux and STH efficiency reaching values of 4.2 gr of H2 h 1 m 2 and STH of 13.5%. Such a noticeable difference is achieved through the collection of albedo radiation from the ground by the bifacial PV system. The system has been tested outdoors for more than 55 h exhibiting very good endurance with no appreciable change in production and eff
Intensification of Hydrogen Production: Pd–Ag Membrane on Tailored Hastelloy-X Filter for Membrane-Assisted Steam Methane Reforming
Dec 2023
Publication
H2 production via membrane-assisted steam methane reforming (MA-SMR) can ensure higher energy efficiency and lower emissions compared to conventional reforming processes (SMR). Ceramic-supported Pd–Ag membranes have been extensively investigated for membrane-assisted steam methane reforming applications with outstanding performance. However costs sealings for integration in the reactor structure and resistance to solicitations remain challenging issues. In this work the surface quality of a low-cost porous Hastelloy-X filter is improved by asymmetric filling with α-Al2O3 of decreasing size and deposition of γ-Al2O3 as an interdiffusion barrier. On the modified support a thin Pd–Ag layer was deposited via electroless plating (ELP) resulting in a membrane with H2/N2 selectivity >10000. The permeation characteristics of the membrane were studied followed by testing for membrane-assisted methane steam reforming. The results showed the ability of the membrane reactor to overcome thermodynamic conversion of the conventional process for all explored operating conditions as well as ensuring 99.3% H2 purity in the permeate stream at 500 ◦C and 4 bar.
Energy, Exergy and Thermoeconomic Analyses on Hydrogen Production Systems Using High-temperature Gas-cooled and Water-cooled Nuclear Reactors
Dec 2023
Publication
The use of nuclear energy is inevitable to reduce the dependence on fossil fuels in the energy sector. High-temperature gas-cooled reactors (HTGRs) are considered as a system suitable for the purpose of reducing the use of fossil fuels. Furthermore eco-friendly mass production of hydrogen is crucial because hydrogen is emerging as a next-generation energy carrier. The unit cost of hydrogen production by the levelized cost of energy (LCOE) method varies widely depending on the energy source and system configuration. In this study energy exergy and thermoeconomic analyses were performed on the hydrogen production system using the HTGR and high-temperature water-cooled nuclear reactor (HTWR) to calculate reasonable unit cost of the hydrogen produced using a thermoeconomic method called modified production structure analysis (MOPSA). A flowsheet analysis was performed to confirm the energy conservation in each component. The electricity generated from the 600 MW HTGR system was used to produce 1.28 kmol/s of hydrogen by electrolysis to split hot water vapor. Meanwhile 515 MW of heat from the 600 MW HTWR was used to produce 8.10 kmol/s of hydrogen through steam reforming and 83.6 MW of electricity produced by the steam turbine was used for grid power. The estimated unit cost of hydrogen from HTGR is approximately USD 35.6/GJ with an initial investment cost of USD 2.6 billion. If the unit cost of natural gas is USD 10/GJ and the carbon tax is USD 0.08/kg of carbon dioxide the unit cost of hydrogen produced from HTWR is approximately USD 13.92/GJ with initial investment of USD 2.32 billion. The unit cost of the hydrogen produced in the scaled-down plant was also considered.
Hydrogen 4.0: A Cyber–Physical System for Renewable Hydrogen Energy Plants
May 2024
Publication
The demand for green hydrogen as an energy carrier is projected to exceed 350 million tons per year by 2050 driven by the need for sustainable distribution and storage of energy generated from sources. Despite its potential hydrogen production currently faces challenges related to cost efficiency compliance monitoring and safety. This work proposes Hydrogen 4.0 a cyber–physical approach that leverages Industry 4.0 technologies—including smart sensing analytics and the Internet of Things (IoT)—to address these issues in hydrogen energy plants. Such an approach has the potential to enhance efficiency safety and compliance through real-time data analysis predictive maintenance and optimised resource allocation ultimately facilitating the adoption of renewable green hydrogen. The following sections break down conventional hydrogen plants into functional blocks and discusses how Industry 4.0 technologies can be applied to each segment. The components benefits and application scenarios of Hydrogen 4.0 are discussed while how digitalisation technologies can contribute to the successful integration of sustainable energy solutions in the global energy sector is also addressed.
Techno-economic Assessment of Green Hydrogen Production Integrated with Hybrid and Organic Ranking Cycle (ORC) Systems
Feb 2024
Publication
This study aims to determine the most cost-effective approach for production of green hydrogen a crucial element for global decarbonization efforts despite its high production costs. The primary research question addresses the optimal and economically viable strategy for green hydrogen production considering various scenarios and technologies. Through a comprehensive analysis of eight scenarios the study employs economic parameters such as net present value minimum production cost payback period and sensitivity analysis. The analysis is validated using estab lished economic metrics and real-world considerations to ensure feasibility. The results suggest that a hybrid system combining solar photovoltaic (PV) with storage and onshore wind turbines is a promising approach yielding a minimum cost of $3.01 per kg of green hydrogen an internal rate of return (IRR) of 5.04% and 8-year payback period. These findings provide a practical so lution for cost-effective green hydrogen production supporting the transition to sustainable en ergy sources. The study also highlights the future potential of integrating solar thermal (CSP) with an organic Rankine cycle (ORC) system for waste heat recovery in hydrogen production. The sensitivity analysis provides the importance of capacity factor levelized cost of hydrogen capital expenditure and discount rate in influencing production costs.
Design of a Multi-inlet Solar Thermochemical Reactor for Steam Methane Reforming with Improved Performance
Feb 2023
Publication
Reactor structure design plays an important role in the performance of solar-thermal methane reforming reactors. Based on a conventional preheating reactor this study proposed a cylindrical solar methane reforming reactor with multiple inlets to vary the temperature field distribution which improved the temperature of the reaction region in the reactor thereby improving the reactor performance. A multi-physical model that considers mass momentum species and energy conservation as well as thermochemical reaction kinetics of methane reforming was applied to numerically investigate the reactor performance and analyze the factors that affect performance improvement. It was found that compared with a conventional preheating reactor the proposed cylindrical reactor with inner and external inlets for gas feeding enhanced heat recovery from the exhausted gas and provided a more suitable temperature field for the reaction in the reactor. Under different operating conditions the methane conversion in the cylindrical reactor with multi-inlet increased by 9.5% to 19.1% and the hydrogen production was enhanced by 12.1% to 40.3% in comparison with the conventional design even though the total reaction catalyst volume was reduced.
Investigation of the Hydrogen Production of the PACER Fusion Blanket Integrated with Fe-Cl Thermochemical Water Splitting Cycle
Aug 2023
Publication
In order to meet the energy demand energy production must be done continuously. Hydrogen seems to be the best alternative for this energy production because it is both an environmentally friendly and renewable energy source. In this study the hydrogen fuel production of the peaceful nuclear explosives (PACER) fusion blanket as the energy source integrated with Fe–Cl thermochemical water splitting cycle have been investigated. Firstly neutronic analyzes of the PACER fusion blanket were performed. Necessary neutronic studies were performed in the Monte Carlo calculation method. Molten salt fuel has been considered mole-fractions of heavy metal salt (ThF4 UF4 and ThF4+UF4) by 2 6 and 12 mol. % with Flibe as the main constituent. Secondly potential of the hydrogen fuel production as a result of the neutronic evaluations of the PACER fusion blanket integrated with Fe–Cl thermochemical cycle have been performed. In these calculations tritium breeding (TBR) energy multi plication factor (M) thermal power ratio (1 − ψ) total thermal power (Phpf) and mass flow rate of hydrogen (m˙ H2 ) have been computed. As a results the amount of the hydrogen production (m˙ H2 ) have been obtained in the range of 232.24x106 kg/year and 345.79 x106 kg/year for the all mole-fractions of heavy metal salts using in the blanket.
Techno-economic Assessment of a Chemical Looping Splitting System for H2 and CO Co-generation
Feb 2022
Publication
The natural gas (NG) reforming is currently one of the low-cost methods for hydrogen production. However the mixture of H2 and CO2 in the produced gas inevitably includes CO2 and necessitates the costly CO2 separation. In this work a novel double chemical looping involving both combustion (CLC) and sorption-enhanced reforming (SE-CLR) was proposed towards the co-production of H2 and CO (CLC-SECLRHC) in two separated streams. CLC provides reactant CO2 and energy to feed SECLRHC which generates hydrogen in a higher purity as well as the calcium cycle to generate CO in a higher purity. Techno-economic assessment of the proposed system was conducted to evaluate its efficiency and economic competitiveness. Studies revealed that the optimal molar ratios of oxygen carrier (OC)/NG and steam/NG for reforming were recommended to be 1.7 and 1.0 respectively. The heat integration within CLC and SECLRHC units can be achieved by circulating hot OCs. The desired temperatures of fuel reactor (FR) and reforming reactor (RR) should be 850 °C and 600 °C respectively. The heat coupling between CLC and SECLRHC units can be realized via a jacket-type reactor and the NG split ratio for reforming and combustion was 0.53:0.47. Under the optimal conditions the H2 purity the H2 yield and the CH4 conversion efficiency were 98.76% 2.31 mol mol-1 and 97.96% respectively. The carbon and hydrogen utilization efficiency respectively were 58.60% and 72.45% in terms of the total hydrogen in both steam and NG. The exergy efficiency of the overall process reached 70.28%. In terms of the conventional plant capacity (75×103 t y-1 ) and current raw materials price (2500 $ t-1 ) the payback period can be 6.2 years and the IRR would be 11.5 demonstrating an economically feasible and risk resistant capability.
Sensing Hydrogen Seeps in the Subsurface for Natural Hydrogen Exploration
Jun 2022
Publication
The recent detection of natural hydrogen seeps in sedimentary basin settings has triggered significant interest in the exploration of this promising resource. If large economical resources exist and can be extracted from the sub-surface this would provide an opportunity for natural hydrogen to contribute to the non-carbon-based energy mix. The detection and exploration of hydrogen gas in the sub-surface is a significant challenge that requires costly drilling sophisticated instrumentation and reliable analytical/sampling methods. Here we propose the application of a commercial-based sensor that can be used to detect and monitor low levels of hydrogen gas emissions from geological environments. The sensitivity selectivity (K > 1000) and stability (<1 ppm/day) of the sensor was evaluated under various conditions to determine its suitability for geological field monitoring. Calibration tests showed that the hydrogen readings from the sensor were within ±20% of the expected values. We propose that chemical sensing is a simple and feasible method for understanding natural hydrogen seeps that emanate from geological systems and formations. However we recommend using this sensor as part of a complete geological survey that incorporates an understanding of the geology along with complementary techniques that provide information on the rock properties.
Everything About Hydrogen Podcast: Scaling Clean Hydrogen Production
Dec 2021
Publication
Today we are joined by our good friends from Enapter. The company is a leader in the clean hydrogen sector focused on AEM electrolyzer technology and innovative software solutions that make it possible to rapidly deploy and scale hydrogen production assets. For those who follow the hydrogen sector regularly it’s been hard not to hear Enapter-related news in 2021 and its impressive trajectory as they have gone public announced the plans for a brand new production facility in Germany (on which they have now begun construction) and most recently the announcement that Enapter was selected as the winner of the prestigious Earthshot prize. To do that we are absolutely delighted to have with us all the way from his home base in Thailand Thomas Chrometzka Chief Strategy Officer at Enapter and one of the people that we enjoy having on the show so much that we have brought him back again to fill us in on what he and Enapter are up to and what they have planned for the future of hydrogen.
The podcast can be found on their website
The podcast can be found on their website
Fabrication of Highly Textured 2D SnSe Layers with Tunable Electronic Properties for Hydrogen Evolution
Jun 2021
Publication
Hydrogen is regarded to be one of the most promising renewable and clean energy sources. Finding a highly efficient and cost-effective catalyst to generate hydrogen via water splitting has become a research hotspot. Two-dimensional materials with exotic structural and electronic properties have been considered as economical alternatives. In this work 2D SnSe films with high quality of crystallinity were grown on a mica substrate via molecular beam epitaxy. The electronic property of the prepared SnSe thin films can be easily and accurately tuned in situ by three orders of magnitude through the controllable compensation of Sn atoms. The prepared film normally exhibited p-type conduction due to the deficiency of Sn in the film during its growth. First-principle calculations explained that Sn vacancies can introduce additional reactive sites for the hydrogen evolution reaction (HER) and enhance the HER performance by accelerating electron migration and promoting continuous hydrogen generation which was mirrored by the reduced Gibbs free energy by a factor of 2.3 as compared with the pure SnSe film. The results pave the way for synthesized 2D SnSe thin films in the applications of hydrogen production.
Techno-Economic Evaluation of Deploying CCS in SMR Based Merchant H2 Production with NG as Feedstock and Fuel
Aug 2017
Publication
Hydrogen is a crucial raw materials to other industries. Globally nearly 90% of the hydrogen or HyCO gas produced is consumed by the ammonia methanol and oil refining industries. In the future hydrogen could play an important role in the decarbonisation of transport fuel (i.e. use of fuel cell vehicles) and space heating (i.e. industrial commercial building and residential heating). This paper summarizes the results of the feasibility study carried out by Amec Foster Wheeler for the IEA Greenhouse Gas R&D Programme (IEA GHG) with the purpose of evaluating the performance and costs of a modern steam methane reforming without and with CCS producing 100000 Nm3 /h H2 and operating as a merchant plant. This study focuses on the economic evaluation of five different alternatives to capture CO2 from SMR. This paper provides an up-to-date assessment of the performance and cost of producing hydrogen without and with CCS based on technologies that could be erected today. This study demonstrates that CO2 could be captured from an SMR plant with an overall capture rate ranging between 53 to 90%. The integration of CO2 capture plant could increase the NG consumption by -0.03 to 1.41 GJ per Nm3 /h of H2. The amount of electricity exported to the grid by the SMR plant is reduced. The levelised cost of H2 production could increase by 2.1 to 5.1 € cent per Nm3 H2 (depending on capture rate and technology selected). This translates to a CO2 avoidance cost of 47 to 70 €/t.
Hydrogen Production by Water Electrolysis with Low Power and High Efficiency Based on Pre‐Magnetic Polarization
Mar 2022
Publication
In this paper a method of efficient hydrogen production using low‐power electrolysis based on pre‐magnetic polarization was proposed in order to improve the rate of hydrogen produc‐ tion by water electrolysis with reduced energy consumption molecular polarity and stress–strain characteristics of distilled water under the condition of a pre‐magnetic field. By constructing a mi‐ crophysical model of hydrogen proton energy‐level transition and a macroscopic mathematical model corresponding to magnetization vector‐polarization hydrogen proton concentration in the pre‐magnetic field the ionic conductivity electrolyte current density interelectrode voltage and hydrogen production efficiency under a varying magnetic field were qualitatively and quantita‐ tively analyzed. In addition an adjustable pre‐magnetic polarization hydrolyzing hydrogen pro‐ duction test platform was set up to verify the effectiveness of the proposed method. The repeated test results within a magnetic field strength range of 0–10000 GS showed that the conductivity of distilled water after pre‐magnetic polarization treatment increased by 2–3 times the electrolytic current density of the PEM (Proton Exchange Membrane) increased with increasing magnetic field strength the voltage between the poles continuously decreased and the hydrogen production rate was significantly improved. When the magnetic field strength reached 10000 GS the rate of hydro‐ gen production by the electrolysis of distilled water increased by 15%–20% within a certain period of time.
Operation Potential Evaluation of Multiple Hydrogen Production and Refueling Integrated Stations Under DC Interconnected Environment
Feb 2022
Publication
Hydrogen production and refueling integrated station can play an important role in the development of hydrogen transportation and fuel cell vehicles and actively promote the energy transformation. By using DC system for hydrogen production and refueling the conversion links can be reduced and the system efficiency can be effectively improved. In this paper a new scheme of DC interconnection for hydrogen production and refueling integrated station is proposed and the modular modeling and operation capability evaluation method are proposed including the characteristic analysis of integrated station the modular modeling and evaluation method for multiple integrated stations under DC interconnection. The DC interconnection system of five integrated stations is constructed and operation capability improvement of integrated stations after adopting the innovative DC interconnection scheme is analyzed. On this basis the system simulation model based on MATLAB/Simulink and physical test platform are built to verify the effectiveness of the theoretical analysis.
Reforming Processes for Syngas Production: A Mini-review on the Current Status, Challenges, and Prospects for Biomass Conversion to Fuels
Mar 2022
Publication
Dedicated bioenergy combined with carbon capture and storage are important elements for the mitigation scenarios to limit the global temperature rise within 1.5 °C. Thus the productions of carbon-negative fuels and chemicals from biomass is a key for accelerating global decarbonisation. The conversion of biomass into syngas has a crucial role in the biomass-based decarbonisation routes. Syngas is an intermediate product for a variety of chemical syntheses to produce hydrogen methanol dimethyl ether jet fuels alkenes etc. The use of biomass-derived syngas has also been seen as promising for the productions of carbon negative metal products. This paper reviews several possible technologies for the production of syngas from biomass especially related to the technological options and challenges of reforming processes. The scope of the review includes partial oxidation (POX) autothermal reforming (ATR) catalytic partial oxidation (CPO) catalytic steam reforming (CSR) and membrane reforming (MR). Special attention is given to the progress of CSR for biomass-derived vapours as it has gained significant interest in recent years. Heat demand and efficiency together with properties of the reformer catalyst were reviewed more deeply in order to understand and propose solutions to the problems that arise by the reforming of biomass-derived vapours and that need to be addressed in order to implement the technology on a big scale.
Improving the Efficiency of PEM Electrolyzers through Membrane-Specific Pressure Optimization
Feb 2020
Publication
Hydrogen produced in a polymer electrolyte membrane (PEM) electrolyzer must be stored under high pressure. It is discussed whether the gas should be compressed in subsequent gas compressors or by the electrolyzer. While gas compressor stages can be reduced in the case of electrochemical compression safety problems arise for thin membranes due to the undesired permeation of hydrogen across the membrane to the oxygen side forming an explosive gas. In this study a PEM system is modeled to evaluate the membrane-specific total system efficiency. The optimum efficiency is given depending on the external heat requirement permeation cell pressure current density and membrane thickness. It shows that the heat requirement and hydrogen permeation dominate the maximum efficiency below 1.6 V while above the cell polarization is decisive. In addition a pressure-optimized cell operation is introduced by which the optimum cathode pressure is set as a function of current density and membrane thickness. This approach indicates that thin membranes do not provide increased safety issues compared to thick membranes. However operating an N212-based system instead of an N117-based one can generate twice the amount of hydrogen at the same system efficiency while only one compressor stage must be added.
Towards the Rational Design of Stable Electrocatalysts for Green Hydrogen Production
Feb 2022
Publication
Now it is time to set up reliable water electrolysis stacks with active and robust electro‐ catalysts to produce green hydrogen. Compared with catalytic kinetics much less attention has been paid to catalyst stability and the weak understanding of the catalyst deactivation mechanism restricts the design of robust electrocatalysts. Herein we discuss the issues of catalysts’ stability evaluation and characterization and the degradation mechanism. The systematic understanding of the degradation mechanism would help us to formulate principles for the design of stable catalysts. Particularly we found that the dissolution rate for different 3d transition metals differed greatly: Fe dissolves 114 and 84 times faster than Co and Ni. Based on this trend we designed Fe@Ni and FeNi@Ni core‐shell structures to achieve excellent stability in a 1 A cm−2 current density as well as good catalytic activity at the same time
Effect of Au Plasmonic Material on Poly M-Toluidine for Photoelectrochemical Hydrogen Generation from Sewage Water
Feb 2022
Publication
This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So this study has a dual benefit for hydrogen generation; at the same time it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min respectively. The complete analyses confirm the chemical structure such as XRD FTIR HNMR SEM and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm) and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte respectively. Moreover all the thermodynamic parameters such as activation energy (Ea) enthalpy (∆H*) and entropy (∆S*) were calculated; additionally a simple mechanism is mentioned for the water-splitting reaction.
Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 ◦C
Apr 2021
Publication
This paper reports on an experimental evaluation of the hydrogen separation performance in a proton exchange membrane system with Pt-Co/C as the anode electrocatalyst. The recovery of hydrogen from H2/CO2 H2/CH4 and H2/NH3 gas mixtures were determined in the temperature range of 100–160 ◦C. The effects of both the impurity concentration and cell temperature on the separation performance of the cell and membrane were further examined. The electrochemical properties and performance of the cell were determined by means of polarization curves limiting current density open-circuit voltage hydrogen permeability hydrogen selectivity hydrogen purity and cell efficiencies (current voltage and power efficiencies) as performance parameters. High purity hydrogen (>99.9%) was obtained from a low purity feed (20% H2 ) after hydrogen was separated from H2/CH4 mixtures. Hydrogen purities of 98–99.5% and 96–99.5% were achieved for 10% and 50% CO2 in the feed respectively. Moreover the use of proton exchange membranes for electrochemical hydrogen separation was unsuccessful in separating hydrogen-rich streams containing NH3 ; the membrane underwent irreversible damage.
The Influence of Hydrogen Sulfide Contaminations on Hydrogen Production in Chemical Looping Processes
Aug 2021
Publication
Chemical looping with iron-based oxygen carriers enables the production of hydrogen from various fossil and biogenic primary energy sources. In applications with real producer gases such as biogas or gasified biomass hydrogen sulfide represents one of the most challenging contaminants. The impact of H2S on the reactivity of a Fe2O3/Al2O3 oxygen carrier material in chemical looping hydrogen production was investigated in the present work. First potential sulfur deactivation mechanisms are discussed in detail on the basis of thermodynamic data. Afterwards an experimental study in a fixed-bed reactor system gave experimental evidence on the fate of sulfur in chemical looping hydrogen systems. The chemisorption of hydrogen sulfide (H2S) was identified as the main cause for the accumulative adsorption of H2S in the reduction phase and was confirmed by ex-situ ICP-EOS analysis. In the subsequent steam oxidation step significant quantities of H2S were released resulting in an undesirable contamination of the hydrogen product gas. The reason was found as weakened sulfur bonds through increasing reactor temperatures caused by the exothermic oxidation reactions. In additional air oxidation steps no further contaminants as sulfur dioxide were identified. A profound interpretation was achieved through the fulfillment of the overall sulfur mass balance within a mean deviation of 3.7%. Quantitative investigations showed that the hydrogen consumption decreased by 12% throughout the reduction phase in the event of 100 ppm H2S in the feed gas
Hydrogen Production in the Swedish Power Sector: Considering Operational Volatilities and Long-term Uncertainties
Nov 2020
Publication
With more renewables on the Swedish electricity market while decommissioning nuclear power plants electricity supply increasingly fluctuates and electricity prices are more volatile. There is hence a need for securing the electricity supply before energy storage solutions become widespread. Electricity price fluctuations moreover affect operating income of nuclear power plants due to their inherent operational inflexibility. Since the anticipated new applications of hydrogen in fuel cell vehicles and steel production producing hydrogen has become a potential source of income particularly when there is a surplus supply of electricity at low prices. The feasibility of investing in hydrogen production was investigated in a nuclear power plant applying Swedish energy policy as background. The analysis applies a system dynamics approach incorporating the stochastic feature of electricity supply and prices. The study revealed that hydrogen production brings alternative opportunities for large-scale electricity production facilities in Sweden. Factors such as hydrogen price will be influential and require in-depth investigation. This study provides guidelines for power sector policymakers and managers who plan to engage in hydrogen production for industrial applications. Although this study was focused upon nuclear power sources it can be extended to hydrogen production from renewable energy sources such as wind and solar.
Setting Thresholds to Define Indifferences and Preferences in PROMETHEE for Life Cycle Sustainability Assessment of European Hydrogen Production
Jun 2021
Publication
The Life Cycle Sustainability Assessment (LCSA) is a proven method for sustainability assessment. However the interpretation phase of an LCSA is challenging because many different single results are obtained. Additionally performing a Multi-Criteria Decision Analysis (MCDA) is one way—not only for LCSA—to gain clarity about how to interpret the results. One common form of MCDAs are outranking methods. For these type of methods it becomes of utmost importance to clarify when results become preferable. Thus thresholds are commonly used to prevent decisions based on results that are actually indifferent between the analyzed options. In this paper a new approach is presented to identify and quantify such thresholds for Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) based on uncertainty of Life Cycle Impact Assessment (LCIA) methods. Common thresholds and this new approach are discussed using a case study on finding a preferred location for sustainable industrial hydrogen production comparing three locations in European countries. The single LCSA results indicated different preferences for the environmental economic and social assessment. The application of PROMETHEE helped to find a clear solution. The comparison of the newly-specified thresholds based on LCIA uncertainty with default thresholds provided important insights of how to interpret the LCSA results regarding industrial hydrogen production.
Goal and Scope in Life Cycle Sustainability Analysis: The Case of Hydrogen Production from Biomass
Aug 2014
Publication
The framework for life cycle sustainability analysis (LCSA) developed within the project CALCAS (Co-ordination Action for innovation in Life-Cycle Analysis for Sustainability) is introducing a truly integrated approach for sustainability studies. However it needs to be further conceptually refined and to be made operational. In particular one of the gaps still hindering the adoption of integrated analytic tools for sustainability studies is the lack of a clear link between the goal and scope definition and the modeling phase. This paper presents an approach to structure the goal and scope phase of LCSA so as to identify the relevant mechanisms to be further detailed and analyzed in the modeling phase. The approach is illustrated with an on-going study on a new technology for the production of high purity hydrogen from biomass to be used in automotive fuel cells.
Transient Numerical Modeling and Model Predictive Control of an Industrial-scale Steam Methane Reforming Reactor
Mar 2021
Publication
A steam methane reforming reactor is a key equipment in hydrogen production and numerical analysis and process control can provide a critical insight into its reforming mechanisms and flexible operation in real engineering applications. The present paper firstly studies the transport phenomena in an industrial-scale steam methane reforming reactor by transient numerical simulations. Wall effect and local non thermal equilibrium is considered in the simulations. A temperature profile of the tube outer wall is given by user defined functions integrated into the ANSYS FLUENT software. Dynamic simulations show that the species distribution is closely related to the temperature distribution which makes the temperature of the reactor tube wall an important factor for the hydrogen production of the reformer and the thermal conductivity of the catalyst network is crucial in the heat transfer in the reactor. Besides there exists a delay of the reformer's hydrogen production when the temperature profile of the tube wall changes. Among inlet temperature inlet mass flow rate and inlet steam-to-carbon (S/C) ratio the mass flow rate is the most influencing factor for the hydrogen production. The dynamic matrix control (DMC) scheme is subsequently designed to manipulate the mole fraction of hydrogen of the outlet to the target value by setting the temperature profile trajectory of the reforming tube with time. The proportional-integral control strategy is also studied for comparison. The closed-loop simulation results show that the proposed DMC control strategy can reduce the overshoot and have a small change of the input variable. In addition the disturbances of feed disturbance can also be well rejected to assure the tracking performance indicating the superiority of the DMC controller. All the results give insight to the theoretical analysis and controller design of a steam methane reformer and demonstrate the potential of the CFD modeling in study the transport mechanism and the idea of combining CFD modelling with controller design for the real application.
Recent Development of Biomass Gasification for H2 Rich Gas Production
Mar 2022
Publication
Biomass gasification for hydrogen (H2) production provides outstanding advantages in terms of renewable energy resources carbon neutral high efficiency and environmental benefits. However the factors influencing H2 production from biomass gasification are complex which makes determining the optimal operating conditions challenging. Biomass gasification also poses challenges owing to the high associated tar content and low gas yield which need to be overcome. This review summarizes the influence of the gasification parameters on H2 production. Catalytic gasification technology and some of the latest catalysts such as composites and special structure catalysts are also summarized herein based on the requirements of high-purity H2 production. Moreover novel technologies such as staged gasification chemical looping gasification and adsorption-enhanced reforming for producing H2 rich gas are introduced. Finally the challenges and prospects associated with biomass gasification for H2 production are presented.
Analysis of Control-System Strategy and Design of a Small Modular Reactor with Different Working Fluids for Electricity and Hydrogen Production as Part of a Decentralised Mini Grid
Mar 2022
Publication
Hydrogen is increasingly being viewed as a significant fuel for future industrial processes as it offers pathways to zero emission. The UK sees hydrogen as one of a handful of low-carbon solutions for transition to net zero. Currently most hydrogen production is from steam reforming of natural gas or coal gasification both of which involve the release of carbon dioxide. Hydrogen production from mini decentralised grids via a thermochemical process coupled with electricity production could offer favourable economics for small modular reactors (SMRs) whereby demand or grid management as a solution would include redirecting the power for hydrogen production when electricity demand is low. It also offers a clean-energy alternative to the aforementioned means. SMRs could offer favourable economics due to their flexible power system as part of the dual-output function. This study objective is to investigate the critical performance parameters associated with the nuclear power plant (NPP) the cycle working fluids and control-system design for switching between electricity and hydrogen demand to support delivery as part of a mini grid system for a reactor power delivering up to approximately 600 MWth power. The novelty of the work is in the holistic parametric analysis undertaken using a novel in-house tool which analyses the NPP using different working fluids with a control function bolt-on at the offtake for hydrogen production. The results indicate that the flow conditions at the offtake can be maintained. The choice of working fluids affects the pressure component. However the recuperator and heat-exchanger effectiveness are considered as efficiency-limiting factors for hydrogen production and electricity generation. As such the benefit of high-technology heat exchangers cannot be underestimated. This is also true when deciding on the thermochemical process to bolt onto the plant. The temperature of the gas at the end of the pipeline should also be considered to ensure that the minimum temperature-requirement status for hydrogen production is me
Everything About Hydrogen Podcast: Could Electrolysers Replicate Moore's Law?
Apr 2020
Publication
On this weeks episode the team are talking all things hydrogen with Sebastian-Justus Schmidt Chairman of Enapter and Thomas Chrometzka Head of Strategy at Enapter. On the show we discuss Enapter’s Anion Exchange Membrane (AEM) electrolyser and why Enapter believe that their modular electrolyser approach will revolutionise the cost of green hydrogen. We also discuss the wide array of use cases and sectors that Enapter are already working with to provide their solution as well as their view on where the current barriers exist for the hydrogen market. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
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