Production & Supply Chain
Autonomous Hydrogen Production for Proton Exchange Membrane Fuel Cells PEMFC
Apr 2020
Publication
This paper focuses on hydrogen production for green mobility applications (other applications are currently under investigation). Firstly a brief state of the art of hydrogen generation by hydrolysis with magnesium is shown. The hydrolysis performance of Magnesium powder ball–milled along with different additives (graphite and transition metals TM = Ni Fe and Al) is taken for comparison. The best performance was observed with Mg–10 wt.% g mixtures (95% of theoretical hydrogen generation yield in about 3 min). An efficient solution to control this hydrolysis reaction is proposed to produce hydrogen on demand and to feed a PEM fuel cell. Tests on a bench fitted with a 100 W Proton Exchange Membrane (PEM) fuel cell have demonstrated the technological potential of this solution for electric assistance applications in the field of light mobility.
How Green is Blue Hydrogen?
Jul 2021
Publication
Hydrogen is often viewed as an important energy carrier in a future decarbonized world. Currently most hydrogen is produced by steam reforming of methane in natural gas (“gray hydrogen”) with high carbon dioxide emissions. Increasingly many propose using carbon capture and storage to reduce these emissions producing so-called “blue hydrogen” frequently promoted as low emissions. We undertake the first effort in a peer-reviewed paper to examine the lifecycle greenhouse gas emissions of blue hydrogen accounting for emissions of both carbon dioxide and unburned fugitive methane. Far from being low carbon greenhouse gas emissions from the production of blue hydrogen are quite high particularly due to the release of fugitive methane. For our default assumptions (3.5% emission rate of methane from natural gas and a 20-year global warming potential) total carbon dioxide equivalent emissions for blue hydrogen are only 9%-12% less than for gray hydrogen. While carbon dioxide emissions are lower fugitive methane emissions for blue hydrogen are higher than for gray hydrogen because of an increased use of natural gas to power the carbon capture. Perhaps surprisingly the greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat again with our default assumptions. In a sensitivity analysis in which the methane emission rate from natural gas is reduced to a low value of 1.54% greenhouse gas emissions from blue hydrogen are still greater than from simply burning natural gas and are only 18%-25% less than for gray hydrogen. Our analysis assumes that captured carbon dioxide can be stored indefinitely an optimistic and unproven assumption. Even if true though the use of blue hydrogen appears difficult to justify on climate ground
Onshore, Offshore or In-turbine Electrolysis? Techno-economic Overview of Alternative Integration Designs for Green Hydrogen Production into Offshore Wind Power Hubs
Aug 2021
Publication
Massive investments in offshore wind power generate significant challenges on how this electricity will be integrated into the incumbent energy systems. In this context green hydrogen produced by offshore wind emerges as a promising solution to remove barriers towards a carbon-free economy in Europe and beyond. Motivated by the recent developments in Denmark with the decision to construct the world’s first artificial Offshore Energy Hub this paper investigates how the lowest cost for green hydrogen can be achieved. A model proposing an integrated design of the hydrogen and offshore electric power infrastructure determining the levelised costs of both hydrogen and electricity is proposed. The economic feasibility of hydrogen production from 2 Offshore Wind Power Hubs is evaluated considering the combination of different electrolyser placements technologies and modes of operations. The results show that costs down to 2.4 €/kg can be achieved for green hydrogen production offshore competitive with the hydrogen costs currently produced by natural gas. Moreover a reduction of up to 13% of the cost of wind electricity is registered when an electrolyser is installed offshore shaving the peak loads.
Fuel Cells and Hydrogen Observatory Hydrogen Molecule Market Report
Sep 2021
Publication
The purpose of the hydrogen molecule market analysis is to track changes in the structure of hydrogen supply and demand in Europe. This report is mainly focused on presenting the current landscape - that will allow for future year-on-year comparisons in order to assess the progress Europe is making with regards to deployment of clean hydrogen production capacities as well as development of demand for clean hydrogen from emerging new hydrogen applications in the mobility sector or in industry. The following report summarizes the hydrogen molecule market landscape and contains data about hydrogen production and consumption in the EEA countries (EU countries together with Switzerland Norway Iceland and Liechtenstein). Hydrogen production capacity is presented by country and by technology whereas the hydrogen consumption data is presented by country and by end-use sector. The analysis undertaken for this report was completed using data available at the end of 2019. Hydrogen market (on both the demand and supply side) is dominated by ammonia and refining industries with three countries (DE NL PL) responsible for almost half hydrogen consumption. Today hydrogen is overwhelmingly produced by reforming of fossil fuels (mostly natural gas). Clean hydrogen production capacities are insignificant with blue hydrogen capacities at below 1% and green hydrogen production capacity below 0.1% of total.
Past, Present and Near Future: An Overview of Closed, Running and Planned Biomethanation Facilities in Europe
Sep 2021
Publication
The power-to-methane technology is promising for long-term high-capacity energy storage. Currently there are two different industrial-scale methanation methods: the chemical one (based on the Sabatier reaction) and the biological one (using microorganisms for the conversion). The second method can be used not only to methanize the mixture of pure hydrogen and carbon dioxide but also to methanize the hydrogen and carbon dioxide content of low-quality gases such as biogas or deponia gas enriching them to natural gas quality; therefore the applicability of biomethanation is very wide. In this paper we present an overview of the existing and planned industrial-scale biomethanation facilities in Europe as well as review the facilities closed in recent years after successful operation in the light of the scientific and socioeconomic context. To outline key directions for further developments this paper interconnects biomethanation projects with the competitiveness of the energy sector in Europe for the first time in the literature. The results show that future projects should have an integrative view of electrolysis and biomethanation as well as hydrogen storage and utilization with carbon capture and utilization (HSU&CCU) to increase sectoral competitiveness by enhanced decarbonization.
Modeling of a High Temperature Heat Exchanger to Supply Hydrogen Required by Fuel Cells Through Reforming Process
Sep 2021
Publication
Hydrogen as a clean fuel and a new energy source can be produced by various methods. One of these common and economical methods of hydrogen production is hydrocarbon vapor modification. This research studies hydrogen production using a propane steam reforming process inside a high temperature heat exchanger. The application of this high temperature heat exchanger in the path of the power supply line is a fuel cell stack unit to supply the required hydrogen of the device. The heat exchanger consists of a set of cylindrical tubes housed inside a packed-bed called a reformer. The energy required to perform the reaction is supplied through these tubes in which high temperature gas is injected and the heat exchanger is insulated to prevent energy loss. The results show that at maximum temperature and velocity of hot gases (900 K and 1.5 m s−1 ) complete consumption of propane can be observed before the outlet of the reformer. Also in the mentioned conditions the maximum hydrogen production (above 92%) is obtained. The best permeability under which the system can perform best is 1×10−9 m2.
Computational Intelligence Approach for Modeling Hydrogen Production: A Review
Mar 2018
Publication
Hydrogen is a clean energy source with a relatively low pollution footprint. However hydrogen does not exist in nature as a separate element but only in compound forms. Hydrogen is produced through a process that dissociates it from its compounds. Several methods are used for hydrogen production which first of all differ in the energy used in this process. Investigating the viability and exact applicability of a method in a specific context requires accurate knowledge of the parameters involved in the method and the interaction between these parameters. This can be done using top-down models relying on complex mathematically driven equations. However with the raise of computational intelligence (CI) and machine learning techniques researchers in hydrology have increasingly been using these methods for this complex task and report promising results. The contribution of this study is to investigate the state of the art CI methods employed in hydrogen production and to identify the CI method(s) that perform better in the prediction assessment and optimization tasks related to different types of Hydrogen production methods. The resulting analysis provides in-depth insight into the different hydrogen production methods modeling technique and the obtained results from various scenarios integrating them within the framework of a common discussion and evaluation paper. The identified methods were benchmarked by a qualitative analysis of the accuracy of CI in modeling hydrogen production providing extensive overview of its usage to empower renewable energy utilization.
Methanol Electrolysis for Hydrogen Production Using Polymer Electrolyte Membrane: A Mini-Review
Nov 2020
Publication
Hydrogen (H2) has attained significant benefits as an energy carrier due to its gross calorific value (GCV) and inherently clean operation. Thus hydrogen as a fuel can lead to global sustainability. Conventional H2 production is predominantly through fossil fuels and electrolysis is now identified to be most promising for H2 generation. This review describes the recent state of the art and challenges on ultra-pure H2 production through methanol electrolysis that incorporate polymer electrolyte membrane (PEM). It also discusses about the methanol electrochemical reforming catalysts as well as the impact of this process via PEM. The efficiency of H2 production depends on the different components of the PEM fuel cells which are bipolar plates current collector and membrane electrode assembly. The efficiency also changes with the nature and type of the fuel fuel/oxygen ratio pressure temperature humidity cell potential and interfacial electronic level interaction between the redox levels of electrolyte and band gap edges of the semiconductor membranes. Diverse operating conditions such as concentration of methanol cell temperature catalyst loading membrane thickness and cell voltage that affect the performance are critically addressed. Comparison of various methanol electrolyzer systems are performed to validate the significance of methanol economy to match the future sustainable energy demands.
Hydrogen Gas Quality for Gas Network Injection: State of the Art of Three Hydrogen Production Methods
Jun 2021
Publication
The widescale distribution of hydrogen through gas networks is promoted as a viable and cost-efficient option for optimising its application in heat industry and transport. It is a key step towards achieving decarbonisation targets in the UK. A key consideration before the injection of hydrogen into the UK gas networks is an assessment of the difference in hydrogen contaminants presence from different production methods. This information is essential for gas regulation and for further purification requirements. This study investigates the level of ISO 14687 Grade D contaminants in hydrogen from steam methane reforming proton exchange membrane water electrolysis and alkaline electrolysis. Sampling and analysis of hydrogen were carried out by the National Physical Laboratory following ISO 21087 guidance. The results of analysis indicated the presence of nitrogen in hydrogen from electrolysis and water carbon dioxide and particles in all samples analysed. The contaminants were at levels below or at the threshold limits set by ISO 14687 Grade D. This indicates that the investigated production methods are not a source of contaminants for the eventual utilisation of hydrogen in different applications including fuel cell electric vehicles (FCEV’s). The gas network infrastructure will require a similar analysis to determine the likelihood of contamination to hydrogen gas.
Durability of Anion Exchange Membrane Water Electrolyzers
Apr 2021
Publication
Interest in the low-cost production of clean hydrogen is growing. Anion exchange membrane water electrolyzers (AEMWEs) are considered one of the most promising sustainable hydrogen production technologies because of their ability to split water using platinum group metal-free catalysts less expensive anode flow fields and bipolar plates. Critical to the realization of AEMWEs is understanding the durability-limiting factors that restrict the long-term use of these devices. This article presents both durability-limiting factors and mitigation strategies for AEMWEs under three operation modes i.e. pure water-fed (no liquid electrolyte) concentrated KOH-fed and 1 wt% K2CO3-fed operating at a differential pressure of 100 psi. We examine extended-term behaviors of AEMWEs at the single-cell level and connect their behavior with the electrochemical chemical and mechanical instability of single-cell components. Finally we discuss the pros and cons of AEMWEs under these operation modes and provide direction for long-lasting AEMWEs with highly efficient hydrogen production capabilities.
Microalgal Hydrogen Production in Relation to Other Biomass‐Based Technologies—A Review
Sep 2021
Publication
Hydrogen is an environmentally friendly biofuel which if widely used could reduce atmospheric carbon dioxide emissions. The main barrier to the widespread use of hydrogen for power generation is the lack of technologically feasible and—more importantly—cost‐effective methods of production and storage. So far hydrogen has been produced using thermochemical methods (such as gasification pyrolysis or water electrolysis) and biological methods (most of which involve anaerobic digestion and photofermentation) with conventional fuels waste or dedicated crop biomass used as a feedstock. Microalgae possess very high photosynthetic efficiency can rapidly build biomass and possess other beneficial properties which is why they are considered to be one of the strongest contenders among biohydrogen production technologies. This review gives an account of present knowledge on microalgal hydrogen production and compares it with the other available biofuel production technologies.
Hydrogen and Oxygen Production via Water Splitting in a Solar-Powered Membrane Reactor—A Conceptual Study
Jan 2021
Publication
Among the processes for producing hydrogen and oxygen from water via the use of solar energy water splitting has the advantage of being carried out in onestep. According to thermodynamics this process exhibits conversions of practical interest at very high temperatures and needs efficient separation systems in order to separate the reaction products hydrogen and oxygen. In this conceptual work the behaviour of a membrane reactor that uses two membranes perm-selective to hydrogen and oxygen is investigated in the temperature range 2000–2500 °C of interest for coupling this device with solar receivers. The effect of the reaction pressure has been evaluated at 0.5 and 1 bar while the permeate pressure has been fixed at 100 Pa. As a first result the use of the membrane perm-selective to oxygen in addition to the hydrogen one has improved significantly the reaction conversion that for instance at 0.5 bar and 2000 °C moves from 9.8% up to 18.8%. Based on these critical data a preliminary design of a membrane reactor consisting of a Ta tubular membrane separating the hydrogen and a hafnia camera separating the oxygen is presented: optimaloperating temperature of the reactor results in being around 2500 °C a value making impracticable its coupling with solar receivers even in view of an optimistic development of this technology. The study has verified that at 2000 °C with a water feed flow rate of 1000 kg h−1 about 200 and 100 m3 h−1 of hydrogen and oxygen are produced. In this case a surface of the hafnia membrane of the order of hundreds m2 is required: the design of such a membrane device may be feasible when considering special reactor configurations.
Solar Thermochemical Hydrogen Production in the USA
Jul 2021
Publication
Hydrogen produced from renewable energy has the potential to decarbonize parts of the transport sector and many other industries. For a sustainable replacement of fossil energy carriers both the environmental and economic performance of its production are important. Here the solar thermochemical hydrogen pathway is characterized with a techno-economic and life-cycle analysis. Assuming a further increase of conversion efficiency and a reduction of investment costs it is found that hydrogen can be produced in the United States of America at costs of 2.1–3.2 EUR/kg (2.4–3.6 USD/kg) at specific greenhouse gas emissions of 1.4 kg CO2-eq/kg. A geographical potential analysis shows that a maximum of 8.4 × 1011 kg per year can be produced which corresponds to about twelve times the current global and about 80 times the current US hydrogen production. The best locations are found in the Southwest of the US which have a high solar irradiation and short distances to the sea which is beneficial for access to desalinated water. Unlike for petrochemical products the transport of hydrogen could potentially present an obstacle in terms of cost and emissions under unfavorable circumstances. Given a large-scale deployment low-cost transport seems however feasible.
Hydrogen for Australia’s Future
Aug 2018
Publication
The Hydrogen Strategy Group chaired by Australia’s Chief Scientist Dr Alan Finkel has today released a briefing paper on the potential domestic and export opportunities of a hydrogen industry in Australia.
Like natural gas hydrogen can be used to heat buildings and power vehicles. Unlike natural gas or petrol when hydrogen is burned there are no CO2 emissions. The only by-products are water vapour and heat.
Hydrogen is the most abundant element in the universe not freely available as a gas on Earth but bound into many common substances including water and fossil fuels.
Hydrogen was first formally presented as a credible alternative energy source in the early 1970s but never proved competitive at scale as an energy source – until now. We find that the worldwide demand for hydrogen is set to increase substantially over coming decades driven by Japan’s decision to put imported hydrogen at the heart of its economy. Production costs are falling technologies are progressing and the push for non-nuclear low-emissions fuels is building momentum. We conclude that Australia is remarkably well-positioned to benefit from the growth of hydrogen industries and markets.
Like natural gas hydrogen can be used to heat buildings and power vehicles. Unlike natural gas or petrol when hydrogen is burned there are no CO2 emissions. The only by-products are water vapour and heat.
Hydrogen is the most abundant element in the universe not freely available as a gas on Earth but bound into many common substances including water and fossil fuels.
Hydrogen was first formally presented as a credible alternative energy source in the early 1970s but never proved competitive at scale as an energy source – until now. We find that the worldwide demand for hydrogen is set to increase substantially over coming decades driven by Japan’s decision to put imported hydrogen at the heart of its economy. Production costs are falling technologies are progressing and the push for non-nuclear low-emissions fuels is building momentum. We conclude that Australia is remarkably well-positioned to benefit from the growth of hydrogen industries and markets.
Platinum Single-atom Catalyst Coupled with Transition Metal/Metal Oxide Heterostructure for Accelerating Alkaline Hydrogen Evolution Reaction
Jun 2021
Publication
Single-atom catalysts provide an effective approach to reduce the amount of precious metals meanwhile maintain their catalytic activity. However the sluggish activity of the catalysts for alkaline water dissociation has hampered advances in highly efficient hydrogen production. Herein we develop a single-atom platinum immobilized NiO/Ni heterostructure (PtSA-NiO/Ni) as an alkaline hydrogen evolution catalyst. It is found that Pt single atom coupled with NiO/Ni heterostructure enables the tunable binding abilities of hydroxyl ions (OH*) and hydrogen (H*) which efficiently tailors the water dissociation energy and promotes the H* conversion for accelerating alkaline hydrogen evolution reaction. A further enhancement is achieved by constructing PtSA-NiO/Ni nanosheets on Ag nanowires to form a hierarchical three-dimensional morphology. Consequently the fabricated PtSA-NiO/Ni catalyst displays high alkaline hydrogen evolution performances with a quite high mass activity of 20.6 A mg−1 for Pt at the overpotential of 100 mV significantly outperforming the reported catalysts.
Introducing Power-to-H3: Combining Renewable Electricity with Heat, Water and Hydrogen Production and Storage in a Neighbourhood
Oct 2019
Publication
In the transition from fossil to renewable energy the energy system should become clean while remaining reliable and affordable. Because of the intermittent nature of both renewable energy production and energy demand an integrated system approach is required that includes energy conversion and storage. We propose a concept for a neighbourhood where locally produced renewable energy is partly converted and stored in the form of heat and hydrogen accompanied by rainwater collection storage purification and use (Power-to-H3). A model is developed to create an energy balance and perform a techno-economic analysis including an analysis of the avoided costs within the concept. The results show that a solar park of 8.7 MWp combined with rainwater collection and solar panels on roofs can supply 900 houses over the year with heat (20 TJ) via an underground heat storage system as well as with almost half of their water demand (36000m3) and 540 hydrogen electric vehicles can be supplied with hydrogen (90 tonnes). The production costs for both hydrogen (8.7 €/kg) and heat (26 €/GJ) are below the current end user selling price in the Netherlands (10 €/kg and 34 €/GJ) making the system affordable. When taking avoided costs into account the prices could decrease with 20–26% while at the same time avoiding 3600 tonnes of CO2 a year. These results make clear that it is possible to provide a neighbourhood with all these different utilities completely based on solar power and rainwater in a reliable affordable and clean way.
Enhanced Performance and Durability of Low Catalyst Loading PEM Water Electrolyser Based on a Short-side Chain Perfluorosulfonic Ionomer
Sep 2016
Publication
Water electrolysis supplied by renewable energy is the foremost technology for producing ‘‘green” hydrogen for fuel cell vehicles. In addition the ability to rapidly follow an intermittent load makes electrolysis an ideal solution for grid-balancing caused by differences in supply and demand for energy generation and consumption. Membrane-electrode assemblies (MEAs) designed for polymer electrolyte membrane (PEM) water electrolysis based on a novel short-side chain (SSC) perfluorosulfonic acid (PFSA) membrane Aquivion with various cathode and anode noble metal loadings were investigated in terms of both performance and durability. Utilizing a nanosized Ir0.7Ru0.3O solid solution anode catalyst and a supported Pt/C cathode catalyst in combination with the Aquivion membrane gave excellent electrolysis performances exceeding 3.2 A cm-2 at 1.8 V terminal cell voltage ( 80% efficiency) at 90 ºC in the presence of a total catalyst loading of 1.6 mg cm−2. A very small loss of efficiency corresponding to 30 mV voltage increase was recorded at 3 A cm 2 using a total noble metal catalyst loading of less than 0.5 mg cm−2 (compared to the industry standard of 2 mg cm−2). Steady-state durability tests carried out for 1000 h at 1 A cm -2 showed excellent stability for the MEA with total noble metal catalyst loading of 1.6 mg cm−2 (cell voltage increase 5 lV/h). Moderate degradation rate (cell voltage increase 15 lV/h) was recorded for the low loading 0.5 mg cm-2 MEA. Similar stability characteristics were observed in durability tests at 3 A cm−2. These high performance and stability characteristics were attributed to the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the Ir and Ru oxide solid solution and the enrichment of Ir species on the surface for the anodic catalyst.
Experimental Characterization of an Alkaline Electrolyser and a Compression System for Hydrogen Production and Storage
Aug 2021
Publication
Storing renewable energy in chemicals like hydrogen can bring various benefits like high energy density seasonal storability possible cost reduction of the final product and the potential to let renewable power penetrate other markets and to overcome their intermittent availability. In the last year’s production of this gas from renewable energy sources via electrolysis has grown its reputation as one feasible solution to satisfy future zero-emission energy demand. To extend the exploitation of Renewable Energy Source (RES) small-scale conversion plants seem to be an interesting option. In view of a possible widespread adoption of these types of plants the authors intend to present the experimental characterization of a small-scale hydrogen production and storage plant. The considered experimental plant is based on an alkaline electrolyser and an air-driven hydrogen compression and storage system. The results show that the hydrogen production-specific consumption is on average 77 kWh/kgH2 . The hydrogen compressor energy requirement is on average 15 kWh/kgH2 (data referred to the driving compressed air). The value is higher than data found in literature (4.4–9.3 kWh/kgH2 ) but the difference can be attributed to the small size of the considered compressor and the choice to limit the compression stages.
Numerical Study on Optics and Heat Transfer of Solar Reactor for Methane Thermal Decomposition
Oct 2021
Publication
This study aims to reduce greenhouse gas emissions to the atmosphere and effectively utilize wasted resources by converting methane the main component of biogas into hydrogen. Therefore a reactor was developed to decompose methane into carbon and hydrogen using solar thermal sources instead of traditional energy sources such as coal and petroleum. The optical distributions were analyzed using TracePro a Monte Carlo ray-tracing-based program. In addition Fluent a computational fluid dynamics program was used for the heat and mass transfer and chemical reaction. The cylindrical indirect heating reactor rotates at a constant speed to prevent damage by the heat source concentrated at the solar furnace. The inside of the reactor was filled with a porous catalyst for methane decomposition and the outside was surrounded by insulation to reduce heat loss. The performance of the reactor according to the cavity model was calculated when solar heat was concentrated on the reactor surface and methane was supplied into the reactor in an environment with a solar irradiance of 700 W/m2 wind speed of 1 m/s and outdoor temperature of 25 °C. As a result temperature methane mass fraction distribution and heat loss amounts for the two cavities were obtained and it was found that the effect on the conversion rate was largely dependent on a temperature over 1000 °C in the reactor. Moreover the heat loss of the full-cavity model decreased by 12.5% and the methane conversion rate increased by 33.5% compared to the semi-cavity model. In conclusion the high-temperature environment of the reactor has a significant effect on the increase in conversion rate with an additional effect of reducing heat loss.
Highly Selective Porous Separator with Thin Skin Layer for Alkaline Water Electrolysis
Feb 2022
Publication
Advanced porous separators with thin selective skin layers to reduce the hydrogen permeation are developed for applications in alkaline water electrolysis. A thin skin layer based on crosslinked polyvinyl alcohol (cPVA) is fabricated on a porous substrate by a facile and scalable ultrasonic spray coating process. As the number of ultrasonic spraying cycles increases the resulting separator demonstrates a decrease in the large-diameter pore fraction an increase in the bubble-point pressure and a reduction in the hydrogen permeability without a significant increase in the areal resistance. As a result the optimized separator with a cPVA skin layer combines a low ionic resistance of 0.267 Ω cm2 a high bubble point pressure of 2.71 bar and a low hydrogen permeability of 1.12 × 10− 11 mol cm− 2 s − 1 bar− 1 . The electrolytic cell assembled with cPVAZ-30 achieves current densities of 861 mA cm− 2 and 1890 mA cm− 2 at 2.0 V and 2.6 V respectively in a 30 wt% KOH electrolyte solution at 80 ◦C.
Bench-Scale Steam Reforming of Methane for Hydrogen Production
Jul 2019
Publication
The effects of reaction parameters including reaction temperature and space velocity on hydrogen production via steam reforming of methane (SRM) were investigated using lab- and bench-scale reactors to identify critical factors for the design of large-scale processes. Based on thermodynamic and kinetic data obtained using the lab-scale reactor a series of SRM reactions were performed using a pelletized catalyst in the bench-scale reactor with a hydrogen production capacity of 10 L/min. Various temperature profiles were tested for the bench-scale reactor which was surrounded by three successive cylindrical furnaces to simulate the actual SRM conditions. The temperature at the reactor bottom was crucial for determining the methane conversion and hydrogen production rates when a sufficiently high reaction temperature was maintained (>800 ◦C) to reach thermodynamic equilibrium at the gas-hourly space velocity of 2.0 L CH4/(h·gcat). However if the temperature of one or more of the furnaces decreased below 700 ◦C the reaction was not equilibrated at the given space velocity. The effectiveness factor (0.143) of the pelletized catalyst was calculated based on the deviation of methane conversion between the lab- and bench-scale reactions at various space velocities. Finally an idling procedure was proposed so that catalytic activity was not affected by discontinuous operation.
Techno-economic Assessment of Hydrogen Production from Seawater
Nov 2022
Publication
Population growth and the expansion of industries have increased energy demand and the use of fossil fuels as an energy source resulting in release of greenhouse gases (GHG) and increased air pollution. Countries are therefore looking for alternatives to fossil fuels for energy generation. Using hydrogen as an energy carrier is one of the most promising alternatives to replace fossil fuels in electricity generation. It is therefore essential to know how hydrogen is produced. Hydrogen can be produced by splitting the water molecules in an electrolyser using the abondand water resources which are covering around ⅔ of the Earth's surface. Electrolysers however require high-quality water with conductivity in the range of 0.1–1 μS/cm. In January 2018 there were 184 offshore oil and gas rigs in the North Sea which may be excellent sites for hydrogen production from seawater. The hydrogen production process reported in this paper is based on a proton exchange membrane (PEM) electrolyser with an input flow rate of 300 L/h. A financially optimal system for producing demineralized water from seawater with conductivity in the range of 0.1–1 μS/cm as the input for electrolyser by WAVE (Water Application Value Engine) design software was studied. The costs of producing hydrogen using the optimised system was calculated to be US$3.51/kg H2. The best option for low-cost power generation using renewable resources such as photovoltaic (PV) devices wind turbines as well as electricity from the grid was assessed considering the location of the case considered. All calculations were based on assumption of existing cable from the grid to the offshore meaning that the cost of cables and distribution infrastructure were not considered. Models were created using HOMER Pro (Hybrid Optimisation of Multiple Energy Resources) software to optimise the microgrids and the distributed energy resources under the assumption of a nominal discount rate inflation rate project lifetime and CO2 tax in Norway. Eight different scenarios were examined using HOMER Pro and the main findings being as follows:<br/>The cost of producing water with quality required by the electrolyser is low compared with the cost of electricity for operation of the electrolyser and therefore has little effect on the total cost of hydrogen production (less than 1%).<br/>The optimal solution was shown to be electricity from the grid which has the lowest levelised cost of energy (LCOE) of the options considered. The hydrogen production cost using electricity from the grid was about US$ 5/kg H2.<br/>Grid based electricity resulted in the lowest hydrogen production cost even when costs for CO2 emissions in Norway that will start to apply in 2025 was considered being approximately US$7.7/kg H2.<br/>From economical point of view wind energy was found to be a more economical than solar.
A Tale of Two Phase Diagrams Interplay of Ordering and Hydrogen Uptake in Pd–Au–H
Apr 2021
Publication
Due to their ability to reversibly absorb/desorb hydrogen without hysteresis Pd–Au nanoalloys have been proposed as materials for hydrogen sensing. For sensing it is important that absorption/desorption isotherms are reproducible and stable over time. A few studies have pointed to the influence of short and long range chemical order on these isotherms but many aspects of the impact of chemical order have remained unexplored. Here we use alloy cluster expansions to describe the thermodynamics of hydrogen in Pd–Au in a wide concentration range. We investigate how different chemical orderings corresponding to annealing at different temperatures as well as different external pressures of hydrogen impact the behavior of the material with focus on its hydrogen absorption/desorption isotherms. In particular we find that a long-range ordered L12 phase is expected to form if the H2 pressure is sufficiently high. Furthermore we construct the phase diagram at temperatures from 250 K to 500 K showing that if full equilibrium is reached in the presence of hydrogen phase separation can often be expected to occur in stark contrast to the phase diagram in para-equilibrium. Our results explain the experimental observation that absorption/desorption isotherms in Pd–Au are often stable over time but also reveal pitfalls for when this may not be the case.
Towards an Understanding of Hydrogen Supply Chains: A Structured Literature Review Regarding Sustainability Evaluation
Oct 2021
Publication
Hydrogen technologies have received increased attention in research and development to foster the shift towards carbon-neutral energy systems. Depending on the specific production techniques transportation concepts and application areas hydrogen supply chains (HSCs) can be anything from part of the energy transition problem to part of the solution: Even more than battery-driven electric mobility hydrogen is a polyvalent technology and can be used in very different contexts with specific positive or negative sustainability impacts. Thus a detailed sustainability evaluation is crucial for decision making in the context of hydrogen technology and its diverse application fields. This article provides a comprehensive structured literature review in the context of HSCs along the triple bottom line dimensions of environmental economic and social sustainability analyzing a total of 288 research papers. As a result we identify research gaps mostly regarding social sustainability and the supply chain stages of hydrogen distribution and usage. We suggest further research to concentrate on these gaps thus strengthening our understanding of comprehensive sustainability evaluations for HSCs especially in social sustainability evaluation. In addition we provide an additional approach for discussion by adding literature review results from neighboring fields highlighting the joint challenges and insights regarding sustainability evaluation.
Cogeneration of Green Hydrogen in a Cascade Hydropower Plant
Apr 2021
Publication
Hydrogen is today an indispensable feedstock in various process industries but the method of its production is mostly not in line with accepted environmental guidelines. With emerging electro-energetic systems with a large share of renewable sources hydrogen is also becoming an important energy carrier which with the possibility of storing surplus energy ensures greater stability of power system operation and energy supply. Therefore the use of electricity from renewable sources is important for the production of green hydrogen using electrolysis. The first part of the article describes the possibilities for hydrogen cogeneration in one of the run-of-river hydropower plants in Slovenia. The implementation costs of the necessary equipment for hydrogen production in the case-study power plant its production costs and the profitability of hydrogen production compared to the sale of electricity are estimated. The criteria according to which the production of hydrogen is more profitable than the sale of electricity at current prices and guaranteed sales is also defined. In the second part of the article a scenario for the use of hydrogen for heating and mobility needs in the nearby local community is presented. For the regular supply of hydrogen in the range of up to 30 kg/h the necessary investment costs for the installation of the appropriate equipment in the hydropower plant are calculated along with an estimation of the payback period of the investment.
Site-Dependent Environmental Impacts of Industrial Hydrogen Production by Alkaline Water Electrolysis
Jun 2017
Publication
Industrial hydrogen production via alkaline water electrolysis (AEL) is a mature hydrogen production method. One argument in favor of AEL when supplied with renewable energy is its environmental superiority against conventional fossil-based hydrogen production. However today electricity from the national grid is widely utilized for industrial applications of AEL. Also the ban on asbestos membranes led to a change in performance patterns making a detailed assessment necessary. This study presents a comparative Life Cycle Assessment (LCA) using the GaBi software (version 6.115 thinkstep Leinfelden-Echterdingen Germany) revealing inventory data and environmental impacts for industrial hydrogen production by latest AELs (6 MW Zirfon membranes) in three different countries (Austria Germany and Spain) with corresponding grid mixes. The results confirm the dependence of most environmental effects from the operation phase and specifically the site-dependent electricity mix. Construction of system components and the replacement of cell stacks make a minor contribution. At present considering the three countries AEL can be operated in the most environmentally friendly fashion in Austria. Concerning the construction of AEL plants the materials nickel and polytetrafluoroethylene in particular used for cell manufacturing revealed significant contributions to the environmental burden.
Electronic Structure and d-Band Center Control Engineering over Ni-Doped CoP3 Nanowall Arrays for Boosting Hydrogen Production
Jun 2021
Publication
To address the challenge of highly efficient water splitting into H2 successful fabrication of novel porous three-dimensional Ni-doped CoP3 nanowall arrays on carbon cloth was realized resulting in an effective self-supported electrode for the electrocatalytic hydrogen-evolution reaction. The synthesized samples exhibit rough curly and porous structures which are beneficial for gaseous transfer and diffusion during the electrocatalytic process. As expected the obtained Ni-doped CoP3 nanowall arrays with a doping concentration of 7% exhibit the promoted electrocatalytic activity. The achieved overpotentials of 176 mV for the hydrogen-evolution reaction afford a current density of 100 mA cm−2 which indicates that electrocatalytic performance can be dramatically enhanced via Ni doping. The Ni-doped CoP3 electrocatalysts with increasing catalytic activity should have significant potential in the field of water splitting into H2. This study also opens an avenue for further enhancement of electrocatalytic performance through tuning of electronic structure and d-band center by doping.
Catalytic Hydrogen Production, Storage and Application
Jul 2021
Publication
Hydrogen is a clean fuel for transportation and energy storage. It has several attractive features including a higher energy content by weight use in fuel cells that produces only water as a by-product storage in small and large quantities by various methods and established transportation and infrastructures. A hydrogen economy consists of three steps i.e. hydrogen production storage and applications. All three steps involved in a hydrogen economy can be divided into catalytic and non-catalytic approaches. For catalytic processes the efficiency highly depends on the type and physico-chemical characteristics of the catalysts. Therefore for the improvement of these catalytic processes the development of highly efficient and stable catalysts is highly required.
Analysis of Hydrogen Production Potential from Waste Plastics by Pyrolysis and In Line Oxidative Steam Reforming
Oct 2021
Publication
A study was carried out on the valorization of different waste plastics (HDPE PP PS and PE) their mixtures and biomass/HDPE mixtures by means of pyrolysis and in line oxidative steam reforming. A thermodynamic equilibrium simulation was used for determining steam reforming data whereas previous experimental results were considered for setting the pyrolysis volatile stream composition. The adequacy of this simulation tool was validated using experimental results obtained in the pyrolysis and in line steam reforming of different plastics. The effect the most relevant process conditions i.e. temperature steam/plastic ratio and equivalence ratio have on H2 production and reaction enthalpy was evaluated. Moreover the most suitable conditions for the oxidative steam reforming of plastics of different nature and their mixtures were determined. The results obtained are evidence of the potential interest of this novel valorization route as H2 productions of up to 25 wt% were obtained operating under autothermal conditions.
A Holistic Consideration of Megawatt Electrolysis as a Key Component of Sector Coupling
May 2022
Publication
In the future hydrogen (H2) will play a significant role in the sustainable supply of energy and raw materials to various sectors. Therefore the electrolysis of water required for industrial‐ scale H2 production represents a key component in the generation of renewable electricity. Within the scope of fundamental research work on cell components for polymer electrolyte membrane (PEM) electrolyzers and application‐oriented living labs an MW electrolysis system was used to further improve industrial‐scale electrolysis technology in terms of its basic structure and systems‐ related integration. The planning of this work as well as the analytical and technical approaches taken along with the essential results of research and development are presented herein. The focus of this study is the test facility for a megawatt PEM electrolysis stack with the presentation of the design processing and assembly of the main components of the facility and stack.
Techno-economic Analysis of Hydrogen Electrolysis from Off-Grid Stand-Alone Photovoltaics Incorporating Uncertainty Analysis
Oct 2020
Publication
Solar-driven electrolysis of water to generate hydrogen is emerging as a viable strategy to decarbonize the global energy economy. However this direction is more expensive than traditional fossil fuel generation of hydrogen and effective pathways to lower this cost need to be identified. Here we report a Monte Carlo approach to explore a wide range of input assumptions to identify key cost drivers targets and localized conditions necessary for competitive stand-alone dedicated PV powered hydrogen electrolysis. We determine the levelized cost of hydrogen (LCOH) considering historical weather data for specific locations to model our PV system and optimize its size compared to the electrolyzer. This analysis and its methods show the potential for green hydrogen production using off-grid PV shows the merits of remote systems in areas of high solar resource and provides cost and performance targets for electrolyzer technologies.
Dynamic Simulation and Thermoeconomic Analysis of a Hybrid Renewable System Based on PV and Fuel Cell Coupled with Hydrogen Storage
Nov 2021
Publication
The production of “green hydrogen” is currently one of the hottest topics in the field of renewable energy systems research. Hydrogen storage is also becoming more and more attractive as a flexible solution to mitigate the power fluctuations of solar energy systems. The most promising technology for electricity-to-hydrogen conversion and vice versa is the reversible solid-oxide cell (SOC). This device is still very expensive but it exhibits excellent performance under dynamic operating conditions compared to the competing devices. This work presents the dynamic simulation of a prototypal renewable plant combining a 50 kW photovoltaic (PV) field with a 50 kW solid-oxide electrolyzer cell (SOEC) and a compressed hydrogen tank. The electricity is used to meet the energy demand of a dwelling located in the area of Campi Flegrei (Naples). The SOC efficiency is simulated by developing a mathematical model in MATLAB®. The model also calculates the cell operating temperature as a function of the input current. Once the optimal values of the operating parameters of the SOC are calculated the model is integrated in the transient system simulation tool (TRNSYS) for dynamic analysis. Furthermore this work presents a parametric analysis of the hydrogen storage system (HSS). The results of the energy and environmental analyses show that the proposed system can reach a primary energy saving by 70% and an amount of saved CO2 of 28 tons/year. Some possible future market scenarios are considered for the economic analysis. In the most realistic case the optimal configuration shows a simple pay back lower than 10 years and a profit index of 46%.
Influence of Cs Promoter on Ethanol Steam-Reforming Selectivity of Pt/m-ZrO2 Catalysts at Low Temperature
Sep 2021
Publication
The decarboxylation pathway in ethanol steam reforming ultimately favors higher selectivity to hydrogen over the decarbonylation mechanism. The addition of an optimized amount of Cs to Pt/m-ZrO2 catalysts increases the basicity and promotes the decarboxylation route converting ethanol to mainly H2 CO2 and CH4 at low temperature with virtually no decarbonylation being detected. This offers the potential to feed the product stream into a conventional methane steam reformer for the production of hydrogen with higher selectivity. DRIFTS and the temperature-programmed reaction of ethanol steam reforming as well as fixed bed catalyst testing revealed that the addition of just 2.9% Cs was able to stave off decarbonylation almost completely by attenuating the metallic function. This occurs with a decrease in ethanol conversion of just 16% relative to the undoped catalyst. In comparison with our previous work with Na this amount is—on an equivalent atomic basis—just 28% of the amount of Na that is required to achieve the same effect. Thus Cs is a much more efficient promoter than Na in facilitating decarboxylation.
Nuclear-Renewables Energy System for Hydrogen and Electricity Production
May 2011
Publication
In the future the world may have large stranded resources of low-cost wind and solar electricity. Renewable electricity production does not match demand and production is far from major cities. The coupling of nuclear energy with renewables may enable full utilization of nuclear and renewable facilities to meet local electricity demands and export pipeline hydrogen for liquid fuels fertilizer and metals production. Renewables would produce electricity at full capacity in large quantities. The base-load nuclear plants would match electricity production with demand by varying the steam used for electricity versus hydrogen production. High-temperature electrolysis (HTE) would produce hydrogen from water using (a) steam from nuclear plants and (b) electricity from nuclear plants and renewables. During times of peak electricity demand the HTE cells would operate in reverse fuel cell mode to produce power substituting for gas turbines that are used for very few hours per year and that thus have very high electricity costs. The important net hydrogen production would be shipped by pipeline to customers. Local hydrogen storage would enable full utilization of long-distance pipeline capacity with variable production. The electricity and hydrogen production were simulated with real load and wind data to understand under what conditions such systems are economic. The parametric case study uses a wind-nuclear system in North Dakota with hydrogen exported to the Chicago refinery market. North Dakota has some of the best wind conditions in the United States and thus potentially low-cost wind. The methodology allows assessments with different economic and technical assumptions - including what electrolyzer characteristics are most important for economic viability.
Catalytic Hydrogen Production from Methane: A Review on Recent Progress and Prospect
Aug 2020
Publication
Natural gas (Methane) is currently the primary source of catalytic hydrogen production accounting for three quarters of the annual global dedicated hydrogen production (about 70 M tons). Steam–methane reforming (SMR) is the currently used industrial process for hydrogen production. However the SMR process suffers with insufficient catalytic activity low long-term stability and excessive energy input mostly due to the handling of large amount of CO2 coproduced. With the demand for anticipated hydrogen production to reach 122.5 M tons in 2024 novel and upgraded catalytic processes are desired for more effective utilization of precious natural resources. In this review we summarized the major descriptors of catalyst and reaction engineering of the SMR process and compared the SMR process with its derivative technologies such as dry reforming with CO2 (DRM) partial oxidation with O2 autothermal reforming with H2O and O2. Finally we discussed the new progresses of methane conversion: direct decomposition to hydrogen and solid carbon and selective oxidation in mild conditions to hydrogen containing liquid organics (i.e. methanol formic acid and acetic acid) which serve as alternative hydrogen carriers. We hope this review will help to achieve a whole picture of catalytic hydrogen production from methane.
A Hot Syngas Purification System Integrated with Downdraft Gasification of Municipal Solid Waste
Jan 2019
Publication
Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resources. However purification of syngas to remove multiple impurities such as particulates tar HCl alkali chlorides and sulfur species is required. This study investigates the feasibility of high temperature purification of syngas from MSW gasification with the focus on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises of a fluidized-bed catalytic tar reformer a filter for particulates and a fixed-bed reactor for dechlorination and then desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nano-structured nickel catalyst supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages. Experimental and thermodynamic modeling results are compared to determine the kinetic constraints in the integrated system. The hot purification system demonstrates up to 90% of tar and sulfur removal efficiency increased total syngas yield (14%) and improved cold gas efficiency (12%). The treated syngas is potentially applicable in gas engines/turbines and solid oxide fuel cells based on the dew points and concentration limits of the remaining tar compounds. Reforming of raw syngas by nickel catalyst for over 20 h on stream shows strong resistance to deactivation. Desulfurization of syngas from MSW gasification containing significantly higher proportion of carbonyl sulfide than hydrogen sulfide traces of tar and hydrogen chloride demonstrates high performance of Ni-Zn sorbents.
Graphitic Carbon Nitride Heterojunction Photocatalysts for Solar Hydrogen Production
Sep 2021
Publication
Photocatalytic hydrogen production is considered as an ideal approach to solve global energy crisis and environmental pollution. Graphitic carbon nitride (g-C3N4) has received extensive consideration due to its facile synthesis stable physicochemical properties and easy functionalization. However the pristine g-C3N4 usually shows unsatisfactory photocatalytic activity due to the limited separation efficiency of photogenerated charge carriers. Generally introducing semiconductors or co-catalysts to construct g–C3N4–based heterojunction photocatalysts is recognized as an effective method to solve this bottleneck. In this review the advantages and characteristics of various types of g–C3N4–based heterojunction are analyzed. Subsequently the recent progress of highly efficient g–C3N4–based heterojunction photocatalysts in the field of photocatalytic water splitting is emphatically introduced. Finally a vision of future perspectives and challenges of g–C3N4–based heterojunction photocatalysts in hydrogen production are presented. Predictably this timely review will provide valuable reference for the design of efficient heterojunctions towards photocatalytic water splitting and other photoredox reactions.
Advanced Catalysts for the Water Gas Shift Reaction
Apr 2022
Publication
The WGS reaction is an exothermic reaction between carbon monoxide and steam to form carbon dioxide and hydrogen. This reaction which has been used industrially for more than 100 years has recently received a great deal of attention from researchers as one of the ways to produce environmentally acceptable hydrogen from fossil fuels in large quantities. For the application of this reaction on an industrial scale the key is choosing the optimal catalysts that can ensure high CO conversion and have a long lifetime under industrial conditions. Therefore new types of catalysts are being developed that meet these requirements better than the Fe- and Cu-based catalysts commonly used in the past. The WGSR on a commercial nickel-based catalyst and a laboratory-prepared copper and cobalt-based catalyst was tested in a laboratory apparatus set up at the University of Chemistry and Technology Prague. The best performance of the laboratory-prepared catalyst was observed for the catalyst with a Cu content of 14.8 wt% and activated in a hydrogen atmosphere. The laboratory-prepared Co-based catalyst showed good WGSR activity in the temperature range of 200–450 ◦C although this was always inferior to that of the Cu-based catalyst. When subjected to the feed gas containing 0.4 mole% H2S the Co-based catalyst showed good resistance to sulphur poisoning. Therefore Co-based catalysts can be considered good sulphur-tolerant intermediate temperature WGSR catalysts.
Hubs and Clusters Approach to Unlock the Development of Carbon Capture and Storage - Case Study in Spain
Jul 2021
Publication
Xiaolong Sun,
Juan Alcalde,
Mahdi Bakhtbidar,
Javier Elío,
Víctor Vilarrasa,
Jacobo Canal,
Julio Ballesteros,
Niklas Heinemann,
Stuart Haszeldine,
Andrew Cavanagh,
David Vega-Maza,
Fernando Rubiera,
Roberto Martínez-Orio,
Gareth Johnson,
Ramon Carbonell,
Ignacio Marzan,
Anna Travé and
Enrique Gomez-Rivas
Many countries have assigned an indispensable role for carbon capture and storage (CCS) in their national climate change mitigation pathways. However CCS deployment has stalled in most countries with only limited commercial projects realised mainly in hydrocarbon-rich countries for enhanced oil recovery. If the Paris Agreement is to be met then this progress must be replicated widely including hydrocarbon-limited countries. In this study we present a novel source-to-sink assessment methodology based on a hubs and clusters approach to identify favourable regions for CCS deployment and attract renewed public and political interest in viable deployment pathways. Here we apply this methodology to Spain where fifteen emission hubs from both the power and the hard-to-abate industrial sectors are identified as potential CO2 sources. A priority storage structure and two reserves for each hub are selected based on screening and ranking processes using a multi-criteria decision-making method. The priority source-to-sink clusters are identified indicating four potential development regions with the North-Western and North-Eastern Spain recognised as priority regions due to resilience provided by different types of CO2 sources and geological structures. Up to 68.7 Mt CO2 per year comprising around 21% of Spanish emissions can be connected to clusters linked to feasible storage. CCS especially in the hard-to-abate sector and in combination with other low-carbon energies (e.g. blue hydrogen and bioenergy) remains a significant and unavoidable contributor to the Paris Agreement’s mid-century net-zero target. This study shows that the hubs and clusters approach can facilitate CCS deployment in Spain and other hydrocarbon-limited countries.
Thermodynamic Assessment of a Hybrid Methane Cracking System for Liquified Hydrogen Production and Enhanced Oil Recovery Using CO2
Oct 2022
Publication
Hydrogen fuel production from methane cracking is a cleaner process compared to steam methane reforming due to zero greenhouse gas emissions. Carbon black that is co-produced is valuable and can be marketed to other industries. As this is a high-temperature process using solar energy can further improve its sustainability. In this study an integrated solar methane cracking system is proposed and the efficient utilization of the hydrogen and carbon products is explored. The carbon by-product is used in a direct carbon fuel cell and oxy- combustion. These processes eliminate the need for carbon capture technologies as they produce pure CO2 exhaust streams. The CO2 produced from the systems is used for enhanced oil recovery to produce crude oil. The produced turquoise hydrogen is liquified to make it suitable for exportation. The process is simulated on Aspen Plus® and its energy and exergy efficiencies are evaluated by carrying out a detailed thermodynamic analysis. A reservoir simulation is used to study the amount of oil that can be produced using the captured CO2. The overall system is studied for oil production over 20 years and energy and exergy of efficiencies 42.18% and 40.18% respectively were found. Enhanced oil recovery improves the recovery rate from 24.8% to 64.3%.
Environmental Impact Assessment of Hydrogen Production via Steam Methane Reforming Based on Emissions Data
Oct 2022
Publication
Steam methane reforming (SMR) using natural gas is the most commonly used technology for hydrogen production. Industrial hydrogen production contributes to pollutant emissions which may differ from the theoretical estimates due to process conditions type and state of installed pollution control equipment. The aim of this study was to estimate the impacts of hydrogen production using facilitylevel real emissions data collected from multiple US EPA databases. The study applied the ReCiPe2016 impact assessment method and considered 12 midpoint and 14 endpoint impacts for 33 US SMR hydrogen production facilities. Global warming impacts were mostly driven by CO2 emissions and contributed to 94.6% of the endpoint impacts on human health while global warming impact on terrestrial ecosystems contributed to 98.3% of the total endpoint impacts on ecosystems. The impacts estimated by direct emissions from the 33 facilities were 9.35 kg CO2e/kg H2 which increased to 11.2 kg CO2e/kg H2 when the full life cycle of hydrogen production including upstream emissions was included. The average global warming impact could be reduced by 5.9% and 11.1% with increases in hydrogen production efficiency by 5% and 10% respectively. Potential impact reductions are also found when natural gas hydrogen production feedstock is replaced by renewable sources with the greatest reduction of 78.1% found in hydrogen production via biomass gasification followed by 68.2% reduction in landfill gas and 53.7% reduction in biomethane-derived hydrogen production.
Hydrogen as Energy Carrier: Techno-economic Assessment of Decentralized Hydrogen Production in Germany
Jun 2021
Publication
Political and scientific discussions on changing German energy supply mix and challenges of such energy transition are already well established. At the supply level energy storage seems to be the biggest challenge ahead for such transition. Hydrogen could be one of the solutions for future energy transition if it is produced using renewable energy resources. In order to analyze the future role of hydrogen its economic performance analysis is inevitable. This has been done in this research for a case study site in Cologne. The potential of hydrogen production with the use of solar electricity powered electrolyzers (alkaline and proton exchange membrane (PEM)) has been analyzed. Both grid connected and off grid modes of solar hydrogen production are considered. Economic performance results are presented for six scenarios. Hydrogen produced with the grid connected solar photovoltaics system coupled with alkaline electrolyzers was found the cheapest with the levelized cost of hydrogen (LCOH) at 6.23 V/kg. These costs are comparable with the current hydrogen price at commercial refueling station in Cologne. On the other hand the LCOH of off grid systems with both alkaline and PEM electrolyzers is expensive as expected the most expensive LCOH among six scenarios reached to 57.61 V/kg.
High Proton-Conductive and Temperature-Tolerant PVC-P4VP Membranes towards Medium-Temperature Water Electrolysis
Mar 2022
Publication
Water electrolysis (WE) is a highly promising approach to producing clean hydrogen. Medium-temperature WE (100–350 ◦C) can improve the energy efficiency and utilize the low-grade water vapor. Therefore a high-temperature proton-conductive membrane is desirable to realize the medium-temperature WE. Here we present a polyvinyl chloride (PVC)-poly(4vinylpyridine) (P4VP) hybrid membrane by a simple cross-linking of PVC and P4VP. The pyridine groups of P4VP promote the loading rate of phosphoric acid which delivers the proton conductivity of the PVC-P4VP membrane. The optimized PVC-P4VP membrane with a 1:2 content ratio offers the maximum proton conductivity of 4.3 × 10−2 S cm−1 at 180 ◦C and a reliable conductivity stability in 200 h at 160 ◦C. The PVC-P4VP membrane electrode is covered by an IrO2 anode and a Pt/C cathode delivers not only the high water electrolytic reactivity at 100–180 ◦C but also the stable WE stability at 180 ◦C.
An Overview of Water Electrolysis Technologies for Green Hydrogen Production
Oct 2022
Publication
Decarbonizing the planet is one of the major goals that countries around the world have set for 2050 to mitigate the effects of climate change. To achieve these goals green hydrogen that can be produced from the electrolysis of water is an important key solution to tackle global decarbonization. Consequently in recent years there is an increase in interest towards green hydrogen production through the electrolysis process for large-scale implementation of renewable energy based power plants and other industrial and transportation applications. The main objective of this study was to provide a comprehensive review of various green hydrogen production technologies especially on water electrolysis. In this review various water electrolysis technologies and their techno-commercial prospects including hydrogen production cost along with recent developments in electrode materials and their challenges were summarized. Further some of the most successful results also were described. Moreover this review aims to identify the gaps in water electrolysis research and development towards the techno-commercial perspective. In addition some of the commercial electrolyzer performances and their limitations also were described along with possible solutions for cost-effective hydrogen production Finally we outlined our ideas and possible solutions for driving cost-effective green hydrogen production for commercial applications. This information will provide future research directions and a road map for the development/implementation of commercially viable green hydrogen projects.
Green Hydrogen from Anion Exchange Membrane Water Electrolysis: A Review of Recent Developments in Critical Materials and Operating Conditions
Mar 2020
Publication
Hydrogen production using water electrolysers equipped with an anion exchange membrane (AEM) a pure water feed and cheap components such as platinum group metal-free catalysts and stainless steel bipolar plates (BPP) can challenge proton exchange membrane (PEM) electrolysis systems as the state of the art. For this to happen the performance of the AEM electrolyzer must match the compact design stability H2 purity and high current densities of PEM systems. Current research aims at bringing AEM water electrolysis technology to an advanced level in terms of electrolysis cell performance. Such technological advances must be accompanied by demonstration of the cost advantages of AEM systems. The current state of the art in AEM water electrolysis is defined by sporadic reports in the academic literature mostly dealing with catalyst or membrane development. The development of this technology requires a future roadmap for systematic development and commercialization of AEM systems and components. This will include basic and applied research technology development & integration and testing at a laboratory scale of small demonstration units (AEM electrolyzer shortstacks) that can be used to validate the technology (from TRL 2–3 currently to TRL 4–5). This review paper gathers together recent important research in critical materials development (catalysts membranes and MEAs) and operating conditions (electrolyte composition cell temperature performance achievements). The aim of this review is to identify the current level of materials development and where improvements are required in order to demonstrate the feasibility of the technology. Once the challenges of materials development are overcome AEM water electrolysis can drive the future use of hydrogen as an energy storage vector on a large scale (GW) especially in developing countries.
System Dynamic Model for the Accumulation of Renewable Electricity using Power-to-Gas and Power-to-Liquid Concepts
Feb 2016
Publication
When the renewable energy is used the challenge is match the supply of intermittent energy with the demand for energy therefore the energy storage solutions should be used. This paper is dedicated to hydrogen accumulation from wind sources. The case study investigates the conceptual system that uses intermitted renewable energy resources to produce hydrogen (power-to-gas concept) and fuel (power-to-liquid concept). For this specific case study hydrogen is produced from surplus electricity generated by wind power plant trough electrolysis process and fuel is obtained by upgrading biogas to biomethane using hydrogen. System dynamic model is created for this conceptual system. The developed system dynamics model has been used to simulate 2 different scenarios. The results show that in both scenarios the point at which the all electricity needs of Latvia are covered is obtained. Moreover the methodology of system dynamics used in this paper is white-box model that allows to apply the developed model to other case studies and/or to modify model based on the newest data. The developed model can be used for both scientific research and policy makers to better understand the dynamic relation within the system and the response of system to changes in both internal and external factors.
Water Electrolysis and Hydrogen in the European Union
Nov 2022
Publication
Renewable and low carbon hydrogen is both an energy carrier able to produce other fuels and downstream products such as the e-fuels or e-ammonia and a decarbonised gas produced through renewable electricity. It has the potential to decarbonise hard to abate sectors which are difficult to directly electrify and play a crucial role in achieving net zero emissions target in 2050. The European Commission has recently outlined the policy context and necessary actions for the development and deployment of renewable and low carbon hydrogen within the 2030 time horizon with the Hydrogen Strategy for a Climate Neutral Europe Communication (the Hydrogen Strategy). The REPowerEU Communication4 has further addressed the joint EU and Member State actions needed in the context of the crisis triggered by the invasion of Ukraine in February 2022 and the necessity to phase out dependence on Russian supplies. The EC has strengthened the policy narrative around hydrogen and increased objectives for a pan European framework accelerating and upscaling the production of RES and low-carbon hydrogen. The main objectives and actions of the REPowerEU Plan which build on the Hydrogen Strategy are the deployment of several tens of GW of electrolyser capacity and the production and imports of 10 Mt and 10 Mt respectively of renewable hydrogen by 2030. Currently the most mature and promising green hydrogen production technology is water electrolysis. The main technologies5 considered in this report are: Alkaline electrolysis Polymer Exchange Membrane (PEM) electrolysis Solid Oxide electrolysis and Anion Exchange Membrane electrolysers (AEM).
True Cost of Solar Hydrogen
Sep 2021
Publication
Green hydrogen will be an essential part of the future 100% sustainable energy and industry system. Up to one-third of the required solar and wind electricity would eventually be used for water electrolysis to produce hydrogen increasing the cumulative electrolyzer capacity to about 17 TWel by 2050. The key method applied in this research is a learning curve approach for the key technologies i.e. solar photovoltaics (PV) and water electrolyzers and levelized cost of hydrogen (LCOH). Sensitivities for the hydrogen demand and various input parameters are considered. Electrolyzer capital expenditure (CAPEX) for a large utility-scale system is expected to decrease from the current 400 €/kWel to 240 €/kWel by 2030 and to 80 €/kWel by 2050. With the continuing solar PV cost decrease this will lead to an LCOH decrease from the current 31–81 €/ MWhH2LHV (1.0–2.7 €/kgH2) to 20–54 €/MWhH2LHV (0.7–1.8 €/kgH2) by 2030 and 10–27 €/MWhH2LHV (0.3–0.9 €/kgH2) by 2050 depending on the location. The share of PV electricity cost in the LCOH will increase from the current 63% to 74% by 2050.
Advances in Hydrogen Production from Natural Gas Reforming
Jun 2021
Publication
Steam natural gas reforming is the preferred technique presently used to produce hydrogen. Proposed in 1932 the technique is very well established but still subjected to perfections. Herein first the improvements being sought in catalysts and processes are reviewed and then the advantage of replacing the energy supply from burning fuels with concentrated solar energy is discussed. It is especially this advance that may drastically reduce the economic and environmental cost of hydrogen production. Steam reforming can be easily integrated into concentrated solar with thermal storage for continuous hydrogen production.
Green and Blue Hydrogen Production: An Overview in Colombia
Nov 2022
Publication
Colombia a privileged country in terms of diversity availability of natural resources and geographical location has set a roadmap for hydrogen as part of the energy transition plan proposed in 2021. To reduce its emissions in the mid-term and foster its economy hydrogen production should be green and blue with specific targets set for 2030 for the hydrogen costs and produced quantities. This work compares the state-of-the-art production of blue and green hydrogen and how Colombia is doing in each pathway. A deeper analysis considers the advantages of Colombia’s natural resources the possible paths the government could follow and the feedstock’s geographical location for hydrogen production and transportation. Then one discusses what may be the next steps in terms of policies and developments to succeed in implementing the plan. Overall it is concluded that green hydrogen could be the faster more sustainable and more efficient method to implement in Colombia. However blue hydrogen could play an essential role if oil and gas companies assess the advantages of carbon dioxide utilization and promote its deployment.
No more items...