Production & Supply Chain
Cooperative Boron and Vanadium Doping of Nickel Phosphides for Hydrogen Evolution in Alkaline and AnionExchange Membrane Water/Seawater Electrolyzers
Mar 2023
Publication
Developing low-cost and high-performance transition metal-based electro-catalysts is crucial for realizing sustainable hydrogen evolution reaction (HER)in alkaline media. Here a cooperative boron and vanadium co-doped nickelphosphide electrode (B V-Ni2P) is developed to regulate the intrinsic elec-tronic configuration of Ni2P and promote HER processes. Experimental andtheoretical results reveal that V dopants in B V-Ni2P greatly facilitate the dis-sociation of water and the synergistic effect of B and V dopants promotes thesubsequent desorption of the adsorbed hydrogen intermediates. Benefitingfrom the cooperativity of both dopants the B V-Ni2P electrocatalyst requires alow overpotential of 148 mV to attain a current density of −100 mA cm−2 withexcellent durability. The B V-Ni2P is applied as the cathode in both alkalinewater electrolyzers (AWEs) and anion exchange membrane water electrolyzers(AEMWEs). Remarkably the AEMWE delivers a stable performance to achieve500 and 1000 mA cm−2 current densities at a cell voltage of 1.78 and 1.92 Vrespectively. Furthermore the developed AWEs and AEMWEs also demon-strate excellent performance for overall seawater electrolysis.
Seawater Treatment Technologies for Hydrogen Production by Electrolysis—A Review
Dec 2024
Publication
Green hydrogen produced by water electrolysis using renewable energy sources (RES) is an emerging technology that aligns with sustainable development goals and efforts to address climate change. In addition to energy electrolyzers require ultrapure water to operate. Although seawater is abundant on the Earth it must be desalinated and further purified to meet the electrolyzer’s feeding water quality requirements. This paper reviews seawater purification processes for electrolysis. Three mature and commercially available desalination technologies (reverse osmosis multiple-effect distillation and multi-stage flash) were examined in terms of working principles performance parameters produced water quality footprint and capital and operating expenditures. Additionally pretreatment and post-treatment techniques were explored and the brine management methods were investigated. The findings of this study can help guide the selection and design of water treatment systems for electrolysis.
Origin and Evolution of Hydrogen-rich Gas Discharges from a Hot Spring in the Eastern Coastal Area of China
Jan 2020
Publication
Unlike the typical low-temperature (< 150 °C) continental geothermal systems usually characterized by high N2 CH4 and CO2 concentrations but a trace H2 concentration the sandstone-dominated Jimo hot spring on China's eastern coast exhibits: (1) abnormally high H2 concentrations (2.4–12.5 vol%) and H2/CH4 (up to 46.5); (2) depleted δD-H2 (−822 to −709‰) comparable to the Kansas hot springs near the Mid-Continent rift system with the most depleted δD-H2 (−836 to −740‰) recorded in nature; and (3) dramatic gas concentration and isotope ratio variations within an area of 0.2 km2 . Gas chemistry and H-C-He-Ne isotope ratios are studied with reference to published H2 isotope data from various systems. The origin of the gas is most likely attributed to: (a) allochthonous abiotic H2 generated by the reduction of water and oxidation of FeII-rich pyroxene and olivine (serpentinization) in the basalt located 2 km away under near-surface conditions and migration to the deep sandstone reservoir; (b) primary thermogenic CH4 produced in the sandstone; (c) mixing with a considerable amount of microbial H2 from shallow fresh and marine sediments; and (d) biotic CH4 with typical abiotic signatures resulting from isotope exchanges with fluids high in H2/CH4 and CO2/CH4 ratios. Allochthonous abiotic H2 in a sandstone-dominated continental geothermal system and massive microbial fermentation-based H2 production in shallow fresh and residual marine sediments with insignificant but differential consumption activity are highlighted. The published hydrogen isotope ratios for H2 produced under various natural geological environmental and experimental conditions have been collected systematically to provide a fundamental framework and an initial tool for restricting the dominant origin of H2.
The Hydrogen-water Collision: Assessing Water and Cooling Demands for Large-scale Green Hydrogen Production in a Warming Climate
Dec 2024
Publication
Hydrogen is expected to play a critical role in future energy systems projected to have an annual demand of 401–660 Mt by 2050. With large-scale green hydrogen projects advancing in water-scarce regions like Australia Chile and the Middle East and North Africa understanding water requirements for large-scale green hydrogen production is crucial. Meeting this future hydrogen demand will necessitate 4010 to 6600 GL of demineralised water annually for electrolyser feedwater if dry cooling is employed or an additional 6015 to 19800 GL for cooling water per year if evaporative cooling is employed. Using International Panel of Climate Change 2050 climate projections this work evaluated the techno-economic implications of dry vs. evaporative cooling for large-scale electrolyser facilities under anticipated higher ambient temperatures. The study quantifies water demands costs and potential operational constraints showing that evaporative cooling is up to 8 times cheaper to implement than dry cooling meaning that evaporative cooling can be oversized to accommodate increased cooling demand of high temperature events at a lower cost. Furthermore of the nations analysed herein Chile emerged as having the lowest cost of hydrogen owing to the lower projected ambient temperatures and frequency of high temperature events.
A Review on the Environmental Performance of Various Hydrogen Production Technologies: An Approach Towards Hydrogen Economy
Nov 2023
Publication
Demand for hydrogen has grown and continues to rise as a versatile energy carrier. Hydrogen can be produced from renewable and non-renewable energy sources. A wide range of technologies to produce hydrogen in an environmentally friendly way have been developed. As the life cycle assessment (LCA) approach has become popular recently including in the hydrogen energy system this paper comprehensively reviews the LCA of hydrogen production technology. A subdivision based on the trends in the LCA studies hydrogen production technology goal and scope definition system boundary and environmental performance of hydrogen production is discussed in this review. Thermochemical hydrogen production is the most studied technology in LCA. However utilizing natural resources especially wind power in the electrolysis process stands out as an environmentally preferable solution when compared to alternative production processes. It is crucial to rethink reactors and other production-related equipment to improve environmental performance and increase hydrogen production efficiency. Since most of the previous LCA studies were conducted in developed countries and only a few were from developing countries a way forward for LCA application on hydrogen in developing countries was also highlighted and discussed. This review provides a comprehensive insight for further research on hydrogen production technology from an LCA perspective.
HyPLANT100: Industrialization from Assembly to the Construction Site for Gigawatt Electrolysis
Apr 2024
Publication
The global push for sustainable energy has heightened the demand for green hydrogen which is crucial for decarbonizing heavy industry. However current electrolysis plant capacities are insufficient. This research addresses the challenge through optimizing large-scale electrolysis construction via standardization modularization process optimization and automation. This paper introduces H2Giga a project for mass-producing electrolyzers and HyPLANT100 investigating largescale electrolysis plant structure and construction processes. Modularizing electrolyzers enhances production efficiency and scalability. The integration of AutomationML facilitates seamless information exchange. A digital twin concept enables simulations optimizations and error identification before assembly. While construction site automation provides advantages tasks like connection technologies and handling cables tubes and hoses require pre-assembly. This study identifies key tasks suitable for automation and estimating required components. The Enapter Multicore electrolyzer serves as a case study showcasing robotic technology for tube fittings. In conclusion this research underscores the significance of standardization modularization and automation in boosting the electrolysis production capacity for green hydrogen contributing to ongoing efforts in decarbonizing the industrial sector and advancing the global energy transition.
Evaluating the Offshore Wind Business Case and Green Hydrogen Production: A Case Study of a Future North Sea Offshore Grid
Jun 2024
Publication
The European Union aims to increase its climate ambition and achieve climate neutrality by 2050. This necessitates expanding offshore wind energy and green hydrogen production especially for hard-to-abate industrial sectors. A study examines the impact of green hydrogen on offshore wind projects specifically focusing on a potential future North Sea offshore grid. The study utilizes data from the TYNDP 2020 Global Ambition scenario 2040 considering several European countries. It aims to assess new transmission and generation capacity utilization and understand the influencing factors. The findings show that incorporating green hydrogen production increases offshore wind utilization and capture prices. The study estimates that by 2040 the levelized cost of hydrogen could potentially decrease to e1.2-1.6/kg H2 assuming low-cost electricity supply and declining capital costs of electrolysers. These results demonstrate the potential benefits and cost reductions of integrating green hydrogen production into North Sea offshore wind projects.
Brief Review of Hydrocarbon-reforming Catalysts Map for Hydrogen Production
Jun 2023
Publication
Hydrogen energy the cleanest fuel presents extensive applications in renewable energy technologies such as fuel cells. However the transition process from carbon-based (fossil fuel) energy to desired hydrogen energy is usually hindered by inevitable scientific technological and economic obstacles which mainly involves complex hydrocarbon reforming reactions. Hence this paper provides a systematic and comprehensive analysis focusing on the hydrocarbon reforming mechanism. Accordingly recent related studies are summarized to clarify the intrinsic difference among the reforming mechanism. Aiming to objectively assess the activated catalyst and deactivation mechanism the rate-determining steps of reforming process have been emphasized summarized and analyzed. Specifically the effect of metals and supports on individual reaction processes is discussed followed by the metalsupport interaction. Current tendency and research map could be established to promote the technology development and expansion of hydrocarbon reforming field. This review could be considered as the guideline for academics and industry designing appropriate catalysts.
Freshwater Supply for Hydrogen Production: An Underestimated Challenges
Jun 2024
Publication
This paper presents a thorough critical literature review aimed at understanding the challenges associated with freshwater supply associated with rapidly growing global hydrogen economies. The review has been prompted by the fact that the hydrogen production projected for 2030 will create at least an additional demand of 2.1 billion cubic meters for freshwater which needs to be addressed to support sustainable development of emerging hydrogen economies. The key solutions explored by this study include seawater and wastewater treatment methods for large-scale freshwater generation along with the newly introduced technique of direct seawater-fed electrolysis. Prior research indicates that desalination technologies including reverse osmosis and membrane distillation also offer promising avenues for large-scale freshwater production at costs comparable to other desalination techniques. Additionally low-temperature desalination methods such as membrane distillation could play a significant role in freshwater production for electrolysis underscoring the importance of exploring waste recovery opportunities within the system (e.g. fuel cell heat recovery). This review also identifies research gaps that need to be addressed to overcome freshwater supply challenges and enhance the sustainability and techno-economic viability of large-scale hydrogen energy systems.
Availability Assessment of an Offshore PEM Seawater Electrolysis: A System-level Approach
Jun 2025
Publication
Green hydrogen is gaining prominence as a sustainable fuel to decarbonize hard-to-electrify industries and complement renewable energy growth. Among clean hydrogen production technologies seawater-based PEM electrolysis systems hold substantial promise. However implementing offshore PEM electrolysis systems faces significant challenges in ensuring long-term availability due to technological infancy and harsh environmental conditions. Ensuring safe and reliable operation is therefore critical to advancing global sustainability goals. While existing research has primarily focused on component-level techno-economic feasibility limited attention has been given to system-level safety and availability analysis particularly for offshore renewable-powered seawater-based PEM electrolysis systems. This study addresses this gap by conducting a comprehensive availability analysis of containerized plug-and-play PEM systems in offshore environments. A Bayesian Network model is employed incorporating Fault Tree Analysis and Reliability Block Diagram approaches for failure and availability analysis at the system level. A maintenance decision support tool using Influence diagram is developed to analyse different maintenance planning strategies impact on system availability improvement. A case study incorporating industrial modular PEM model is utilised to analyse the developed model effectiveness. The study identifies 81 availability states with the hydrogen generation subsystem being the most critical to system performance. Comparative analysis shows that applying redundancy across all subsystems improves availability by 18.54% but reduces Expected Utility by 4.94%. The optimal strategy involves redundancy for seawater purification cooling and monitoring subsystems with preventive maintenance for hydrogen generation achieving a maximum EU of 5.29 × 106. This framework supports decision-makers in evaluating system availability under uncertain offshore conditions optimizing maintenance strategies and ensuring resilience for large-scale H2 production.
Enhancing Flexibility in Wind-powered Hydrogen Production Systems through Coordinated Electrolyzer Operation
Jun 2025
Publication
Wind-powered water electrolysis for hydrogen production is a sustainable and environmentally friendly energy technology. However the inherent intermittency and variability of wind power significantly damage the stability and efficiency of the hydrogen production system. To enhance the operational flexibility and system efficiency a novel wind-hydrogen production system is proposed which integrates a new coordination of the conventional alkaline electrolyzers (AEL) and proton exchange membrane electrolyzers (PEMEL) for optimizing the dynamic operation of the system under fluctuating wind power. The developed approach employs variational mode decomposition to classify wind power fluctuations into different frequency components which are then allocated to suitable type of electrolyzers. The configurations of the developed system are optimized using the non-dominated sorting genetic algorithm and the operating scenarios are dynamically analyzed through clustering techniques. Compared to the AEL-only system the proposed system demonstrates significant enhancements with energy efficiency and internal rate of return increased by 5.78% and 10.65% respectively. Meanwhile the coordinated operation extends the continuous operating time of the AEL by 7.08%. The proposed approach enhances the economic viability and operational stability of wind-powered hydrogen production providing a valuable reference for industrial green hydrogen applications.
Two-Stage Anaerobic Digestion for Green Energy Production: A Review
Jan 2025
Publication
Anaerobic digestion (AD) is a biotechnological process in which the microorganisms degrade complex organic matter to simpler components under anaerobic conditions to produce biogas and fertilizer. This process has many environmental benefits such as green energy production organic waste treatment environmental protection and greenhouse gas emissions reduction. It has long been known that the two main species (acidogenic bacteria and methanogenic archaea) in the community of microorganisms in AD differ in many aspects and the optimal conditions for their growth and development are different. Therefore if AD is performed in a single bioreactor (single-phase process) the optimal conditions are selected taking into account the slow-growing methanogens at the expense of fast-growing acidogens affecting the efficiency of the whole process. This has led to the development of two-stage AD (TSAD) in recent years where the processes are divided into a cascade of two separate bioreactors (BRs). It is known that such division of the processes into two consecutive BRs leads to significantly higher energy yields for the two-phase system (H2 + CH4) compared to the traditional single-stage CH4 production process. This review presents the state of the art advantages and disadvantages and some perspectives (based on more than 210 references from 2002 to 2024 and our own studies) including all aspects of TSAD—different parameters’ influences types of bioreactors microbiology mathematical modeling automatic control and energetical considerations on TSAD processes.
Water Requirements for Hydrogen Production: Assessing Future Demand and Impacts on Texas Water Resources
Jan 2025
Publication
Hydrogen is emerging as a critical component in the global energy transition providing a low-carbon alternative for sectors such as industry and transportation. This paper aims to comprehensively address water usage in hydrogen production by exploring the water demands of different production methods and their implications for water management particularly in Texas. Key variables influencing water consumption are identified and potential water demands under different hydrogen market scenarios are estimated. Using spatial analysis regions where hydrogen production may stress local water resources are identified alongside policy recommendations for sustainable water use.
A Review of Hydrogen Production Methods and Power Electronics Converter Topologies for Green Hydrogen Applications
Nov 2024
Publication
Hydrogen has been receiving a lot of attention in the last few years since it is seen as a viable yet not thoroughly dissected alternative for addressing climate change issues namely in terms of energy storage and therefore great investments have been made towards research and development in this area. In this context a study about the main options for hydrogen production along with the analysis of a variety of the main power electronics converter topologies for such applications is presented as the purpose of this paper. Much of the analyzed available literature only discusses a few types of hydrogen production methods so it becomes crucial to include an analysis of all known types of methods for producing hydrogen according to their production type along with the color code associated with each type and highlighting the respective contextualization as well as advantages and disadvantages. Regarding the topologies of power electronics converters most suitable for hydrogen production and more specifically for green hydrogen production a list of them was analyzed through the available literature and a discussion of their advantages and disadvantages is presented. These topologies present the advantage of having a low ripple current output which is a requirement for the production of hydrogen.
H2 Transport in Sedimentary Basin
Aug 2025
Publication
Natural hydrogen is generated by fairly deep processes and/or in low-permeability rocks. In such contexts fluids circulate mainly through the network of faults and fractures. However hydrogen flows from these hydrogen-generating layers can reach sedimentary rocks with more typical permeability and porosity allowing H2 flows to spread out rather than be concentrated in fractures. In that case three different H2 transport modes exist: advection (displacement of water carrying dissolved gas) diffusion and free gas Darcy flow. Numerical models have been run to compare the efficiency of these different modes and the pathway they imply for the H2 in a sedimentary basin with active aquifers. The results show the key roles of these aquifers but also the competition between free gas flow and the dissolved gas displacement which can go in opposite directions. Even with a conservative hypothesis on the H2 charge a gaseous phase exists at few kilometers deep as well as free gas accumulation. Gaseous phase displacement could be the faster and diffusion is neglectable. The modeling also allows us to predict where H2 is expected in the soil: in fault zones eventually above accumulations and more likely due to exsolution above shallow aquifers.
A Perspective on Low-Temperature Water Electrolysis - Challenges in Alkaline and Acidic Technology
Dec 2017
Publication
Water electrolysis is considered as an important technology for an increased renewable energy penetration. This perspective on low-temperature water electrolysis joins the dots between the interdisciplinary fields of fundamental science describing physicochemical processes engineering for the targeted design of cell components and the development of operation strategies. Within this aim the mechanisms of ion conduction gas diffusion corrosion and electrocatalysis are reviewed and their influence on the optimum design of separators electrocatalysts electrodes and other cell components are discussed. Electrocatalysts for the water splitting reactions and metals for system components are critically accessed towards their stability and functionality. On the basis of the broad scientific analysis provided challenges for the design of water electrolyzers are elucidated with special regard to the alkaline or acidic media of the electrolyte.
Voltage Losses in Zero-gap Alkaline Water Electrolysis
Apr 2021
Publication
Reducing the gap between the electrodes and diaphragm to zero is an often adopted strategy to reduce the ohmic drop in alkaline water electrolyzers for hydrogen production. We provide a thorough account of the current–voltage relationship in such a zero-gap configuration over a wide range of electrolyte concentrations and current densities. Included are voltage components that are not often experimentally quantified like those due to bubbles hydroxide depletion and dissolved hydrogen and oxygen. As is commonly found for zero-gap configurations the ohmic resistance was substantially larger than that of the separator. We find that this is because the relatively flat electrode area facing the diaphragm was not active likely due to separator pore blockage by gas the electrode itself and or solid deposits. Over an e-folding time-scale of ten seconds an additional ohmic drop was found to arise likely due to gas bubbles in the electrode holes. For electrolyte concentrations below 0.5 M an overpotential was observed associated with local depletion of hydroxide at the anode. Finally a high supersaturation of hydrogen and oxygen was found to significantly increase the equilibrium potential at elevated current densities. Most of these voltage losses are shown to be easily avoidable by introducing a small 0.2 mm gap greatly improving the performance compared to zero-gap.
Optimal Operation Strategy for Wind–Photovoltaic Power-Based Hydrogen Production Systems Considering Electrolyzer Start-Up Characteristics
Aug 2024
Publication
Combining electrolytic hydrogen production with wind–photovoltaic power can effectively smooth the fluctuation of power and enhance the schedulable wind–photovoltaic power which provides an effective solution to solve the problem of wind–photovoltaic power accommodation. In this paper the optimization operation strategy is studied for the wind–photovoltaic power-based hydrogen production system. Firstly to make up for the deficiency of the existing research on the multi-state and nonlinear characteristics of electrolyzers the three-state and power-current nonlinear characteristics of the electrolyzer cell are modeled. The model reflects the difference between the cold and hot starting time of the electrolyzer and the linear decoupling model is easy to apply in the optimization model. On this basis considering the operation constraints of the electrolyzer hydrogen storage tank battery and other equipment the optimization operation model of the wind–photovoltaic power-based hydrogen production system is developed based on the typical scenario approach. It also considers the cold and hot starting time of the electrolyzer with the daily operation cost as the goal. The results show that the operational benefits of the system can be improved through the proposed strategy. The hydrogen storage tank capacity will have an impact on the operation income of the wind–solar hydrogen coupling system and the daily operation income will increase by 0.32% for every 10% (300 kg) increase in the hydrogen storage tank capacity.
Advances in Whole-cell Photobiological Hydrogen Production
Jan 2021
Publication
Solar energy is the largest energy source on Earth. In contrast to the limited andgreenhouse gases-emitting fossil fuels solar energy is inexhaustible carbonneutral and nonpolluting. The conversion of this most abundant but highlydiffused source into hydrogen is increasingly attractive. In nature photosyntheticmicroorganisms exploit solar energy to produce hydrogen via photosynthesiswhich is also known as photobiological hydrogen production. More recentlyvarious types of artificial materials have been developed to hybrid microorgan-isms for converting solar energy into hydrogen namely semiartificial photo-synthesis hydrogen production. Herein the strategies for converting solar energyinto hydrogen with whole-cell biocatalyst are summarized and their potentials forfuture social sustainable development are discussed.
An Overview of the Photocatalytic Water Splitting over Suspended Particles
Jan 2021
Publication
The conversion of solar to chemical energy is one of the central processes considered in the emerging renewable energy economy. Hydrogen production from water splitting over particulate semiconductor catalysts has often been proposed as a simple and a cost-effective method for largescale production. In this review we summarize the basic concepts of the overall water splitting (in the absence of sacrificial agents) using particulate photocatalysts with a focus on their synthetic methods and the role of the so-called “co-catalysts”. Then a focus is then given on improving light absorption in which the Z-scheme concept and the overall system efficiency are discussed. A section on reactor design and cost of the overall technology is given where the possibility of the different technologies to be deployed at a commercial scale and the considerable challenges ahead are discussed. To date the highest reported efficiency of any of these systems is at least one order of magnitude lower than that deserving consideration for practical applications.
In-situ Direct Seawater Electrolysis Using Floating Platform in Ocean with Uncontrollable Wave Motion
Jun 2024
Publication
Direct hydrogen production from inexhaustible seawater using abundant offshore wind power offers a promising pathway for achieving a sustainable energy industry and fuel economy. Various direct seawater electrolysis methods have been demonstrated to be effective at the laboratory scale. However larger-scale in situ demonstrations that are completely free of corrosion and side reactions in fluctuating oceans are lacking. Here fluctuating conditions of the ocean were considered for the first time and seawater electrolysis in wave motion environment was achieved. We present the successful scaling of a floating seawater electrolysis system that employed wind power in Xinghua Bay and the integration of a 1.2 Nm3 h−1 -scale pilot system. Stable electrolysis operation was achieved for over 240 h with an electrolytic energy consumption of 5 kWh Nm−3 H2 and a high purity (>99.9%) of hydrogen under fluctuating ocean conditions (0~0.9 m wave height 0~15 m s−1 wind speed) which is comparable to that during onshore water electrolysis. The concentration of impurity ions in the electrolyte was low and stable over a long period of time under complex and changing scenarios. We identified the technological challenges and performances of the key system components and examined the future outlook for this emerging technology.
Renewable Hydrogen Production Steps Up Wastewater Treatment under Low-carbon Electricity Sources - A Call Forth Approach
Sep 2024
Publication
Switching to renewable resources for hydrogen production is essential. Present hydrogen resources such as coal oil and natural gas are depleted and rapidly moving to a dead state and they possess a high carbon footprint. Wastewater is a promising avenue in searching for a renewable hydrogen production resource. Profuse techniques are preferred for hydrogen production. Among them electrolysis is great with wastewater against biological processes by hydrogen purity. Present obstacles behind the process are conversion efficiency intensive energy and cost. This review starts with hydrogen demand wastewater availability and their H2 potential then illustrates the three main types of electrolysis. The main section highlights renewable energy-assisted electrolysis because of its low carbon footprint and zero emission potential for various water electrolysis. High-temperature steam solid oxide electrolysis is a viable option for future scaling due to the versatile adoption of photo electric and thermal energy. A glance at some effective aspirations to large-scale H2 economics such as co-generation biomass utilization Microbial electrolysis waste to low-cost green electrode Carbon dioxide hydrogenation and minerals recovery. This study gives a broader view of facing challenges via versatile future perspectives to eliminate the obstacles above. renewable green H2 along with a low carbon footprint and cost potential to forward the large-scale wastewater electrolysis H2 production in addition to preserving the environment from wastewater and fossil fuel. Geographical and seasonal availability constraints are unavoidable; therefore energy storage and coupling of power sources is essential to attain consistent supply. The lack of regulations and policies supporting the development and adoption of these technologies did not reduce the gap between research and implementation. Life cycle assessment of this electrolysis process is rarely available so we need to focus on the natural effect of this process on the environment.
Techno-economic and Environmental Assessment of Green Hydrogen Production via Biogas Reforming with Membrane-based CO2 Capture
Jan 2025
Publication
Reduction of the carbon dioxide emissions is a vital important environmental element in achieving the global climate neutrality. The integration of renewables and the Carbon Capture Utilization and Storage (CCUS) technologies is seen as an important pillar for overall decarbonization. This work presents several innovative concepts in which the biogas reforming process in integrated with pre- and post-combustion CO2 capture using membranes for green hydrogen production. The assessment evaluates the most relevant techno-economic and environmental performances for 100 MWth green hydrogen plant capacity. Several biogas reforming designs with and without CO2 capture capability were evaluated. In respect to the CO2 capture rate several pre- and postcombustion systems provided decarbonization yields between 55% up to 99%. The results show that the decarbonized membrane-based green hydrogen production shows attractive performances such as high energy efficiency (55–60%) reduced energy and cost penalties for CO2 capture (3.6–15.5 net efficiency points depending on the carbon capture rate) low specific CO2 emissions at system level (down to 2 kg/MWh green hydrogen) and overall negative carbon emission for whole biogas value chain (up to − 468 kg/MWh green hydrogen). This analysis clearly shows how the integration of renewables with CCUS technologies can deliver applications with negative CO2 emissions for climate neutrality.
Solar-driven, Highly Sustained Splitting of Seawater into Hydrogen and Oxygen Fuels
Mar 2019
Publication
Electrolysis of water to generate hydrogen fuel is an attractiverenewable energy storage technology. However grid-scale fresh-water electrolysis would put a heavy strain on vital water re-sources. Developing cheap electrocatalysts and electrodes that cansustain seawater splitting without chloride corrosion could ad-dress the water scarcity issue. Here we present a multilayer anodeconsisting of a nickel–iron hydroxide (NiFe) electrocatalyst layeruniformly coated on a nickel sulfide (NiSx) layer formed on porousNi foam (NiFe/NiSx-Ni) affording superior catalytic activity andcorrosion resistance in solar-driven alkaline seawater electrolysisoperating at industrially required current densities (0.4 to 1 A/cm2)over 1000 h. A continuous highly oxygen evolution reaction-active NiFe electrocatalyst layer drawing anodic currents towardwater oxidation and an in situ-generated polyatomic sulfate andcarbonate-rich passivating layers formed in the anode are respon-sible for chloride repelling and superior corrosion resistance of thesalty-water-splitting anode.
On-site Solar Powered Refueling Stations for Green Hydrogen Production and Distribution: Performances and Costs
Jan 2022
Publication
Today the hydrogen is considered an essential element in speeding up the energy transition and generate important environmental benefits. Not all hydrogen is the same though. The “green hydrogen” which is produced using renewable energy and electrolysis to split water is really and completely sustainable for stationary and mobile applications. This paper is focused on the techno-economic analysis of an on-site hydrogen refueling station (HRS) in which the green hydrogen production is assured by a PV plant that supplies electricity to an alkaline electrolyzer. The hydrogen is stored in low pressure tanks (200 bar) and then is compressed at 900 bar for refueling FCHVs by using the innovative technology of the ionic compressor. From technical point of view the components of the HRS have been sized for assuring a maximum capacity of 450 kg/day. In particular the PV plant (installed in the south of Italy) has a size of 8MWp and supplies an alkaline electrolyzer of 2.1 MW. A Li-ion battery system (size 3.5 MWh) is used to store the electricity surplus and the grid-connection of the PV plant allows to export the electricity excess that cannot be stored in the battery system. The economic analysis has been performed by estimating the levelized cost of hydrogen (LCOH) that is an important economic indicator based on the evaluation of investment operational & maintenance and replacement costs. Results highlighted that the proposed on-site configuration in which the green hydrogen production is assured is characterized by a LCOH of 10.71 €/kg.
The Effect of Carbon Taxonomy on Renewable Hydrogen Production: A Techno-economic and Environmental Assessment
Dec 2024
Publication
From navigating the rainbow of colours to the lack of consensus in establishing a common taxonomy the labelling and definition of green or renewable hydrogen presents a growing challenge. In this context carbon taxonomy is understood through five critical aspects: carbon intensity temporal and geographical correlation additionality of renewable energy generation and different system boundaries in Life Cycle Assessment (LCA). This study examines the effect of carbon taxonomy on the design and operation of Power-to-Gas (PtG) systems for renewable hydrogen production including the electricity supply portfolio via Power Purchase Agreements (PPA) and grid-connected electrolysis. To this end an optimisation model combining energy system modelling and LCA is developed and then applied to a case study in the Japanese context. The importance of the PPA portfolio in securing cheap and low-carbon electricity to produce hydrogen is addressed. To support this evaluation process an eco-efficiency metric is introduced and proved to be a comprehensive tool for evaluating renewable hydrogen production. Regarding carbon taxonomies the findings emphasize additionality as the key determinant factor followed by temporal correlation and the definition of carbon intensity thresholds. The application of a cradle-togate LCA boundary influenced the cabron intensity accounting playing an unexpected role on the design and optimal PtG dispatch strategy.
Safety Assessment of Hydrogen Production Using Alkaline Water Electrolysis
Aug 2024
Publication
This paper presents a comprehensive safety assessment of hydrogen production using Alkaline Water Electrolysis (AWE). The study utilizes various risk assessment methodologies including Hazard Identification (HAZID) What-If analysis Fault Tree Analysis (FTA) Event Tree Analysis (ETA) and Bow Tie analysis to systematically identify and evaluate potential hazards associated with the AWE process. Key findings include the identification of critical hazards such as hydrogen leaks oxygen-related risks and maintenance challenges. The assessment emphasizes the importance of robust safety measures including preventive and mitigative strategies to manage these risks effectively. Consequence modeling highlights significant threat zones for thermal radiation and explosion risks underscoring the need for comprehensive safety protocols and emergency response plans. This work contributes valuable insights into hydrogen safety providing a framework for risk assessment and mitigation in hydrogen production facilities crucial for the safe and sustainable development of hydrogen infrastructure in the global energy transition.
Review of Reforming Processes for the Production of Green Hydrogen from Landfill Gas
Dec 2024
Publication
The growing challenges of climate change the depletion of fossil fuel reserves and the urgent need for carbon-neutral energy solutions have intensified the focus on renewable energy. In this perspective the generation of green hydrogen from renewable sources like biogas/landfill gas (LFG) offers an intriguing option providing the dual benefits of a sustainable hydrogen supply and enhanced waste management through energy innovation and valorization. Thus this review explores the production of green hydrogen from biogas/LFG through four conventional reforming processes specifically dry methane reforming (DMR) steam methane reforming (SMR) partial oxidation reforming (POX) and autothermal reforming (ATR) focusing on their mechanisms operating parameters and the role of catalysts in hydrogen production. This review further delves into both the environmental aspects specifically GWP (CO2 eq·kg−1 H2) emissions and the economic aspects of these processes examining their efficiency and impact. Additionally this review also explores hydrogen purification in biogas/LFG reforming and its integration into the CO2 capture utilization and storage roadmap for net-negative emissions. Lastly this review highlights future research directions focusing on improving SMR and DMR biogas/LFG reforming technologies through simulation and modeling to enhance hydrogen production efficiency thereby advancing understanding and informing future research and policy initiatives for sustainable energy solutions.
Efficient Solar-powered PEM Electrolysis for Sustainable Hydrogen Production: An Integrated Approach
Apr 2024
Publication
The coupling of photovoltaics (PVs) and PEM water electrolyzers (PEMWE) is a promising method for generating hydrogen from a renewable energy source. While direct coupling is feasible the variability of solar radiation presents challenges in efcient sizing. This study proposes an innovative energy management strategy that ensures a stable hydrogen production rate even with fuctuating solar irradiation. By integrating battery-assisted hydrogen production this approach allows for decentralized grid-independent renewable energy systems mitigating instability from PV intermittency. The system utilizes electrochemical storage to absorb excess energy during periods of low or very high irradiation which falls outside the electrolyzer’s optimal power input range. This stored energy then supports the PV system ensuring the electrolyzer operates near its nominal capacity and optimizing its lifetime. The system achieves an efciency of 7.78 to 8.81% at low current density region and 6.6% at high current density in converting solar energy into hydrogen.
Profitability of Hydrogen Production: Assessment of Investments in Electrolyser Under Various Market Circumstances
Aug 2024
Publication
Although hydrogen is increasingly seen as a crucial energy carrier in future zero-carbon energy system a profitable exploitation of electrolysers requires still high amounts of subsidies. To analyze the profitability of electrolysers attention has to be paid not only to the costs but also to the interaction between electricity and hydrogen markets. Using a model of internationally integrated electricity and hydrogen markets this paper analyses the profitability of electrolysers plants in various future market circumstances. We find that in particular the future supply of renewable electricity the demand for electricity as well as the prices of natural gas and carbon strongly affect the profitability of electrolysis. In order to make massive investments in electrolysers profitable with significantly lower subsidy requirements the amount of renewable electricity generation needs to grow strongly and the carbon prices should be higher while the demand for electricity should not increase accordingly. This research underscores the critical role of market conditions in shaping the viability of hydrogen electrolysis providing valuable insights for policymakers and stakeholders in the transition to a zero-carbon energy system.
Recent Advancements of Polymeric Membranes in Anion Exchange Membrane Water Electrolyzer (AEMWE): A Critical Review
Apr 2023
Publication
The formation of green hydrogen from water electrolysis is one of the supreme methodologies for understanding the well-organized consumption of sporadic renewable energies and the carbon-free future. Among the different electrolysis techniques the evolving anion exchange membrane water electrolysis (AEMWE) shows the utmost promise for manufacturing green hydrogen in an inexpensive way. In the present review we establish the most current and noteworthy achievements of AEMWE which include the advancements in increasing the ionic conductivity and understanding the mechanism of degradation of AEM and the most important topics regarding the designing of the electrocatalyst. The crucial issues that affect the AEMWE behavior are highlighted and future constraints and openings are also discussed. Furthermore this review article provides the appreciated strategies for producing extremely dynamic and robust electrocatalysts and evolving the construction of AEMWE equipment.
Process Integration of Hydrogen Production Using Steam Gasification and Water-Gas Shift Reactions: A Case of Response Surface Method and Machine Learning Techniques
May 2024
Publication
An equilibrium-based steady-state simulator model that predicts and optimizes hydrogen production from steam gasification ofbiomass is developed using ASPEN Plus software and artificial intelligence techniques. Corn cob’s chemical composition wascharacterized to ensure the biomass used as a gasifier and with potential for production of hydrogen. Artificial intelligence is usedto examine the effects of the significant input variables on response variables such as hydrogen mole fraction and hydrogen energycontent. Optimizing the steam-gasification process using response surface methodology (RSM) considering a variety of biomass-steam ratios was carried out to achieve the best results. Hydrogen yield and the impact of main operating parameters wereconsidered. A maximum hydrogen concentration is found in the gasifier and water-gas shift (WGS) reactor at the highest steam-to-biomass (S/B) ratio and the lowest WGS reaction temperature while the gasification temperature has an optimum value. ANFISwas used to predict hydrogen of mole fraction 0.5045 with the input parameters of S/B ratio of 2.449 and reactor pressure andtemperature of 1 bar and 848°C respectively. With the steam-gasification model operating at temperature (850°C) pressure (1 bar)and S/B ratio of 2.0 an ASPEN simulator achieved a maximum of 0.5862 mole fraction of hydrogen while RSM gave an increaseof 19.0% optimum hydrogen produced over the ANFIS prediction with the input parameters of S/B ratio of 1.053 and reactorpressure and temperature of 1 bar and 850°C respectively. Varying the gasifier temperature and S/B ratio have on the other handa crucial effect on the gasification process with artificial intelligence as a unique tool for process evaluation prediction andoptimization to increase a significant impact on the products especially hydrogen.
Is the Polish Solar-to-Hydrogen Pathway Green? A Carbon Footprint of AEM Electrolysis Hydrogen Based on an LCA
Apr 2023
Publication
Efforts to direct the economies of many countries towards low-carbon economies are being made in order to reduce their impact on global climate change. Within this process replacing fossil fuels with hydrogen will play an important role in the sectors where electrification is difficult or technically and economically ineffective. Hydrogen may also play a critical role in renewable energy storage processes. Thus the global hydrogen demand is expected to rise more than five times by 2050 while in the European Union a seven-fold rise in this field is expected. Apart from many technical and legislative barriers the environmental impact of hydrogen production is a key issue especially in the case of new and developing technologies. Focusing on the various pathways of hydrogen production the essential problem is to evaluate the related emissions through GHG accounting considering the life cycle of a plant in order to compare the technologies effectively. Anion exchange membrane (AEM) electrolysis is one of the newest technologies in this field with no LCA studies covering its full operation. Thus this study is focused on a calculation of the carbon footprint and economic indicators of a green hydrogen plant on the basis of a life cycle assessment including the concept of a solar-to-hydrogen plant with AEM electrolyzers operating under Polish climate conditions. The authors set the range of the GWP indicators as 2.73–4.34 kgCO2eq for a plant using AEM electrolysis which confirmed the relatively low emissivity of hydrogen from solar energy also in relation to this innovative technology. The economic profitability of the investment depends on external subsidies because as developing technology the AEM electrolysis of green hydrogen from photovoltaics is still uncompetitive in terms of its cost without this type of support.
Green Hydrogen Generation in Alkaline Solution Using Electrodeposited Ni-Co-nano-graphene Thin Film Cathode
Apr 2024
Publication
Green hydrogen generation technologies are currently the most pressing worldwide issues ofering promising alternatives to existing fossil fuels that endanger the globe with growing global warming. The current research focuses on the creation of green hydrogen in alkaline electrolytes utilizing a Ni-Co-nano-graphene thin flm cathode with a low overvoltage. The recommended conditions for creating the target cathode were studied by electrodepositing a thin Ni-Co-nano-graphene flm in a glycinate bath over an iron surface coated with a thin copper interlayer. Using a scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) mapping analysis the obtained electrode is physically and chemically characterized. These tests confrm that Ni Co and nano-graphene are homogeneously dispersed resulting in a lower electrolysis voltage in green hydrogen generation. Tafel plots obtained to analyze electrode stability revealed that the Ni-Co-nano-graphene cathode was directed to the noble direction with the lowest corrosion rate. The Ni-Co-nano-graphene generated was used to generate green hydrogen in a 25% KOH solution. For the production of 1 kg of green hydrogen utilizing Ni-Co-nano-graphene electrode the electrolysis efciency was 95.6% with a power consumption of 52 kwt h−1 whereas it was 56.212. kwt h−1 for pure nickel thin flm cathode and 54. kwt h−1 for nickel cobalt thin flm cathode respectively.
Assessment of Wind Energy Potential for the Production of Renewable Hydrogen in Sindh Province of Pakistan
Apr 2019
Publication
In this study we developed a new hybrid mathematical model that combines wind-speed range with the log law to derive the wind energy potential for wind-generated hydrogen production in Pakistan. In addition we electrolyzed wind-generated power in order to assess the generation capacity of wind-generated renewable hydrogen. The advantage of the Weibull model is that it more accurately reflects power generation potential (i.e. the capacity factor). When applied to selected sites we have found commercially viable hydrogen production capacity in all locations. All sites considered had the potential to produce an excess amount of wind-generated renewable hydrogen. If the total national capacity of wind-generated was used Pakistan could conceivably produce 51917000.39 kg per day of renewable hydrogen. Based on our results we suggest that cars and other forms of transport could be fueled with hydrogen to conserve oil and gas resources which can reduce the energy shortfall and contribute to the fight against climate change and global warming. Also hydrogen could be used to supplement urban energy needs (e.g. for Sindh province Pakistan) again reducing energy shortage effects and supporting green city programs.
Steam Reforming of Biomass Gasification Gas for Hydrogen Production: From Thermodynamic Analysis to Experimental Validation
Jun 2023
Publication
Biomass gasification produces syngas composed mainly of hydrogen carbon monoxide carbon dioxide methane water and higher hydrocarbons till C4 mainly ethane. The hydrocarbon content can be upgraded into richer hydrogen streams through the steam reforming reaction. This study assessed the steam reforming process at the thermodynamic equilibrium of five streams with different compositions from the gasification of three different biomass sources (Lignin Miscanthus and Eucalyptus). The simulations were performed on Aspen Plus V12 software using the Gibbs energy minimization method. The influence of the operating conditions on the hydrogen yield was assessed: temperature in the range of 200 to 1100 ◦C pressures of 1 to 20 bar and steamto‑carbon (S/C) molar ratios from 0 (only dry reforming) to 10. It was observed that operating conditions of 725 to 850 ◦C 1 bar and an S/C ratio of 3 enhanced the streams’ hydrogen content and led to nearly complete hydrocarbon conversion (>99%). Regarding hydrogen purity the stream obtained from the gasification of Lignin and followed by a conditioning phase (stream 5) has the highest hydrogen purity 52.7% and an hydrogen yield of 48.7%. In contrast the stream obtained from the gasification of Lignin without any conditioning (stream 1) led to the greatest increase in hydrogen purity from 19% to 51.2% and a hydrogen yield of 61.8%. Concerning coke formation it can be mitigated for S/C molar ratios and temperatures >2 and 700 ◦C respectively. Experimental tests with stream 1 were carried out which show a similar trend to the simulation results particularly at high temperatures (700–800 ◦C).
Self-Sustaining Control Strategy for Proton-Exchange Membrane Electrolysis Devices Based on Gradient-Disturbance Observation Method
Mar 2023
Publication
This paper proposes a self-sustaining control model for proton-exchange membrane (PEM) electrolysis devices aiming to maintain the temperature of their internal operating environment and thus improve the electrolysis efficiency and hydrogen production rate. Based on the analysis of energy–substance balance and electrochemical reaction characteristics an electrothermal-coupling dynamic model for PEM electrolysis devices was constructed. Considering the influence of the input energy–substance and the output hydrogen and oxygen of PEM electrolysis devices on the whole dynamic equilibrium process the required electrical energy and water molar flow rate are dynamically adjusted so that the temperature of the cathode and the anode is maintained near 338.15 K. The analytical results show that the hydrogen production rate and electrolysis efficiency are increased by 0.275 mol/min and 3.9% respectively by linearly stacking 100 PEM electrolysis devices to form a hydrogen production system with constant cathode and anode operating temperatures around 338.15 K in the self-sustaining controlled mode
Everything About Hydrogen Podcast: Easter Eggs
Feb 2023
Publication
On today’s episode of Everything About Hydrogen we speak with Raffi Garabedian CEO and Co-Founder of Electric Hydrogen (EH2) a deep decarbonization company pioneering new technology for low cost high efficiency fossil free hydrogen systems. By using electrolyzers many times larger than the industry standard EH2 aims to help eliminate more than 30% of global GHG emissions from difficult to electrify sectors like steel ammonia and freight.
We are excited to learn more from Raffi about the EH2 technology lessons learned by scaling First Solar and what we might expect to see next.
The podcast can be found on their website.
We are excited to learn more from Raffi about the EH2 technology lessons learned by scaling First Solar and what we might expect to see next.
The podcast can be found on their website.
Anion Exchange Membrane Water Electrolysis from Catalyst Design to the Membrane Electrode Assembly
Jul 2022
Publication
Anion exchange membrane (AEM) electrolysis aims to combine the benefits of alkaline electrolysis such as stability of the cheap catalyst and advantages of proton-exchange membrane systems like the ability to operate at differential pressure fast dynamic response low energy losses and higher current density. However as of today AEM electrolysis is limited by AEMs exhibiting insufficient ionic conductivity as well as lower catalyst activity and stability. Herein recent developments and outlook of AEM electrolysis such as cost-efficient transition metal catalysts for hydrogen evolution reaction and oxygen evolution reaction AEMs ionomer electrolytes ionomer catalyst–electrolyte interaction and membrane-electrode assembly performance and stability are described.
Everything About Hydrogen Podcast: Reaching for the Stars
Mar 2023
Publication
Today Everything About Hydrogen had a chance to speak with Paul Barrett the CEO of Hysata and dig into what makes this electrolysis company different.
The podcast can be found on their website.
The podcast can be found on their website.
Methane Pyrolysis in a Liquid Metal Bubble Column Reactor for CO2-Free Production of Hydrogen
Oct 2023
Publication
In light of the growing interest in hydrogen as an energy carrier and reducing agent various industries including the iron and steel sector are considering the increased adoption of hydrogen. To meet the rising demand in energy-intensive industries the production of hydrogen must be significantly expanded and further developed. However current hydrogen production heavily relies on fossil-fuel-based methods resulting in a considerable environmental burden with approximately 10 tons of CO2 emissions per ton of hydrogen. To address this challenge methane pyrolysis offers a promising approach for producing clean hydrogen with reduced CO2 emissions. This process involves converting methane (CH4 ) into hydrogen and solid carbon significantly lowering the carbon footprint. This work aims to enhance and broaden the understanding of methane pyrolysis in a liquid metal bubble column reactor (LMBCR) by utilizing an expanded and improved experimental setup based on the reactor concept previously proposed by authors from Montanuniversitaet in 2022 and 2023. The focus is on investigating the process parameters’ temperature and methane input rate with regard to their impact on methane conversion. The liquid metal temperature exhibits a strong influence increasing methane conversion from 35% at 1150 ◦C to 74% at 1250 ◦C. In contrast the effect of the methane flow rate remains relatively small in the investigated range. Moreover an investigation is conducted to assess the impact of carbon layers covering the surface of the liquid metal column. Additionally a comparative analysis between the LMBCR and a blank tube reactor (BTR) is presented.
Environmental Assessment of Hydrogen Utilization in Various Applications and Alternative Renewable Sources for Hydrogen Production: A Review
May 2023
Publication
Rapid industrialization is consuming too much energy and non-renewable energy resources are currently supplying the world’s majority of energy requirements. As a result the global energy mix is being pushed towards renewable and sustainable energy sources by the world’s future energy plan and climate change. Thus hydrogen has been suggested as a potential energy source for sustainable development. Currently the production of hydrogen from fossil fuels is dominant in the world and its utilization is increasing daily. As discussed in the paper a large amount of hydrogen is used in rocket engines oil refining ammonia production and many other processes. This paper also analyzes the environmental impacts of hydrogen utilization in various applications such as iron and steel production rocket engines ammonia production and hydrogenation. It is predicted that all of our fossil fuels will run out soon if we continue to consume them at our current pace of consumption. Hydrogen is only ecologically friendly when it is produced from renewable energy. Therefore a transition towards hydrogen production from renewable energy resources such as solar geothermal and wind is necessary. However many things need to be achieved before we can transition from a fossil-fuel-driven economy to one based on renewable energy
Carbon-negative Hydrogen: Exploring the Techno-economic Potential of Biomass Co-gasification with CO2 Capture
Sep 2021
Publication
The hydrogen economy is receiving increasing attention as a complement to electrification in the global energy transition. Clean hydrogen production is often viewed as a competition between natural gas reforming with CO2 capture and electrolysis using renewable electricity. However solid fuel gasification with CO2 capture presents another viable alternative especially when considering the potential of biomass to achieve negative CO2 emissions. This study investigates the techno-economic potential of hydrogen production from large-scale coal/ biomass co-gasification plants with CO2 capture. With a CO2 price of 50 €/ton the benchmark plant using commercially available technologies achieved an attractive hydrogen production cost of 1.78 €/kg with higher CO2 prices leading to considerable cost reductions. Advanced configurations employing hot gas clean-up membrane-assisted water-gas shift and more efficient gasification with slurry vaporization and a chemical quench reduced the hydrogen production cost to 1.50–1.62 €/kg with up to 100% CO2 capture. Without contingencies added to the pre-commercial technologies the lowest cost reduces to 1.43 €/kg. It was also possible to recover waste heat in the form of hot water at 120 ◦C for district heating potentially unlocking further cost reductions to 1.24 €/kg. In conclusion gasification of locally available solid fuels should be seriously considered next to natural gas and electrolysis for supplying the emerging hydrogen economy.
Recent Advances in Power-to-X Technology for the Production of Fuels and Chemicals
Jun 2019
Publication
Environmental issues related to greenhouse gas emissions are progressively pushing the transition toward fossil-free energy scenario in which renewable energies such as solar and wind power will unavoidably play a key role. However for this transition to succeed significant issues related to renewable energy storage have to be addressed. Power-to-X (PtX) technologies have gained increased attention since they actually convert renewable electricity to chemicals and fuels that can be more easily stored and transported. H2 production through water electrolysis is a promising approach since it leads to the production of a sustainable fuel that can be used directly in hydrogen fuel cells or to reduce carbon dioxide (CO2) in chemicals and fuels compatible with the existing infrastructure for production and transportation. CO2 electrochemical reduction is also an interesting approach allowing the direct conversion of CO2 into value-added products using renewable electricity. In this review attention will be given to technologies for sustainable H2 production focusing on water electrolysis using renewable energy as well as on its remaining challenges for large scale production and integration with other technologies. Furthermore recent advances on PtX technologies for the production of key chemicals (formic acid formaldehyde methanol and methane) and fuels (gasoline diesel and jet fuel) will also be discussed with focus on two main pathways: CO2 hydrogenation and CO2 electrochemical reduction.
An Economic Performance Improving and Analysis for Offshore Wind Farm-Based Islanded Green Hydrogen System
Jul 2024
Publication
When offshore wind farms are connected to a hydrogen plant with dedicated transmission lines for example high-voltage direct current the fluctuation of wind speed will influence the efficiency of the alkaline electrolyzer and deteriorate the techno-economic performance. To overcome this issue firstly an additional heating process is adopted to achieve insulation for the alkaline solution when power generated by wind farms is below the alkaline electrolyzer minimum power threshold while the alkaline electrolyzer overload feature is used to generate hydrogen when wind power is at its peak. Then a simplified piecewise model-based alkaline electrolyzer techno-economic analysis model is proposed. The improved economic performance of the islanded green hydrogen system with the proposed operation strategy is verified based on the wind speed data set simulation generated by the Weibull distribution. Lastly the sensitivity of the total return on investment to wind speed parameters was investigated and an islanded green hydrogen system capacity allocation based on the proposed analysis model was conducted. The simulation result shows the total energy utilization increased from 62.0768% to 72.5419% and the return on investment increased from 5.1303%/month to 5.9581%/month when the proposed control strategy is adopted.
Steam Electrolysis for Green Hydrogen Generation. State of the Art and Research Perspective
Jul 2024
Publication
With renewable energy sources projected to become the dominant source of electricity hydrogen has emerged as a crucial energy carrier to mitigate their intermittency issues. Water electrolysis is the most developed alternative to generate green hydrogen so far. However in the past two decades steam electrolysis has attracted increasing interest and aims to become a key player in the portfolio of electrolytic hydrogen. In practice steam electrolysis follows two distinct operational approaches: Solid Oxide Electrolysis Cell (SOEC) and Proton Exchange Membrane (PEM) at high temperature. For both technologies this work analyses critical cell components outlining material characteristics and degradation issues. The influence of operational conditions on the performance and cell durability of both technologies is thoroughly reviewed. The analytical comparison of the two electrolysis alternatives underscores their distinct advantages and drawbacks highlighting their niche of applications: SOECs thrive in high temperature industries like steel production and nuclear power plants whereas PEM steam electrolysis suits lower temperature applications such as textile and paper. Being PEM steam electrolysis less explored this work ends up by suggesting research lines in the domain of i) cell components (membranes catalysts and gas diffusion layers) to optimize and scale the technology ii) integration strategies with renewable energies and iii) use of seawater as feedstock for green hydrogen production.
Recent Advances in Membrane-based Electrochemical Hydrogen Separation: A Review
Feb 2021
Publication
In this paper an overview of commercial hydrogen separation technologies is given. These technologies are discussed and compared—with a detailed discussion on membrane-based technologies. An emerging and promising novel hydrogen separation technology namely electrochemical hydrogen separation (EHS) is reviewed in detail. EHS has many advantages over conventional separation systems (e.g. it is not energy intensive it is environmentally-friendly with near-zero pollutants it is known for its silent operation and the greatest advantage simultaneous compression and purification can be achieved in a one-step operation). Therefore the focus of this review is to survey open literature and research conducted to date on EHS. Current technological advances in the field of EHS that have been made are highlighted. In the conclusion literature gaps and aspects of electrochemical hydrogen separation that require further research are also highlighted. Currently the cost factor lack of adequate understanding of the degradation mechanisms related to this technology and the fact that certain aspects of this technology are as yet unexplored (e.g. simultaneous hydrogen separation and compression) all hinder its widespread application. In future research some attention could be given to the aforementioned factors and emerging technologies such as ceramic proton conductors and solid acids.
Potential Cost Savings of Large-scale Blue Hydrogen Production via Sorption-enhanced Steam Reforming Process
Jan 2024
Publication
As countries work towards achieving net-zero emissions the need for cleaner fuels has become increasingly urgent. Hydrogen produced from fossil fuels with carbon capture and storage (blue hydrogen) has the potential to play a significant role in the transition to a low-carbon economy. This study examined the technical and economic potential of blue hydrogen produced at 600 MWth(LHV) and scaled up to 1000 MWth(LHV) by benchmarking sorption-enhanced steam reforming process against steam methane reforming (SMR) autothermal gasheated reforming (ATR-GHR) integrated with carbon capture and storage (CCS) and SMR with CCS. Aspen Plus® was used to develop the process model which was validated using literature data. Cost sensitivity analyses were also performed on two key indicators: levelised cost of hydrogen and CO2 avoidance cost by varying natural gas price electricity price CO2 transport and storage cost and carbon price. Results indicate that at a carbon price of 83 £/tCO2e the LCOH for SE-SR of methane is the lowest at 2.85 £/kgH2 which is 12.58% and 22.55% lower than that of ATR-GHR with CCS and SMR plant with CCS respectively. The LCOH of ATR-GHR with CCS and SMR plant with CCS was estimated to be 3.26 and 3.68 £/kgH2 respectively. The CO2 avoidance cost was also observed to be lowest for SE-SR followed by ATR-GHR with CCS then SMR plant with CCS and was observed to reduce as the plant scaled to 1000 MWth(LHV) for these technologies.
Alkaline Electrolysis for Hydrogen Production at Sea: Perspectives on Economic Performance
May 2023
Publication
Alkaline electrolysis is already a proven technology on land with a high maturity level and good economic performance. However at sea little is known about its economic performance toward hydrogen production. Alkaline electrolysis units operate with purified water to split its molecules into hydrogen and oxygen. Purified water and especially that sourced from the sea has a variable cost that ultimately depends on its quality. However the impurities present in that purified water have a deleterious effect on the electrolyte of alkaline electrolysis units that cause them to drop their energy efficiency. This in turn implies a source of economic losses resulting from the cost of electricity. In addition at sea there are various options regarding the electrolyte management of which the cost depends on various factors. All these factors ultimately impact on the levelized cost of the produced hydrogen. This article aims to shed some light on the economic performance of alkaline electrolysis units operating under sea conditions highlighting the knowledge gaps in the literature and initiating a debate in the field.
On the Cost of Zero Carbon Hydrogen: A Techno-economic Analysis of Steam Methane Reforming with Carbon Capture and Storage
May 2023
Publication
This article challenges the view that zero carbon hydrogen from steam methane reforming (SMR) is prohibitively expensive and that the cost of CO2 capture increases exponentially as residual emissions approach zero; a flawed narrative often eliminating SMR produced hydrogen as a route to net zero. We show that the capture and geological storage of 100% of the fossil CO2 produced in a SMR is achievable with commercially available post-combustion capture technology and an open art solvent. The Levelised Cost of Hydrogen (LCOH) of 69£/MWhth HHV (2.7£/kg) for UK production remains competitive to other forms of low carbon hydrogen but retains a hydrogen lifecycle carbon intensity of 5 gCO2e/MJ (LHV) due to natural gas supply chain and embodied greenhouse gas (GHG) emissions. Compensating for the remaining lifecycle GHG emissions via Direct Air Capture with geological CO2 Storage (DACCS) increases the LCOH to 71–86 £/MWhth HHV (+3–25%) for a cost estimate of 100–1000 £/tCO2 for DACCS and the 2022 UK natural gas supply chain methane emission rates. Finally we put in perspective the cost of CO2 avoidance of fuel switching from natural gas to hydrogen with long term price estimates for natural gas use and DACCS and hydrogen produced from electrolysis.
No more items...