Production & Supply Chain

Multi-production plant is an idea highlighting cost- and energy-saving purposes. However just integrating different sub-systems is not desired and the output and performance based on evaluation criteria must be assessed. In this study an integrated energy conversion system composed of solid oxide fuel cell (SOFC) solid oxide electrolyzer cell (SOEC) and Rankine steam cycle is proposed to develop a multi-production system of power heat and hydrogen to alleviate energy dissipation and to preserve the environment by utilizing and extracting the most possible products from the available energy source. With this regard natural gas and water are used to drive the SOEC and the Rankine steam cycle respectively. The required heat and power demand of the electrolyzer are designed to be provided by the fuel cell and the Rankine cycle. The feasibility of the designed integrated system is evaluated through comprehensive exergy-based analysis. The technical performance of the system is evaluated through exergy assessment and it is obtained that the SOFC and the SOEC can achieve to the high exergy efficiency of 84.8% and 63.7% respectively. The designed system provides 1.79 kg/h of hydrogen at 125 kPa. In addition the effective designed variables on the performance of the designed integrated system are monitored to optimize the system’s performance in terms of technical efficiency cost-effectivity and environmental considerations. This assessment shows that 59.4 kW of the available exergy is destructed in the combustion chamber. Besides the techno-economic analysis and exergoenvironmental assessment demonstrate the selected compressors should be re-designed to improve the cost-effectivity and decline the negative environmental impact of the designed integrated energy conversion system. In addition it is calculated that the SOEC has the highest total cost and also the highest negative impact on the environment compared to other designed units in the proposed integrated energy conversion system.

The high energy consumption and production of undesired oxygen greatly restrict the wide adoption of water electrolysis for hydrogen production. In a paper recently published in Nature Catalysis Wang and coworkers rationally introduce aldehydes for oxidation at anode to replace oxygen evolution reaction which can produce hydrogen and value-added products at low potential realizing efficient bipolar hydrogen production with high-purity. Moreover these aldehydes are biomass-derived and contribute to sustainable hydrogen production

A new and active material in the form of ZnIn₂S₄ microspheres decorated by CuInS₂ quantum dots have been obtained by hydrothermal method for the first time. The optimum amount of CuInS₂ quantum dots (1.13 wt.%) introduced into rection medium during ZnIn₂S₄ microspheres synthesis increased the photocatalytic H₂ generation rate by 2.5 times than that of bare ZnIn₂S₄ photocatalysis under visible light irradiation. This sample exhibited strong photoactivity in the extended visible range up to 540 nm with 30.6% apparent quantum efficiency (λ = 420 nm).

Recently ammonia is being considered for fuelling gas turbines as a new sustainable source. It can undergo thermal cracking producing nitrogen hydrogen and unburned ammonia thus enabling the use of these chemicals most efficiently for combustion purposes. Ammonia being carbon-free may allow the transition towards a hydrogen economy. However one of the main constraints of this fuelling technique is that although the combustion of ammonia produces no CO2 there is a large NOx proportion of emissions using this fuel. In this work cracked ammonia obtained from a modified combustion rig designed at Cardiff University was used to simulate a swirl burner under preheating conditions via heat exchangers. The primary objective of this system is to find new ways for the reduction of NOx emissions by injecting various amounts of ammonia/hydrogen at different mixtures downstream of the primary flame zone. The amount of injected ammonia/hydrogen mixture (X) taken from the thermal cracking system was ranged from 0%-4% (vol %) of the total available fuel in the system while the remaining gas (1.00-X) was then employed as primary fuel into the burner. CHEMKIN- PRO calculations were conducted by employing a novel chemical reaction code developed at Cardiff University to achieve the goal of this paper. The predictions were performed under low pressure and rich conditions with an equivalence ratio ϕ =1.2 in a swirl burner previously characterised at output powers of ~10 kW. Ammonia and hydrogen blends were evaluated from 50% NH3 (vol %) with the remaining gas as hydrogen continuing in steps of 10% (vol %) NH3 increments. Results showed that the minimum unburned ammonia and higher flame temperature were achieved at 60%-40% NH3-H2 when compared to other blends but with high NO emissions. These NO levels were reduced by injecting a small amount of NH3/H2 mixture (X=4 %) downstream the primary zone in a generated circulations promoted by the new design of the burner which affecting the residence time hence reducing the NO emission in the exhaust gas.

In view of the recent interest in the transformation of renewable energy into a new energy vector that did not produce by combustion greenhouse gases emissions the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) commissioned this report to a con­sultancy to get a better understanding of the industrial perspectives of water electrolysis in Europe. and the role that public support has in that evolution.

The non-interconnected islands of Greece can benefit from the comprehensive use of RES to avoid water droughts and ensure energy autonomy. The present paper analyzes an HRES with two possible operating scenarios. Both of them include a wind park of 27.5 MW capacity an 1175 m3/day desalination plant and a 490000 m3/day water tank in Lemnos Greece. Regarding the wind power 70% is used in the HRES while the rest is channeled directly to the grid. The main difference comes down to how the wind energy is stored either in the form of hydraulic energy or in the form of hydrogen. The lifespan of the system is 25 years such as the produced stochastic series of rainfall temperature and wind of the area. Through the comparison of the operating scenarios the following results arise: (i) the water needs of the island are fully covered and the irrigation needs have a reliability of 66% in both scenarios. (ii) Considering the energy needs the pumping storage seems to be the most reliable solution. (iii) However depending on the amount of wind energy surplus the use of hydrogen could produce more energy than the hydroelectric plant.

The need for a rapid transformation to low-carbon economies has rekindled hydrogen as a promising energy carrier. Yet the full range of environmental consequences of large-scale hydrogen production remains unclear. Here prospective life cycle analysis is used to compare different options to produce 500 Mt/yr of hydrogen including scenarios that consider likely changes to future supply chains. The resulting environmental and human health impacts of such production levels are further put into context with the Planetary Boundaries framework known human health burdens the impacts of the world economy and the externality-priced production costs that embody the environmental impact. The results indicate that climate change impacts of projected production levels are 3.3–5.4 times higher than the allocated planetary boundary with only green hydrogen from wind energy staying below the boundary. Human health impacts and other environmental impacts are less severe in comparison but metal depletion and ecotoxicity impacts of green hydrogen deserve further attention. Priced-in environmental damages increase the cost most strongly for blue hydrogen (from ∼2 to ∼5 USD/kg hydrogen) while such true costs drop most strongly for green hydrogen from solar photovoltaic (from ∼7 to ∼3 USD/kg hydrogen) when applying prospective life cycle analysis. This perspective helps to evaluate potentially unintended consequences and contributes to the debate about blue and green hydrogen.

Integrating the exergy and economic analyses of water electrolyzers is the pivotal way to comprehend the interplay of system costs and improve system performance. For this a 3D numerical model based on COMSOL Multiphysics Software (version 5.6 COMSOL Stockholm Sweden) is integrated with the exergy and exergoeconomic analysis to evaluate the exergoeconomic performance of the proton exchange membrane water electrolysis (PEMWE) under different operating conditions (operating temperature cathode pressure current density) and design parameter (membrane thickness). Further the gas crossover phenomenon is investigated to estimate the impact of gas leakage on analysis reliability under various conditions and criteria. The results reveal that increasing the operating temperature or decreasing the membrane thickness improves both the efficiency and cost of hydrogen exergy while increasing the gas leakage through the membrane. Likewise raising the current density and the cathode pressure lowers the hydrogen exergy cost and improves the economic performance. The increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency due to the gas crossover are more noticeable at higher pressures. As the cathode pressure rises from 1 to 30 bar at a current density of 10000 A/m2 the increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency are increased by 37.6 kJ/mol 4.49 USD/GJ and 7.1% respectively. The cheapest green electricity source which is achieved using onshore wind energy and hydropower reduces hydrogen production costs and enhances economic efficiency. The growth in the hydrogen exergy cost is by about 4.23 USD/GJ for a 0.01 USD/kWh increase in electricity price at the current density of 20000 A/m2. All findings would be expected to be quite useful for researchers engaged in the design development and optimization of PEMWE.

Instead of storing the energy produced by photovoltaic panels in batteries for later use to power electric loads green hydrogen can also be produced and used in transportation heating and as a natural gas alternative. Green hydrogen is produced in a process called electrolysis. Generally the electrolyser can generate hydrogen from a fluctuating power supply such as renewables. However due to the startup time of the electrolyser and electrolyser degradation accelerated by multiple shutdowns an idle mode is required. When in idle mode the electrolyser uses 10% of the rated electrolyser load. An energy management system (EMS) shall be applied where a storage technology such as a lithium-ion capacitor or lithium-ion battery is used. This paper uses a state-machine EMS of PV microgrid for green hydrogen production and energy storage to manage the hydrogen production during the morning from solar power and in the night using the stored energy in the energy storage which is sized for different scenarios using a lithium-ion capacitor and lithium-ion battery. The mission profile and life expectancy of the lithium-ion capacitor and lithium-ion battery are evaluated considering the system’s local irradiance and temperature conditions in the Australian climate. A tradeoff between storage size and cutoffs of hydrogen production as variables of the cost function is evaluated for different scenarios. The lithium-ion capacitor and lithium-ion battery are compared for each tested scenario for an optimum lifetime. It was found that a lithium-ion battery on average is 140% oversized compared to a lithium-ion capacitor but a lithium-ion capacitor has a smaller remaining capacity of 80.2% after ten years of operation due to its higher calendar aging while LiB has 86%. It was also noticed that LiB is more affected by cycling aging while LiC is affected by calendar aging. However the average internal resistance after 10 years for the lithium-ion capacitor is 264% of the initial internal resistance while for lithium-ion battery is 346% making lithium-ion capacitor a better candidate for energy storage if it is used for grid regulation as it requires maintaining a lower internal resistance over the lifetime of the storage.

The economic and ecological production of green hydrogen by water electrolysis is one of the major challenges within Carbon2Chem and other power-to-X projects. This paper presents an evaluation of the different water electrolysis technologies with respect to their specific energy demand carbon footprint and the forecast production costs in 2030. From a current perspective alkaline water electrolysis is evaluated as the most favorable technology for the cost-effective production of low-carbon hydrogen with fluctuating renewables.

Sustainable Development Goals establish the main challenges humankind is called to tackle to assure equal comfort of living worldwide. Among these the access to affordable renewable energy and clean water are overriding especially in the context of developing economies. Reversible Solid Oxide Cells (rSOC) are a pivotal technology for their sector-coupling potential. This paper aims at studying the implementation of such a technology in new concept PV-hybrid energy storage mini-grids with close access to seawater. In such assets rSOCs have a double useful effect: charge/discharge of the bulk energy storage combined with seawater desalination. Based on the outcomes of an experimental proof-of-concept on a single cell operated with salty water the operation of the novel mini-grid is simulated throughout a solar year. Simulation results identify the fittest mini-grid configuration in order to achieve energy and environmental optimization hence scoring a renewable penetration of more than 95% marginal CO2 emissions (13 g/kWh) and almost complete coverage of load demand. Sector-coupling co-production rate (desalinated water versus electricity issued from the rSOC) is 0.29 L/kWh.

In this paper a feasibility study was carried out to evaluate cyclic adsorption processes for capturing CO2 from either shifted synthesis gas or H2 PSA tail gas of an industrial-scale SMR-based hydrogen plant. It is expected that hydrogen is to be widely used in place of natural gas in various industrial sectors where electrification would be rather challenging. A SMR-based hydrogen plant is currently dominant in the market as it can produce hydrogen at scale in the most economical way. Its CO2 emission must be curtailed significantly by its integration with CCUS. Two Vacuum Pressure Swing Adsorption (VPSA) systems including a rinse step were designed to capture CO2 from an industrial-scale SMR-based hydrogen plant: one for the shifted synthesis gas and the other for the H2 PSA tail gas. Given the shapes of adsorption isotherms zeolite 13X and activated carbon were selected for tail gas and syngas capture options respectively. A simple Equilibrium Theory model developed for the limiting case of complete regeneration was taken to analyse the VPSA systems in this feasibility study. The process performances were compared to each other with respect to product recovery bed productivity and power consumption. It was found that CO2 could be captured more cost-effectively from the syngas than the tail gas unless the desorption pressure was too low. The energy consumption of the VPSA was comparable to those of the conventional MDEA processes.

This paper explores the implications of siting a bioenergy with carbon capture and storage (BECCS) facility to carbon emission performances for three case-study supply chains using the Carbon Navigation System (CNS) model. The three case-study supply chains are a wheat straw derived BECCS-power a municipal solid waste derived BECCS-waste-to-energy and a sawmill residue derived BECCS-hydrogen. A BECCS facility needs to be carefully sited taking into consideration its local low carbon infrastructure available biomass and geography for successful deployment and achieving a favorable net-negative carbon balance. On average across the three supply chains a 10 km shift in the siting of the BECCS facility results in an 8.6–13.1% increase in spatially explicit supply chain emissions. BECCS facilities producing low purity CO2 at high yields have lower spatial emissions when located within the industrial clusters while those producing high purity CO2 at low yields perform better outside the clusters. A map is also generated identifying which of the three modeled supply chains delivers the lowest spatially explicit supply chain emission options for any given area of the UK at a 1 MtCO2/yr capture scale.

Hydrogen energy is considered one of the cleanest and most promising alternatives to fossil fuel because the only combustion product is water. The development of water splitting electrocatalysts with Earth abundance cost-efficiency and high performance for large current density industrial applications is vital for H2 production. However most of the reported catalysts are usually tested within relatively small current densities (< 100 mA cm−2 ) which is far from satisfactory for industrial applications. In this minireview we summarize the latest progress of effective non-noble electrocatalysts for large current density hydrogen evolution reaction (HER) whose performance is comparable to that of noble metal-based catalysts. Then the design strategy of intrinsic activities and architecture design are discussed including self-supporting electrodes to avoid the detachment of active materials the superaerophobicity and superhydrophilicity to release H2 bubble in time and the mechanical properties to resist destructive stress. Finally some views on the further development of high current density HER electrocatalysts are proposed such as scale up of the synthesis process in situ characterization to reveal the micro mechanism and the implementation of catalysts into practical electrolyzers for the commercial application of as-developed catalysts. This review aimed to guide HER catalyst design and make large-scale hydrogen production one step further.

Hydrogen is a low or zero-carbon energy source that is considered the most promising and potential energy carrier of the future. In this study the energy sources feedstocks and various methods of hydrogen production from power generation are comparatively investigated in detail. In addition this study presents an economic assessment to evaluate cost-effectiveness based on different economic indicators including sensitivity analysis and uncertainty analysis. Proton exchange membrane fuel cell (PEMFCs) technology has the most potential to be developed compared to several other technologies. PEMFCs have been widely used in various fields and have advantages (i.e. start-up zero-emissions high power density). Among the various sources of uncertainty in the sensitivity analysis the cost estimation method shows inflationary deviations from the proposed cost of capital. This is due to the selection process and untested technology. In addition the cost of electricity and raw materials as the main factors that are unpredictable.

The competitiveness of biofuels may be increased by integrating biomass gasification plants with electrolysis units which generate hydrogen to be combined with carbon-rich syngas. This option allows increasing the yield of the final product by retaining a higher amount of biogenic carbon and improving the resilience of the energy sector by favoring electric grid services and sector coupling. This article illustrates a techno-economic comparative analysis of three flexible power and biomass to methanol plants based on different gasification technologies: direct gasification indirect gasification and sorptionenhanced gasification. The design and operational criteria of each plant are conceived to operate both without green hydrogen addition (baseline mode) and with hydrogen addition (enhanced mode) following an intermittent use of the electrolysis system which is turned on when the electricity price allows an economically viable hydrogen production. The methanol production plants include a gasification section syngas cleaning conditioning and compression section methanol synthesis and purification and heat recovery steam cycle to be flexibly operated. Due to the high oxygen demand in the gasifier the direct gasification-based plant obtains a great advantage to be operated between a minimum load to satisfy the oxygen demand at high electricity prices and a maximum load to maximize methanol production at low electricity prices. This allows avoiding large oxygen storages with significant benefits for Capex and safety issues. The analysis reports specific fixed-capital investments between 1823 and 2048 €/kW of methanol output in the enhanced operation and LCOFs between 29.7 and 31.7 €/GJLHV. Economic advantages may be derived from a decrease in the electrolysis capital investment especially for the direct gasification-based plants which employ the greatest sized electrolyzer. Methanol breakeven selling prices range between 545 and 582 €/t with the 2019 reference Denmark electricity price curve and between 484 and 535 €/t with an assumed modified electricity price curve of a future energy mix with increased penetration of intermittent renewables.

In order to adopt water electrolyzers as a main hydrogen production system it is critical to develop inexpensive and earth-abundant catalysts. Currently both half-reactions in water splitting depend heavily on noble metal catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. The efforts within this field for the discovery of efficient and stable earth-abundant catalysts (EACs) have increased exponentially the last few years. The development of EACs for the oxygen evolution reaction (OER) in acidic media is particularly important as the only stable and efficient catalysts until now are noble-metal oxides such as IrOx and RuOx. On the hydrogen evolution reaction (HER) side there is significant progress on EACs under acidic conditions but there are very few reports of these EACs employed in full PEM WE cells. These two main issues are reviewed and we conclude with prospects for innovation in EACs for the OER in acidic environments as well as with a critical assessment of the few full PEM WE cells assembled with EACs.

Hydrogen is currently being promoted because of its advantages as an energy vector its potential 12 to decarbonise the economy and strategical implications in terms of energy security. Hydrogen 13 from high-temperature electrolysis coupled with concentrated solar power (CSP) is especially 14 interesting since it enhances the last two aspects and could benefit from significant technological 15 progress in the coming years. However there is a lack of studies assessing its future 16 environmental performance. This work fills this gap by carrying out a prospective life cycle 17 assessment based on the expected values of key performance parameters in 2030. The results 18 show that parabolic trough CSP coupled with a solid oxide electrolyser is a promising solution 19 under environmental aspects. It leads to a prospective hydrogen carbon footprint (1.85 kg CO2 20 eq/kg H2) which could be classified as low-carbon according to current standards. The 21 benchmarking study for the year 2030 shows that the assessed system significantly decreases the 22 hydrogen carbon footprint compared to future hydrogen from steam methane reforming (81% 23 reduction) and grid electrolysis (51%) even under a considerable penetration of renewable energy 24 sources.

Replacing fossil fuels with energy sources and carriers that are sustainable environmentally benign and affordable is amongst the most pressing challenges for future socio-economic development. To that goal hydrogen is presumed to be the most promising energy carrier. Electrocatalytic water splitting if driven by green electricity would provide hydrogen with minimal CO2 footprint. The viability of water electrolysis still hinges on the availability of durable earth-abundant electrocatalyst materials and the overall process efficiency. This review spans from the fundamentals of electrocatalytically initiated water splitting to the very latest scientific findings from university and institutional research also covering specifications and special features of the current industrial processes and those processes currently being tested in large-scale applications. Recently developed strategies are described for the optimisation and discovery of active and durable materials for electrodes that ever-increasingly harness first principles calculations and machine learning. In addition a technoeconomic analysis of water electrolysis is included that allows an assessment of the extent to which a large-scale implementation of water splitting can help to combat climate change. This review article is intended to cross-pollinate and strengthen efforts from fundamental understanding to technical implementation and to improve the ‘junctions’ between the field’s physical chemists materials scientists and engineers as well as stimulate much-needed exchange among these groups on challenges encountered in the different domains.

The combination of methane steam reforming technology and CCS (Carbon Capture and Storage) technology has great potential to reduce carbon emissions in the process of hydrogen production. Different from the traditional idea of capturing CO2 (Carbon Dioxide) in the exhaust gas with high work consumption this study simultaneously focuses on CO2 separation from fuel gas and recycling. A new hydrogen production system is developed by methane steam reforming coupled with carbon capture. Separated and captured high-purity carbon dioxide could be recycled for methane dry reforming; on this basis a new methane-dry-reforming-driven hydrogen production system with a carbon dioxide reinjection unit is innovatively proposed. In this study the energy flow and irreversible loss in the two newly developed systems are analyzed in detail through energy and exergy balance analysis. The advantages are explored from the perspective of hydrogen production rate natural gas consumption and work consumption. In addition in consideration of the integrated performance an optimal design analysis was conducted. In terms of hydrogen production the new system based on dry reforming is better with an advantage of 2.41%; however it is worth noting that the comprehensive thermal performance of the new steam reforming system is better reaching 10.95%. This study provides new ideas for hydrogen production from a low carbon emission perspective and also offers a new direction for future distributed energy system integration.

Ambitious decarbonization pathways to limit the global temperature rise to well below 2 ◦C will require largescale CO2 removal from the atmosphere. One promising avenue for achieving this goal is hydrogen production from biomass with CO2 capture. The present study investigates the techno-economic prospects of a novel biomass-to-hydrogen process configuration based on the gas switching integrated gasification (GSIG) concept. GSIG applies the gas switching combustion principle to indirectly combust off-gas fuel from the pressure swing adsorption unit in tubular reactors integrated into the gasifier to improve efficiency and CO2 capture. In this study these efficiency gains facilitated a 5% reduction in the levelized cost of hydrogen (LCOH) relative to conventional O2-blown fluidized bed gasification with pre-combustion CO2 capture even though the larger and more complex gasifier cancelled out the capital cost savings from avoiding the air separation and CO2 capture units. The economic assessment also demonstrated that advanced gas treatment using a tar cracker instead of a direct water wash can further reduce the LCOH by 12% and that the CO2 prices in excess of 100 €/ton consistent with ambitious decarbonization pathways will make this negative-emission technology economically highly attractive. Based on these results further research into the GSIG concept to facilitate more efficient utilization of limited biomass resources can be recommended.

An investigation was conducted to determine the effects of operating parameters for various electrode types on hydrogen gas production through electrolysis as well as to evaluate the efficiency of the polymer electrolyte membrane (PEM) electrolyzer. Deionized (DI) water was fed to a single-cell PEM electrolyzer with an active area of 36 cm2 . Parameters such as power supply (50–500 mA/cm2 ) feed water flow rate (0.5–5 mL/min) water temperature (25−80 ◦C) and type of anode electrocatalyst (0.5 mg/cm2 PtC [60%] 1.5 mg/cm2 IrRuOx with 1.5 mg/cm2 PtB 3.0 mg/cm2 IrRuOx and 3.0 mg/cm2 PtB) were varied. The effects of these parameter changes were then analyzed in terms of the polarization curve hydrogen flowrate power consumption voltaic efficiency and energy efficiency. The best electrolysis performance was observed at a DI water feed flowrate of 2 mL/min and a cell temperature of 70 ◦C using a membrane electrode assembly that has a 3.0 mg/cm2 IrRuOx catalyst at the anode side. This improved performance of the PEM electrolyzer is due to the reduction in activation as well as ohmic losses. Furthermore the energy consumption was optimal when the current density was about 200 mA/cm2 with voltaic and energy efficiencies of 85% and 67.5% respectively. This result indicates low electrical energy consumption which can lower the operating cost and increase the performance of PEM electrolyzers. Therefore the optimal operating parameters are crucial to ensure the ideal performance and durability of the PEM electrolyzer as well as lower its operating costs.

The production and application of hydrogen an environmentally friendly energy source have been attracting increasing interest of late. Although steam methane reforming (SMR) method is used to produce hydrogen it is difficult to build a high-fidelity model because the existing equation-oriented theoretical model cannot be used to clearly understand the heat-transfer phenomenon of a complicated reforming reactor. Herein we developed an artificial neural network (ANN)-based data-driven model using 485710 actual operation datasets for optimizing the SMR process. Data preprocessing including outlier removal and noise filtering was performed to improve the data quality. A model with high accuracy (average R2 = 0.9987) was developed which can predict six variables through hyperparameter tuning of a neural network model as follows: syngas flow rate; CO CO2 CH4 and H2 compositions; and steam temperature. During optimization the search spaces for nine operating variables namely the natural gas flow rate for the feed and fuel hydrogen flow rate for desulfurization water flow rate and temperature air flow rate SMR inlet temperature and pressure and low-temperature shift (LTS) inlet temperature were defined and applied to the developed model for predicting the thermal efficiencies for 387420489 cases. Subsequently five constraints were established to consider the feasibility of the process and the decision variables with the highest process thermal efficiency were determined. The process operating conditions showed a thermal efficiency of 85.6%.

The electrification of final energy uses is a key strategy to reach the desired scenario with zero greenhouse gas emissions. Many of them can be electrified with more or less difficulty but there is a part that is difficult to electrify at a competitive cost: heavy road transport maritime and air transport and some industrial processes are some examples. For this reason the possibility of using other energy vectors rather than electricity should be explored. Hydrogen can be considered a real alternative especially considering that this transition should not be carried out immediately because initially the electrification would be carried out in those energy uses that are considered most feasible for this conversion. The Canary Islands’ government is making considerable efforts to promote a carbon-free energy mix starting with renewable energy for electricity generation. Still in the early–mid 2030s it will be necessary to substitute heavy transport fossil fuel. For this purpose HOMER software was used to analyze the feasibility of hydrogen production using surplus electricity produced by the future electricity system. The results of previous research on the optimal generation MIX for Grand Canary Island based exclusively on renewable sources were used. This previous research considers three possible scenarios where electricity surplus is in the range of 2.3–4.9 TWh/year. Several optimized scenarios using demand-side management techniques were also studied. Therefore based on the electricity surpluses of these scenarios the optimization of hydrogen production and storage systems was carried out always covering at least the final hydrogen demand of the island. As a result it is concluded that it would be possible to produce 3.5 × 104 to 7.68 × 104 t of H2/year. In these scenarios 3.15 × 105 to 6.91 × 105 t of water per year would be required and there could be a potential production of 2.8 × 105 to 6.14 × 105 t of O2 per year.

A combined ultra-short-term wind power prediction strategy with high robustness based on least squares support vector machine (LSSVM) has been proposed in order to solve the wind abandonment caused by wind power randomness and realize efficient hydrogen production under wide power fluctuation. Firstly the original wind power data is decomposed into sub-modes with different bandwidth by variational modal decomposition (VMD) which reduces the influence of random noise and mode mixing significantly. Then dragonfly algorithm (DA) is introduced to optimize LSSVM kernel function and the combined ultra-short-term wind power prediction strategy which meets the time resolution and accuracy requirements of electrolytic cell control has been established finally. This model is validated by a wind power hydrogen production demonstration project output in the middle east of China. The superior prediction accuracy for high volatility wind power data is verified and the algorithm provides theoretical basis to improve the control of wind power hydrogen production system

The gasification technology of refuse-derived fuels (RDF) can represent a future alternative to the global hydrogen production and a pathway for the development of the circular economy. The paper presents an innovative way of utilizing RDF through their oxygen/steam co-gasification with bituminous coal to hydrogen rich gas. Five different RDF samples (RDF1÷RDF5) were investigated. The in-depth analyses of the co-gasification of bituminous coal blends with different amounts of RDF (10 15 and 20%w/w) under various temperature conditions were conducted with the application of Hierarchical Clustering Analysis (HCA). The results of the research study revealed a decrease in the total gas yield as well as in the hydrogen yield observed with the increase in the RDF fraction in the fuel blend. The lowest hydrogen yield and the highest carbon conversion were noted for the co-gasification tests of coal blends with 20%w/w for all the studied RDFs. The SEM-EDS (Scanning Electron Microscopy with Energy Dispersive Spectroscopy) and WDXRF (Wavelength Dispersive X-ray Fluorescence) results showed a significantly higher H2 yield in RDF2 co-gasification with coal in comparison with all the remaining RDFs due to the higher concentration of calcium in the sample. The molecular structure analysis of polymers using Fourier transform infrared spectroscopy (FTIR) demonstrated that the most prevalent synthetic polymers in RDF2 are polyethylene terephthalate and polyvinyl chloride characterized by the lowest thermal stability compared to polyethylene and polypropylene.

Catalytic decomposition of methane (CDM) is a novel technology for turquoise hydrogen production with solid carbon as the by-product instead of CO2. A computational fluid dynamics model was developed to simulate the CDM process in a 3D fixed bed reactor accounting for the impact of carbon deposition on catalytic activity. The model was validated with experimental data and demonstrated its capability to predict hydrogen concentration and catalyst deactivation time under varying operating temperatures and methane flow rates. The catalyst lifespan was characterized by the maximum carbon yield (i.e. gC/gcat) which is a crucial indicator for determining the cost of hydrogen generation. Parametric studies were performed to analyse the effect of inlet gas composition and operating pressure on CDM performance. Various CH4/H2 ratios were simulated to improve the methane conversion efficiency generating a higher amount of hydrogen while increasing the maximum carbon yield up to 49.5 gC/gcat. Additionally higher operating pressure resulted in higher methane decomposition rates which reflects the nature of the chemical kinetics.

Photocatalysts lead vitally to water purifications and decarbonise environment each by wastewater treatment and hydrogen (H2 ) production as a renewable energy source from waterphotolysis. This work deals with the photocatalytic degradation of ciprofloxacin (CIP) and H2 production by novel silver-nanoparticle (AgNPs) based ternary-nanocomposites of thiolated reducegraphene oxide graphitic carbon nitride (AgNPs-S-rGO2%@g-C3N4 ) material. Herein the optimised balanced ratio of thiolated reduce-graphene oxide in prepared ternary-nanocomposites played matchlessly to enhance activity by increasing the charge carriers’ movements via slowing down charge-recombination ratios. Reduced graphene oxide (rGO) >2 wt.% or < 10 nm. Therefore AgNPs-S-rGO2%@g-C3N4 has 3772.5 µmolg−1 h −1 H2 production which is 6.43-fold higher than g-C3N4 having cyclic stability of 96% even after four consecutive cycles. The proposed mechanism for AgNPs-S-rGO2%@g-C3N4 revealed that the photo-excited electrons in the conduction-band of g-C3N4 react with the adhered water moieties to generate H2 .

Biomass gasification is a versatile thermochemical process that can be used for direct energy applications and the production of advanced liquid and gaseous energy carriers. In the present work the results are presented concerning the H2 production at a high purity grade from biomass feedstocks via steam/oxygen gasification. The data demonstrating such a process chain were collected at an innovative gasification prototype plant coupled to a portable purification system (PPS). The overall integration was designed for gas conditioning and purification to hydrogen. By using almond shells as the biomass feedstock from a product gas with an average and stable composition of 40%-v H2 21%-v CO 35%-v CO2 2.5%-v CH4 the PPS unit provided a hydrogen stream with a final concentration of 99.99%-v and a gas yield of 66.4%.

Solar-to-hydrogen plants are predominantly based on steam electrolysis. Steam electrolysis requires water electricity and heat. The excess electric energy is generally converted into hydrogen via an electrolyser. The use of waste heat in hydrogen generation process promises energy efficiency improvement and production fluctuation reductions. This work investigates the techno-economic performance of the proposed system which recovers the waste heat from molten carbonate fuel cell and uses solar energy to produce steam. Comparison of thermally assisted solar system with corresponding solar system is done. The fuel cell provides 80% of the required thermal energy. The solar PV array provides the required electricity. The thermally assisted solar-to-hydrogen system annual energy efficiency (38.5 %) is higher than that of solar- to- hydrogen system. The investment cost of the proposed system is 2.4 % higher than that using only solar parabolic trough collector for the same required amount of heat. The advantage is that the fuel cell simultaneously produces electricity and heat. The recovery of waste heat allows getting an annual overall efficiency of 63.2 % for the molten carbonate fuel cell. It yields 2152 MWh of electricity per year. The 1 MW electrolysers annually generates 74 tonnes of hydrogen.

Ammonia is an industrial chemical and the basic building block for the fertilizer industry. Lately attention has shifted towards using ammonia as a carbon-free energy vector due to the ease of transportation and storage in liquid state at − 33 ◦C and atmospheric pressure. This study evaluates the prospects of blue and green ammonia as future energy carriers; specifically the gas switching reforming (GSR) concept for H2 and N2 co-production from natural gas with inherent CO2 capture (blue) and H2 generation through an optimized value chain of wind and solar power electrolysers cryogenic N2 supply and various options for energy storage (green). These longer term concepts are benchmarked against conventional technologies integrating CO2 capture: the Kellogg Braun & Root (KBR) Purifier process and the Linde Ammonia Concept (LAC). All modelled plants utilize the same ammonia synthesis loop for a consistent comparison. A cash flow analysis showed that the GSR concept achieved an attractive levelized cost of ammonia (LCOA) of 332.1 €/ton relative to 385.1–385.9 €/ton for the conventional plants at European energy prices (6.5 €/GJ natural gas and 60 €/MWh electricity). Optimal technology integration for green ammonia using technology costs representative of 2050 was considerably more expensive: 484.7–772.1 €/ton when varying the location from Saudi Arabia to Germany. Furthermore the LCOA of the GSR technology drops to 192.7 €/ton when benefitting from low Saudi Arabian energy costs (2 €/GJ natural gas and 40 €/MWh electricity). This cost difference between green and blue ammonia remained robust in sensitivity analyses where input energy cost (natural gas or wind/solar power) was the most influential parameter. Given its low production costs and the techno-economic feasibility of international ammonia trade advanced blue ammonia production from GSR offers an attractive pathway for natural gas exporting regions to contribute to global decarbonization.

Variable low-cost low-carbon electricity that would otherwise be curtailed may provide a substantial economic opportunity for entities that can flexibly adapt their electricity consumption. We used historical hourly weather data over the contiguous U.S. to model the characteristics of least-cost electricity systems dominated by variable renewable generation that powered firm and flexible electricity demands (loads). Scenarios evaluated included variable wind and solar power battery storage and dispatchable natural gas with carbon capture and storage with electrolytic hydrogen representing a prototypical flexible load. When flexible loads were small excess generation capacity was available during most hours allowing flexible loads to operate at high capacity factors. Expanding the flexible loads allowed the least-cost systems to more fully utilize the generation capacity built to supply firm loads and thus reduced the average cost of delivered electricity. The macro-scale energy model indicated that variable renewable electricity systems optimized to supply firm loads at current costs could supply 25% or more additional flexible load with minimal capacity expansion while resulting in reduced average electricity costs (10% or less capacity expansion and 10% to 20% reduction in costs in our modeled scenarios). These results indicate that adding flexible loads to electricity systems will likely allow more full utilization of generation assets across a wide range of system architectures thus providing new energy services with infrastructure that is already needed to supply firm electricity loads.

The European Hydrogen Strategy and the new « Fit for 55 » package indicate the urgent need for the alignment of policy with the European Green Deal and European Union (EU) climate law for the decarbonization of the energy system and the use of hydrogen towards 2030 and 2050. The increasing carbon prices in EU Emission Trading System (ETS) as well as the lack of dispatchable thermal power generation as part of the Coal exit are expected to enhance the role of Combined Heat and Power (CHP) in the future energy system. In the present work the use of renewable hydrogen for the decarbonization of CHP plants is investigated for various fossil fuel substitution ratios and the impact of the overall efficiency the reduction of direct emissions and the carbon footprint of heat and power generation are reported. The analysis provides insights on efficient and decarbonized cogeneration linking the power with the heat sector via renewable hydrogen production and use. The levelized cost of hydrogen production as well as the levelized cost of electricity in the power to hydrogen to combined heat and power system are analyzed for various natural gas substitution scenarios as well as current and future projections of EU ETS carbon prices.

Green hydrogen represents a promising solution for renewable energy application and carbon footprint reduc tion. However its production through renewable energy powered water electrolysis is hindered by significant cost arising from repair maintenance and economic losses due to unexpected downtimes. Although reliability engineering is highly effective in addressing such issues there is limited research on its application in the hydrogen field. To present the state-of-the-art research this study aims to explore the potential of reducing these events through reliability engineering a widely adopted approach in various industries. For this purpose it examines past accidents occurred in water electrolysis plants from the hydrogen incident and accident database (HIAD 2.1). Besides a literature review is performed to analyze the state-of-the-art application of reliability engineering techniques such as failure analysis reliability assessment and reliability-centered maintenance in the hydrogen sector and similar industries. The study highlights the contributions and potentials of reliability engineering for efficient and stable green hydrogen production while also discussing the gaps in applying this approach. The unique challenges posed by hydrogen’s physical properties and innovative technologies in water electrolysis plants necessitate advancement and specialized approaches for reliability engineering.

Methanol reforming is considered to be one of the most promising hydrogen production technologies for hydrogen fuel cells. It is expected to solve the problem of hydrogen storage and transportation because of its high hydrogen production rate low cost and good safety. However the strong nonlinearity and slow response of the pressure and temperature subsystems pose challenges to the tracking control of the methanol reforming hydrogen production system. In this paper two internal model-based temperature and pressure controllers are proposed in which the temperature is adjusted by controlling the air flow and the pressure is adjusted by controlling the opening of the backpressure valve. Firstly a lumped parameter model of the methanol reforming hydrogen production system is constructed using MATLAB/Simulink® (produced by MathWorks in Natick Massachusetts USA). In addition the transfer function model of the system is obtained by system identification at the equilibrium point and the internal model controller is further designed. The simulation results show that the control method achieves the robustness of the system and the temperature and pressure of the reforming reactor can quickly and accurately track the target value when the load changes. Small-load step tests indicate stable tracking of the temperature and pressure for the reforming reactor without steady-state errors. Under large-temperature step signal testing the response time for the reforming temperature is about 148 s while the large-pressure step signal test shows that the response time for the reforming pressure is about 8 s. Compared to the PID controller the internal model controller exhibits faster response zero steady-state error and no overshoot. The results show that the internal model control method has strong robustness and dynamic characteristics.

Anode flooding is one of the critical issues in developing a proton exchange membrane (PEM)-based electrochemical hydrogen pump. Improving the hydrophobicity of the gas diffusion layer (GDL) has been studied as an approach to mitigating anode flooding in electrochemical pumps. A mixture of Nafion™ and oxidized carbon nanotubes (O-CNT) has been applied to the porous gas diffusion medium in the hydrogen pump cell. The coating renders the GDL hydrophobic with an effective contact angle of 130°. Electrochemical pump testing has shown that with the help of the coating the flood-recovery performance of the hydrogen pump was greatly improved. A hydrogen pump cell with an uncoated GDL was not able to recover from a flooded state while a hydrogen pump cell with a coated GDL was able to recover its performance in about 100 s.

Oceanic energy sources notably offshore wind and wave power present a significant opportunity to generate green hydrogen through water electrolysis. This approach allows for offshore hydrogen production which can be efficiently transported through existing pipelines and stored in various forms offering a versatile solution to tackle the intermittency of renewable energy sources and potentially revolutionize the entire electrical grid infrastructure. This research focusses on assessing the technical and economic feasibility of this method in six strategic coastal regions in Morocco: Laayoune Agadir Essaouira Eljadida Casablanca and Larache. Our proposed system integrates offshore wind turbines oscillating water column wave energy converters and PEM electrolyzers to meet energy demands while aligning with global sustainability objectives. Significant electricity production estimates are observed across these regions ranging from 14 MW to 20 MW. Additionally encouraging annual estimates of hydrogen production varying between 20 and 40 tonnes for specific locations showcase the potential of this approach. The system’s performance demonstrates promising efficiency rates ranging from 13% to 18% while maintaining competitive production costs. These findings underscore the ability of oceanic energy-driven green hydrogen to diversify Morocco’s energy portfolio bolster water resilience and foster sustainable development. Ultimately this research lays the groundwork for comprehensive energy policies and substantial infrastructure investments positioning Morocco on a trajectory towards a decarbonized future powered by innovative and clean technologies.

Sustainable hydrogen production is key to achieving zero-emission targets and a hydrogen-based economy. Hydrogen production methods vary in terms of resource technology and system efficiency. This work analyzes the thermodynamics of fourteen hydrogen production pathways using Gibbs free energy minimization to examine the effects of pressure (1–60 bar) temperature (100–1000 ◦C) and feed composition using reactant conversion and product selectivity as key indicators of reaction performance. The impact of simultaneous reactions on hydrogen production is also discussed. From the results full conversion (100 %) independent of parameter variations at 1 bar pressure was observed for biomass gasification and steam reforming of glycerol methanol ethanol and bio-oil reactions. However H2 selectivity in all tested reactions except for NH3 dissociation and the splitting of water and H2S is greatly affected by side reactions. Finally the thermodynamic results of all reactions are compared and validated with published experiments followed by an evaluation of the challenges and opportunities in hydrogen production. The study provides optimal reaction parameters and a comprehensive comparison of H2 production processes aiding in designing and developing processes based on regional resource availability. Additionally it highlights the potential for both local and remote hydrogen production pathways from various renewable energy sources.

The electrocatalytic seawater splitting has become an important and necessary way for large-scale hydrogen production with challenges ahead. In this review a brief introduction to the reaction mechanism of seawater electrocatalytic process is first provided including the cathodic hydrogen evolution reaction and the anodic oxygen evolution reaction as well as the competitive chloride evolution reaction. Recent progress in transition metal phosphides-based catalysts for seawater electrolysis such as phosphorus doped transition metals binary metal phosphides and structural engineering are then evaluated and discussed. Finally the challenges and opportunities of transition metal phosphides are proposed and discussed.

Hydrogen produced using renewable energy from offshore wind provides a versatile method of energy storage and power-to-gas concepts. However few dedicated floating offshore electrolyser facilities currently exist and therefore conditions of the offshore environment on hydrogen production cost and efficiency remain uncertain. Therefore this review focuses on the conversion of electrical energy to hydrogen using water electrolysis located in offshore areas. The challenges associated with the remote locations fluctuating power and harsh conditions are highlighted and recommendations for future electrolysis system designs are suggested. The latest research in polymer electrolyte membrane alkaline and membraneless electrolysis are evaluated in order to understand their capital costs efficiency and current research status for achieving scaled manufacturing to the GW scale required in the next three decades. Operating fundamentals that govern the performance of each device are investigated and future recommendations of research specifically for the integration of water electrolysers with offshore wind turbines is presented.

The application of hydrogen energy produced by proton exchange membrane electrolyzer (PEMEC) is conducive to the solution of the greenhouse effect and the energy crisis. In order to understand the development trends and research hotspot of PEMEC in recent years a total of 1874 research articles related to this field from 2003 to 2023 were obtained from the Web of Science Core Collection (WoS CC) database. The visualization software VOSviewer is used for bibliometric analysis and the research progress hotspots and trends in the PEMEC field are summarized. It was found that in the past two decades literature in the PEMEC field has shown a trend of stable increase at first and then rapidly increasing. And it is in a stage of rapid growth after 2021.Renewable Energy previously published research articles related to PEMEC with the highest frequency of citations. There are a total of 6128 researchers in this field but core authors only account for 4.5% of the total. Although China entered this field later than the United States and Canada it has the largest number of research articles. The research results provide a comprehensive overview of various aspects in the PEMEC field which is beneficial for researchers to grasp the development hotspots of PEMEC.

Chemical looping dry reforming of methane (CLDRM) using perovskites as a catalyst is considered a promising option for producing hydrogen from biogas. In this work the life-cycle performance of a system compiling a CLDRM unit paired with a water gas shift unit a pressure swing adsorption unit and a combined cycle scheme to provide steam and electricity was assessed. The main data needed to reflect the behavior of the reforming reaction was obtained experimentally and implemented in an Aspen Plus® simulation. Inventory data was obtained through process simulation and used to assess the environmental performance of the process in terms of carbon footprint acidification freshwater eutrophication ozone depletion photochemical ozone formation and depletion of minerals and metals. Overall the environmental viability of the production of green hydrogen from biogas was found to be heavily dependent on the biogas leakage in anaerobic digestion plants. The CLDRM system was benchmarked against a conventional DRM implementation for the same feedstock. While the conventional DRM plant environmentally outperformed the perovskite-based CLDRM the latter might present advantages from an implementation point of view.

Water splitting is an effective strategy to produce renewable and sustainable hydrogen energy. Especially seawater splitting avoiding use of the limited freshwater resource is more intriguing. Nowadays electrocatalysts explored for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using natural seawater or saline electrolyte have been increasingly reported. To better understand the current status and challenges of the electrocatalysts for HER and OER from seawater we comprehensively review the recent advances in electrocatalysts for seawater splitting. The fundamentals challenges and possible strategies for seawater splitting are firstly presented. Then the recently reported electrocatalysts that explored for HER and OER from seawater are summarized and discussed. Finally the perspectives in the development of high-efficient electrocatalysts for seawater splitting are also proposed.

The decarbonization of industry heating and transportation is a major challenge for many countries’ energy transition. Hydrogen is a direct low-carbon fuel alternative to natural gas offering a higher flexibility in the range of possible applications yet currently most hydrogen is produced using carbonintensive steam methane reforming due to cost considerations. Therefore this study explores the economics of a prominent low-carbon method of hydrogen production comparing the cost of hydrogen generation from offshore wind farms with and without grid electricity imports to conventional hydrogen production methods. A novel techno-economic model for offshore electrolysis production costs is presented which makes hydrogen production fully dispatchable leveraging geological salt-cavern storage. This model determines the lifetime costs aportioned across the system components as well as the Levelized Cost of Hydrogen (LCOH). Using the United Kingdom as a case study LCOH from offshore wind power is calculated to be €8.68 /kgH2 using alkaline electrolysis (AEL) €10.49 /kgH2 using proton exchange membrane electrolysis (PEMEL) and €10.88 /kgH2 with grid electricity to backup the offshore wind power. A stochastic Monte-Carlo model is used to asses the uncertainty on costs and identify the cost of capital electrolyser and wind farm capital costs and cost of electricity as the most important drivers of LCOH across the different scenarios. Reducing the capital cost to comparative levels observed on today’s wind farms alone could see AEL LCOH fall to €5.32 /kgH2 near competitive with conventional generation methods.

This study presents a comprehensive 4E (energy exergy economic and exergo-environmental) analysis of a solar-powered multi-generation system (MGS) that integrates parabolic trough collectors (PTCs) thermal energy storage (TES) an organic Rankine cycle (ORC) an absorption refrigeration cycle (ARC) a proton exchange membrane electrolyzer (PEME) and a reverse osmosis (RO) unit to simultaneously produce electricity cooling potable water and hydrogen. A complete thermodynamic model is developed in Engineering Equation Solver (EES) to evaluate the system from technical economic and environmental perspectives. Results indicate that the MGS can convert solar energy into multiple outputs with energy and exergy efficiencies of 12.2% and 4.3% respectively. The highest and lowest energy efficiencies are found in PEME (58.6%) and ORC (7.4%) while the highest and lowest exergy efficiencies are related to PEME (57.4%) and PTC (11.9%) respectively. Despite notable environmental impacts from the complex subsystems (particularly PTC and PEME) the system demonstrates strong economic performance with a net present value of approximately USD 8 million an internal rate of return of 30% and a payback period of 3.8 years. Sensitivity analysis shows that increasing solar radiation reduces the number of required PTCs and shortens payback time with less effect on energy and exergy efficiencies due to increased thermal and radiative losses.

Hydrogen has attracted growing research interest due to its exceptionally high energy per mass content and being a clean energy carrier unlike the widely used hydrocarbon fuels. With the possibility of long-term energy storage and re-electrification hydrogen promises to promote the effective utilization of renewable and sustainable energy resources. Clean hydrogen can be produced through a renewable-powered water electrolysis process. Although alkaline water electrolysis is currently the mature and commercially available electrolysis technology for hydrogen production it has several shortcomings that hinder its integration with intermittent and fluctuating renewable energy sources. The proton exchange membrane water electrolysis (PEMWE) technology has been developed to offer high voltage efficiencies at high current densities. Besides PEMWE cells are characterized by a fast system response to fluctuating renewable power enabling operations at broader partial power load ranges while consistently delivering high-purity hydrogen with low ohmic losses. Recently much effort has been devoted to improving the efficiency performance durability and economy of PEMWE cells. The research activities in this context include investigations of different cell component materials protective coatings and material characterizations as well as the synthesis and analysis of new electrocatalysts for enhanced electrochemical activity and stability with minimized use of noble metals. Further many modeling studies have been reported to analyze cell performance considering cell electrochemistry overvoltage and thermodynamics. Thus it is imperative to review and compile recent research studies covering multiple aspects of PEMWE cells in one literature to present advancements and limitations of this field. This article offers a comprehensive review of the state-of-the-art of PEMWE cells. It compiles recent research on each PEMWE cell component and discusses how the characteristics of these components affect the overall cell performance. In addition the electrochemical activity and stability of various catalyst materials are reviewed. Further the thermodynamics and electrochemistry of electrolytic water splitting are described and inherent cell overvoltage are elucidated. The available literature on PEMWE cell modeling aimed at analyzing the performance of PEMWE cells is compiled. Overall this article provides the advancements in cell components materials electrocatalysts and modeling research for PEMWE to promote the effective utilization of renewable but intermittent and fluctuating energy in the pursuit of a seamless transition to clean energy.

The global push for clean hydrogen production has identified nuclear energy particularly high-temperature gas-cooled reactors (HTGRs) as a promising solution due to their ability to provide high-temperature heat. This study conducted a techno-economic analysis of hydrogen production in Saudi Arabia using the pebble bed modular reactor (HTRPM) focusing on two methods: high-temperature steam electrolysis (HTSE) and the sulfur– iodine (SI) thermochemical cycle. The Hydrogen Economic Evaluation Program (HEEP) was used to assess the economic viability of both methods considering key production factors such as the discount rate nuclear power plant (NPP) capital cost and hydrogen plant efficiency. The results show that the SI cycle achieves a lower levelized cost of hydrogen (LCOH) at USD 1.22/kg H2 compared to HTSE at USD 1.47/kg H2 primarily due to higher thermal efficiency. Nonetheless HTSE offers simpler system integration. Sensitivity analysis reveals that variations in the discount rate and NPP capital costs significantly impact both production methods while hydrogen plant efficiency is crucial in determining overall economics. The findings contribute to the broader discourse on sustainable hydrogen production technologies by highlighting the potential of nuclear-driven methods to meet global decarbonization goals. The paper concludes that the HTR-PM offers a viable pathway for large-scale hydrogen production in Saudi Arabia aligning with the Vision 2030 objectives.

This paper reports on the experimental data analysis and numerical results carried out by algorithms in order to meet the provisions of Industry 4.0 in the field of research of Solid Oxide Fuel Cell/Electrolyzer. A performance mapping of the analyzed SOFC/SOE systems is developed in order to enhance system efficiency when it is fed by biofuels. The analyses concern the main operative parameters such as pressure temperature fuel compositions and other main system parameters such as fuel and oxidant utilization factors and the recirculation of anode exhaust stream gas.

Despite Iran’s considerable renewable energy (RE) potential and excellent wind capacity and high solar radiation levels these sources contribute only a small fraction of the country’s total energy production. This paper addresses the techno-economic viability of gray hydrogen production by these renewables with a particular focus on solar energy. Given the considerable potential of solar energy and the strategic location of Shahrekord it would be an optimal site for a hydrogen generation plant integrated with a solar field. HOMER Pro 3.18.3 software was utilized to model and optimize the levelized cost of hydrogen (LCOH) of steam reforming using different hydrocarbons in various scenarios. The results of this study indicate that natural gas (NG) reforming represents the most cost-effective method of gray hydrogen production in this city with an LCOH of −0.423 USD/kg. Other hydrocarbons such as diesel gasoline propane methanol and ethanol have a price per kilogram of produced hydrogen as follows: USD −0.4 USD −0.293 USD 1.17 USD 1.48 and USD 2.15. In addition integrating RE sources into hydrogen production was found to be viable. Moreover by implementing RE technologies CO2 emissions can be significantly reduced and energy security can be achieved.

Methanol which can be derived from sustainable energy sources such as biomass solar power and wind power is widely considered an ideal hydrogen carrier for distributed and mobile hydrogen production. In this study a comprehensive comparison of the thermodynamic and techno-economic performance of the aqueous phase reforming (APR) and steam reforming (SR) of methanol was conducted using Aspen Plus and CAPCOST software to evaluate the commercial feasibility of the APR process. Thermodynamic analysis based on the Gibbs free energy minimization method reveals that while APR and SR have similar energy demands APR achieves higher energy efficiency by avoiding losses from evaporation and compression. APR typically operates at higher pressures and lower temperatures compared to SR suppressing CO formation and increasing hydrogen fraction but reducing methanol single-pass conversion. A techno-economic comparison of APR and SR for a distributed hydrogen production system with a 50 kg/h hydrogen output shows that although APR requires higher fixed operating costs and annual capital charges it benefits from lower variable operating costs. The minimum hydrogen selling price for APR was calculated to be 7.07 USD/kg compared to 7.20 USD/kg for SR. These results suggest that APR is a more economically viable alternative to SR for hydrogen production.