Hydrogen Production Potential Research Articles

Coordinated planning for offshore wind and electricity–hydrogen system based on SDDP: A case study of coastal provinces in China

The coordinated development of offshore wind and electricity–hydrogen systems (OW-EHS) has the potential to enhance the utilization of renewable energy sources and achieve carbon neutrality. This article presents a case study of nine coastal provinces in China and designs four scenarios to analyze the economic benefits and potential hydrogen production capacity of OW-EHS. A multi-stage stochastic dual dynamic programming based approach is proposed for integrating OW-EHS, exploring offshore wind energy as both a primary electricity source for coastal regions and a clean, sustainable energy source for electrolyzers. It accounts for variations in hydrogen demand, wind uncertainty, load profiles, and electricity price dynamics, offering a holistic perspective on the feasibility and benefits of collaborative offshore wind and electricity–hydrogen systems. A comparative analysis highlights the effectiveness of the proposed planning approach, demonstrating its capacity to maximize the overall system benefits, encompassing both the optimal levelized cost of energy and hydrogen production. The new discoveries elucidate the unique attributes and advantages of each coastal province in OW-EHS. This research provides a tailored blueprint for coastal provinces in China to harness their offshore wind potential and accelerate progress towards carbon neutrality.

Hydrogen generation via NaBH4 hydrolysis over cobalt-modified niobium oxide catalysts

The increasing concentration of CO₂ in the atmosphere, primarily driven by fossil fuel combustion, is a major contributor to global warming and one of the most pressing environmental challenges of the 21st century. In response, the development of sustainable energy technologies, such as hydrogen (H₂) production, has become crucial in the global transition to a low-carbon economy. In this study, we explored the catalytic activity of cobalt-modified niobium-based catalysts for hydrogen generation through the hydrolysis of NaBH₄. The catalysts were characterized using XRD, FTIR, XPS, SEM-EDX, and N₂ adsorption-desorption. XRD analysis revealed that the synthesized Nb₂O₅ (Nb₂O₅ Synt.) and Nb₂O₅/Co (Nb₂O₅/Co Synt.) exhibited amorphous structures, while the commercial Nb₂O₅ (Nb₂O₅ Com.) and its Co-modified composite displayed orthorhombic phases. The Nb₂O₅/Co Synt. catalyst achieved a surface area of 33.1 m2/g, significantly surpassing that of the commercial Nb₂O₅. The Nb₂O₅/Co Synt. catalyst exhibited superior catalytic activity, yielding 250 mL of hydrogen in 60 min, in contrast to other catalysts that showed no activity under identical conditions. This enhanced activity was attributed to the presence of surface hydroxyl groups and metallic Co nanoparticles, following the Langmuir-Hinshelwood bimolecular mechanism. Temperature was identified as a critical factor in the H₂ production rate, with a calculated activation energy of 11.37 kJ/mol. Moreover, the Nb₂O₅/Co Synt. catalyst demonstrated excellent reusability, maintaining stable performance after multiple reaction cycles, highlighting its potential for sustainable hydrogen production.

Cutting-Edge PCN-ZnO Nanocomposites with Experimental and DFT Insights into Enhanced Hydrogen Evolution Reaction.

Polymeric carbon nitride (PCN) and PCN-ZnO nanocomposites are promising candidates for catalysis, particularly for hydrogen evolution reactions (HER). However, their catalytic efficiency requires enhancement to fully realize their potential. This study aims to improve the HER performance of PCN by synthesizing PCN-ZnO nanocomposites using melamine as a precursor. Two synthesis methods were employed: thermal condensation (Method 1) and liquid exfoliation (Method 2). Method 1 resulted in a composite with a 2.44 eV energy gap and reduced particle size, with significantly enhanced performance as a bifunctional electrocatalyst for simultaneous hydrogen and oxygen production. In contrast, Method 2 produced a nanocomposite with an enhanced surface area and a minor alteration in the band gap. In alkaline electrolytes, the PCN-ZnO0.4 nanocomposite synthesized with Method 1 exhibited high HER performance with an overpotential of 281 mV, outperforming pristine PCN (382 mV) and ZnO (302 mV), along with improved oxygen evolution reaction (OER) activity. Further analysis in a two-electrode alkaline electrolyzer using PCN-ZnO0.4 nanocomposite as both the anode and cathode demonstrated its promise as a bifunctional electrocatalyst. Density functional theory (DFT) calculations explained the enhanced catalytic activity of the PCN-ZnO nanocomposite, confirming that hydrogen evolution occurs through the Heyrovsky process, consistent with experimental results. Notably, the solar-to-hydrogen (STH) efficiency of the PCN-ZnO nanocomposite was four times greater, at 21.7% compared to 5.2% for the PCN monolayer, underscoring its potential for efficient solar-driven hydrogen production. This work paves the way for future advancements in the design of high-performance electrocatalysts for sustainable energy applications.

A joint Cournot equilibrium model for the hydrogen and electricity markets

Hydrogen production through renewable energy-powered electrolysis is pivotal for fostering a sustainable future hydrogen market. In the electricity sector, hydrogen production bears an additional demand that affects electricity price, and mathematical models are needed for the joint simulation, analysis, and planning of electricity and hydrogen sectors. This study develops a Cournot and a perfect competition model to analyze the links of the electricity and hydrogen sectors. In contrast to other solving methods approaches, the Cournot model is solved by convex reformulation techniques, substantially easing the resolution. The case studies, focusing on the Iberian Peninsula, demonstrate the region's potential for competitive hydrogen production, and the advantages of perfect competition to maximize the use of renewable energies, in contrast to Cournot's oligopoly, where the exercise of market power raises electricity prices. Sensitivity analyses highlight the importance of strategic decision-making in mitigating market inefficiencies, with valuable insights for stakeholders and policymakers.

Tuning the photocatalytic performance of halide perovskites for efficient solar hydrogen production: A DFT study of CsGeCl3-xXx (X= Br, I)

Photoelectrochemical water splitting holds immense potential for sustainable hydrogen production to address mounting energy demands. However, the development of efficient and cost-effective photocatalysts remains a significant challenge. Perovskites, recognized for their cost-effectiveness and tunable characteristics, show potential as viable candidates in this context. Our investigation is the first to mark the photocatalytic efficacy of CsGeCl3. The findings reveal a modest solar-to-hydrogen (STH) efficiency of 0.74 % due to its wide bandgap energy. Halide mixing with iodine and bromine significantly improves the STH efficiencies, reaching approximately 8.47 %. In addition, applying uniaxial compressive stress further boosts the efficiency to 14.6 %. In this study, we employed the density functional theory (DFT) through the WIEN2k software to scrutinize the structural, electronic, optical, photocatalytic, and thermoelectric properties of all the studied structures. Furthermore, the study evaluated the compounds' capacity for CO2 photoreduction, susceptibility to degradation, and the influence of pH on their photocatalytic performance. The insights gained from this work contribute to the development of efficient and cost-effective perovskite-based photocatalysts for renewable hydrogen production.

Unlocking development of green hydrogen production through techno-economic assessment of wind energy by considering wind resource variability: A case study

Generating hydrogen from renewable energy sources is widely recognized as an effective strategy for addressing critical challenges in the energy sector while contributing to the reduction of greenhouse gas emissions. This study aims to assess the wind energy potential for electricity and hydrogen production in five locations on Sumba Island using 10 years (2011–2020) of data from the NASA's POWER Project. A wind variability assessment was performed on five wind turbines ranging from 500 kW to 1.5 MW and using electrolysis technology. The results indicated a hydrogen production potential of 25–57 tons per year. Economic analysis of hydrogen production for Haharu reveals an attractive internal rate of return (IRR) of 43% with a payback period (PBP) of 2.25 years and a net present value (NPV) of 1.3 MM USD, the levelized cost of electricity (LCOE) of 0.0241 USD/kWh, and the levelized cost of Hydrogen (LCOH) of 1.01 USD/kg. Sensitivity analysis underscores the critical influence of investment and revenue on project profitability, highlighting their substantial impact on determining a project's success or failure. These findings emphasize the potential of Sumba Island as a hub for sustainable energy production to meet the growing demand for clean and renewable energy sources.

Future pathways for green hydrogen: Analyzing the nexus of renewable energy consumption and hydrogen development in Chinese cities

Hydrogen energy offers a promising pathway for achieving zero-carbon urban energy consumption. This study quantitatively analyzes the patterns of hydrogen energy development and its linked to electricity consumption in China's urban areas. It investigates the spatial relationships between hydrogen energy expansion, the potential for green hydrogen production, and overall energy use. Utilizing a coupling coordination degree (CCD) model and a panel vector autoregressive (PVAR) model, the research explores the dynamic interactions between urban hydrogen energy development and the transition to renewable energy sources. In line with Chinese government policy, the study also conducts a scenario analysis of green hydrogen production by 2030, proposing a consumption strategy that balances environmental sustainability with economic growth. The key conclusions are as follows: (1) There is a spatial mismatch between the locations where hydrogen energy is being developed and where the potential for green hydrogen production is greatest. Cities with higher electricity consumption demonstrate stronger synergies in the coordinated development of hydrogen and renewable energy. (2) The development of hydrogen energy significantly accelerates the transition to renewable energy consumption in urban areas, with this impact being more substantial than that of the utilization capacity alone. (3) Hydrogen production in the Plan Scenario is significantly higher than in the Pessimistic Scenario, underscoring the critical importance of implementing renewable hydrogen projects in provinces with high production potential. Future trends in green hydrogen consumption at the provincial level indicate that addressing the challenges of efficient inter-provincial transportation of hydrogen energy remains essential.

Evaluation of Green and Blue Hydrogen Production Potential in Saudi Arabia

The Kingdom of Saudi Arabia has rich renewable energy resources, specifically wind and solar in addition to geothermal beside massive natural gas reserves. This paper investigates the potential of both green and blue hydrogen production for five selected cities in Saudi Arabia. To accomplish the said objective, a techno-economic model is formulated. Four renewable energy scenarios are evaluated for a total of 1.9 GW installed capacity to reveal the best scenario of Green Hydrogen Production (GHP) in each city. Also, Blue Hydrogen Production (BHP) is investigated for two cases of Steam Methane Reforming (SMR) with different percentages of carbon capture. The two BHP scenarios were compared with a base case scenario of hydrogen production from natural gas without CCS/U (gray hydrogen). The economic analysis for both GHP and BHP is performed by calculating the Levelized Cost of Hydrogen (LCOH) and cash flow. The LCOH for GHP range for all cities ($3.27/kg–$12.17/kg)) with the lowest LCOH is found for NEOM city (50% PV and 50% wind) ($3.27/kg). LCOH for the three SMR cases are $0.534/kg, $0.647/kg, and $0.897/kg for SMR wo CCS/U, SMR 55% CCS/U, and SMR 90% CCS/U respectively.

Uniform carbon pillars array grown on boron doped diamond for high-performance supercapacitors and hydrogen evolution reactions

Carbon materials have marvelous ability in energy storage and microelectronics as a result of the high specific surface area and electrical conductivity. However, the low stability and the low power density caused by low potential window make it particularly difficult for their application in aqueous electrolysis. In this study, boron doped diamond (BDD) with wide potential window is used as substrate and Ni as catalyst to grow uniform carbon pillars (CP) by microwave plasma chemical vapor deposition method. The composite structure (CP/BDD) yields significant specific capacity (91.64 mF cm−2 at 0.1 mA cm−2) and cycling stability (92.3 % retention rate after 20,000 cycles) when used as the electrode of supercapacitors, superior to most of BDD-based electrodes. The prepared symmetrical supercapacitor devices maintain their excellent electrochemical performance characteristics (power density of 4.4 mW cm−2 and energy density of 13.4 μW h cm−2), as well as high cycling stability. In addition, the electrode has considerable application potential in electrochemical hydrogen production with low hydrogen evolution potential and small Tafel slope value. These results illustrate the potential of BDD based composites for using as energy storage electrodes for electronic products and energy conversion equipment.

Unlocking Efficient Alkaline Hydrogen Evolution Through Ru-Sn Dual Metal Sites and a Novel Hydroxyl Spillover Effect.

Alkaline hydrogen evolution reaction (HER) has great potential in practical hydrogen production but is still limited by the lack of active and stable electrocatalysts. Herein, the efficient water dissociation process, fast transfer of adsorbed hydroxyl and optimized hydrogen adsorption are first achieved on a cooperative electrocatalyst, named as Ru-Sn/SnO2 NS, in which the Ru-Sn dual metal sites and SnO2 heterojunction are constructed based on porous Ru nanosheet. The density functional theory (DFT) calculations and in situ infrared spectra suggest that Ru-Sn dual sites can optimize the water dissociation process and hydrogen adsorption, while the existence of SnO2 can induce the unique hydroxyl spillover effect, accelerating the hydroxyl transfer process and avoiding the poison of active sites. As results, Ru-Sn/SnO2 NS display remarkable alkaline HER performance with an extremely low overpotential (12mV at 10mA cm-2) and robust stability (650h), much superior to those of Ru NS (27mV at 10mA cm-2 with 90h stability) and Ru-Sn NS (16mV at 10mA cm-2 with 120h stability). The work sheds new light on designing of efficient alkaline HER electrocatalyst.

Evaluating the techno-economic potential of large-scale green hydrogen production via solar, wind, and hybrid energy systems utilizing PEM and alkaline electrolyzers

The study evaluates the potential of solar, wind, and hybrid PV/WT renewable energy systems for green hydrogen production in four Iraqi cities. Through a comparative analysis of six distinct scenarios involving the deployment of 60 MWp solar panels, 30 MWp wind turbines, and 45 MWp hybrid PV/WT systems, the research aims to ascertain the most energy-efficient and cost-effective strategy for hydrogen generation. This evaluation is aligned with the operational capacities of two types of water electrolyzers: Alkaline (AWE) and proton exchange membrane (PEM), each with a 17.5 MWp capacity. Employing the HOMER Pro software for system simulation and optimization, and considering a project timeline from 2022 to 2042, the study identifies Anbar City as the prime location for green hydrogen production, highlighting solar PV panels as the most economical option with the lowest levelized cost of energy at US $4.5/MWh. The analysis further demonstrates that hydrogen production costs are US $1.98/kg for AWE electrolyzers and US $2.72/kg for PEM electrolyzers, with net present costs of US $26.31 million and US $35.91 million, respectively. Moreover, the annual hydrogen output is estimated at 1.11 million kg for AWE and 1.19 million kg for PEM electrolyzers. These insights significantly contribute to the strategic planning and development of Iraqi green hydrogen sector, offering a valuable framework for policymakers and stakeholders invested in sustainable energy transitions.

Potentials of Green Hydrogen Production in P2G Systems Based on FPV Installations Deployed on Pit Lakes in Former Mining Sites by 2050 in Poland

Green hydrogen production is expected to play a major role in the context of the shift towards sustainable energy stipulated in the Fit for 55 package. Green hydrogen and its derivatives have the capacity to act as effective energy storage vectors, while fuel cell-powered vehicles will foster net-zero emission mobility. This study evaluates the potential of green hydrogen production in Power-to-Gas (P2G) systems operated in former mining sites where sand and gravel aggregate has been extracted from lakes and rivers under wet conditions (below the water table). The potential of hydrogen production was assessed for the selected administrative unit in Poland, the West Pomerania province. Attention is given to the legal and organisational aspects of operating mining companies to identify the sites suitable for the installation of floating photovoltaic facilities by 2050. The method relies on the use of GIS tools, which utilise geospatial data to identify potential sites for investments. Basing on the geospatial model and considering technical and organisational constraints, the schedule was developed, showing the potential availability of the site over time. Knowing the surface area of the water reservoir, the installed power of the floating photovoltaic plant, and the production capacity of the power generation facility and electrolysers, the capacity of hydrogen production in the P2G system can be evaluated. It appears that by 2050 it should be feasible to produce green fuel in the P2G system to support a fleet of city buses for two of the largest urban agglomerations in the West Pomerania province. Simulations revealed that with a water coverage ratio increase and the planned growth of green hydrogen generation, it should be feasible to produce fuel for net-zero emission urban mobility systems to power 200 buses by 2030, 550 buses by 2040, and 900 buses by 2050 (for the bus models Maxi (40 seats) and Mega (60 seats)). The results of the research can significantly contribute to the development of projects focused on the production of green hydrogen in a decentralised system. The disclosure of potential and available locations over time can be compared with competitive solutions in terms of spatial planning, environmental and societal impact, and the economics of the undertaking.

STUDY THE POTENTIAL OF CYANOBACTERIA - ANABAENA VARIABILIS A-1 IN BIOHYDROGEN PRODUCTION

The production of biohydrogen by phototrophic microorganisms is a promising and complex biotechnology that can contribute to reducing greenhouse gas emissions. However, achieving successful biohydrogen production requires identifying active strains with the required characteristics and selecting suitable strategies for improving strains for photobiotechnological hydrogen production. In this study, our aim was to identify promising hydrogen producers among cyanobacteria and understand the mechanisms of this process and the conditions for increasing hydrogen production. We obtained five new strains of cyanobacteria from different ecosystems and evaluated their potential for hydrogen production. Based on our screening, we identified the cyanobacterium Anabaena variabilis A-1 as having the highest growth rate and biomass yield, which determined its high productivity. We subsequently genetically identified and studied the physiological and biochemical properties of this strain to determine its potential for hydrogen production. Our results showed that Anabaena variabilis A-1 was characterized by high productivity, nitrogenase enzyme activity, and hydrogen release, producing 8.67 μmol H2/mg chl/h of hydrogen in the dark. We also found that this strain released hydrogen 3.7 times more in the dark than in the light, and hydrogen production was observed in the first day after anaerobic cultivation. Addition of 50 mmol NaHCO3 + 25 mmol HEPES to this strain increased hydrogen release by 1.1 times. In conclusion, our study identified Anabaena variabilis A-1 as a promising cyanobacteria strain for biohydrogen production. Its high productivity, nitrogenase enzyme activity, and genetic manipulability make it a suitable model organism for studying various physiological processes and metabolic pathways in photosynthetic cells. We recommend further studies to explore the full potential of this strain for future biohydrogen production.

Harnessing solar energy for sustainable green hydrogen production in Türkiye: Opportunities, and economic viability

Hydrogen emerges as a promising solution for Türkiye, offering opportunities to enhance renewable energy production and reduce greenhouse gas emissions. Türkiye has significant potential for green hydrogen production, leveraging its abundant renewable energy resources and lower installation costs for renewable energy-based power plants.This study assesses the impact of capital expenditure (CAPEX) on the Levelized Cost of Hydrogen (LCOH) in Türkiye, focusing on both current and projected costs. The LCOH ranges from $3.79/kgH2 to $5.11/kgH2 for low and high CAPEX scenarios, given Türkiye's solar electricity cost of $40.32/MWh in 2024. Looking ahead to 2035, achieving Türkiye's hydrogen cost target of $2.4/kgH2 will require reducing electricity costs to $31/MWh for low CAPEX and $15.3/MWh for high CAPEX. The current electricity cost of $40.3/MWh is significantly above these targets, highlighting the need for substantial technological advancements and cost-reduction strategies to meet future economic objectives for sustainable hydrogen production.

Assessing hydrogen production potential from carbonate and shale source rocks: A geochemical investigation

The global push towards achieving net-zero carbon dioxide emissions by 2050 shows the urgency of transitioning to a hydrogen-based economy, with clean hydrogen fuel emerging as a fundamental component of future energy consumption. This study explores hydrogen production from geological sources, specifically organic-rich Shale and Carbonate mudrocks, as a significant and sustainable method for natural hydrogen production. Recognizing the critical challenge posed by the interaction of hydrogen with rock-forming minerals and organic matter during production, this research emphasizes the need for a comprehensive understanding of the geochemical composition of these rock materials. To assess the feasibility and implications of utilizing organic-rich source rocks for hydrogen production, we conducted thorough analyses of source rock samples from different formations. The representatives’ samples were subjected to comprehensive analyses including Rock-Eval pyrolysis, X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM) examinations, and gas chromatography (GC) analysis of the produced gas. Our results revealed that the high total organic carbon (TOC) samples (average 14.7 %) with Type I and II kerogens yielded substantial hydrogen-rich gases, approximately 44.71 % and 36.02 % for SH-O1 and JOS samples, respectively. JOS produced slightly higher hydrocarbon gases (∼50 %) compared to SH-O1 (∼45 %), along with more H2S (5.78 %), due to higher total sulfur content. In contrast, the SH-C1 sample, characterized by very low TOC (0.27 %), predominantly quartz and muscovite minerals (>78 %), and Type IV kerogen, produced higher CO2 (22.09 %) and minimal hydrogen (1.27 %), highlighting the influence of mineralogical and geochemical composition. This study suggests that hydrocarbon source rocks with high organic matter content hold significant potential for maximizing energy gas recovery (>85 %, including hydrogen and hydrocarbons) through the pyrolysis of their kerogen content. These findings demonstrate the viability of hydrogen gas production from unconventional sources such as organic-rich shales, potentially impacting strategies for sustainable energy production and contributing significantly to global decarbonization efforts.

Optimizing power output in direct formic acid fuel cells using palladium film mediation: experimental and DFT studies

Low-temperature hydrogen production from environmentally friendly liquid fuels such as methanol, ethanol, and formic acid for miniature fuel cells used in powering portable electronic devices is attracting reasonable attention. In this study, we present the findings from the decomposition of formic acid and subsequent power generation within a microfluid fuel cell. The fuel cell system was engineered to incorporate a palladium membrane at the anode and a modified carbon Torray paper at the cathode. To assess fuel cell performance, we employed chronopotentiometry and cyclic voltammetric electro­chemical techniques. This simple fuel cell could achieve a current peak of 3.17 µW by utilizing 2.50 M HCOOH solution and 2.26 µW with 0.1 M solution, all at room temperature. Finally, to provide a deeper understanding of the reactivity and HCOOH decomposition pathways on various palladium surfaces, we conducted density functional theory (DFT) studies. Our DFT investigations revealed that the Pd(111) surface exhibited more negative adsorption energy compared to other surfaces, suggesting its propensity for a more isomeric crystal morphology. This research underscores the promising potential of low-temperature hydrogen production using safe liquid fuels in microfuel cell applications for portable electronic devices.

A novel Al/BiCl3/γ-Al2O3 composite for small-sized fuel cell: Fabrication, performance and mechanisms

Small-sized fuel cell is an ideal and promising power source for portable devices due to its long-term electricity supply and free of CO2 emission. However, its commercialization is obstructed by reliable hydrogen source, which should be non-corrosiveness, as compact as possible, stable and controllable high purity hydrogen supply. In this study, a novel in situ hydrogen production material Al/BiCl3/γ-Al2O3 composite is synthesized, which exhibits high hydrogen yield, fast hydrogen production rate and outstanding storage stability. The hydrogen production performance of Al/BiCl3/γ-Al2O3 can be adjusted by changing BiCl3:γ-Al2O3 weight ratio, additive content and milling time. XRD and SEM results indicate that surface cracks, active surface and metal Bi produced in fabrication process lead to the high hydrolysis activity of Al/BiCl3/γ-Al2O3. Mechanism analyses reveal that hydrogen production process is the results of pitting, microgalvanic effect and catalytic effect. Taking into account hydrogen production performance, capacity and cost, Al/5 wt%BiCl3/5 wt%γ-Al2O3 milled for 2 h is a potential hydrogen production material, which can in situ supply hydrogen for small-sized fuel cell.

Hydrogen Production from Wave Power Farms to Refuel Hydrogen-Powered Ships in the Mediterranean Sea

The maritime industry is a major source of greenhouse gas (GHG) emissions, largely due to ships running on fossil fuels. Transitioning to hydrogen-powered marine transportation in the Mediterranean Sea requires the development of a network of hydrogen refueling stations across the region to ensure a steady supply of green hydrogen. This paper explores the technoeconomic viability of harnessing wave energy from the Mediterranean Sea to produce green hydrogen for hydrogen-powered ships. Four promising island locations—near Sardegna, Galite, Western Crete, and Eastern Crete—were selected based on their favorable wave potential for green hydrogen production. A thorough analysis of the costs associated with wave power facilities and hydrogen production was conducted to accurately model economic viability. The techno-economic results suggest that, with anticipated cost reductions in wave energy converters, the levelized cost of hydrogen could decrease to as low as 3.6 €/kg, 4.3 €/kg, 5.5 €/kg, and 3.9 €/kg for Sardegna, Galite, Western Crete, and Eastern Crete, respectively. Furthermore, the study estimates that, in order for the hydrogen-fueled ships to compete effectively with their oil-fueled counterparts, the levelized cost of hydrogen must drop below 3.5 €/kg. Thus, despite the competitive costs, further measures are necessary to make hydrogen-fueled ships a viable alternative to conventional diesel-fueled ships.

Future hydrogen economies imply environmental trade-offs and a supply-demand mismatch

Hydrogen will play a key role in decarbonizing economies. Here, we quantify the costs and environmental impacts of possible large-scale hydrogen economies, using four prospective hydrogen demand scenarios for 2050 ranging from 111–614 megatonne H2 year−1. Our findings confirm that renewable (solar photovoltaic and wind) electrolytic hydrogen production generates at least 50–90% fewer greenhouse gas emissions than fossil-fuel-based counterparts without carbon capture and storage. However, electrolytic hydrogen production could still result in considerable environmental burdens, which requires reassessing the concept of green hydrogen. Our global analysis highlights a few salient points: (i) a mismatch between economical hydrogen production and hydrogen demand across continents seems likely; (ii) region-specific limitations are inevitable since possibly more than 60% of large hydrogen production potentials are concentrated in water-scarce regions; and (iii) upscaling electrolytic hydrogen production could be limited by renewable power generation and natural resource potentials.

Efficient dark-fermentation biohydrogen production by Shigella flexneri SPD1 from biowaste-derived sugars through green solvents approach

This study evaluated the dark-fermentative hydrogen (H2) production potential of isolated and identified Shigella flexneri SPD1 from various pure (glucose, fructose, sucrose, lactose, and galactose) and biowastes (coconut coir, cotton fiber, groundnut shells, rice-, and wheat-straws)-derived sugars. Among sugars, S. flexneri SPD1 exhibited high H2 production of up to 3.20 mol/mole of hexose using glucose (5.0 g/L). The pre-treatment of various biowastes using green solvents (choline chloride and lactic acid mixture) and enzymatic hydrolysis resulted in the generation of up to 36.0 g/L of sugars. The maximum H2 production is achieved up to 2.92 mol/mol of hexose using cotton-hydrolysate. Further, the upscaling of bioprocess up to 5 L of capacity resulted in a maximum yield of up to 3.06 mol/mol of hexose. These findings suggested that S. flexneri SPD1, a novel H2-producer, can be employed to develop a circular economy-based approach to produce clean energy.