India

The current study evaluates the feasibility of a forward osmosis membrane bioreactor (FO-MBR) for dark fermentation aiming at simultaneous biohydrogen production and wastewater treatment. Optimal microbial inoculation was achieved via heat-treated activated sludge enriching Clostridium sensu stricto 1 and yielding up to 2.21 mol H2.(mol hexose)− 1 in batch mode. In continuous operation a substrate concentration of 4.4 g L− 1 and a hydraulic retention time (HRT) of 12 h delivered the best results producing 1.51 mol H2.(mol hexosesupplied) − 1 . The FO-MBR configured with a 1.1 m2 hollow fiber side-stream membrane module and operated under dynamic HRT (2.5–12 h) dependent on membrane flux was integrated with intermittent CSTR (Continuous stirred tank reactor) operation to counter metabolite accumulation. This system outperformed a conventional CSTR achieving a hydrogen yield of 1.78 mol H2.(mol hexosesupplied) − 1 . Remarkable treatment efficiencies were observed with BOD5 COD and TOC removal rates of 95.32 % 99.02 % and 99.10 % respectively and an 83.8 % reduction in total waste volume. Additionally the FO-MBR demonstrated strong antifouling performance with 96.14 % water flux recovery achieved after a brief 5 min hydraulic rinse following 47.5 h of continuous highstrength broth exposure. These results highlight the FO-MBR system’s ability as a sustainable and highperformance alternative for integrated hydrogen production and effluent treatment. Further studies are recommended to address long-term fouling control and metabolite management for industrial scalability.

Green hydrogen (GH2) a sustainable and clean energy carrier is increasingly regarded as a solution to energy challenges and environmental issues. Industrial wastewater possesses a significant potential for hydrogen generation using biological chemical and electrochemical methods. This review analysis evaluates progress in GH2 production from industrial wastewater highlighting its environmental and cost benefits. Process optimization technological improvements and enhancements in catalysts for chemical and electrochemical hydrogen generation are also provided. It also considers the integration of GH2 production methods with wastewater treatment procedures to achieve synergistic benefits including enhanced pollutant removal and energy recovery. Challenges associated with GH2 production include substrate variability economic viability reactor scalability and environmental sustainability are also discussed. Also this review provides a future outlook to promote sustainable energy solutions and tackle global environmental issues related to GH2 from industrial wastewater.

The reliance on hydrogen as part of the transition towards a low-carbon economy will require developing dedicated pipeline infrastructure. This deployment will be shaped by regulatory frameworks governing investment and access conditions ultimately structuring how the commodity is traded. The paper assesses the market design for hydrogen infrastructure assuming the application of unbundling requirements. For this purpose it develops a general economic framework for regulating pipeline infrastructure focusing on asset specificity market power and access rules. The paper assesses the scope of application of infrastructure regulation which can be set to individual pipelines or to entire networks. When treated as entire networks the infrastructure can provide flexibility to enhance market liquidity. However this requires establishing network monopolies which rely on central planning and reduce the overall dynamic efficiency of the sector. The paper further compares the regulation applied to US and EU natural gas pipeline infrastructure. Based on the different challenges faced by the EU hydrogen sector including absence of wholesale concentration and large infrastructure needs the paper draws lessons for a regulatory framework establishing the main building blocks of a hydrogen target model. The paper recommends a review of the current EU regulatory framework in the Hydrogen and Decarbonised Gas Package to enable i) the application of regulation to individual pipelines rather than entire networks; ii) the use of negotiated third-party access light-touch regulation and possibly marketbased coordination mechanisms for the access to the infrastructure and iii) a more significant role for long-term capacity contracts to underpin infrastructure investments.

Hydrogen energy has been proposed as a reliable and sustainable source of energy which could play an integral part in demand for foreseeable environmentally friendly energy. Biomass fossil fuels waste products and clean energy sources like solar and wind power can all be employed for producing hydrogen. This comprehensive review paper provides a thorough overview of various hydrogen storage technologies available today along with the benefits and drawbacks of each technology in context with storage capacity efficiency safety and cost. Since safety concerns are among the major barriers to the broad application of H2 as a fuel source special attention has been paid to the safety implications of various H2 storage techniques. In addition this paper highlights the key challenges and opportunities facing the development and commercialization of hydrogen storage technologies including the need for improved materials enhanced system integration increased awareness and acceptance. Finally recommendations for future research and development with a particular focus on advancing these technologies towards commercial viability.

Metal-organic frameworks (MOFs) have emerged as promising candidates for solid-state hydrogen storage owing to their exceptional specific surface area high pore volume and chemically tunable structural properties. In this work a diverse set of experimentally synthesized MOFs were evaluated to model and predict hydrogen storage capacity (wt%) using 4 key descriptors which are Brunauer–Emmett–Teller (BET) surface area pore volume operating pressure and temperature. Correlation analysis revealed positive associations between BET surface area pressure and pore volume with storage capacity and a negative association with temperature consistent with physisorption mechanism. Six machine learning models were developed: support vector regression (SVR) artificial neural networks (ANN) random forest (RF) Gaussian process regression (GPR) gradient boosting (GB) and a Committee of Expert Systems (CES) integrating all base learners. While GB was the top-performing standalone model the CES delivered the highest predictive fidelity (R2 = 0.9958 MSE = 0.0094) as confirmed by parity plots and residual analysis. SHapley Additive exPlanations (SHAP) corroborated the statistical feature rankings consistently identifying BET surface area and pressure as the most influential positive contributors in alignment with adsorption thermodynamics. Paired t-tests on root-mean-square error (RMSE) values confirmed statistically significant CES improvements over all individual models. The CES framework thus offers a dataefficient accurate and interpretable approach for rapid MOF screening with straightforward adaptability to other porous materials and adsorption-based energy storage systems.

Rapid urbanization and globalization are causing a rise in the energy demand within the residential sector. Currently majority of the energy demand for the residential sector being supplied from fossil fuels these sources account for greenhouse gas emissions responsible for anthropogenic-driven climate change. About 85 % of the world’s energy demands are being met by non-renewable sources of energy. An immediate need to shift towards renewable energy sources to generate electricity is the need of the hour. These long-standing renewable energy sources including solar hydropower and wind energy have been crucial pillars of sustainable energy for years. However as their implementation has matured we are increasingly recognizing their limitations. Issues such as the scarcity of suitable locations and the significant carbon footprint associated with constructing renewable energy infrastructure are becoming more apparent. Hydrogen has been found to play a vital role as an energy carrier in framing the energy picture in the 21st century. Currently about 1 % of the global energy demands are being met by hydrogen energy harnessed through renewable methods. Its low carbon emissions when compared to other methods lower comparative production costs and high energy efficiency of 40–60 % make it a suitable choice. Integrating hydrogen production systems with other renewable source of energy such as solar and wind energy have been discussed in this review in detail. With the concepts of green buildings or net zero energy buildings gaining attraction integration of hydrogen-based systems within residential and office sectors through the use of devices such as micro–Combined Heat and Power devices (mCHP) have proven to be effective and efficient. These devices have been found to save the consumed energy by 22 % along with an effective reduction in carbon emissions of 18 % when used in residential sectors. Using the rejected energy from other processes these mCHP devices can prove to be vital in meeting the energy demands of the residential sector. Through the support of government schemes mCHP devices have been widely used in countries such as Japan and Finland and have benefitted from the same. Hydrogen storage is critical for efficient operation of the integrated renewable systems as improper storage of the hydrogen produced could lead to human and environmental disasters. Using boron hydrides or ammonia (121 kg H2/m3 ) or through organic carriers hydrogen can be stored safely and easily regenerated without loss of material. A thorough comparison of all the renewable sources of energy that are used extensively is required to evaluate the merits of using hydrogen as an energy carrier which has been addressed in this review paper. The need to address the research gap in application of mCHP devices in the residential sector and the benefits they provide has been addressed in this review. With about 2500 GW of energy ready to be harnessed through the mCHP devices globally the potential of mCHP systems globally are discussed in detail in this paper. This review discusses challenges and solutions to hydrogen production storage and ways to implement hydrogen technology in the residential sector. This review allows researchers to build a renewable alternative with hydrogen as a clean energy vector for generating electricity in residential systems.

Green hydrogen is emerging as a key driver in global decarbonization efforts particularly in hard-to-abate sectors such as steel manufacturing ammonia production and long-distance transportation. This study evaluates the techno-economic and environmental aspects of green hydrogen production storage and integration with renewable energy systems. Electrolysis remains the dominant production method with efficiency rates ranging from 70–80% for Alkaline Electrolyzers (AEL) 75–85% for Proton Exchange Membrane Electrolyzers (PEMEL) and up to 90% for Solid Oxide Electrolyzers (SOEL). Capital costs are steadily decreasing with AEL costs falling from $1200/kW in 2018 to $800/kW in 2024 while PEMEL costs are projected to decline to $600/kW by 2030. Green hydrogen significantly reduces carbon emissions with a footprint of 0.5–1 kg CO₂ per kg of H₂ compared to 10–12 kg for gray hydrogen and 1–3 kg for blue hydrogen. Its potential to cut global CO₂ emissions by 6 gigatons annually by 2050 underscores its role in climate action. However its high water demand—approximately 9 liters per kilogram of hydrogen—necessitates efficient management strategies such as desalination and recycling. Economically green hydrogen is becoming more competitive with its levelized cost decreasing from $6/kg in 2018 to $3–4/kg in 2024 and projections indicating a further drop to $1.50/kg by 2030. Global investments exceeding $500 billion in 2024 along with major projects like Saudi Arabia's NEOM Green Hydrogen Project and Australia's Asian Renewable Energy Hub are accelerating adoption. Policy frameworks such as the EU Hydrogen Strategy and the U.S. Inflation Reduction Act further support deployment. Despite progress challenges remain in infrastructure storage and regulatory frameworks necessitating continued innovation and international collaboration. Green hydrogen aligns with key Sustainable Development Goals (SDGs) including SDG 7 (Affordable and Clean Energy) SDG 9 (Industry Innovation and Infrastructure) and SDG 13 (Climate Action). As the world transitions to a low-carbon economy green hydrogen presents a transformative opportunity contingent on sustained technological advancements investment and policy support.

More than 80% of the energy from fossil fuels is utilized in homes and industries. Increased use of fossil fuels not only depletes them but also contributes to global warming. By 2050 the usage of fossil fuels will be approximately lower than 80% than it is today. There is no yearly variation in the amount of CO2 in the atmosphere due to soil and land plants. Therefore an alternative source of energy is required to overcome these problems. Biohydrogen is considered to be a renewable source of energy which is useful for electricity generation rather than relying on harmful fossil fuels. Hydrogen can be produced from a variety of sources and technologies and has numerous applications including electricity generation being a clean energy carrier and as an alternative fuel. In this review a detailed elaboration about different kinds of sources involved in biohydrogen production various biohydrogen production routes and their applications in electricity generation is provided.

The global energy landscape is rapidly shifting toward cleaner lower-carbon electricity generation necessitating a transition to alternate energy sources. Hydrogen particularly green hydrogen looks to be a significant solution for facilitating this transformation as it is produced by water electrolysis with renewable energy sources such as solar irradiations wind speed and biomass residuals. Traditional energy systems are costly and produce energy slowly due to unpredictability in resource supply. To address this challenge this work provides a novel technique that integrates a multi-renewable energy system using multi objective optimization algorithm to meets the machine learning-based forecasted load model. Several forecasting models including Autoregressive Integrated Moving Average(ARIMA) Random Forest and Long Short-Term Memory Recurrent Neural Network (LSTMRNN) are assessed for develop the statistical metrics values such as RMSE MAE and MAPE. The selected Non-Sorting Moth Flame Optimization (NSMFO) algorithm demonstrates technological prowess in efficiently achieving global optimization particularly when handling multiple objective functions. This integrated method shows enormous promise in technological economic and environmental terms emphasizing its ability to promote energy sustainability targets.

Pressure vessels are used for large commercial and industrial applications such as softening filtration and storage. It is expected that high-pressure hydrogen storage vessels will be widely used in hydrogen-fuelled vehicles. Progressive failure properties the burst pressure and fatigue life should be taken into account in the design of composite pressure vessels. In this work the model and analysis of hydrogen storage vessels along with complete structural and thermal analysis. Liquid hydrogen is seen as an outstanding candidate for the fuel of high altitude long-endurance unmanned aircraft. The design of lightweight and super-insulated storage tanks for cryogenic liquid hydrogen is since long identified as crucial to enable the adoption of the liquid hydrogen. The basic structural design of the airborne cryogenic liquid hydrogen tank was completed in this paper. The problem of excessive heat leakage of the traditional support structure was solved by designing and using a new insulating support structure. The thermal performance of the designed tank was evaluated. The structure of the tank was analyzed by the combination of the film container theory and finite element numerical simulation method. The structure of the adiabatic support was analyzed by using the Hertz contact theory and numerical simulation method. A simple and effective structure analysis method for a similar container structure and point-contact support structure was provided. Bases for further structural optimization design of hydrogen tank will be provided also. The analysis will be carried out with different materials like titanium nickel alloy and some coated powders like alumina Titania and zirconium oxide. The results will be compared with that.