Techno-economic and life-cycle assessment of hydrogen production pathways in the Middle East and North African region

Blue hydrogen production plays a vital role in the global energy transition by offering a low-carbon alternative to conventional fossil fuels, helping to mitigate climate change and reduce greenhouse gas emissions. This study explores an integrated approach to blue hydrogen production by combining sorption-enhanced steam methane reforming (SE-SMR) with chemical looping water splitting (CLWS). The process was analyzed using Aspen Plus (Version 12.1) to evaluate its performance and energy efficiency. Methane (CH4) is converted into high-purity hydrogen (H2) (99.8%) while maintaining thermal self-sufficiency through heat supplied by the CLWS air reactor operating at 950°C. For a feed rate of 1000 kmol/h of methane, the system requires 59MW of thermal energy and yields 2.63 moles of hydrogen per mole of methane. The integrated configuration achieves a net efficiency of 79.3%, surpassing the conventional CLC + SE-SMR method. These findings suggest that the proposed system offers a promising pathway for sustainable hydrogen production with reduced carbon emissions.

ABSTRACT The synthesis of aromatic amines requires harsh conditions or the use of fossil‐derived hydrogen (H 2 ). Here, we address this limitation by demonstrating photocatalytic transfer hydrogenation (PTH) of nitroarenes into anilines employing plastic hydrolysates as electron and proton (hydrogen) donors under ambient temperature and pressure. PTH is achieved using a cobalt‐promoted molybdenum sulfide ( Co MoS 2 ) electrocatalyst integrated with a carbon nitride (CN x ) semiconductor photocatalyst in acidic aqueous solution. Co MoS 2 reduces nitroarenes to anilines at –0.7 V versus RHE with a Faradaic yield of 70% and superior activity to platinum. The Co MoS 2 ‐CN x photocatalyst produces anilines under simulated solar light (AM 1.5 G, 25°C), achieving 83%–99% yield from 24 nitroarenes using 4‐methylbenzyl alcohol as a model hydrogen donor. Acid hydrolysis of condensation polymers provides a source of alcoholic monomers in aqueous solution that can be used as a sustainable hydrogen donor for PTH in >80% yield using AM 1.5G or LED (405 nm, 33 mW cm −2 ) irradiation. A technoeconomic analysis (TEA) at pilot scale producing 1 t aniline day − 1 using polyethylene terephthalate (PET) reveals a cut in cradle‐to‐gate emissions by ∼77% using PTH with Co MoS 2 ‐CN x compared to conventional Pd/C hydrogenation with H 2 from steam methane reforming (SMR‐H 2 ) and a revenue‐generating levelized cost of aniline (LCOA) when co‐produced with terephthalic, acetic, and formic acids.

The synthesis of aromatic amines requires harsh conditions or the use of fossil-derivedhydrogen (H2). Here, we address this limitation by demonstrating photocatalytic transfer hydrogenation (PTH) of nitroarenes into anilines employing plastic hydrolysates as electron and proton (hydrogen) donors under ambient temperature and pressure. PTH is achieved using a cobalt-promoted molybdenum sulfide (CoMoS2) electrocatalyst integrated with a carbon nitride (CNx) semiconductor photocatalyst in acidic aqueous solution. CoMoS2 reduces nitroarenes to anilines at -0.7V versus RHE with a Faradaic yield of 70% and superior activity to platinum. The CoMoS2-CNx photocatalyst produces anilines under simulated solar light (AM 1.5G, 25°C), achieving 83%-99% yield from 24 nitroarenes using 4-methylbenzyl alcohol as a model hydrogen donor. Acid hydrolysis of condensation polymers provides a source of alcoholic monomers in aqueous solution that can be used as a sustainable hydrogen donor for PTH in >80% yield using AM 1.5G or LED (405 nm, 33 mW cm-2) irradiation. A technoeconomic analysis (TEA) at pilot scale producing 1t aniline day- 1 using polyethylene terephthalate (PET) reveals a cut in cradle-to-gate emissions by ∼77% using PTH with CoMoS2-CNx compared to conventional Pd/C hydrogenation with H2 from steam methane reforming (SMR-H2) and a revenue-generating levelized cost of aniline (LCOA) when co-produced with terephthalic, acetic, and formic acids.

Solar-integrated blue hydrogen production with optimized post-combustion carbon capture: A techno-economic and exergoeconomic assessment

Methane steam reforming (MSR) is the most widely used industrial process for hydrogen production. However, catalyst deactivation, carbon emissions, and energy inefficiencies limit its sustainable performance. Therefore, improving catalyst selection and optimizing operating conditions are essential for efficient hydrogen generation. This study proposes an artificial intelligence-driven framework to optimize catalyst–condition combinations in MSR systems. The framework integrates Hybrid Golden Beetle Optimization (HGBO), VIKOR-based multi-criteria decision making, and Convolutional Long Short-Term Memory (ConvLSTM) modeling. HGBO explores the solution space and generates Pareto-optimal combinations of catalysts and operating conditions. These solutions are then ranked using the VIKOR method. The ranking considers hydrogen yield, methane conversion, energy efficiency, CO2 emissions, and catalyst lifetime. Economic feasibility is also included in the decision process. ConvLSTM modeling captures spatiotemporal relationships in catalyst and process data and predicts catalyst degradation under different operating conditions. The framework is evaluated using 620 experimentally reported MSR cases collected from the published literature within industrial ranges of 600–1200 °C, 1–40 bar, and H2O/CH4 ratios of 1–6. The optimized configurations achieve hydrogen yields up to 98.5%, energy efficiency approaching 99%, and reduced CO2 emissions of about 0.85 kg h−1. The results provide practical guidance for catalyst selection and process optimization in industrial hydrogen production systems.

The direct conversion of CH 4 and CO 2 into syngas garners significant attention as a promising strategy for greenhouse gas utilization. However, the development of highly active and stable catalysts remains a significant challenge. Here, Ni-based catalysts supported on Al 2 O 3 and promoted with alkaline–earth metals (Ca, Mg, Sr, and Ba) are prepared via an impregnation method and systematically characterized using various analytical techniques. The catalytic performance is evaluated in the combined steam and dry reforming of methane. Among the investigated promoters, Sr notably enhances CH 4 and CO 2 adsorption capacities and improves the reducibility of Ni active sites. The catalyst containing 9 wt% Sr exhibits the smallest Ni particle size and the highest catalytic activity. Sr doping modifies surface basicity, oxygen vacancies, and metal–support interactions, thereby enhancing CO 2 adsorption and Ni dispersion. However, excessive Sr loading causes the formation of Sr–aluminate phases (SrAl 2 O 4 and SrAl 4 O 7 ) that negatively affects the catalytic performance. In-situ diffuse reflectance infrared Fourier transform spectroscopy analysis clearly demonstrates improved adsorption of CH 4 and CO 2 and formation of carbonate species, providing insight into the surface reaction mechanism. Kinetic studies reveal that the lower apparent activation energy is attributed to enhanced surface reactivity. Long-term stability tests demonstrate steady CH 4 and CO 2 conversions over 500-h without detectable carbon deposition. Overall, Sr incorporation stabilizes Ni particles, suppresses sintering, and preserves active surface area, thereby markedly improving the catalytic performance. • Ca, Mg, Sr, Ba were added to Ni/Al 2 O 3 for combined steam and dry reforming of CH 4 . • Sr enhanced adsorption of CH 4 and CO 2 and improved reducibility of Ni active sites. • Ni-9Sr/Al 2 O 3 exhibited the highest activity, achieving 94 % CH 4 and 66 % CO 2 conversion. • Effect of Sr promoter was due to Ni dispersion, oxygen vacancies, and basicity. • The overall reaction mechanism was also comprehensively evaluated.

This present work investigates the potential advantages of combining exothermic catalytic methane oxidation with endothermic catalytic reforming of methane over a dual-catalyst bed to produce syngas, partly similar to the autothermal reforming (ATR) of methane. Noncatalytic oxidation of methane, hot-spot formation, coking, and catalyst stability are the major challenges in the traditional ATR process, and using two catalysts to sequentially combine the oxidation and reforming was shown to address the aforementioned challenges. An oxidation catalyst (Pd/CeO2/Al2O3) and mesoporous alumina-supported (MAl) bimetallic RhNi and NiCo catalysts as reforming catalysts were chosen and packed in a fixed-bed catalytic reactor as layers and in a blended form. The sequential layer of Pd/CeO2/Al2O3 and NiCo/MAl, as well as the blended form of Pd/CeO2/alumina and RhNi/MAl, was able to reform methane using steam and oxygen as the oxidant feed to produce syngas with excellent catalyst stability. The Pd/CeO2/Al2O3 catalyst demonstrated methane oxidation capability, achieving high activity at temperatures as low as 290 °C and generating substantial heat at higher temperatures, sufficient to initiate the downstream reforming reactions over the reforming catalyst. The H2/CO ratio present in the as-produced syngas was higher than that of the CO-rich syngas obtained by dry methane reforming (DRM) and catalytic partial oxidation (CPOX) but lower than the ratio obtained from steam reforming of methane (SRM) and ATR processes. DFT studies revealed that the combination of exothermic oxidation and endothermic reforming in a dual-catalyst bed improved the activity of reforming and enhanced the syngas production as well as the catalyst stability.

ABSTRACT This study presents a performance evaluation of a conventional steam power plant integrated with a chemical energy storage system based on the reversible methane steam reforming. By enabling the plant to run in two modes, charging and discharging, operational flexibility is attained. In cases of low grid demand, a portion of the boiler steam output is redirected to an endothermic reformer, where additional thermal energy is preserved as synthesis gas. The stored energy is released through the exothermic methanation process and used to power a secondary cycle in higher demand. At design condition, the system achieves a round-trip thermal efficiency of 83%. In addition, the operation points of the primary turbine, increased the efficiency from 33.6% to 41%, resulting in a total plant efficiency of 31.43%, Parametric evaluation suggests that steam diversion and machine scale enhance overall performance. Overall, the integrated system provides an efficient solution to energy time shifting.

New Zealand’s kiwifruit and apple industries generate substantial quantities of organic residues during thinning and harvest, much of which is composted or disposed of in landfills due to logistical constraints. This study evaluates the potential of these residues as feedstock for biomethane production via anaerobic digestion (AD), followed by hydrogen generation through steam methane reforming (SMR). Two feedstock mixtures were examined: a 50:50 kiwifruit–apple blend and a 40:40:20 kiwifruit–apple–potato mixture, designed to mitigate acidification. Cow manure served as a cost-effective inoculum. Physicochemical analysis confirmed high moisture and volatile solids content, indicating strong biodegradability, although low nitrogen content suggests the need for co-digestion in full scale systems. Biomethane potential (BMP) tests yielded up to 45 mL CH4/gVS at an ISR of 4, corresponding to 46.5% carbon conversion. Scaling to an annual waste volume of 476 t suggests a potential biomethane yield of approximately 18,000 m3. SMR simulations demonstrated technical feasibility, with methane conversion increasing from 46% under baseline conditions to >85% under optimized steam to carbon ratios and residence times. Hydrogen yields of ~7600 m3/year were estimated. This study provides a practical foundation for valorizing fruit waste into renewable biomethane and hydrogen, supporting New Zealand’s circular economy and decarbonization goals.

Composite score-based analysis of carbon capture strategies for sustainable natural gas-to-methanol: A comprehensive assessment

Hydrogen is widely recognized as a key energy carrier for enabling deep decarbonization across power generation, transportation, and energy-intensive industrial sectors. However, large-scale deployment from renewable energy remains constrained by the efficiency and cost of current production routes. This review provides a comprehensive assessment of hydrogen production technologies, encompassing both thermochemical processes and electrolysis-based green hydrogen systems. Conventional pathways, including steam methane reforming (SMR) and coal and biomass gasification, are evaluated from thermodynamic and kinetic perspectives, with emphasis on reaction energetics, process efficiency, and carbon emissions. The thermodynamics and kinetics of water electrolysis are examined in detail, highlighting the roles of Gibbs free energy, overpotentials, temperature, and kinetically sluggish oxygen evolution reactions. Recent advances in alkaline, proton exchange membrane (PEM), and solid oxide electrolyzer cells (SOECs) are critically assessed with respect to efficiency, durability, scalability, and compatibility with variable renewable electricity. Emerging electrocatalysts, particularly layered double hydroxide (LDH)-based materials, are discussed as effective routes for accelerating oxygen evolution kinetics and reducing system-level electrolysis losses. By explicitly linking thermodynamic and kinetic constraints with system-level loss analysis and catalyst development, this review presents a unified framework for evaluating hydrogen production technologies beyond conventional efficiency comparisons. The analysis demonstrates that efficiency improvements in hydrogen production are fundamentally constrained by irreversible anodic kinetics rather than thermodynamic minimum work, positioning LDH-based oxygen evolution catalysts as the most impactful lever for near-term cost and performance gains in water electrolysis. • Fossil-based hydrogen supplies >95% via SMR and gasification, emitting ∼830 Mt CO 2 yr −1 . • Reaction enthalpies quantify reforming and gasification thermodynamic limits. • Electrolysis efficiency is limited by OER activation losses. • LDH catalysts reduce anodic overpotential and improve electrolyzer efficiency. • A unified thermodynamic–kinetic framework evaluates hydrogen pathway scalability.

Ni-Al2O3 supported on metallic 3D-printed monolith with TPMS structure applied in the dry and steam reforming of methane

Facet-engineered Pt/CeO2 oxygen carriers for efficient low-temperature chemical looping steam methane reforming

Southeast Asia is home to a large and growing fleet of coal power plants. One proposed policy response is to support the deployment of ammonia co-combustion technology to reduce greenhouse gas emissions from coal power generation while continuing to meet growing electricity demand. The effectiveness of the technology depends on accurately assessing the emissions reduction potential of ammonia co-combustion. We quantify the emissions reduction potential of ammonia co-combustion for the ASEAN coal fleet, taking into account the carbon intensity of ammonia production across four different ammonia production technologies. We then compare net emissions with and without ammonia co-combustion with a modelled pathway for the Southeast Asia's coal power generation consistent with a ‘well-below’ 2 °C warming scenario. Our results show ammonia co-combustion could increase the cumulative emissions by 7 % relative to the continued use of coal when ammonia is produced using the present business-as-usual method of Haber Bosch incorporating steam methane reforming. We also find co-combusting with ammonia produced via electrolysis with renewable energy offers up to 43 % emissions reduction in the coal fleet, assuming a 40-year operating lifetime. However, even with widespread use of the technology, findings suggest early retirement or substantive emissions savings elsewhere in the economy will be required for emissions to be consistent with limiting warming to 2 °C. Rigorous assessment of CO 2 mitigation measures is critical in enabling policy-makers to choose ‘least regrets’ decarbonisation pathways for emissions intensive power generation technologies. • Emissions reduction potential of ammonia co-combustion in the ASEAN coal fleet were quantified. • Ammonia co-combustion could increase the cumulative emissions by 7 %. • Early retirement of coal power plants will be required to be consistent with 2 °C climate target.

Process design for sorption-enhanced chemical looping steam methane reforming: Selection of process configuration and combustible gas type

Thiswork addresses the decarbonization of the ammonia industry,which relies almost exclusively on the Haber-Bosch (HB) process andaccounts for more than 1% of anthropogenic carbon dioxide emissions.The first section of the HB process, the Steam Methane Reforming (SMR),is identified as the primary target for decarbonization, where fossilfuels are used as (i) feedstock for hydrogen (H2) productionand (ii) a source for process heat. A methodology is proposed to graduallyincorporate green H2 in the HB process, thus, reducingfossil fuel intake. The methane-fed HB process is modeled in Aspen Plus, where several process modifications are proposed.This includes an analysis of the most relevant point of green H2 injection and how to adapt plant operation to satisfy allprocess constraints, while minimizing methane consumption. The processlimitations that are subject to this operation strategy were identifiedby increasing the green H2 incorporation fraction. Themain bottleneck of this strategy relates to SMR operation, namelythe increase in the secondary reformer’s outlet temperature.A partial bypass of the primary reformer is suggested to prevent thisunit from overheating. This additional modification proved effectivein controlling the temperature, enabling green H2 incorporationof up to 60% while satisfying all process constraints.

Natural gas (NG) reforming dominates global hydrogen production through three chemistry routes: autothermal (ATR), steam-methane reforming (SMR), and partial oxidation (POX). Hydrogen plants generate substantial amounts of CO2, and reducing the carbon intensity is vital for sustainable development. There is a lack of technoeconomic analyses exploring hydrogen production by natural gas partial oxidation (POX). This work examines two pathways to mitigate CO2 in POX plants by using recoverable heat from the process to (1) integrate the plant with an electrolyzer to enhance hydrogen production and (2) integrate with CCS (blue hydrogen). Design regimes are identified for the integrated POX-CCS process. Technoeconomic analyses show the trade-off between hydrogen costs and the reduction in CO2 emissions. Results show that electrolyzer integration is limited due to the electrolyzer’s large power demand, while CCS integration achieves 95% emission reductions with only 9% cost increase. A life-cycle assessment compares the integrated POX system with conventional SMR and electrolysis.

ABSTRACT Hydrogen (H2) is a clean energy carrier, yet selecting an economically and industrially viable production pathway remains challenging due to competing technical, economic, and environmental trade-offs. This study develops a structured multi-criteria decision-making (MCDM) framework to evaluate ten H2 production technologies using nine criteria relevant to industrial applicability, including cost, efficiency, operating conditions, and environmental performance. A hybrid approach integrating the Analytic Hierarchy Process (AHP) with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to generate technology rankings, which are subsequently validated through the Multi-Objective Optimization by Ratio Analysis (MOORA) method and sensitivity analysis. The results identify Steam Methane Reforming (SMR) as the most viable option under current techno-economic conditions, offering high H2 yield (74%) and low production cost ($0.75 kg−1 H2), despite its environmental impact. Plasma reforming and coal gasification emerge as competitive alternatives, whereas electrolysis exhibits low emissions but remains cost-intensive. Thermolysis and bio-based routes, including bio-photolysis, photocatalysis, and fermentation, show favorable environmental performance but are constrained by limited yield and scalability. The proposed framework provides a transparent and adaptable decision-support tool for comparing H2 production pathways under evolving industrial and sustainability priorities.

Bimetallic PtNi/CeO2 catalysts were successfully synthesized via a mechanochemical approach, specifically ball milling, and evaluated for methane steam reforming (MSR). A fractional factorial design of experiments was employed to systematically explore the effects of key milling parametersmilling frequency, milling time, and ball-to-powder ratioon the catalysts' structural properties and catalytic performance. The catalysts were characterized by X-ray diffraction, H2 temperature-programmed reduction, transmission electron microscopy, and Raman spectroscopy. Catalytic activity tests were performed in a plug flow reactor under a high gas hourly space velocity (200,000 mL gcat -1 h-1) at a steam-to-carbon ratio of 2 between 700 and 950 °C. The mechanochemically synthesized catalysts were benchmarked against those prepared via incipient wetness impregnation. The most active milled catalysts achieved a methane conversion rate of ca. 22 mol CH4 gNi -1 h-1 at 700 °C (83.5% methane conversion for a PtNi/CeO2 mechanochemically synthesized), outperforming the impregnated counterpart (64% methane conversion under the same reaction conditions). Notably, increasing the milling intensity resulted in enhanced catalytic activity, with milling frequency emerging as the most influential factorcorrelating with the formation of smaller NiO particles. To elucidate the role of Pt addition, in situ X-ray absorption near-edge structure (XANES) and near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) measurements were conducted on the most active milled catalysts under MSR conditions. NAP-XPS revealed surface segregation of Pt during MSR, alongside an inhibitory effect on solid carbon deposition, suggesting the potential for a coke-resistant catalyst. These findings highlight the power of mechanochemical synthesis in tuning catalyst properties, offering a scalable and efficient route to high-performance catalysts for methane reforming and hydrogen production.