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[Display omitted] • Incineration bottom ash (IBA) was good support for Ni in catalytic toluene reforming. • An activation stage was observed for Ni/IBA because of the metal-support interaction. • Formation of Ni-FeO x improves the redox ability and is responsible for activation. • Resistance to coking is due to the FeO x and alkali and alkaline earth metals in IBA. The incineration bottom ash (IBA) was impregnated with nickel to catalyze toluene (tar surrogate) steam reforming. A toluene conversion of >80 % was achieved at 800℃ without activity decay in a 100-h test for 15 %Ni/IBA. An activation stage was observed for Ni/IBA catalysts in the initial 50 ∼ 400 min under different reaction conditions. A series of experiments and characterizations were performed to explore the possible mechanisms for the activation. It was found that the iron species in IBA gradually migrated to the catalyst surface and formed a Ni-FeO x complex owing to the metal-support interaction. The synergy of Ni-FeO x played an important role in improving the activity of Ni/IBA due to the enhanced lattice oxygen activity. Additionally, Ni/IBA catalysts showed a much lower coke deposition rate than Ni/Al 2 O 3 (1.12 vs. 3.45 mg-C/g cat ∙h) because of the variable states of FeO x and the abundant basic sites caused by the alkali and alkaline earth metals contained in IBA. [ABSTRACT FROM AUTHOR]

Methane reforming is gaining attention because of its potential to be converted into energy-dense fuels or high-value chemicals. In addition to the production of syngas (H2+CO), the utilization of CO2 can help reduce greenhouse gases. Water steam is typically used to increase the output of H2. This study evaluated the potential of thermal plasma technology to produce clean hydrogen, carbon monoxide, and carbon black from methane by applying a thermodynamic equilibrium model. A comparative analysis of three cases of methane processing (pyrolysis, dry reforming, and steam reforming) is presented to provide a comprehensive understanding of the potential of thermal plasma technology for methane conversion. [ABSTRACT FROM AUTHOR]

Based on the principles of thermodynamic reaction equilibrium, a simulation method enhanced by the nano-CaO reactive sorption CO 2 for hydrogen production from biomass steam reforming has been established. MATLAB R2022b software has been utilized to calculate the composition concentration of the product gas. Detailed simulations have been conducted to understand the changes in gas component concentration and yield under various reaction conditions, includes temperatures, steam to biomass (S/B) molar ratios, and CaO to carbon (CaO/C) molar ratios. The result demonstrated that temperature plays a significant role in both the concentration and yield of hydrogen. At an optimal reaction temperature of 650 °C, the concentration of H 2 in the product reaches 77% (S/B = 2 and CaO/C = 0.5). S/B molar ratio over 2 is necessary to increase the H 2 concentration. The study also reveals CaO/C molar ratio 0.5 enable successful removal of CO 2 generated by reaction. The application of nano-CaO notably enhanced the efficiency of hydrogen production from biomass steam reforming, leading to a 25% increase in H 2 concentration and a boost in H 2 yield to 50 mL/g Biomass , and reaction temperature decrease 200 °C compared to the case without CaO. [Display omitted] • A thermodynamic simulation method using the nano-CaO reactive sorption enhanced biomass steam reforming was established. • Simulated calculations the optimal process conditions for maximizing H 2 concentration and yield. • The simulation revealed that an S/B molar ratio of 2 serves as a critical point for H 2 concentration. • Nano-CaO/C molar ratio of 0.5 was found to be sufficient for CO 2 removal. [ABSTRACT FROM AUTHOR]

Hydrogen, a form of energy that is both clean and renewable, is now being researched and developed as a potential source of alternative energy. There are many different kinds of microbial systems that have the potential to be utilised in the manufacturing of biohydrogen. Thermophiles are found as potential producers of hydrogen, at a high rate, in adverse operating conditions. Temperature, pH, and concentration of substrates play a crucial role in affecting the metabolism of these microorganisms. Sustainable production of hydrogen is feasible when organic waste is employed as a potential feedstock. The overall yield of hydrogen production procedures demands improvements, to turn them into commercial applications. The integration of two-stage processes may contribute to an overall increase in energy output. As examples of second-stage processes, biomethanation, microbial electrolysis cells, photo-fermentation, and microbial fuel cells have been the subject of extensive research. This article provides an overview of the photocatalytic method for producing biohydrogen, including its fundamentals and underlying mechanisms, as well as other biological methods of hydrogen production. This process exhibits reduced energy consumption and demonstrates environmental friendliness by potentially utilising waste material as a substrate. [ABSTRACT FROM AUTHOR]

Direct ethanol fuel cell (DEFC) is promising source for mobile and portable applications, but the electrocatalysts are based on metal noble alloys or doping elements to minimize the incomplete ethanol oxidation and poisoning effect. While the main problem persists, this study describes the enhancement of ethanol oxidation reaction by adding graphene (G) to Vulcan XC-72R carbon black (C) metal support, with different C/G ratios. The Graphene was prepared from exfoliated graphite following by dried at ambient temperature. The 60 wt% graphene hybrid support enhances the current density at 5% cyclic voltammetry (CV) and 127% chronoamperometry (CA) higher than carbon pure support in acid electrolyte, whereas in alkaline, graphene (60 wt%) showed the highest electrochemical activity with an increase of current 82% (CV) and 130% (CA). Therefore, we demonstrated the enhancement of the catalyst electrochemical activity in both electrolytes through a simple synthesis method. The 40 wt% carbon and 60 wt% graphene hybrid support achieving higher performance in ethanol oxidation, evidencing a potential application in DEFC. [ABSTRACT FROM AUTHOR]

Hydrogen, as a promising energy carrier, can be extracted from renewable biomass derived acetic acid (HAc). Ni-based catalysts supported on solid solution of Sm2−xPrxO3±δ were prepared using a coprecipitation method and evaluated in auto-thermal reforming (ATR) of HAc for hydrogen production. The results revealed that Pr species infiltrated the Sm2O3 lattice and formed a solid solution structure with oxygen vacancy defects, in which the redox process of Sm3+ + Pr3+ Sm2+ + Pr4+ enhanced oxygen mobility, facilitating gasification of the coking precursor and suppressing carbon deposition. DFT analysis also confirmed that Pr doping into the Sm2−xPrxO3±δ solid solution significantly lowered the energy barrier by 112 kJ mol−1 for formation of oxygen vacancies. Additionally, the interaction between Ni0 and Sm2−xPrxO3±δ effectively improved the dispersion of Ni0 metal particles, inhibiting sintering of Ni species. Consequently, the NSP10 catalyst (Ni0.80Sm1.72Pr0.24O3.74±δ) exhibited outstanding catalytic performance for hydrogen production: the conversion of HAc approached 100%, while the hydrogen yield remained stable at 2.75 mol-H2/mol-HAc. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) methane (CH 4) reforming (H 2 SMR) is a promising process for sustainable energy production from conventional fuels, offering triple benefits for generating clean hydrogen (H 2), consuming toxic H 2 S, and producing an economically valuable by-product carbon disulfide (CS 2). In this work, we studied the optimal operating conditions and assessed the economic feasibility of the non-catalytic H 2 SMR process, employing a combination of kinetic modeling, process modeling, and techno-economic analysis. Plug flow reactor simulations were performed with our newly developed mechanism to shed light on the optimal operating conditions. It was concluded that a H 2 S/CH 4 molar feed ratio of 2 results in the highest hydrogen production rate, and a feed ratio of 1–2 and a temperature of 1100–1300 °C are needed to maximize the CS 2 production rate. However, feed ratios higher than 2 increase the conversion rate of CH 4 and therefore benefit the purity of the H 2 product. Comparing the cases for a feed ratio of 2 at 1300 °C and a feed ratio of 9 at 1200 °C, the cost is significantly higher for the feed ratio of 9, mainly attributed to the higher electricity cost for higher inlet flow rate and H 2 S recycling, as well as the cost for the additional steam required during the preheating process. The cost of hydrogen production by H 2 SMR process could be as low as $1.47/kgH 2 for a feed ratio of 2 and solar PV as an energy source, which is more competitive than a cost of $1.97/kgH 2 for the steam methane reforming process. Furthermore, since CS 2 is a valuable by-product, the higher amount of CS 2 formed at a feed ratio of 2 becomes the main source of revenue, which completely covers the cost of hydrogen production. This study demonstrates the huge potential of H 2 SMR process as a clean and economic-competitive way to produce hydrogen. • Studied H 2 SMR process using kinetic, process modeling, and techno-economic analysis. • Discussed optimal operating conditions for maximizing H 2 and CS 2 yields. • Conducted sensitivity analysis of power source and feed ratio on H 2 production cost. • Concluded that CS 2 yield in H 2 SMR could cover the cost of H 2 production. [ABSTRACT FROM AUTHOR]

Flow of a fluid past a body is a very complicated phenomenon. Computational fluid dynamics is used for studying the characteristics of flow past an array of hemispherical protrusions that is disposed on the wall surfaces of a millisecond microchannel reactor. Protrusions can be used to improve the transport processes involved, but the causes of the phenomena are still incompletely understood. Parametric analyses are performed under different sets of circumstances to delineate the role of geometric features and operation conditions in reactor performance. Dimensionless quantities are used to simplify the characterization of the reactor system with multiple interacting transport phenomena. The mechanisms involved in the intensified processes are analysed, and performance improvement recommendations are presented. The results indicate that the protruded reactor behaves effectively and good yields can be obtained with only milliseconds residence of the mixtures within the channels. The reactor offers the unique advantage for hydrogen production from methanol in that process intensification is realized while preserving the energy balance between the exothermic and endothermic processes. However, the flow rates, feed compositions, and channel dimensions must be adjusted as needed to maximize production of hydrogen and minimize pressure drops. While the thermal diffusivity dominates the overall reactor behaviour, expectable compromises have to be made between hydrogen productivity and pressure drop. The results have implications for hydrogen production and beyond for the study of transport phenomena in microchemical systems. [Display omitted] • The protruded reactor behaves effectively and good yields can be obtained. • Process intensification is realized while preserving the energy balance. • The thermal diffusivity dominates the overall reactor behaviour. • Compromises have to be made between productivity and pressure drop. • Protrusions are very effective in improving the transport processes involved. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the economic feasibility of leveraging H 2 generated from biogas for 28 sanitary landfill consortia in the state of Minas Gerais, Brazil. Two processes were analyzed: steam methane reforming (SMR) and pyrolysis reforming. Both were assessed via the economic analyses of Net Present Value (NPV), Levelized Cost of Hydrogen (LCOH) and Internal Rate of Return (IRR). Potential biogas production from sanitary landfills was estimated along with the production of hydrogen and ammonia. Installation (CAPEX) along with operation and maintenance (OPEX) costs were estimated for the biogas purification processes and attainment of H 2. The sales rate for H 2 as a fuel source was derived for each consortium. The capacity for ammonia attainment from H 2 was determined as well as the Levelized Cost of Ammonia (LCOA). The installed capacity of the consortia varied from 18,332.05 to 2,470,525.30 kg H 2 /year. The LCOH varied from 7.01 US$/kg to 44.45 US$/kg. Comparing the three scenarios, the Steam Methane Reforming (SMR) without CO 2 capture obtained the best economic results; however, this scenario leads to the emission of CO 2. The novelty of this research resides in the use of biogas to obtain H 2 and ammonia, as well as in comparing SMR with pyrolysis. The consortium CIDES showed the best economic results. The reformation processes of CH 4 in H 2 with zero CO 2 emissions obtained the best LCOH values, thus making it less competitive in relation to fossil fuels. Public policy changes are necessary to incentivize the production and use of H 2 and ammonia from biogas. • Economic feasibility of leveraging H 2 from biogas for sanitary landfill in Brazil. • Two processes were analyzed: steam methane reforming and pyrolysis reforming. • Biogas production was estimated along with the production of hydrogen and ammonia. • Ammonia attainment from H 2 and the Levelized Cost of Ammonia were determined. • Installed capacity of consortia varied from 12,738.08 to 1,716,651.77 kgH 2 /year. [ABSTRACT FROM AUTHOR]

Integrating hydrogen (H 2) production systems within natural gas (NG) supply chains can support smoothening transition to cleaner energy resources by utilizing existing infrastructures. This work investigates the dynamic conversion of boil-off gas (BOG) using steam methane reforming (SMR) to produce H 2 within liquified natural gas (LNG) process. The study extends beyond technical considerations to encompass a socio-economic approach, exploring optimal H 2 allocation to different monetization techniques (e.g., ammonia and methanol) subject to final market price and demand data. Dynamic simulation showed an excellent ability to address the variations in BOG flow, change in LNG temperature and pressure drop within the LNG supply chain, highlighting the need for adaptive flowrate and process setpoints. The H 2 productivity and yield are dependent on steam flow rates, steam to carbon ration (S/C) and energy input to the system. Optimizing the reformer temperature is the best practice to enhanced the conversion of BOG to H 2. Allocating approximately 74% of the produced H 2 to CO 2 -free ammonia production, and the remainder to methanol via CO 2 hydrogenation, achieves an annual profitability of $1.36 billion. However, when considering variable demand and price data over ten years, the model proposes flexible annual H 2 allocation to both monetization routes, resulting in an average yearly profitability of $6.84 billion. These findings underscore the importance of integrating interactive simulation approaches to address exogenous and endogenous uncertainties, providing a robust strategy against risks. The comprehensive approach presented in this study contributes to the understanding and strategic planning of H 2 production within LNG supply chains, emphasizing adaptability and economic viability in the dynamic landscape of the energy transition. • Integrating hydrogen generation into LNG supply networks helps move to cleaner energy. • Economic/technical feasibility of SMR for H 2 production from BOG was presented. • Aspen HYSYS model was developed to ensure reliable, safe, and optimal H 2 production. • Implementing flexible H 2 allocation strategies in response to market conditions generates significant economic gains. • Annual allocation flexibility for economic performance increased profitability by 80% ($6.84B). [ABSTRACT FROM AUTHOR]

Dry reforming of acetic acid (DRA) was first-time investigated on 10%Ni/Al 2 O 3 at varied temperatures within 923–973 K employing several CO 2 :CH 3 COOH ratios of 1.5:2; 1:1; and 2:1. Depending on NiO particle size and location on support surface or inside the porous support structure, the H 2 reduction of NiO phase to active metallic Ni0 form was evidenced at different reduction temperatures within 550–950 K and the estimated degree of reduction was about 73.68%. Weak, medium, and strong basic centres were evidenced on 10%Ni/Al 2 O 3 via CO 2 desorption measurement. Increasing DRA temperature improved both CH 3 COOH and CO 2 conversions with the corresponding apparent activation energy of 100.71 and 58.50 kJ mol−1. As CO 2 partial pressure was increased from 0 to 40 kPa, the initial CH 3 COOH conversion was noticeably enhanced from 30.5% to 97.8% whilst H 2 /CO ratio always remained less than unity (0.73–0.77). Notably, DRA was a two-step process and barely negligible CH 4 intermediate product was evidenced since it was promptly reformed by CO 2 into syngas. The Ni0 active form was not susceptible to oxidation during DRA and carbon deposited on spent catalyst surface was heterogeneous in nature with the evident co-existence of amorphous and graphitic carbons. [Display omitted] • For the first time, acetic acid dry reforming was conducted for H 2 production. • Apparent activation energy for CH 3 COOH conversion was about 100.71 kJ mol−1. • H 2 /CO ratio was 0.73–0.77 preferred for downstream Fischer-Tropsch synthesis. • Filamentous and graphitic carbons co-existed on spent catalyst surface. [ABSTRACT FROM AUTHOR]

The production of hydrogen-rich gas used in fuel cell-powered cars from steam reforming and sorption-enhanced steam reforming of ethanol was studied over nickel-impregnated mesoporous carbon catalyst in conventional and microwave heated reactor systems. Two important process intensification methods, sorption-enhanced reforming and microwave heating, were investigated to obtain a sustainable and energy-efficient system. Higher hydrogen yield was observed in the microwave heated system compared to the conventional heated system. With an increase in the reaction temperature, the hydrogen yield and hence the hydrogen concentration were increased in both systems. Sorption-enhanced steam reforming resulted in very high hydrogen purity, higher than 97 %, containing no carbon monoxide and carbon dioxide before the breakthrough point in the microwave system at 500 °C. The outperformance of the microwave system compared to the conventional system was proved in terms of the hydrogen yield and purity. • Nickel impregnated mesoporous carbon catalyst has a high microwave absorption capacity in the microwave system. • Higher hydrogen yield and purity were achieved in the microwave system. • Sorption-enhanced results revealed very high H 2 purity in the MW reactor at 500 °C during the first 25 min of the reaction. • The enhancement in hydrogen yield and purity in the MW system are evidence of its superiority to the conventional system. [ABSTRACT FROM AUTHOR]

Photothermal synergistic catalysis (PTSC) offers promising potential for the dry reforming of methane (DRM) to produce syngas, but designing suitable catalysts suitable for photothermal processes poses significant challenges. In this study, we present a core-shell catalyst consisting of a SiO2 shell encapsulating Ni loaded on the CeO2–ZrO 2 support, which proved to be well-suited for PTSC-DRM under milder conditions. Compared to traditional thermal catalysis (TC), PTSC at 600 °C exhibited superior CH4/CO2 conversions (63.5 %/55.9 %) and higher H 2 /CO yields (137.0 mmol·g -1 ·h -1 /182.9 mmol·g -1 ·h -1). The TOFs under PTSC-DRM are 1.3–2.9 times higher than the corresponding TOFs in TC-DRM. The catalyst demonstrated strong stability during a 60-h aging test, which can be attributed to the restricted migration of Ni and the accelerated movement of oxygen induced by illumination via structure effect which also lead to the boosted activity benefited from a reduced bandgap of 2.2 eV and improved charge separation/migration efficiency during PTSC reaction. [Display omitted] • Boosted syngas production via photothermal synergistic dry reforming of CH 4. • A novel core-shell structured Ni/CeO 2 –ZrO 2 @SiO 2 catalyst tailored for photothermal synergistic reaction. • Enhanced activity and anti-carbon performance of the catalyst due to the encapsulation of SiO 2. [ABSTRACT FROM AUTHOR]

Hydrogen, a potential and high-energy green fuel, offers a solution to the environmental concerns arising from the imprudent use of fossil fuels. As an alternative energy carrier, it can be produced using various conventional and advanced technologies, aiming for a decarbonized energy future. Currently, H 2 production heavily depends on fossil fuels, which results in carbon emissions and makes the process energy-intensive, posing a significant risk.This review article discusses the commonly employed hydrogen production approaches, their current opportunities, and their strategic design towards a global hydrogen economy. Various reforming methods are also explored, along with the specific raw ingredients used in the generation process. Additionally, the production of bio-hydrogen is addressed, with a special focus on fermentation (dark and photo-fermentation), direct bio-photolysis, and indirect bio-photolysis. Bio-hydrogen is gaining popularity due to its environmentally friendly nature and the wide range of feed materials available for its production.The review provides comprehensive information on the biological conversion processes for H 2 production. While numerous researches have been reported, there is still room for improving the efficiency of large-scale H 2 production to meet the growing demand. [Display omitted] • Physical material related hydrogen applications. • Hydrogen production technologies and its strategic design towards hydrogen economy. • Different types of reforming methods have been discussed for production purposes. • Production of biohydrogen with fermentation and biophotolysis processes. • Spectacular mechanism of biological conversion processes for H 2 production. [ABSTRACT FROM AUTHOR]

Hydrogen is an ideal energy carrier manufactured mainly by the natural gas steam reforming hydrogen production process. The concentrations of  CH 4 ,  CO ,  CO 2 , and  H 2  in this process are key variables related to product quality, which thus need to be controlled accurately in real-time. However, conventional measurement methods for these concentrations suffer from significant delays or huge acquisition and upkeep costs. Virtual sensors effectively compensate for these shortcomings. Unfortunately, previously developed virtual sensors have not fully considered the complex characteristics of the hydrogen production process. Therefore, a virtual sensor model, called "moving window-based dynamic variational Bayesian principal component analysis (MW-DVBPCA)" is developed for key gas concentration estimation. The MW-DVBPCA considers complicated characteristics of the hydrogen production process, involving dynamics, time variations, and transportation delays. Specifically, the dynamics are modeled by the finite impulse response paradigm, the transportation delays are automatically determined using the differential evolution algorithm, and the time variations are captured by the moving window method. Moreover, a comparative study of data-driven virtual sensors is carried out, which is sporadically discussed in the literature. Meanwhile, the performance of the developed MW-DVBPCA is verified by the real-life natural gas steam reforming hydrogen production process. [ABSTRACT FROM AUTHOR]

Methane steam reforming is the foremost method for hydrogen production, and it has been studied through experiments and diverse computational models to enhance its energy efficiency. This study focuses on employing an artificial neural network as a model of the methane steam reforming process. The proposed data-driven model predicts the output mixture's composition based on reactor operating conditions, such as the temperature, steam-to-methane ratio, nitrogen-to-methane ratio, methane flow, and nickel catalyst mass. The network, a feedforward type, underwent training with a comprehensive dataset augmentation strategy that augments the primary experimental dataset through interpolation and theoretical simulations of the process, ensuring a robust model training phase. Additionally, it introduces weights to evaluate the relative significance of different data categories (experimental, interpolated, and theoretical) within the dataset. The optimal artificial neural network architecture was determined by evaluating various configurations, with the aim of minimizing the mean squared error (0.00022) and maximizing the Pearson correlation coefficient (0.97) and Spearman correlation coefficient (1.00). [ABSTRACT FROM AUTHOR]

This study assessed a Ni/Al2O3 structured catalyst for steam reforming of toluene (SR-T) and naphthalene (SR-N) mixture feeds (SR-TN). The catalyst achieved around 100% conversion for SR-T and SR-N in a 10-hour reaction but experienced notable deactivation in the SR-TN system over 3 hours. Post-SR-TN, the catalyst showed higher coke deposition than after SR-T and SR-N, possibly explaining the varied deactivation. The impact of reaction temperature and catalyst weight-to-flow rate ratio (W/Ftotal) was explored, revealing that higher temperature and W/Ftotal ratio increased catalyst life and reduced coke deposition. Stable performance was observed for 50 hours under optimal conditions, exhibiting remarkable durability in steam reforming of model tar compounds. Characterization of deposited coke using field-emission scanning electron microscopy (FE-SEM) and Raman spectroscopy revealed lower crystallinity in the SR-TN system, suggesting a potential link to reforming activity decrease. [ABSTRACT FROM AUTHOR]

A potassium (K)-promoted Ru-based siliceous molecular sieve catalyst, K-nRu-MCM-41, was successfully synthesized via a hydrothermal method. The combined analysis of XRD, FT-IR and XPS data revealed that Ru exists in the framework of the molecular sieves as RuO2 species, leading to structural alterations. SEM and TEM images demonstrated that Ru doping disrupts the morphology of the molecular sieves, while K addition effectively preserves the original morphology and further enhances particle dispersion. The ammonia decomposition performance test indicated that K promotes the activity of the molecular sieve catalysts. At 450 °C and 12 000 mL gcat−1 h−1, K-4Ru-MCM-41 achieved 82.7% ammonia conversion and 253.6 mmol gRu−1 min−1 hydrogen production, respectively, which was a 7.6% increase in ammonia conversion compared with 4Ru-MCM-41. Furthermore, the K-4Ru-MCM-41 catalyst exhibited excellent reusability, maintaining its stable catalytic activity performance after 30 h. [ABSTRACT FROM AUTHOR]

The present study proposes La and Sr‐containing La1−xSrxNi0.8Zr0.2O3 (x=0.1, 0.2, 0.4, 0.6, 0.8) perovskites as potential catalysts for bi‐reforming of methane (BRM) with CO2 and steam to produce hydrogen rich syngas. The catalysts were prepared by sol‐gel method and characterized using various techniques such as XRD, H2‐TPR, BET, CO2‐TPD and CHNS analysis. The characterization studies revealed that metal‐support interaction increased with the increase in the composition of Sr and the reduction behavior of Ni found to vary with the addition of Sr. The total energy calculations reveal that the addition of Sr to the LNZ system shirnks the volume due to low atomic and high ionic radii of Sr over La, which increases the total energy of system driving towards instability with increasing doping concentration of Sr. CO2‐TPD results suggest that a small amount of Sr can change the basicity of the support. The BRM activity results revealed that La0.8Sr0.2Ni0.8Zr0.2O3 perovskite is the most promising and active catalyst. The proposed catalysts are found to be advantageous w.r.t less carbon deposition due to the increased dispersion, small crystalline size, and required basicity of the support. The disclosed catalyst has shown excellent stability for a studied period of 100 h. [ABSTRACT FROM AUTHOR]

In situ methanol steam reforming for hydrogen production is a promising technology to provide a hydrogen source for full cells. However, the conventional methanol steam reforming usually encounters catalyst inefficiency and instability, which make its industrial application difficult. This work proposes a novel and stable Ni-based catalyst supported by spongy mesoporous alumina and achieves an enhancement of hydrogen production. The prepared Ni/γ-Al2O3 catalyst exhibits a higher hydrogen production yield of 0.26 mol h-1 than the commercial Ni/γ-Al2O3-Com catalyst (0.21 mol h-1) at 450 °C, with an improvement of the hydrogen flow rate of 23.8%. The Ni/γ-Al2O3 catalyst also presents a much superior performance to the reported noble metal-based catalysts and Ni-based catalysts. The special spongy mesoporous structure provides favorable conditions for high catalytic activity, mainly based on the high dispersion of the Ni metal site and the high catalyst stability. The Ni metal particles are highly dispersed over spongy mesoporous Al2O3 with an average particle size of only 3.7 nm. Characterization analysis shows that the spongy mesoporous structure of the catalyst enables quick adsorption of the reactants and reaction intermediates, and the highly dispersed Ni metal site can lead to the rapid dehydrogenation of methanol to increase the hydrogen yield. Moreover, the stability of the prepared Ni/γ-Al2O3-5H catalyst is much superior to that of the commercial Ni/γ-Al2O3-Com catalyst, where Ni/γ-Al2O3-5H retained 100% of methanol conversion for 12 h, and the spongy mesoporous structure and the high dispersion of Ni particles were also well maintained. In addition, the reaction mechanism of methanol steam reforming over the Ni/γ-Al2O3-5H catalyst is revealed in detail, especially based on the in situ DRIFTS characterization results. This research provides valuable insights for the development of catalytic methanol steam reforming for hydrogen production and in the field of green chemistry. [ABSTRACT FROM AUTHOR]

This article explores the use of oligomerized [Cu-O-Cu] species on zeolites as catalysts for the plasma-catalytic one-step steam reforming of methane to methanol and hydrogen. The researchers found that the Cu/MOR catalyst performed the best, achieving a 6.8% methane conversion and 73.1% methanol selectivity. They also compared the performance of different Cu/zeolite catalysts and determined that the specific surface area did not significantly impact catalytic performance. The study provides valuable insights into the development of more sustainable and efficient methods for methane conversion. [Extracted from the article]

Ni-incorporated Mg–Al type hydrotalcite-like catalytic materials were synthesized following impregnation and co-precipitation routes, and their catalytic performances were compared in the dry-reforming reaction of methane. The effects of Ru impregnation on the catalytic performance of Ni-incorporated Mg–Al were also investigated. Results showed that the catalytic performance of the Ni-incorporated Mg–Al type catalyst (NiMgAlO), which was prepared by the co-precipitation route, was highly stable during dry-reforming reaction tests performed at 600 °C, extending up to 24 h. The fractional conversion of CO2 (0.42) was higher than the fractional conversion of CH4 (0.29) due to the contribution of the reverse water gas shift reaction. However, the contribution of the reverse water gas shift reaction to the product distribution was much less with the catalyst prepared following the impregnation route (Ni@MgAlO). This difference was shown to be mainly due to the state of the nickel in the catalyst structures. Ni-impregnated Ca–Al type hydrotalcite-like catalyst (Ni@CaAlO) was also synthesized and tested in dry reforming of methane. Results obtained with the Ni-impregnated Ca–Al type catalyst showed some changes in its structure and the formation of some CaCO3 during the dry reforming reaction. The comparison of the performances of Ni-impregnated Mg–Al and Ca–Al type catalysts showed a higher amount of coke on the surface of Ni@CaAlO than Ni@MgAlO. It was also concluded that significant coke minimization and highly stable catalytic performance could be achieved by the impregnation of 1 % Ru to the NiMgAlO catalyst. The amount of coke deposited on the catalyst decreased from about 30 % to less than 5 %, by Ru impregnation. The decrease of the surface area of the Ru-impregnated catalyst was also only about 3 % after 240 min of reaction time. [ABSTRACT FROM AUTHOR]

Hydrogen is widely considered as the energy carrier of the future, but the rather high energy losses for its production are often neglected. The major current hydrogen production technology is steam methane reforming of fossil gas, but there is a growing interest in producing hydrogen sustainably from water using electrolysis. This article examines four main hydrogen production chains and two transportation options (pipeline and ship) from North Africa to Europe, analyzing the costs and environmental impacts of each. The core objective is to determine the most promising hydrogen provision method and location from an economic and ecological point of view, including the required transport. An important finding of this analysis is that both options, importing green hydrogen and producing it in Europe, may be relevant for a decarbonized energy system. The emphasis should be on green hydrogen to achieve carbon emission reductions. If blue hydrogen is also considered, attention should be paid to the often-neglected methane emissions upstream. • Imports and local production of hydrogen are equally important. • Emphasis should be on green hydrogen to cut emissions. • Regarding blue hydrogen, attention should be paid to the methane emissions upstream. [ABSTRACT FROM AUTHOR]

The aim of this work is the preparation and the electrification of Ni_CeO 2 _Al 2 O 3 /OBSiC (Oxygen Bonded SIlicon Carbide) based foams used in two different endothermic reactions for H 2 production: methane steam reforming and ammonia cracking. In particular, the heating of the catalytic foams occurs by the Joule effect, and to guarantee a uniform temperature profile in both the axial and radial direction, two different heating resistances were used. In addition, the high tortuosity together with the very high thermal conductivity of the OBSIC carrier, allow to overcome the heat and mass transfer limitations achieving a better control of the reaction behavior. Wet impregnation method was adopted for the Ni and Ce deposition, while the final catalysts was characterized through Hg penetration technique, Scanning Electron Microscope (SEM), N 2 adsorption @77 K for the specific surface areas (SSA) determination and X-ray diffraction (XRD). The methane steam reforming and ammonia cracking tests were both carried out, in the same reactor, but at different space velocity values (WHSV). The results obtained are exciting, not only in terms of equilibrium approach and hydrogen production, but also in terms of energy consumption as kWh/Nm3 of H 2 produced. In particular, in the case of methane steam reforming the results showed an energy consumption E [kWh/Nm3 H 2 ] equal to 1.21 obtained at WHSV equal to 6.2 h−1, very close to the theoretical limit of 0.98 kW h/Nm3 H 2. Also, for ammonia cracking, the energy consumption was very promising considering the scale of our reactor, with 1.5 kW h/Nm3 H 2 obtained at a WHSV of 2.27 h−1, considering the theoretical limit equal to 0.71 kW h/Nm3 H 2. [Display omitted] • Joule heated structured catalyst on SiC foam as heat source for endothermic reactions. • Ni/CeO 2 –Al 2 O 3 -based catalyst was used for MSR and ammonia cracking reaction. • Good equilibrium approach was obtained for methane conversion and hydrogen yield. • The calculated energy consumption (kWh/Nm3) is very close to the theoretical limit value. • Nickel as an active species avoid the use of noble metals. [ABSTRACT FROM AUTHOR]

Steam reforming of glycerol (GSR) to produce hydrogen has been considered a sustainable and low-cost route for hydrogen production. The selection of a suitable catalyst support is crucial for achieving efficient hydrogen production at lower temperatures. CeO 2 has been widely used in heterogeneous catalysis and exhibits excellent low-temperature catalytic performance. However, different calcination mode may influence catalyst performance. In this study, the Ni/CeO 2 catalyst prepared by rapid calcination mode (Ni/CeO 2 -RC), was used for hydrogen production from GSR, and the Ni/CeO 2 catalyst with the conventional programmed-heating calcination method (Ni/CeO 2 -PC) was applied for comparison. The effect of different calcination modes on the physico-chemical properties of the catalysts was investigated through multiple characterizations such as N 2 adsorption-desorption, X-ray diffraction, hydrogen temperature programmed reduction, transmission electron microscopy, X-ray photoelectron spectroscopy, H 2 chemisorption, CO-oxygen storage capacity and conversion, temperature programmed oxidation, and Raman spectroscopy. The rapid calcination mode promoted stronger metal-support interactions in Ni/CeO 2 -RC, inducing the formation of nickel species highly susceptible to reduction due to the electronic effect. Additionally, rapid calcination facilitated the increased incorporation of nickel particles into the cerium dioxide lattice, leading to lattice distortions, thereby contributing to the formation of more oxygen vacancies. The abundant oxygen vacancies promoted the activation of water, thus realizing the high H 2 selectivity of Ni/CeO 2 -RC. Moreover, the strong oxygen storage-release ability of Ni/CeO 2 -RC facilitated the oxidative effect of carbon deposition and the strong Ni–CeO 2 interaction effectively inhibit sintering of nickel nanoparticles on Ni/CeO 2 -RC. Therefore, Ni/CeO 2 -RC exhibited outstanding catalytic stability, remaining active for 35 h without deactivation, whereas Ni/CeO 2 -PC rapidly deactivated after 25 h of reaction. [Display omitted] • Ni/CeO 2 catalyst with rapid calcination enhances catalytic stability of the catalyst. • Nickel-ceria interaction modulates active nickel and oxygen vacancies. • Strong nickel-ceria interaction is achieved through rapid calcination. • Ni/CeO 2 catalyst with rapid calcination inhibits the formation of carbon deposition. [ABSTRACT FROM AUTHOR]

This study focuses on the use of H‐ZSM‐5 catalyst modified with transition metals for the conversion of ethanol into liquid fuel hydrocarbons. The HZSM‐5 catalyst was synthesized hydrothermally, and the transition metal (0.5 wt%) was incorporated by the incipient wetness impregnation method. The synthesized catalysts were tested in a fixed‐bed reactor at varying weight hourly space velocities (WHSVs) and temperatures to investigate their effects on the selectivity of the liquid hydrocarbon product. The pure and metal‐doped catalysts were characterized using XRD, FTIR, SEM–EDX, PSD, BET, N2 adsorption–desorption, and NH3‐TPD. The metal species were evenly dispersed on the catalyst support without affecting the porous framework significantly. The modification did not alter the morphology of the catalyst; however, the particle size was altered slightly. The pore distribution plot confirms the hierarchical porous framework of the catalyst. This unique feature facilitates internal diffusion and accelerates mass transfer, improving the selectivity and distribution of the liquid product. The catalytic evaluation showed ethanol conversion of more than 97% for all catalysts tested. A low space velocity (5 h−1) favored gaseous (C1‐C4) hydrocarbons, but more liquid products (C5+) were generated at 12 h−1 (at 350 and 400 °C), with metal‐doped catalysts showing higher selectivity (> 79%). In comparison with the unmodified catalysts, the metal‐doped catalysts enhanced the production of aromatics (benzene), with Ni/HZSM‐5 showing higher selectivity (> 4%). This study showed that the synthesized catalysts are active in the selective production of liquid hydrocarbon and improve the transformation of ethanol to fuel‐range hydrocarbons. [ABSTRACT FROM AUTHOR]

In this study, a series of nickels supported on gamma alumina with a metal dosage ranging from 0.5 to 3 wt.% were prepared and employed as the catalysts. The effect of nickel dosage on material properties, reaction performance, and catalyst deactivation was investigated. At a low dosage, the nickel-free having low metal-support interaction contributed significantly to the total active site. The basicity of the material was enhanced along with the increase in nickel loading. The presence of active metal showed a great impact at the beginning leading to big improvements in feedstock conversion. However, beyond a nickel dosage of 2 wt.%, further additions did not noticeably influence the reaction performance. Regarding catalyst deactivation, different carbon species were observed on catalyst surface, depending on the nickel dosage. Catalysts with less than 2 wt.% nickel exhibited amorphous carbon as the dominant morphology on the spent catalyst. In contrast, catalysts with 2Ni/Al2O3 and 3Ni/Al2O3 compositions showed graphitic carbon as the main side product. These findings provide insights into the relationship between nickel dosage, catalyst properties, and catalytic performance in methane dry reforming. By understanding the effects of nickel loading on material properties and reaction behavior, researchers can optimize catalyst design and develop more efficient and stable catalysts for sustainable syngas production. [ABSTRACT FROM AUTHOR]

Catalytic aqueous‐phase reforming (APR) of wet biomass such as microalgae and activated sludge is a potential technique for the production of H2‐rich gaseous products. In the present work, model compounds such as ethylene glycol, xylose and alanine were selected as representatives of the polyols, carbohydrates and proteins in wet biomass. APR trials were performed in a stirred batch reactor using commercial Pt/Al2O3 and Ru/Al2O3 catalysts. The reforming reactions were investigated at different conditions: temperature (T), 498 to 518 K, feed concentration, 1 to 5 wt. %, catalyst loading (ω), 2 to 6 kg/m3, and reaction time (t), 1 to 6 h. The commercial Pt/Al2O3 catalyst exhibited higher reforming activity. The influence of reaction parameters on turnover frequency (TOFH₂), hydrogen yield (Y‐H2) and carbon‐to‐gas conversion (C to G conversion) was studied. The values of TOFH₂ for Pt/Al2O3 were measured at T = 518 K, ω = 2 kg/m3 and t = 3 h using 1 wt% feed and these values were 19.2, 4 and 6 1/min for ethylene glycol, xylose and alanine. The values of TOFH₂ over Ru/Al2O3 under identical conditions were: ethylene glycol–12.4, xylose–1.4 and alanine–5.4 1/min. The activation energies for H2 production from ethylene glycol, xylose and alanine over Pt/Al2O3 and Ru/Al2O3 catalysts were determined. APR of the mixture of model compounds was also studied over laboratory‐made Pt/Al2O3 and Ru/Al2O3 catalysts at the optimum reaction conditions. Thus, this work has provided crucial insights into the production of H2 from model compounds of wet biomass using Al2O3‐supported catalysts. [ABSTRACT FROM AUTHOR]

Compared with the relatively simple monometallic and bimetallic oxide catalytic systems, polymetallic catalysts have attracted much attention in recent years. CuO–(Y2O3)(1−x)/2(CeO2)x (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) polymetallic catalyst for hydrogen production by methanol steam reforming(MSR) was prepared by sol–gel method and characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, X‐ray photoelectron spectroscopy (XPS), and Specific surface area and pore size analyser(BET) techniques. XRD results show that the diffraction peaks of CuO–(Y2O3)0.4(CeO2)0.2 are sharp and intense, indicating that it is highly crystalline. SEM results show that the pore structure of catalyst becomes loose with the increase of Ce doping amount, and the catalyst particles become more uniform in size and more loose in shape. The BET results show that compared with other catalysts, CuO–(Y2O3)0.4(CeO2)0.2 catalyst has larger specific surface area, which improves the catalytic performance. XPS results showed that CuO–(Y2O3)0.4(CeO2)0.2 still had catalytic activity after reduction treatment. The results of MSR showed that the doping amount of cerium and the reaction conditions affected the catalytic performance of the catalyst. Ce doping promoted the synergistic effect of Cu and Y, and the hydrogen production of CuO–(Y2O3)0.4(CeO2)0.2 was the highest (about 6.74 × 10−3 mol/min/gcat). Ce doping leads to the change of CO/CO2 selectivity in gas products. The CO selectivity of CuO–(Y2O3)0.4(CeO2)0.2 catalyst is only 2% under the catalytic conditions of 400°C, W/M 4:1, and LHSV 20 h−1, which shows good catalytic activity. [ABSTRACT FROM AUTHOR]

One promising idea to use excess glycerol generated during biodiesel fabrication is to produce hydrogen (H2) via the steam reforming of glycerol (GSR). This study combined GSR and water-gas shift (WGS) reactors to minimize energy usage and carbon monoxide (CO) emissions while augmenting H2 production. Choice of a Ni/γ-Al2O3 catalyst for the GSR reaction at 0.101 MPa and 923 K resulted in a product stream having 66.12% and 9.68% H2 and CO, respectively. For the WGS reactor, a Pt/HAP catalyst achieved 100% conversion of CO at 0.101 MPa and 723 K. Combining the two catalysts at an optimized temperature of 923 K for over 15 h resulted in H2 and CO levels at 69.85% and 1.77%, respectively: thus, increasing the production rate of H2 by 5% while reducing CO by 81%. Coking did occur during the GSR reaction. Overall, the combined reactor has potential to reduce complexity and energy usage. [ABSTRACT FROM AUTHOR]

[Display omitted] Hydrogen is widely regarded as a sustainable energy carrier with tremendous potential for low-carbon energy transition. Solar photovoltaic-driven water electrolysis (PV-E) is a clean and sustainable approach of hydrogen production, but with major barriers of high hydrogen production costs and limited capacity. Steam methane reforming (SMR), the state-of-the-art means of hydrogen production, has yet to overcome key obstacles of high reaction temperature and CO 2 emission for sustainability. This work proposes a solar thermo-electrochemical SMR approach, in which solar-driven mid/low-temperature SMR is combined with electrochemical H 2 separation and in-situ CO 2 capture. The feasibility of this method is verified experimentally, achieving an average methane conversion of 96.8% at a dramatically reduced reforming temperature of 400–500 °C. The underlying mechanisms of this method are revealed by an experimentally calibrated model, which is further employed to predict its performance for thermo-electrochemical hydrogen production. Simulation results show that a net solar-to-H 2 efficiency of 26.25% could be obtained at 500 °C, which is over 11 percentage points higher than that of PV-E; the first-law thermodynamic efficiency reaches up to 63.27% correspondingly. The enhanced efficiency also leads to decreased fuel consumption and lower CO 2 emission of the proposed solar-driven SMR system. Such complementary conversion of solar PV electricity, solar thermal energy, and low-carbon fuel provides a synergistic and efficient means of sustainable H 2 production with potentially long-term solar energy storage on a vast scale. [ABSTRACT FROM AUTHOR]

In order to achieve the hydrogen economy and respond to initial hydrogen demand appropriately, a hydrogen production and operation methodology is required to secure the economic feasibility of long-term on-site HRS. This study proposes a novel investment strategy for on-site hydrogen production to meet future hydrogen demand. The optimal investment strategy based on the dual-modal mode of combined autothermal reforming (ATR) and steam methane reforming (SMR) is proposed for hydrogen production using natural gas (NG) as a raw material. To predict hydrogen demand from 2020 to 2030, the machine learning (ML) technique was adopted. R 2 and MSE as result using ML were 0.9936 and 6.88 × 10 − 5 , respectively. In addition, the ATR-SMR hydrogen strategy (ASHS) process was analyzed and compared with the SMR-SMR and ATR-ATR hydrogen strategy (SSHS and AAHS) processes in terms of optimal operation rate, storage tank management, economics, and environmental impacts. The operation rate of proposed hydrogen production processes was determined by the hydrogen demand and storage tank level, and the optimal investment plan to install additional hydrogen process depends on the total amount of hydrogen production. In this study, these results were observed due to the effective combination of the strengths of ATR and SMR. Consequently, the ASHS had the best cost-effectiveness (LCOH at $5.63/kg H2) and environmental friendliness (unit CO2eq emissions at 10.21 kg CO2eq/kg H2 and 1.73 kg CO2eq/kg H2 with CCS). This study includes sensitivity analysis and a comparison of CO2 taxes by the country for three proposed hydrogen production processes. It could contribute to the optimal operation of the on-site hydrogen production system in preparation for future hydrogen demand. [ABSTRACT FROM AUTHOR]

Hydrogen can be produced from several feedstocks and technologies, making it an important partner in the energy transition to neutral carbon societies. Hydrogen production can be based on renewable feedstocks, such as agricultural residues, which are highly available and economical. However, a comprehensive analysis of all available hydrogen production technologies must be done. Therefore, this work focused on developing a comparative analysis of the sustainability of the main hydrogen production technologies. Technologies with the greatest opportunity for development were simulated and evaluated from a sustainability perspective. Techno-energetic, economic, environmental, and social indicators were used to calculate a comprehensive sustainability index (S Id). Steam biomethane reforming (SBMR) and electrolysis (EL) were the schemes with the highest S Id based on the techno-energetic and environmental dimensions. However, the S Id decreased substantially when the economic dimension was considered because SBMR presented high capital and operating costs, and EL had low technical performance. On the other hand, thermochemical and biological technologies require further research to decrease the environmental burden and improve the mass yield of the process. Therefore, each production scheme involves different disadvantages that must be resolved to increase the opportunities for hydrogen development. [Display omitted] • The sustainability index made it possible to establish the development opportunity presented by each technology considering different dimensions of analysis. • Steam biomethane reforming and gasification processes are more efficient and economically viable than electrolytic and biological technologies. • The cost of hydrogen production in electrolytic processes is highly dependent on the primary source of electricity. • Hydrogen production by biological processes requires more research on improving yields and production costs. • The scheme with the highest sustainability indexes was the steam biomethane reforming scheme. [ABSTRACT FROM AUTHOR]

The effect of aluminum as a promoter for cobalt and iron catalysts was investigated. The unsupported Fe–Al and Co–Al catalysts were synthesized by co-precipitation, and their catalytic activity in methane decomposition was evaluated. The physiochemical properties of Fe–Al and Co–Al were thoroughly investigated by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET and Raman spectroscopy. Fe–Al has a larger pore surface area than Co–Al and the morphology of the two is different. The Co–Al sample contains cobalt aluminate and cobalt oxide. The Fe–Al sample on the other hand, consists of Fe 2 O 3 (65.4%) and hercynite FeAl 2 O 4 (34.5%). The XPS analysis confirms the presence of the different oxides Fe3+, Fe2+, Co2+, Co3+ and Al 2 O 3 on the surface of the samples. Raman results indicate the cation distribution between tetrahedral and octahedral sites. The Fe–Al catalyst shows a higher catalytic activity for methane conversion (95%), a hydrogen formation rate of 176.10 × 10−5 mol H 2 g−1min−1, and no sign of deactivation during 300 min. In contrast, Co–Al deactivated rapidly after ∼30 min. TEM images of spent catalysts show the presence of various forms of deposited carbon: carbon nano-onions (CNOs), multi-walled carbon nanotubes (MWCNTs) and bamboo-like carbon nanotubes (BCNTs). [Display omitted] • Unsupported Fe–Al and Co–Al were used as catalysts for methane decomposition. • 90% Fe–Al was a highly active, stable catalyst compared with 90% Co–Al. • XPS confirm the presence of Fe3+, Fe2+, Co2+, Co3+, Al 2 O 3 in fresh catalysts. • The Fe 3 C, FeAl 2 O 4 and αCo are the active species for methane decomposition. • Various forms of carbon nanostructure were deposited on spent catalysts. [ABSTRACT FROM AUTHOR]

Formic acid is used as a green carrier for hydrogen storage and production. Here, in order to achieve rapid dehydrogenation of formic acid, the catalyst PdNi/OPDA-MWCNTs is synthesized by reducing bimetallic PdNi nanoparticles on o-phenylenediamine (OPDA) modified multi-walled carbon nanotubes (MWCNTs). Ultrafine metal nanoparticles with a size of 2.6 nm are obtained in the presence of amine groups. The catalyst system Pd0.7Ni0.3/OPDA-MWCNTs catalyzes hydrogen production from formic acid in an additive-free environment with excellent activity, reaching the turnover frequency (TOF) value of 1303 h−1 at 323 K. This is comparable to most reported values. In addition, the catalyst maintains good catalytic activity in five-cycle tests under the same conditions. [ABSTRACT FROM AUTHOR]

Series of La‐doped Mg−Al composite oxides were prepared by co‐precipitation method and used as catalysts for the synthesis of diethyl carbonate (DEC) via transesterification of ethylene carbonate (EC) with ethanol (EtOH). SEM, XRD, FT‐IR and XPS results confirmed that the introduction of La enhanced the interaction with MgO. The 8 mol % La‐doped Mg−Al composite oxide (calcined catalyst named HTC‐0.8 La) produced strong interactions and improved lattice oxygen content (27.84 %). Based on the N2 adsorption‐desorption and CO2‐TPD results, the HTC‐0.8 La catalysts possessed abundant multistage mesoporous structure, high strong base density and strength (0.941 mmol ⋅ g−1). Therefore, the HTC‐0.8La catalyst exhibited high catalytic activity with 58.5 % yield of DEC and 94.7 % selectivity to DEC (EC: EtOH molar ratio=1 : 6, reaction time=1.5 h, reaction temperature=150 °C and catalyst amount=3.2 wt %). Based on the correlation between catalytic activity and alkalinity, the yield of DEC was positively and linearly related to the strong alkali density of the catalyst. After five replicate experiments, the DEC yield after recovery and roasting reached 54.1 %, indicating that HTC‐0.8La is a renewable heterogeneous catalyst. [ABSTRACT FROM AUTHOR]

In continuation of the previous part, this paper comprehensively focuses on energy, exergy, exergo-economic, and environmental (4E) analyses of two prioritized clean hydrogen (H 2) supply chains pathways. The first scenario relies on domestic demand , involves blue H 2 production and storage using steam methane reforming coupled with carbon capture and storage through H 2 conversion to hydrogen carriers in liquid form (ammonia and methanol) aligned with the existing infrastructure. The second scenario involves green H 2 production from photovoltaic panels as the power source follows by storing H 2 in liquid form which is more suitable to export. The findings indicate that the blue H 2 system outperforms the green H 2 system in terms of energy and exergy, boasting 41.38% and 22.15% compared to 12.16% and 12.75%, respectively. However, when examining economic parameters, the blue H 2 system shows a total cost rate of 1976 US$/h, a net profit of $747.2 million (mn) at the end of its lifetime, and a payback period of approximately nine years. Conversely, the green H 2 system demonstrates economic indicators of a 125.2 $/h as a total cost rate, $1.26 billion (bn) net profit, and an 8.17 year payback period. Moreover, the production cost rates for blue and green H 2 are 1.32 $/kg and 2.55 $/kg, respectively; while the CO 2 emissions rate in the blue H 2 system is 10.71 kg/s. The green H 2 system prevents 19.84 kg/s of CO 2 emissions resulted a significant environmental cost reduction of 2.28 $/kg H 2. This analysis facilitates a thorough comparison of these two clean H 2 production and storage systems, offering insights for policymakers across performance, economic, and environmental dimensions. • A comprehensive 4E analysis was applied for the selected H 2 value chain scenarios. • Blue H 2 scenario is superior economically while environmentally the green one takes precedence. • Carbon credit makes the green H 2 scenario emerges frontrunner utilizing PV solar technology. • Methanol was recognized as the most cost-effective H 2 carrier for storage in Iran. [ABSTRACT FROM AUTHOR]

A series of nickel (Ni) catalysts were prepared using zeolites Y with different cation types (Na, Mg, Ca, Sr, Ba, Ce, and La) as supports and characterized by using XRD, BET, ICP-OES, XPS, and TEM , as well as NH 3 -TPD, CO 2 -TPD, and H 2 -TPR techniques. Their catalytic performances in decomposition of ammonia (NH 3) to hydrogen (H 2) were evaluated with a fixed-bed flow reactor system. The catalytic activities of the prepared catalysts for NH 3 decomposition decreased in the order of Ni/SrY > Ni/BaY > Ni/LaY > Ni/CaY > Ni/NaY > Ni/MgY > Ni/CeY. The high activity of Ni/SrY catalyst may be attributed to its small Ni nanoparticle size, high basicity and strong interaction between highly dispersed Ni nanoparticles and SrY support. At 600 °C and GHSV of 9000 mLNH 3 ·g cat −1·h−1, 98.0 % NH 3 conversion with about 105.2 mmol min−1·g Ni −1 H 2 formation rate can be accomplished over Ni/SrY catalyst. [Display omitted] • High-activity Ni/Y catalysts were prepared on various cation-exchanged zeolite Y. • Ni/SrY catalyst showed high activity and stability for ammonia decomposition. • Ni/SrY shows superior activity due to its small Ni particle size, high basicity, and strong metal-support interaction. [ABSTRACT FROM AUTHOR]

This research investigates hydrogen production from urban pruning waste biomass through combined hydrothermal treatment and aqueous phase reforming. Optimization of treatment parameters (temperature, time and pH) yielded a hydrolysate rich in water-soluble compounds. The most effective conditions were found at 180 °C and 60 min, achieving a balanced hydrolysis and solubilization of lignocellulosic waste. Low pH, induced by organic acids from the waste, drove hydrotreatment, but further acid addition hindered solubilization. Aqueous phase reforming at 220 °C with a carbon-supported Pt catalyst resulted in enhanced carbon conversion and H 2 production at an initial carbon concentration of 1,000 mg/L. Increasing Pt load from 3 to 5 % wt. improved production and selectivity, plateauing at 7.5 % wt. Optimal conditions demonstrated a H 2 production of 17 mmol per gram of dissolved organic carbon, affirming the viability of this scheme for pruning waste valorization. [Display omitted] • Lignocellulosic biomass hydrolyzed and hydrolysate used as feed for APR. • Mild conditions at hydrolysis result in higher hydrogen production by APR. • Best APR results for hydrolysate obtained at 200 °C for 1 h • 80 % TOC conversion and 17 mmolH 2 /gTOC achieved at APR. [ABSTRACT FROM AUTHOR]

This work presents a multi-functional NiCoCe-based catalyst for crude oil steam reforming for hydrogen production. Arab Light (AL) and Arab Extra Light (AXL) were centrifuged to reduce the asphaltenes and sequentially steam reformed in a fixed bed reactor. Results showed that the NiCoCe catalyst was stable and highly selective under reaction conditions and in cyclic operation. The physicochemical properties of the catalyst were determined via inductively coupled plasma–optical emission spectrometry, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The high dispersion of the NiCo alloy on a Mg–Al support was crucial for ensuring the hydrocarbon reforming in the presence of heteroatomic species. • Multi-functional NiCoCe-based catalyst for crude oil to hydrogen. • Process based on steam reforming of different Arabian crudes. • Arabian light and Arabian extra light are centrifuged to reduce the asphaltenes. • The cyclic operation helped to sustain the catalyst activity and stability. • Continued hydrogen production for 14 h. [ABSTRACT FROM AUTHOR]

This review explores the viability of selectively upgrading methanol to formate as a potential route for hydrogen production, with a particular emphasis on replacing the anodic oxygen evolution reaction in electrolyzers. Transition metal-based electrocatalysts demonstrate significant potential for selectively upgrading methanol to formate. The review elucidates the challenges associated with noble metal-based electrocatalysts, including catalyst deactivation resulting from carbon monoxide (CO) intermediate adsorption and restricted methanol-to-formate selectivity. Mechanistic insights are delved into, with a focus on electrochemical methanol oxidation pathways such as O–H and C–H activation. The impact of methanol concentration on selectivity is examined, alongside the interaction between methanol oxidation and oxygen evolution. Catalyst composition is scrutinized, highlighting nickel-based and Ni-free materials, while exploring strategies to reduce cell voltage, advanced characterization techniques (e.g., in-situ Raman, X-ray absorption fine structure spectroscopy), nanotechnology advancements, and cost-effective hydrogen production through methanol-assisted water splitting. Additionally, the review underscores the potential of methanol upgrading for hydrogen production, acknowledges existing challenges, and proposes innovative avenues for future research. • Investigates methanol assisted H 2 production. • Highlights electrode degradation and selectivity limits. • Proposes innovative catalyst design research. [ABSTRACT FROM AUTHOR]

The properties of supports (such as oxygen vacancies, oxygen species properties, etc.) significantly impact the anti-carbon ability due to their promotional effect on the activation of CO2 in dry reforming of methane (DRM). Herein, pyrochlore-type La2Ce2O7 compounds prepared using co-precipitation (CP), glycine nitrate combustion (GNC) and sol–gel (S-G) methods, which have highly thermal stability and unique oxygen mobility, are applied as supports to prepare Ni-based catalysts for DRM. The effect of the calcining temperature (500, 600 and 700 °C) on La2Ce2O7(CP) has also been investigated. Based on multi-technique characterizations, it is found that the synthesis method and calcination temperature can influence the particle size of the La2Ce2O7 support. Changes in particle size strongly modulate the pore volume, specific surface area and numbers of surface oxygen vacancies of the La2Ce2O7 support. As a result, the distribution of supported Ni components is affected due to the different metal–support interaction, thereby altering the activity of the catalysts for cracking CH4. Moreover, the supports' abilities to adsorb and activate CO2 are also adjusted accordingly, accelerating the removal of the carbon deposited on the catalysts. Finally, La2Ce2O7(CP 600) with an appropriate particle size exhibits the best catalytic activity and stability in DRM. [ABSTRACT FROM AUTHOR]

A series of boron-promoted Ni-Co/Ca catalysts were synthesized by the sol–gel method to enhance syngas generation from biomass pyrolysis. The efficiency of these catalysts was evaluated during the pyrolysis of rice straw in a fixed-bed reactor, varying the Ni/Co ratio, boron addition, calcination temperature, and residence time. The catalysts underwent comprehensive characterization using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (H2-TPR). The results indicated that the Ni-Co/Ca catalysts yielded superior syngas compared to singular Ni or Co catalysts, suggesting a synergistic interplay between nickel and cobalt. The incorporation of 4% boron significantly decreased the particle size of the active metals, enhancing both the catalytic activity and stability. Optimal syngas production was achieved under the following conditions: a biomass-to-catalyst mass ratio of 2:1, a Ni-Co ratio of 1:1, a calcination temperature of 400 °C, a pyrolysis temperature of 800 °C, and a 20 min residence time. These conditions led to a syngas yield of 431.8 mL/g, a 131.28% increase over the non-catalytic pyrolysis yield of 188.6 mL/g. This study not only demonstrates the potential of Ni-Co/Ca catalysts in biomass pyrolysis for syngas production but also provides a foundation for future catalyst performance optimization. [ABSTRACT FROM AUTHOR]

A two-stage process of biomass pyrolysis and dry/steam reforming for adjustable H2/CO syngas production is proposed. This process can not only control the ratio of H2/CO, but also realize the utilization of coke generated in the gasification process and reduce the energy consumption of biomass gasification, as well as the utilization of CO2. The process model was built after the pyrolysis experiment, and the thermodynamics of dry/steam reforming was studied under different reforming temperature, CO2/C, and H2O/C. With the increase in reforming temperature, the volume of CO increases gradually, and the volume of H2 increases first and then decreases. With the increase in CO2/C, the volume of CO increases gradually and the volume of H2 decreases gradually, while with the increase in H2O/C, the volume of CO decreases and the volume of H2 increases, so diverse-H2/CO-ratio syngas can be obtained by adjusting the H2O and CO2 input as well as the reforming temperature. For the production of syngas with H2/CO = 2, by comparing the total volume of gas produced and energy consumption, the optimum reforming conditions are obtained: CO2/C = 0.5, H2O/C = 2, and the reforming temperature is 770 ℃. Similarly, the optimum reforming conditions for the production of syngas with H2/CO = 3 are: CO2/C = 0, H2O/C = 2, and the reforming temperature is 770 ℃. [ABSTRACT FROM AUTHOR]

A kinetic theory, known as the Langmuir–Hinshelwood–Hougen–Watson adsorption model, is applied to describe the steam methane reforming (SMR) in a 500 kW scale micro chemically recuperated gas turbine (CRGT) cycle. The response surface models of important performance parameters, including the methane conversion, carbon monoxide selectivity, and chemically recuperated heat as a function of the temperature, pressure, steam-to-carbon ratio, and contact time are numerically obtained based on the cases selected by the central composite design. The factors affecting the SMR performance are analyzed, and the reformer performance is optimized using both the desirability function combined with the response surface methodology and the second generation non-dominated sorting genetic algorithm. Finally, performance of the optimized reformer and electrical efficiency of the micro CRGT cycle with the reformer are evaluated. Results reveal that the efficiency of the micro CRGT is 40.70%, which is much higher than the typical high-efficiency micro gas trubine without reformer. [Display omitted] • Steam methane reforming kinetics in micro chemically recuperated gas turbine. • Analyses of factors affecting reforming performance using response surface method. • Reformer optimizing by desirability function combined with response surface method. • Reformer optimizing by a second generation non-dominated sorting genetic algorithm. • Micro gas turbine cycle with the optimized reformer has an efficiency of 40.70%. [ABSTRACT FROM AUTHOR]

HP austenitic stainless steel undergoes microstructural aging due to prolonged exposure to oxidizing and corrosive atmospheres in steam reforming furnaces. The derived aging states are classified by its service temperature and microstructural markers and monitoring it is important to residual life assessment. In this regard it was used a portable Eddy Current inspection system with the aid of machine learning classification tools, characterizing aging states in HP steel in real-time. The classification profile of a 12-meter tube was acquired, validated through Field Metallurgical Replication. The developed Eddy Current inspection system successfully differentiates three regions, revealing a progression of aging states. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the system configuration and operating conditions for a full-scale plant for hydrogen (H2) production from biomass. We considered pretreatment and upgrade processes for generating pure biomethane and the steam methane reforming reaction for H2 production. The pretreatment of biogas occurs under atmospheric conditions and produces methane and carbon dioxide while capturing various toxic gases such as hydrogen sulfide. After the upgrade process, biomethane with a purity of 98 % is generated via a pressure swing adsorption and membrane separation system. The pure biomethane is then transported to the H2 production facilities and converted to H2 gas via steam methane reforming, thereby producing highly pure H2 (99.995 %). The full-scale plant can produce over 300 kg of H2 per day with an operating efficiency of over 90 %. The findings from this study can help further the understanding of the operating conditions and system configuration for a full-scale plant for H2 production plant from biomass. [ABSTRACT FROM AUTHOR]

Chemical looping steam methane reforming (CL-SMR) is one of the most potential methods for large-scale syngas production. As the key to CL-SMR, the development of oxygen carrier (OC) is typically limited by the factors of CH 4 conversion, H 2 selectivity and resistance to carbon deposition. However, the nonuniform distribution of metals in OC leads to unstable conversion rate and severe carbon deposition due to metal stacking effects. Therefore, the layer double hydroxides (LDHs) were introduced into OC preparation to achieve uniform metal distribution and solve the above problems. Moreover, different enhanced OCs derived from LDHs precursors were prepared to investigate the effects of divalent metal, Ni/Fe (N/I), Methane/OCs (M/O) and reaction temperature, as well as the adaptability and performance of CL-SMR. The results showed that uniformly dispersed Ni–Fe–Al OC possessed promising CH 4 conversion of 94.32%, H 2 selectivity of 72.61%, CO selectivity of 77.46%, stability of syngas production with H 2 /CO ratio of 2 and low carbon deposition of 5.28%. Further, the increase of N/I from 0.5:2.5 to 2.5:0.5 caused an increase in CH 4 conversion, H 2 selectivity and CO selectivity by 95.04%, 598.82% and 68.19%, respectively. However, the highest N/I ratio led to severe carbon deposition (17.57%) in the Ni 2.5 Fe 0.5 Al OC. Furthermore, Ni–Fe–Al OC with uniformly dispersed active metal exhibited a good stability and suitability in wide-range of M/O and temperature. In addition, H 2 selectivity gradually improved with the increase of M/O, but higher M/O of 1.2 resulted in higher carbon deposition (7.99%). Further, the increase of temperature was beneficial to the OC performance, but excessive temperature (950 °C) led to OC sintering. Moreover, this Ni 2 FeAl OC maintained good catalytic ability and lattice oxygen stability after long-term reaction. [Display omitted] • Metals of LDHs derived oxygen carriers are dispersed at the molecular level. • Molecularly dispersed Ni–Fe–Al oxygen carriers show good CL-SMR performance. • Ni 2 FeAl oxygen carrier shows good suitability in wide-range of M/O and temperature. • Higher N/I ratio can lead to more carbon deposition in the oxygen carriers. • Excessive temperature can lead to severe sintering of the oxygen carrier. [ABSTRACT FROM AUTHOR]

The previously proposed stationary mathematical model provides a reliable description of n-hexadecane (diesel surrogate) reforming over the Rh/Ce 0·75 Zr 0·25 O 2-δ /θ-Al 2 O 3 /FeCrAl structured catalyst. In its continuation this work represents the experimental studies and the model of the autothermal reforming process of hexadecane in a mixture with o-xylene and 1-methylnaphthalene. The reaction scheme is supplemented with reactions to account for steam reforming and oxidation of added aromatics compounds and selection of corresponding kinetic parameters is performed. The dynamic process of the reformer start until reaching the steady state is simulated by the non-stationary model in this work. The resulting mathematical and kinetic models provide a good description of the experiments performed with the reproduction of the dynamics of the observed outlet gas components concentrations and the catalyst temperature. The application of this model can be useful when considering the reforming of multicomponent mixtures or optimization of the dynamic start reformer process. • Mathematical modeling of diesel + aromatic autothermal reforming process is performed. • Non-stationary model for reformer start process is considered. • The reaction scheme and selected kinetics describe the process with a good accuracy. [ABSTRACT FROM AUTHOR]