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The present work utilizes a response surface optimization technique to optimize hydrogen-rich syngas production through the process of methane dry reforming (DRM). This optimization is achieved by employing a bimetallic Mn–Ni/La 2 O 3 catalyst. The study aimed to evaluate the impact of three key parameters, namely reaction temperature, time on stream (TOS), and gas hourly space velocity (GHSV), on the hydrogen to carbon monoxide (H 2 /CO) ratio in syngas during the DRM. The Mn–Ni/La 2 O 3 catalyst, synthesized using the sequential wet impregnation technique, exhibited suitable physicochemical properties necessary for DRM reaction, as evidenced by the obtained characterization data. Among the five models examined, it was found that the quadratic versus 2FI model substantially fit the experimental data, as evidenced by a p-value <0.05. The analysis of variance (ANOVA) conducted on the quadratic response surface model compared to the 2FI model demonstrated that both the reaction temperature and the TOS had a significant impact on the H 2 /CO ratio in the syngas. The only significant interaction factor was the relationship between the reaction temperature and the TOS. Under the specified optimal circumstances of 15 000 ml/g.h, 850 °C, and 258.15 min, an H 2 /CO ratio of 0.98 was achieved. The resulting H 2 /CO ratio of 0.98 is almost 1, indicating its suitability as a feedstock for methanol production in the Fischer-Tropsch synthesis (FTS). • The Mn–Ni/La 2 O 3 catalyst exhibited suitable properties necessary for DRM reaction. • Temperature and time had a substantial impact on the H 2 /CO ratio in the syngas. • The response surface quadratic model is statistically significant to fit the experimental data. • At optimized conditions H 2 /CO ratio of 0.98 was obtained for the syngas. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive techno-economic analysis of the world's first large-scale commercial Power-to-X (PtX) plant in Kassø, Denmark. This innovative facility combines solar photovoltaic (PV), an electrical grid, green hydrogen production, methanol synthesis, and district heating in an integrated system. We conduct an in-depth analysis to explore optimal operating conditions, the potential for sector coupling within the power and heat sectors, and the economic feasibility of the integrated system. In particular, we study different scenarios considering changes in solar PV power generation, electricity market price, CO 2 price, and methanol price to explore their impacts on the system performance. Our results show that the electrolyzer's operation, a pivotal component of the system, heavily depends on the electricity spot price as well as the methanol price. Based on the green production of methanol, a premium price of 4800 DKK/t (0.64 €/t) is considered in this study (selling price of 8400 DKK/t). The results show that in case of high electricity prices (2022 spot market) or no premium price for methanol, the optimum annual production of methanol decreases by 58% and 67%, respectively. Furthermore, we observe that the variability of solar power output significantly impacts the plant's performance and economic viability, as it supplies about 30% of the plant's power consumption. Although the results are unique to the Kassø plant, the study's techniques and insights can be applied to other comparable systems around the world. The study also highlights how crucial it is to take market, climate, and technical factors into account when developing and running integrated energy systems. • Techno-economic analysis of the world's first large-scale commercial Power-to-X (PtX) plant in Kassø, Denmark. • Insights to optimal operating conditions, sector coupling potential, and economic feasibility of Power-to-Methanol plants. • Analysis of the impact of market dynamics on the operational efficiency and economic viability of the integrated plant. • Study of the role of intermittent solar power and its impact on the performance and economic sustainability of the plant. [ABSTRACT FROM AUTHOR]

Hydrogen production by catalytic aqueous phase reforming (APR) of biomass oxygenated derivatives in relatively mild conditions is a promising way to produce hydrogen. In this work, Pt/CeO 2 -HT, Pt/La–CeO 2 -HT and PtLa/CeO 2 catalysts were synthesized by a novel photochemical reduction method and applied to the methanol APR. Extensive characterizations have proved that the mild catalyst preparation method gave it a high dispersion of Pt species and the addition of La modified the metal-support interaction. The results showed that La-modified Pt/La–CeO 2 -HT and PtLa/CeO 2 catalysts exhibited better catalytic performance than the Pt/CeO 2 -HT catalyst, among which the hydrogen yield was the highest for the surface La-modified PtLa/CeO 2 catalyst (177.7 mmol/g cat). This was mainly attributed to the surface modification of La resulted in a significant increase in the number of moderately strong basic sites and surface oxygen vacancies in the PtLa/CeO 2 catalyst. The enhancement of catalyst basicity effectively promoted the dissociation of H 2 O to produce hydroxyl groups, while a large number of surface oxygen vacancies provided more active sites for the adsorption and dissociation of H 2 O. And their synergistic behavior efficiently facilitated the water gas shift (WGS) reaction, resulting in a significant increase in hydrogen yield of methanol APR. Associated with the in situ DRIFTS analyzes and the results indicated by WGS reaction, possible promotion mechanism was proposed. [Display omitted] • Highly-dispersed APR catalysts were prepared by a novel photochemical reduction method. • The PtLa/CeO 2 catalyst exhibited the highest catalytic activity and H 2 yield (177.7 mmol/g cat). • Possible reaction mechanism of the synergistic effect on oxygen vacancies and basic sites is verified. [ABSTRACT FROM AUTHOR]

As the core part of a microreactor, the reaction carrier provides reaction site and energy supply for hydrogen production. Among various types of reaction carriers, porous reaction carriers with complex flow path structures can effectively improve hydrogen production performance, and thus are widely applied in fuel cells. To optimize the structure of catalyst carriers and improve the efficiency of hydrogen production of methanol reforming, we designed four TPMS porous carrier structures, namely structures D, G, P and IWP, and analyzed the effect of carrier structure and parameters on hydrogen production reaction in theory. After that, we manufactured TPMS carriers with varied structures and parameters using 3D printing, and designed and carried out loading tests, flow velocity simulation experiments and pressure drop calculation to study the influence of the structure morphology on load intensity, heat and mass transfer and other performance indexes with catalyst load. Finally, we carried out hydrogen production experiments in microreactors with different TPMS structures, from which we obtained an pattern influence of hydrogen production conversion rate and hydrogen velocity etc. At different velocities and temperatures. The experimental results indicate that structure type and parameters of TPMS node and porosity have a great effect on the performance of hydrogen production. Specifically, structure D performs the best and structure P performs the worst in hydrogen production. When the velocity is 1.7 ml/h and the temperature is 250 °C, the maximum difference of the hydrogen conversion rate between D and P structure can reach to 22 %, and that of the hydrogen velocity can reach to 0.02 mol/h. • Different catalyst carriers with TPMS structure were fabricated by 3D printing. • Load performance of TPMS structure with different porosities and loads was studied. • Impact of different TPMS on heat and mass transfer was analyzed. • Structure D and G outperformed structure P and IWP in hydrogen production. [ABSTRACT FROM AUTHOR]

This study aims a techno-economic analysis of a plant that produces methanol by hydrogenating carbon dioxide in the waste gas from an oil refinery using the electricity from floating photovoltaic power plant. First, carbon dioxide in the flue gas is captured in the carbon capture plant (CCP), and the hydrogen obtained from the seawater in the hydrogen plant (HP) with the help of photovoltaic energy is combined in the methanol plant (MPP) to produce methanol fuel. Using the Engineering Equation Solver (EES), a calculation was made of the amount of energy required and the number of solar panels or wind turbines that would be required to meet this demand, and then the environmental impact of the methanol plant was investigated. The Libyan Az-Zawiya oil refinery was considered for the case study due to its high solar potential, proximity to the sea and energy security. Systems' processes for CO 2 emissions, heat integration, energy efficiency, and thermo-economic performance were all taken into consideration. Renewable energy, synthetic fuel, and the methanol plant showed efficiencies of 0.21%, 0.5872%, and 0.1626%, respectively, and at the optimum density of the electrolyzer, 2.2 kA/m2, the efficiency of the electrolyzer was 0.782%. According to this study, all output parameters increase with the increase in the flue gas in the process, showing that flue gas is the most important input parameter affecting the outputs. The total cost of the plant for 30 years of operation was found to be $11.350 billion, with a production capacity of over 43.360 million tons of methanol, which equates to $412.9 per ton and $0.4129 per kg. Environmentally, the rate of captured emissions was about 4890 tons per day, and the mitigation rate was approximately 4513 tons per day. According to the results, the current plant is competitive with other clean synthetic fuel production plants. • High CO2 reduction potential. • Renewable hydrogen and methanol production. • On-demand hydrogen generation is provided with PEM electrolysis. • Hydrogen generation costs are competitive with other methods. [ABSTRACT FROM AUTHOR]

Sustainable cement-clay composite is used as the support of bimetallic Ni–Cu/Al 2 O 3 catalysts for hydrogen production from methanol steam reforming (MSR) reaction. The results indicate that higher methanol conversion and hydrogen yield can be obtained using composite supported catalysts. The cement-clay composite possesses CO 2 absorption capability, which can enhance MSR performance. In the cases of a large proportion of cement, the CO 2 concentration in the product is decreased by 1–2% where methanol conversion and hydrogen yield are not reduced. By varying the catalyst compositions such as Ni content, Ni–Cu/Al 2 O 3 loading, and the weight ratio of cement and clay, 100% methanol conversion can be achieved as Ni content and Ni–Cu/Al 2 O 3 loading increase. However, the CO concentration also increases due to the enhanced reverse water gas shift reaction. The results of the prepared 12 cement-clay-supported cases show the best performance with methanol conversion of 100%, hydrogen yield of 2.85 mol·(mol CH 3 OH)−1, and CO concentration of 5.90%. The scanning electron microscope images indicate no sintering of the spent catalyst, and the thermogravimetric analysis shows low coke formation on the catalyst surface. Overall, cement-clay replacing metal components in catalysts can efficiently reduce costs and intensify hydrogen production. [Display omitted] • This study investigates hydrogen production the methanol steam reforming. • Novel Ni–Cu/Al 2 O 3 catalysts using cement and clay composite as a support are prepared. • Cement-clay composite possesses CO 2 absorption capability to enhance H 2 production. • The highest CH 3 OH conversion is 100% and the highest H 2 yield is 2.85 (mol·mol CH 3 OH)−1. • Cement and clay replacing metal components in catalysts can efficiently reduce costs. [ABSTRACT FROM AUTHOR]

In the present study, techno-economic-environmental optimization of a solar-boosted energy system generating power, freshwater, and methanol as a promising clean fuel has been undertaken. A heliostat field with variable mirrors is used in a gas turbine cycle to decrease the necessity of burning much hydrocarbon fuel. By using pressure swing adsorption, 80% of the contained carbon dioxide of the exiting stream of the gas turbine is recovered and stored. In addition, by exploiting the waste heat of the exiting stream of the gas turbine, an organic Rankin cycle, a multi-effect distillation with thermal vapor compression, and a single effect absorption chiller are driven. Furthermore, a proton exchange membrane electrolyzer is utilized to generate hydrogen and portions of stored hydrogen and carbon dioxide go through the methanol synthesis reaction to produce desired methanol. A comprehensive parametric study through the 4E analysis has been carried out to detect the influential design parameters to set the decision variables for the optimization process. In the end, due to the complexity of the system, a deep neural network is developed to lower the computational time. The findings of the deep neural network-based optimization show the optimal solution in which the total cost rate of the system, exergy efficiency, and the emitted carbon dioxide values are 1.26 $/s, 46.25%, and 0.58 kg/s, respectively. • A novel solar-boosted plant including C O 2 capture and utilization is studied. • Stored hydrogen is used to synthesize methanol as promising fuel. • 4E analysis is carried out to propose an eco-friendly system with lower emissions. • Using the developed ANN, the optimization runtime decreased from 72 h to 40 min. • The exergy efficiency value is 46.25% in the optimal design. [ABSTRACT FROM AUTHOR]

Fuel synthesis through CO 2 hydrogenation is receiving much attention to decarbonizing the transport sector of future energy systems. In this study, an integrated system is proposed and investigated from a thermo-economic point of view to produce power and synthetic methane and methanol. The proposed system includes an externally fired gas turbine, Rankine cycle, organic Rankine cycle, proton exchange membrane electrolyzer, molten carbonate fuel cell and methane and methanol synthesis units. CO 2 hydrogenated under three different scenarios to produce methane-only, methanol-only and dual-production assuming various operating loads of electrolyzer. The influence of the key parameters on the system performance is assessed via response surface method and finally, the system performance is optimized. Under the base conditions, overall exergy efficiency, levelized cost of electricity, methanol and methane is estimated to be 36.8 %, 37.6, 92.8 and 79.4 $/MWh, respectively. Under the optimized conditions for the methane-only scenario, the overall exergy efficiency, levelized cost of electricity and methane is found to be 34.8 %, 36.7 $/MWh and 77.3 $/MWh, respectively. • A biomass-driven system is investigated to produce power and synthetic fuel. • Captured CO 2 via molten carbonate fuel cell is hydrogenated to produce synthetic fuel. • Three different scenarios are evaluated: producing methane, methanol and both. • Multi-objective optimization is conducted. • Minimum cost of electricity and methane is 36.7 and 77.3 $/MWh, respectively. [ABSTRACT FROM AUTHOR]

Variable Renewable Energy Sources are crucial for decarbonizing industries and efficient energy storage. Hydrogen storage technologies are limited in their large-scale capabilities. PtL technology can synthesize alternative fuels like methanol, which can be used in existing energy infrastructures to produce liquid fuel. The paper presents an innovative approach for utilizing in-situ thermal energy, using a hot reservoir rock (HRR) system for methanol synthesis at high temperature and pressure in an underground large-scale natural reservoir reactor. This approach aims to integrate renewable energy technologies into a single energy generation and fuel production system, including the direct utilization of renewable sources. Solutions from the oil and gas industry can be adapted to this action, such as continuous injection, alternate injection, separate injection, or chemical flooding. Conventional geothermal reservoirs, HDR systems, and depleted hydrocarbon reservoirs can be used as "underground reactors". However, it was also noted that there are challenges, such as catalyst distribution and the complexity of reservoir pore space. • Reservoir rock as a geochemical reactor for underground in-situ e-methanol synthesis. • Synergy between energy storage, CCUS, e-methanol production, and geothermal energy. • Effective use of surplus renewable energy with hydrogen technologies. • Risk reduction related to chemical processing and high environmental neutrality. • Use of resources related to the oil and gas industry for the energy transition. [ABSTRACT FROM AUTHOR]

Conventional Cu-based catalysts are affected by disadvantages, such as uneven temperature distribution, non-uniformity of mass and heat transfer, slow heating rate, and difficult replacement. To address these, a three-dimensional (3D) Zn-incorporated Joule-heated carbon nanofiber aerogel (CNFA)-supported Cu catalyst, was prepared via a facile one-pot method. The optimized catalyst, Cu 10 –Zn 10 /CNFA, exhibited an 83.1% conversion of CH 3 OH and 0.01% selectivity of CO at 250 °C. This improvement was due to Zn species acting as both an isolating agent, which inhibited thermal transmigration and aggregation of Cu-containing nanoparticles during heat treatment, and a combining agent, which provided numerous Cu–ZnO interfaces that enabled strong interactions between Cu and ZnO, which improved the activity and stability of the methanol steam reforming (MSR) reaction. This study reveals the feasibility of utilizing Joule-heated CNFA-supported catalysts for MSR reactions and opens a new avenue for designing and fabricating 3D-ordered porous catalysts related to this transformation. A 3D Zn-incorporated Joule-heated carbon nanofiber aerogel (CNFA)-supported Cu-based catalyst, where the monolith is applied as either a reactor or a Joule-heating component, is prepared for MSR reaction. [Display omitted] • A 3D Zn-incorporated Joule-heated CNFA-supported Cu catalyst was prepared. • The Cu-Zn/CNFA catalyst was applied as a reactor and Joule-heating component. • The catalyst exhibited 83.1% conversion of CH 3 OH and 0.01% selectivity of CO. • This catalyst may help preserve natural resources by enhancing H 2 production. [ABSTRACT FROM AUTHOR]

Microchannel reactors involve chemical-reaction engineering problems in their design and operation, with heat and mass transfer considerations dominating their practicability and efficiency. Study of the fundamental transport phenomena necessitates their description in sophisticated mathematical form. The present study seeks to address this particular problem by investigating the effects of various factors on the transport processes in a heterogeneously catalysed microchannel steam reforming reactor. Numerical modelling for reactor design was performed using a model that accounted for complex catalyst dynamics. Dimensionless number analyses were conducted to understand the nature of the transport processes. The reactor performance was evaluated by means of various parameters, and design recommendations were made. Different operating limit lines were mapped out, and various definitions of energy efficiency were distinguished. The results indicated that the use of microchannel technology enables the achievement of unusually favourable conversion. While mass-transfer limitations are dominant, the reaction is practically feasible at millisecond contact times. A maximum output power in excess of 70 watts per channel can be reached, and energy efficiencies up to about 70 percent are available. The operating limit line can be changed as desirable to maintain the desired product yield throughout the range of conditions. While an optimum velocity for maximum efficiency exists, the flow rate and catalyst loading must be carefully adjusted to simultaneously control the conversion and maximum power within certain needed limits. [Display omitted] • The reaction is practically feasible at millisecond contact times. • A maximum output power in excess of 70 watts per channel can be reached. • Energy efficiencies up to about 70 percent are available. • Operating limit lines of methanol breakthrough and maximum power are mapped out. • An optimum flow velocity for maximum energy efficiency does exist. [ABSTRACT FROM AUTHOR]

A potential measure to mitigate climate change and high energy consumption is the conversion of the abundant carbon dioxide (CO 2) in industrial flue gas into value-added products. Herein, combined with the 300,000 tonnes of electrolytic manganese metal technical renovation project of Tianyuan Manganese Industry in Ningxia, the methanol production performed using 10,000 tonnes of CO 2 annually is simulated. The hydrogen produced by alkaline hydro-electrolysis through solar and wind power generation is mixed with the CO 2 purified in the manganese dioxide roasting workshop of the self-made manganese plant and fed into the methanol reactor with a Cu/Zn/Al/Zr catalyst. The methanol thus obtained is sold after separation and purification. The water at the bottom of the rectifying column is mixed with fresh water and circulated in the water electrolytic unit for hydrogen production. The design of the supporting photovoltaic (PV) power generation systems is simulated using TRNSYS18 software. Results show that the optimal reaction temperature, pressure and space velocity for methanol preparation using this system are 501 K, 50 bar and 5.9 m3/kg cat h, respectively. Simulation results indicate that the proposed methanol production process boasts a higher energy efficiency and process yield than the conventional process. Consequently, potential annual profits would increase by USD6.71 × 107 along with reduced greenhouse gas emissions. This study thus provides a novel approach for cogeneration of green methanol while reducing industrial waste gas emission. [Display omitted] • Employing industrial manganese flue gas as the primary feedstock. • Integration of clean and traditional energy sources to produce green methanol. • Full process methanol yield is 72.61 %. • The cost of producing methanol is only USD 0.598/kg. [ABSTRACT FROM AUTHOR]