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The direct conversion of methane to methanol has attracted increasing interest due to abundant and low-cost natural gas resources. Herein, by anchoring Cr-oxo/-oxyhydroxides on UiO-66 metal–organic frameworks, we demonstrate that reactive anionic oxyl radicals can be formed by controlling the coordination environment based on the results of density functional theory calculations. The anionic oxyl radicals produced at the completely oxidized CrVI site acted as the active species for facile methane activation. The thermodynamically stable CrVI-oxo/-oxyhydroxides with the anionic oxyl radicals catalyze the activation of the methane C–H bond through a homolytic mechanism. An analysis of the results showed that the catalytic performance of the active oxyl species correlates with the reaction energy of methane activation and H adsorption energies. Following methanol formation, N2O can regenerate the active sites on the most stable CrVI oxyhydroxides, i.e., the Cr(O)4Hf species. The present study demonstrated that the anionic oxyl radicals formed on the anchored CrVI oxyhydroxides by tuning the coordination environment enabled facile methane activation and facilitated methanol production. [ABSTRACT FROM AUTHOR]

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]

Sustainable hydrogen generation is preferred over production from fossil sources in the context of a carbon‐neutral economy. As a result, production costs for CO2‐based products are estimated to be much higher than those of their fossil equivalents. Hence, it is essential to optimize process chains regarding their hydrogen efficiency. In this study, a concept for the directly coupled production of CO2‐based methanol and formaldehyde in a modified silver catalyst process is evaluated regarding the utilization of H2. Detailed simulations in Aspen Plus allow the comparison to the separately operated synthesis of green methanol and formaldehyde. By directly connecting both production steps, utilization ratios of introduced H2 and CO2 could be improved, reaching values of 98 % and 99 %, respectively. [ABSTRACT FROM AUTHOR]

• Biomethanol production from biomass gasification represents a circular economy approach for chemicals production. • Advanced configurations based on membranes for obtaining cleaning syngas from biomass are discussed. • The implementation of microchannels reaction technology is proposed to enhance the chemical engineering aspects of biomethanol production. • The production of biomethanol has an important socio-ecomnomic impact. The Intergovernmental Panel on Climate Change (IPCC) recognises the pivotal role of renewable energies in the future energy system and the achievement of the zero-emission target. The implementation of renewables should provide major opportunities and enable a more secure and decentralised energy supply system. Renewable fuels provide long-term solutions for the transport sector, particularly for applications where fuels with high energy density are required. In addition, it helps reducing the carbon footprint of these sectors in the long-term. Information on biomass characteristics feedstock is essential for scaling-up gasification from the laboratory to industrial-scale. This review deals with the transformation biogenic residues into a valuable bioenergy carrier like biomethanol as the liquid sunshine based on the combination of modified mature technologies such as gasification with other innovative solutions such as membranes and microchannel reactors. Tar abatement is a critical process in product gas upgrading since tars compromise downstream processes and equipment, for this, membrane technology for upgrading syngas quality is discussed in this paper. Microchannel reactor technology with the design of state-of-the-art multifunctional catalysts provides a path to develop decentralised biomethanol synthesis from biogenic residues. Finally, the development of a process chain for the production of (i) methanol as an intermediate energy carrier, (ii) electricity and (iii) heat for decentralised applications based on biomass feedstock flexible gasification, gas upgrading and methanol synthesis is analysed. [Display omitted] [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]

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]

H2 generation from methanol‐water mixtures often requires high pressure and high temperature (200–300 °C). However, CO can be easily generated and poison the catalytic system under such high temperature. Therefore, it is highly desirable to develop the efficient catalytic systems for H2 production from methanol at room temperature, even at sub‐zero temperatures. Herein, carbon nanotube‐supported Pt nanocomposites are designed and synthesized as high‐performance nano‐catalysts, via stabilization of Pt nanoparticles onto carbon nanotube (CNT), for H2 production upon methanol dehydrogenation at sub‐zero temperatures. Therein, the optimal Pt/CNT nanocomposite presents the superior catalytic performance in H2 production upon methanol dehydrogenation at the expense of B2(OH)4, with the TOF of 299.51 min‐130 oC. Compared with other common carriers, Pt/CNT exhibited the highest catalytic performance in H2 production, emphasizing the critical role of CNT in methanol dehydrogenation. The confinement of Pt nanoparticles by CNTs is conducive to inhibiting the aggregation of Pt nanoparticles, thereby significantly increasing its catalytic performance and stability. The kinetic study, detailed mechanistic insights, and density functional theory (DFT) calculation confirm that the breaking of O─H bond of CH3OH is the rate‐controlling step for methanol dehydrogenation, and both H atoms of H2 are supplied by methanol. Interestingly, H2 is also successfully produced from methanol dehydrogenation at −10 °C, which absolutely solves the freezing problem in the H2 evolution upon water‐splitting reaction. [ABSTRACT FROM AUTHOR]

Hydrogen is considered as a potential alternative and sustainable energy carrier, but its safe storage and transportation are still challenging due to its low volumetric energy density. Notably, C1-based substrates, methanol and formaldehyde, containing high hydrogen contents of 12.5 wt% and 6.7 wt%, respectively, can release hydrogen on demand in the presence of a suitable catalyst. Advantageously, both methanol and aqueous formaldehyde are liquid at room temperature, and hence can be stored and transported considerably more safely than hydrogen gas. Moreover, these C1-based substrates can be produced from biomass waste and can also be regenerated from CO2, a greenhouse gas. In this review, the recent progress in hydrogen production from methanol and formaldehyde over noble to non-noble metal complex-based molecular transition metal catalysts is extensively reviewed. This review also focuses on the critical role of the structure–activity relationship of the catalyst in the dehydrogenation pathway. [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]

The transition towards sustainable and renewable energy sources is imperative in mitigating the environmental impacts of escalating global energy consumption. Methanol, with its versatile applications and potential as a clean energy carrier, a precursor chemical, and a valuable commodity, emerges as a promising solution within the realm of renewable energy technologies. This work explores the integration of electrochemistry with solar power to drive efficient methanol production processes, focusing on electrochemical reduction (ECR) of CO2 and methane oxidation reaction (MOR) as pathways for methanol synthesis. Through detailed analysis and calculations, we evaluate the thermodynamic limits and realistic solar-to-fuel (STF) efficiencies of ECR and MOR. Our investigation encompasses the characterization of multijunction light absorbers, determination of thermoneutral potentials, and assessment of STF efficiencies under varying conditions. We identify the challenges and opportunities inherent in both ECR and MOR pathways, shedding light on catalyst stability, reaction kinetics, and system optimization, thereby providing insights into the prospects and challenges of solar-driven methanol synthesis, offering a pathway towards a cleaner and more sustainable energy future. [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]

Formic acid (FA) is a bulk chemical and a promising hydrogen energy carrier. The development of FA production from renewable biomass instead of multiple-step production from diminishing fossil resources is attractive. Formaldehyde (FAld) is another bulk chemical but industrial production requires high temperatures (250–600 °C). Herein, efficient oxidation of biomass to FA coupled with low-energy FAld production was developed using heteropoly acids as catalysts. Biomass and derivatives were oxidized to FA in yields of up to 88.6% while methanol was selectively oxidized to FAld at 90–190 °C with a markedly enhanced reaction rate. The synergistic mechanism has been unveiled that biomass activates methanol oxidation by boosting the catalytic redox cycle to form hydroxyl radicals and methanol scavenges the hydroxyl radicals to inhibit the overoxidation of biomass. This work opens up a promising direction for efficient FA production from biomass coupled with low-energy oxidation of alcohols to aldehydes. [ABSTRACT FROM AUTHOR]

Methanol steam reforming (MSR) provides an alternative way for efficient production and safe transportation of hydrogen but requires harsh conditions and complicated purification processes. In this work, an efficient electrochemical‐assisted MSR reaction for pure H2 production at lower temperature (~140 °C) is developed by coupling the electrocatalysis reaction into the MSR in a polymer electrolyte membrane electrolysis reactor. By electrochemically assisted, the two critical steps including the methanol dehydrogenation and water‐gas shift reaction are accelerated, which is attributed to decreasing the methanol dehydrogenation energy and promoting the dissociation of H2O to OH* by the applied potential. Furthermore, the reduced H2 partial pressure by the hydrogen oxidation and reduction process further promotes MSR. The combination of these advantages not only efficiently decreases the MSR temperature but also achieves the high rate of hydrogen production of 505 mmol H2 g Pt−1 h−1 with exceptionally high H2 selectivity (99 %) at 180 °C and a low voltage (0.4 V), and the productivity is about 30‐fold than that of traditional MSR. This study opens up a new avenue to design novel electrolysis cells for hydrogen production. [ABSTRACT FROM AUTHOR]

Methanol steam reforming (MSR) provides an alternative way for efficient production and safe transportation of hydrogen but requires harsh conditions and complicated purification processes. In this work, an efficient electrochemical‐assisted MSR reaction for pure H2 production at lower temperature (~140 °C) is developed by coupling the electrocatalysis reaction into the MSR in a polymer electrolyte membrane electrolysis reactor. By electrochemically assisted, the two critical steps including the methanol dehydrogenation and water‐gas shift reaction are accelerated, which is attributed to decreasing the methanol dehydrogenation energy and promoting the dissociation of H2O to OH* by the applied potential. Furthermore, the reduced H2 partial pressure by the hydrogen oxidation and reduction process further promotes MSR. The combination of these advantages not only efficiently decreases the MSR temperature but also achieves the high rate of hydrogen production of 505 mmol H2 g Pt−1 h−1 with exceptionally high H2 selectivity (99 %) at 180 °C and a low voltage (0.4 V), and the productivity is about 30‐fold than that of traditional MSR. This study opens up a new avenue to design novel electrolysis cells for hydrogen production. [ABSTRACT FROM AUTHOR]

The methanol economy is an attractive approach to tackle the current concerns over the depletion of natural resources and the global warming intrinsically associated with the use of fossil fuels. This can be achieved by hydrogenation of carbon dioxide to produce methanol, a liquid fuel with potential use in civil transportation. In this study, we aim to pinpoint the intermediates that are involved in the catalytic CO2 conversion into methanol on pure zirconia (ZrO2), Cu and Cu/ZrO2 systems. To accomplish this, we make use of infrared (IR) spectroscopy measurements and quantum chemical simulations within the hybrid density functional theory (DFT) framework. At 250 °C and p~30 bar, the main species formed on the partially hydroxylated ZrO2 is bidentate formate, whereas the co‐production of bicarbonate is relevant upon cooling to T=25 °C. On pure Cu, the IR fingerprints of methanol and carbon dioxide indicate their presence in the gas phase and surface environment, albeit formate/formic acid and methoxy species are also detected at these experimental conditions. The production of methanol on Cu/ZrO2 is mostly dependent on the Cu catalyst, but the higher amount of the methoxy intermediate can be correlated with the consumption of formate adsorbed on ZrO2 or at the Cu/ZrO2 interface. On the Cu/ZrO2 mixture, the reaction mechanism is likely to involve formate as the main intermediate, instead of CO which would result from the reverse water‐gas shift reaction. Ultimately, the higher activity shown by the Cu/ZrO2 mixture might be associated with the extra‐production of methoxy/methanol catalyzed by ZrO2 in the presence of Cu. [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]

Carbon capture and carbon reuse in the chemical plants is one of the attractive prospective approaches to decrease the concerns about global warming and climate change. In the present study, is focused on the synthesis gas production from carbon dioxide in a methanol synthesis plant. In this regard, two methanol processes are proposed based on CO 2 separation, recycling, and reforming. In the first scenario, CO 2 is separated and recycled to the conventional reformer, while the process is equipped by a CO 2 separation unit and dry methane reformer in the second scenario. The proposed processes are simulated and a sensitivity analysis is performed to investigated the effect of inputs on methanol productivity and carbon conversion. The operational parameters of proposed processes are optimized to enhance methanol productivity and CO 2 conversion. Then, the processes are compared from energy efficiency, carbon efficiency, CO 2 emission rate and methanol productivity viewpoints. The results showed that, in the second proposed scenario, methanol production rate approach to 5367 tons per day in comparison to 5030 tons per day for industrial unit. In addition, modification of conventional methanol process based on the second scenario could decrease CO 2 emission rate about 56 tons per day. [Display omitted] • Two novel methanol synthesis techniques based on CO 2 separation, recycling, and reforming were simulated. • A comparison was made between the industrial unit and two proposed configurations from the environmental and process aspect. • Various effects of operating conditions on the methanol production rate and CO 2 emissions were evaluated. • A sensitivity analysis was performed, and operational parameters were optimized to improve the proposed systems' performance. [ABSTRACT FROM AUTHOR]

This study investigates the potential of utilizing date palm waste as a sustainable feedstock for gasification and methanol production while aiming to optimize the process parameters for enhanced efficiency. The approach employed in this research involves the utilization of Aspen Plus simulation software to model both the gasification and methanol synthesis processes. The model accounts for various operating parameters, including the steam to biomass ratio and gasification temperature, to comprehensively assess their impact on the product gas composition. Furthermore, the Aspen Plus model's accuracy is validated through the comparison of its predictions with experimental data obtained from literature sources. Key findings from this study indicate that the optimal conditions for steam gasification of date palm waste are achieved at a steam to biomass ratio of 0.9 and a gasification temperature of 800 °C. Under these conditions, the resulting syngas composition comprises 58.38% hydrogen (H2) and 24.21% carbon monoxide (CO). Additionally, the study reveals that the ideal conditions for methanol synthesis involve operating at a pressure of 50 bar and a temperature of 220 °C, resulting in a methanol Production capacity of 368.98 kg/h. The findings of this study hold significant promise and satisfaction for real-world applications, particularly in the context of the three demonstrators currently under construction as part of the "REFFECT AFRICA" project. • The Date palm waste can be effectively used to produce syngas and methanol. • A gasification model based on minimization of Gibbs free energy was developed using ASPEN Plus. • The operating conditions determine the composition of the resulting syngas. • Rigorous evaluation of methanol synthesis conditions. [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]

Cu/ZnO/Al2O3 catalysts used to synthesize methanol undergo extensive deactivation during use, mainly due to sintering. Here, we report on formulations wherein deactivation has been substantially reduced by the targeted use of a small quantity of a Si-based promoter, resulting in accrued activity benefits that can exceed a factor of 1.8 versus unpromoted catalysts. This enhanced stability also provides longer lifetimes, up to double that of prior generation catalysts. Detailed characterization of a library of aged catalysts has allowed the most important deactivation mechanisms to be established and the chemical state of the silicon promoter to be identified. We show that silicon is incorporated within the ZnO lattice, providing a pronounced improvement in the hydrothermal stability of this component. These findings have important implications for sustainable methanol production from H2 and CO2. [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]

Many metal coordination compounds catalyze CO2 electroreduction to CO, but cobalt phthalocyanine hybridized with conductive carbon such as carbon nanotubes is currently the only one that can generate methanol. The underlying structure–reactivity correlation and reaction mechanism desperately demand elucidation. Here we report the first in situ X‐ray absorption spectroscopy characterization, combined with ex situ spectroscopic and electrocatalytic measurements, to study CoPc‐catalyzed CO2 reduction to methanol. Molecular dispersion of CoPc on CNT surfaces, as evidenced by the observed electronic interaction between the two, is crucial to fast electron transfer to the active sites and multi‐electron CO2 reduction. CO, the key intermediate in the CO2‐to‐methanol pathway, is found to be labile on the active site, which necessitates a high local concentration in the microenvironment to compete with CO2 for active sites and promote methanol production. A comparison of the electrocatalytic performance of structurally related porphyrins indicates that the bridging aza‐N atoms of the Pc macrocycle are critical components of the CoPc active site that produces methanol. In situ X‐ray absorption spectroscopy identifies the active site as Co(I) and supports an increasingly non‐centrosymmetric Co coordination environment at negative applied potential, likely due to the formation of a Co−CO adduct during the catalysis. [ABSTRACT FROM AUTHOR]

Many metal coordination compounds catalyze CO2 electroreduction to CO, but cobalt phthalocyanine hybridized with conductive carbon such as carbon nanotubes is currently the only one that can generate methanol. The underlying structure–reactivity correlation and reaction mechanism desperately demand elucidation. Here we report the first in situ X‐ray absorption spectroscopy characterization, combined with ex situ spectroscopic and electrocatalytic measurements, to study CoPc‐catalyzed CO2 reduction to methanol. Molecular dispersion of CoPc on CNT surfaces, as evidenced by the observed electronic interaction between the two, is crucial to fast electron transfer to the active sites and multi‐electron CO2 reduction. CO, the key intermediate in the CO2‐to‐methanol pathway, is found to be labile on the active site, which necessitates a high local concentration in the microenvironment to compete with CO2 for active sites and promote methanol production. A comparison of the electrocatalytic performance of structurally related porphyrins indicates that the bridging aza‐N atoms of the Pc macrocycle are critical components of the CoPc active site that produces methanol. In situ X‐ray absorption spectroscopy identifies the active site as Co(I) and supports an increasingly non‐centrosymmetric Co coordination environment at negative applied potential, likely due to the formation of a Co−CO adduct during the catalysis. [ABSTRACT FROM AUTHOR]

The preparation process for the composites CuO/ZnO/γ-Al2O3, which can be used as the main component of catalysts for large-tonnage methanol production and carbon monoxide conversion, was investigated by means of x-ray phase, x-ray crystalline, and synchronous thermal analysis as well as scanning electron microscopy, and low-temperature adsorption-desorption of nitrogen. The influence of the production method and the nature and intensity of processing on the phase composition of the resulting precursors and the physicochemical properties of the resulting composites was determined. The processes occurring at the stage of mechanochemical activation of a mixture of anhydrous oxides CuO/ZnO/γ-Al2O3 and a mixture of oxides with ammonium carbonate and ethanedioic [oxalic] acid were studied. The optimal parameters for obtaining CuO/ZnO/γ-Al2O3 composites with a developed specific surface and porous structure were determined. [ABSTRACT FROM AUTHOR]

This study focused on improving the energy demand of conventional large-scale natural gas to methanol flow sheet where even a small efficiency improvement has significant economics and carbon emissions benefits. A conventional flow sheet, case A, was based on best available literature information. A case B where the conventional cryogenic air separation unit (ASU) is replaced with the novel ion transport membrane (ITM) oxygen unit was developed. The ITM oxygen is also heat integrated into the autothermal reformer (ATR) process. A case C where the methanol synthesis process is configured into a gas turbine cycle was developed from further modifying case B. The flow sheets were constructed and modelled in Aspen Plus V10 and, heat and material balance results are reported. To our knowledge, the integration of ITM oxygen membranes into the ATR-based methanol process has not been assessed previously. Energy and exergy results are generated and analysed. It was found that is it possible to replace the cryogenic ASU with the ITM oxygen for oxygen production in the ATR process. There is enough process syngas heat available to provide the ITM oxygen unit heating requirement and to generate process steam feed to the ATR. Case A was found to consume only 12 % natural gas as utility fuel which is lower than typical SMR-based methanol processes. This reduced to about 5 % in case B and C. Power production improved by 47 % in case B and 68 % in case C compared to case A. A thermal efficiency definition suitable for combined process steam, power and oxygen production was proposed. This showed that integration of a high temperature gas power cycle enables combined steam (heat) and power configuration which has a higher efficiency compared to single cycles, such as the steam cycles. The overall plant exergy losses decreased by up to 21 %. • Cryogenic air separation processes consume large amounts of energy for air compression. • Autothermal reforming technology is preferred for large scale methanol production from gas. • Ion transport membrane (ITM) technology is an alternative to cryogenic air separation. • Integration of ITM with methanol production creates opportunities to improve efficiency, and reduce exergy losses. • Adequate heat is available from the hot synthesis gas stream to provide to the ITM process. [ABSTRACT FROM AUTHOR]

This work presents a techno-economic and greenhouse gas emissions assessment of a proposed low-carbon methanol production process. The process takes a novel low-carbon methanol production method and reduces its emissions further by integrating a solar thermal energy (STE) system to provide for its electricity requirements. The authors investigate three different scenarios for the STE system, analysing the effects of solar irradiance design point, and the impact of thermal energy storage on system performance. Case-1 (15.57 MW) was designed for daytime operation and sized for the maximum annual solar irradiance, with Case-2 (24.91 MW) incorporating thermal energy storage to enable 24-hour operation. Case-3 (48.66 MW) also utilised thermal energy storage to enable 24-hour operation, but was sized for the minimum annual solar irradiance. The methanol process and the STE system were modelled in Aspen Plus and Aspen HYSYS, with the simulation data being used with mass and energy balances to conduct a techno-economic and greenhouse gas emissions assessment. The standalone methanol plant was estimated to emit 0.37 t CO2/t CH3OH, with the integration of the STE system reducing this to 0.29 (Case-1), 0.23 (Case-2), and 0.10 (Case-3), resulting in one of the lowest emitting traditional methanol production methods available. The cost of abatement of these remaining emissions through carbon capture and storage was also considered. The economic analysis found that the integrated processes in Case-1 and 2 were financially viable, resulting in a net present value of $247 million and $72 million respectively. The net present value was reduced to $185 and $21 million when considering the cost of carbon capture and storage. Conversely, the net present value for Case-3 was negative, requiring an increase in the price of methanol to ∼" role="presentation" style="font-size: 90%; display: inline-block; position: relative;">∼∼$600/t, and a reduction in the cost of capital to ∼" role="presentation" style="font-size: 90%; display: inline-block; position: relative;">∼∼8%, to become financially viable. [ABSTRACT FROM AUTHOR]

Tuning the anionic site of catalyst supports can impact reaction pathways by creating active sites on the support or influencing metal‐support interactions when using supported metal nanoparticles. This study focuses on CO2 hydrogenation over supported Cu nanoparticles, revealing a 3‐fold increase in methanol yield when replacing oxygen anions with hydrides in the perovskite support (Cu/BaTiO2.8H0.2 yields ~146 mg/h/gCu vs. Cu/BaTiO3 yields ~50 mg/h/gCu). The contrast suggests that significant roles are played by the support hydrides in the reaction. Temperature programmed reaction and isotopic labelling studies indicate that BaTiO2.8H0.2 surface hydride species follow a Mars van Krevelen mechanism in CO2 hydrogenation, promoting methanol production. High‐pressure steady‐state isotopic transient kinetic analysis (SSITKA) studies suggest that Cu/BaTiO2.8H0.2 possesses both a higher density and more active and selective sites for methanol production compared to Cu/BaTiO3. An operando high‐pressure diffuse reflectance infrared spectroscopy (DRIFTS)‐SSITKA study shows that formate species are the major surface intermediates over both catalysts, and the subsequent hydrogenation steps of formate are likely rate‐limiting. However, the catalytic reactivity of Cu/BaTiO2.8H0.2 towards the formate species is much higher than Cu/BaTiO3, likely due to the altered electronic structure of interface Cu sites by the hydrides in the support as validated by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Background: One carbon (C1) molecules such as methanol have the potential to become sustainable feedstocks for biotechnological processes, as they can be derived from CO2 and green hydrogen, without the need for arable land. Therefore, we investigated the suitability of the methylotrophic yeast Ogataea polymorpha as a potential production organism for platform chemicals derived from methanol. We selected acetone, malate, and isoprene as industrially relevant products to demonstrate the production of compounds with 3, 4, or 5 carbon atoms, respectively. Results: We successfully engineered O. polymorpha for the production of all three molecules and demonstrated their production using methanol as carbon source. We showed that the metabolism of O. polymorpha is well suited to produce malate as a product and demonstrated that the introduction of an efficient malate transporter is essential for malate production from methanol. Through optimization of the cultivation conditions in shake flasks, which included pH regulation and constant substrate feeding, we were able to achieve a maximum titer of 13 g/L malate with a production rate of 3.3 g/L/d using methanol as carbon source. We further demonstrated the production of acetone and isoprene as additional heterologous products in O. polymorpha, with maximum titers of 13.6 mg/L and 4.4 mg/L, respectively. Conclusion: These findings highlight how O. polymorpha has the potential to be applied as a versatile cell factory and contribute to the limited knowledge on how methylotrophic yeasts can be used for the production of low molecular weight biochemicals from methanol. Thus, this study can serve as a point of reference for future metabolic engineering in O. polymorpha and process optimization efforts to boost the production of platform chemicals from renewable C1 carbon sources. [ABSTRACT FROM AUTHOR]

Tuning the anionic site of catalyst supports can impact reaction pathways by creating active sites on the support or influencing metal‐support interactions when using supported metal nanoparticles. This study focuses on CO2 hydrogenation over supported Cu nanoparticles, revealing a 3‐fold increase in methanol yield when replacing oxygen anions with hydrides in the perovskite support (Cu/BaTiO2.8H0.2 yields ~146 mg/h/gCu vs. Cu/BaTiO3 yields ~50 mg/h/gCu). The contrast suggests that significant roles are played by the support hydrides in the reaction. Temperature programmed reaction and isotopic labelling studies indicate that BaTiO2.8H0.2 surface hydride species follow a Mars van Krevelen mechanism in CO2 hydrogenation, promoting methanol production. High‐pressure steady‐state isotopic transient kinetic analysis (SSITKA) studies suggest that Cu/BaTiO2.8H0.2 possesses both a higher density and more active and selective sites for methanol production compared to Cu/BaTiO3. An operando high‐pressure diffuse reflectance infrared spectroscopy (DRIFTS)‐SSITKA study shows that formate species are the major surface intermediates over both catalysts, and the subsequent hydrogenation steps of formate are likely rate‐limiting. However, the catalytic reactivity of Cu/BaTiO2.8H0.2 towards the formate species is much higher than Cu/BaTiO3, likely due to the altered electronic structure of interface Cu sites by the hydrides in the support as validated by density functional theory (DFT) calculations. [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]

[Display omitted] • 2D CFD simulations and optimisation of an industrial-scale MeOH synthesis reactor. • Model predicts a temperature hot-spot and an excessive pressure drop. • Response surface reveals the impact of the reactor design on key output parameters. • Optimised reactor achieves 6.9 % higher MeOH production with 75 % lower pressure drop. • Higher yields could lead to more economic and sustainable MeOH production. Achieving our decarbonisation goals for the maritime transport sector requires the bulk production of liquid hydrocarbon fuels, suitable for the existing infrastructure, such as methanol (MeOH). For this, optimisation of fixed bed chemical reactors is vital. Unlike demonstration-scale setups, optimising the design of such reactors using Computational Fluid Dynamics (CFD) models is both cheaper and faster. In this study, using a 2D pseudo-homogeneous CFD model, a single tube from a multi-tubular industrial-scale MeOH reactor is simulated. Using available experimental data, the CFD model was validated yielding excellent accuracy, with an average error of 2.6 %. The model identified a temperature hot-spot near the bed entrance, while the predicted pressure drop was 11 % of the operating pressure. Both effects could considerably reduce the efficiency of the reactor, either by catalyst deactivation or by increasing the compressor requirements, respectively. Through a parametric study where the tube's length and diameter were varied within the ±50 % range, 53 total cases are produced and solved, creating an extensive pareto set of data for the key output parameters, such as methanol production, pressure, and temperature. A response surface was also generated, revealing the interconnection between the tube's design and the operating parameters. This enabled a performance optimisation of the reactor design for two industrially relevant scenarios, with the optimised reactor achieving a 6.9 % higher MeOH yield and a 75 % reduced pressure drop. Through industrial involvement, the reactor can be further optimised, and would act as a critical foundation for more extensive techno-economic and socio-economic evaluations for sustainable carbon–neutral methanol production. [ABSTRACT FROM AUTHOR]

This work proposes a novel zero–CO 2 –emission energy system to meet thermal and electrical energy needs of the cities without emitting CO 2 while using natural gas as a primary energy source. Since the system uses available technologies, it is envisioned as a part of transition towards net-zero sustainable economy. At the core of the system is production of hydrogen via pyrolysis of methane which has recently achieved technological maturity of industrial scale production. Natural gas combustion in a combined heat and power (CHP) unit produces electrical and thermal energy required by the city and by the energy system itself. CO 2 produced by CHP is captured via MEA absorption and converted to methanol via synthesis with hydrogen while also producing carbon black. We consider different carbon reduction scenarios, urbanization levels, system operation conditions, operational costs, capital costs, and energy and material prices in evaluating the system. If such systems are deployed worldwide, subject to produced methanol being equal to the current demand (111 Million ton/yr), they would eliminate 44 Million t/yr CO 2 emissions from existing methanol plants and 160 Millon t/yr CO 2 emissions from standalone energy systems that provide heating and cooling for 40 Million people. • Novel zero–CO 2 –emission energy system meets cities' thermal and electrical needs. • Light industries, housing, public facilities, and sustainable energy are integrated. • Elimination of 60 % and 100 % of current CO 2 emissions. • CO 2 tax, urbanization levels, operation conditions, and prices impact on system design. • Current technology path: CCHP, Methane pyrolysis, CO 2 MEA Capture, MeOH synthesis. [ABSTRACT FROM AUTHOR]

• A visual 4-needle electrode plasma reactor is optimized for hydrogen production. • Directed optimization of configuration parameters is crucial. • The H 2 flow rate increases by 118.3% with the array electrode configuration. • An intriguing energy consumption of 1.28 kWh/Nm3H 2 by array electrode is achieved. Methanol emerges as a promising candidate for on-board hydrogen production, owing to its sustainability and safety attributes. This study focuses on optimizing hydrogen production from methanol decomposition utilizing a liquid-phase array electrode plasma discharge reactor featuring gliding arc discharge. Various factors affecting hydrogen production, such as discharge parameters, electrode structure, and the conductivity of methanol–water solutions, are systematically examined. Comparative analysis revealed that, under identical discharge power, the array high-voltage electrode outperforms a single electrode in terms of hydrogen yield, with the maximum hydrogen flow rate significantly increased by 118.3 % to 1188.54 mL/min. Furthermore, the array-needle ring electrode configuration is proven to be more favorable for liquid-phase gliding arc discharge, demonstrating superior hydrogen production and energy efficiency compared to the array-needle hole-plate configuration, with a best H 2 selectivity of 65 % and a prime energy conversion efficiency of 71.12 %. Additionally, a higher conductivity of methanol–water solution leads to a lower hydrogen flow rate, failing to trigger reforming reactions to enhance hydrogen concentration in the syngas. Generally, optimization efforts result in an impressive 33.8 % reduction in energy consumption for hydrogen production, achieving an optimal energy consumption of 1.28 kWh/Nm3H 2 in the array electrode setup. This study provides valuable insights into the intricacies of liquid-phase gliding arc discharge for methanol-based hydrogen production, offering a foundation for optimizing reactor configurations and operational parameters to maximize efficiency and minimize energy consumption. [ABSTRACT FROM AUTHOR]

[Display omitted] • 82 methanogenic strain were screened for methane production from carbon dioxide sequestration. • The isolate Methanobacterium sp. M11, efficiently produced 7.90 mol of methane from 8.34 mol of CO 2. • Integration of methanogenic bioreactor with methanotrophic reactor for methanol production. • Maximum methanol productivity was obtained from Methyloceanibacter sp. M31 was 0.470 mol in 24 h. Carbon dioxide (CO 2) poses a significant threat, contributing to global warming and climate change. This study focused on isolating efficient CO 2 -reducing methanogens and methanotrophs for converting methane into methanol. Samples from diverse regions in India were collected and processed, yielding 82 methanogenic and 48 methylotrophic isolates. Methanogenic isolate M11 produced a higher amount of methane, reaching 2.9 mol L−1 on the sixth day of incubation at 35 °C, pH 7.0, and CO 2 :H 2 (80:20) as feeding rates. Under optimized conditions, isolate M11 effectively converted 8.3 mol CO 2 to 7.9 mol methane in 24 h. Methylotrophic isolate M31 demonstrated significant soluble methane monooxygenase activity (450 nmol/ml) and produced 0.4 mol methanol in 24 h. 16S rRNA analysis identified Methanobacterium sp. and Methyloceanibacter sp. among the isolates, elucidating their taxonomic diversity. This study offers valuable insights into methanogens' potential in CO 2 sequestration and methane conversion to methanol through methanotrophism, a promising sustainable biofuel production. [ABSTRACT FROM AUTHOR]

• TEA for our RWGSR/MeS-MCR technology compared to four other competitive processes. • RWGSR/MeS-MCR attains ∼80 % conversion, much higher than the equilibrium conversion. • RWGSR/MeS-MCR outperforms other four processes in energy efficiency and economics. • By 2030, RWGSR/MeS-MCR will match commercial MeOH costs (400–600 $/ton) per U.S. DOE targets. We introduced recently a CO 2 capture and utilization (CCU) technology that produces methanol (MeOH), from waste CO 2 employing a novel configuration combining a reverse water gas shift reactor (RWGSR) with a membrane contactor reactor for MeOH synthesis (MeS-MCR). The integrated RWGSR/MeS-MCR process overcomes the challenges direct CO 2 conversion into MeOH faces and achieves carbon conversions exceeding 80 %, significantly surpassing the equilibrium conversion of ∼ 20–30 % for the MeS reaction. In this study, a techno-economic analysis (TEA) was conducted on the RWGSR/MeS-MCR process along with four other CO 2 -to-MeOH CCU processes. Key economic parameters, as well as the energy efficiency, were analyzed with respect to CO 2 and renewable hydrogen (H 2) costs and plant capacity. The study revealed that the RWGSR/MeS-MCR technology has the highest energy efficiency and the best economic performance among all the technologies investigated. All technologies offer the significant societal benefit of capturing and utilizing waste CO 2 , but under present CO 2 and renewable H 2 costs, they cannot currently compete cost-wise with conventional MeOH production methods. However, under a future scenario whereby government incentives lower the CO 2 cost and technological advances decrease the price of renewable H 2 , the proposed RWGSR/MeS-MCR process and another catalytic technology (CAMERE) become price competitive. [Display omitted] [ABSTRACT FROM AUTHOR]

• A bio-process model for combined methanol and power production from bio-oil is proposed. • The cleanest possible bio-process was proposed using optimization by GA. • 70.6 % reduction in GWP through rigorous optimization and waste heat recovery was achieved. • 15.1 % increase in annual economic return rate under optimal operation was achieved. • 2.176 Mton/year reductions in CO 2 emissions per % of the methanol market gained can be achieved. Traditional methanol production from natural gas is well-studied, but there is a lack of research on environmentally optimizing bio-based methanol production. This study focuses on optimizing the combined production of bio-methanol and power from bio-oil using a comprehensive bio-process model. The research includes a novel framework for environmental, technical, and economic optimization of bio-oil to methanol and power to determine the most eco-friendly and cost-effective approach. An organic Rankine cycle (ORC) is also integrated for waste heat recovery. The results of this study revealed that the bio-based process with ORC showed a 22.6 % reduction in global warming potential impact (GWP) per kilogram of methanol, compared to the bio-based process without ORC. Also, by implementing the most environmentally friendly process, GWP will be reduced by 70.6 % per kg methanol compared to base sub-optimal operation. The results showed that for the process with the addition of ORC, after performing multi-objective optimization, under the optimal conditions, the economic annual rate of return increased from 19.6 % to 34.7 %. Finally, it was revealed that if the considered technology is commercialized, for every percentage of the methanol market it gains, it will contribute to 2.176 million tons CO 2 -eq/year less emissions. [ABSTRACT FROM AUTHOR]

A novel tubular photo-thermo-reactor with coaxial baffles and dual (photo-thermo- and thermo-) catalyst beds is proposed, integrated with the commercially-mature parabolic trough concentrators (EuroTrough ET-100 model) with high scalability for high-efficient H 2 production from solar-driven methanol steam reforming. The optical-flow-thermal-chemical multiphysics coupled model, which incorporates the experimental data of photo-thermo-catalytic reaction kinetics, have been established to optimize the geometric and operational conditions of the proposed reactor. It is demonstrated that the systematic solar hydrogen production efficiency up to 21.2 % considering the pumping power and the solar-to-hydrogen efficiency up to 30.6 % without considering the energy cost have been achieved in the best case. The reason for the excellent performance is two-fold. On the one hand, the existence of coaxial baffles guides multiple penetrations of the gaseous reactants through the catalyst beds thus guarantees sufficient contact between them. On the other hand, the design of coaxial dual-bed guarantees cascaded utilizations of both photo-thermo-catalysis and thermo-catalysis thus realizes higher utilization efficiency of full-spectrum solar energy. Considering the compatibility to the commercially-mature optical concentrator, this work exemplifies a practically promising route of effective full-spectrum solar-to-chemical conversion. [ABSTRACT FROM AUTHOR]

The yield of methanol is heavily influenced by the composition of the syngas which varies from waste type and gasification conditions. This study uniquely explores machine learning (ML) and artificial neural network (ANN) algorithms with shapley additive values (SHAP) analysis to predict syngas compositions and interpret the complexities of waste gasification. Aspen Plus is then utilized to investigate the impact of syngas compositions on the economics of methanol production. Among the different ML models, gradient boosting regression achieved remarkable accuracy in predicting carbon monoxide and carbon dioxide, while ANN excelled in predicting nitrogen and hydrogen based on the coefficient of determination (>0.95). The feature importance analysis demonstrated the gasification agent type as the most important feature. Steam gasification of waste sawdust, straw, and wood chips showed the highest methanol yield. Economic analysis indicated the lowest levelized cost of methanol (LCMeOH) to be 1195.79 USD/MT which further decreased to 933.97 USD/MT upon hydrogen addition. Uncertainty analysis using Monte Carlo method showed the possible minimum LCMeOH to be 254.05 USD/MT. This study provides a comprehensive picture of the economic viability of waste-to-methanol production and provides an important reference for stakeholders on a global scale to quickly assess the feasibility of waste-to-energy projects. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • One traditional and three novel biomass-to-methanol (BTM) processes are proposed. • Clean H 2 production pathways are used to maximize carbon utilization potential. • Novel BTM processes all enhance methanol production and carbon mitigation. • Integration of methane pyrolysis pathway is preferred in technical performances. • Deployment of methane chemical looping pathway shows stronger economic advantages. Concerns about depleted fossil fuels and the climate crisis have intensified the interest in producing biomass-derived methanol. However, the traditional biomass-to-methanol (BTM) process suffers from low carbon conversion ability and serious CO 2 emissions caused by the water–gas-shift (WGS) unit. In this study, three novel BTM processes coupled with solid oxide electrolysis, methane pyrolysis, and methane chemical looping technologies are proposed to eliminate WGS unit, and the systematic heat integration is considered to achieve energy cascade utilization. Meanwhile, process performances are comprehensively evaluated to compare the technical, economic, and environmental attractiveness of three novel BTM processes. It is found that compared with the original BTM process, three novel processes significantly improve carbon efficiency by 22%. Meanwhile, CO 2 emissions are reduced by 60%. Moreover, the application of methane chemical looping technology is more economical, and the associated net production cost decreases by more than 30%. Additionally, the BTM process coupled with solid oxide electrolysis is more environmentally friendly, whereas the process with methane pyrolysis technology is more exergy-efficient. Overall, the integrated processes have significant application prospects for carbon conversion and mitigation ability as well as economic attractiveness. [ABSTRACT FROM AUTHOR]

Ethanol synthesis through CO 2 hydrogenation has shown great promise in contributing to carbon neutrality. Herein, we for the first time present the phosphorus-substitution of atomically dispersed Rh-N 4 sites for the title reaction. The as-formed Rh-N 3 P 1 sites enable the reaction product notably switching from nearly total methanol (91.3%) towards major ethanol (81.8%) with a high TOF of 420.7 h−1. This outstanding promotion in both ethanol formation and CO 2 conversion (69% higher) could be assigned to the donation of electron from P atom effectively weakening C-O bond in CH 3 OH* , facilitating its cleavage into CH 3 * , and enabling the coupling between CO* and CH 3 *. The presence of Rh-P site pair assists C-O bond activation with a longer bond length owing to a strong affinity of P atom to O atom in CH 3 OH*. This research underscores the importance of tuning the coordination and electronic environment of active metal sites for site pair synergistic catalysis. [Display omitted] • Switchable production from methanol towards ethanol by substituting N with P. • Rh-N 3 P 1 sites, at optimum conditions, achieved a high TOF of 420.7 h−1 for ethanol formation. • The Rh-P site pair synergistic catalysis for promoting C-O bond activation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomass gasification to produce tunable syngas for methanol model was developed. • Overcame the challenge that biomass syngas cannot be directly utilized for methanol. • Effects of Steam/BBF, CaO/BBF and CO 2 /Biochar on the syngas were investigated. • Conducted exergy and global warming potential analyses of the system. The production of methanol through biomass gasification is a hot topic in current research. However, the challenge lies in obtaining the correct H 2 /CO ratio, as the syngas generated from biomass gasification cannot be directly utilized for methanol synthesis. This paper proposed a biomass sorption-enhanced gasification coupled with carbon utilization to produce tunable syngas for methanol synthesis model in Aspen Plus. The effects of Steam/BBF, CaO/BBF and CO 2 fraction on the composition and high heating value (HHV) of syngas were evaluated. This paper focused on the H 2 /CO ratio, the exergy efficiency and the global warming potential (GW). The study found that with the CO 2 fraction of 0.6, the H 2 /CO ratio in the syngas approximated 2, with a yield of 257.19 kmol/h, making it suitable for methanol synthesis. The exergy efficiency of the system was ∼ 64 %, with the sorption enhanced water gas shift unit, gasification unit, power generation unit and methanol synthesis unit being the primary sources of exergy loss. Furthermore, in the global warming potential analysis, BBF gasification for methanol production stage and the biomass processing stage accounted for more than 97 % of the total GW. Improving the gasification for methanol production unit was crucial for enhancing the overall sustainability of the system. This study provides valuable insights into biomass sorption-enhanced H 2 production and biomass-to-methanol conversion. [ABSTRACT FROM AUTHOR]

• Utilizing CO 2 and H 2 S waste streams for sustainable methanol production. • Improving methanol yields and value-added product generation. • Reducing operational costs and environmental emissions. • Employing factorial design and ANOVA for process optimization. • Increasing profitability through energy integration. Greenhouse gas emissions, specifically CO 2 and H 2 S, are recognized as a serious environmental issue. To address this, various strategies have been suggested. Among these, an economic-environmental study is presented, focusing on a methanol production process that utilizes CO 2 and H 2 S waste streams from a natural gas sweetening plant. The study aims to identify conditions that enhance the production of value-added products and increase methanol yields while reducing costs. Given the complexity of processes involving numerous variables such as pressure, temperature, flow rates, and others, pinpointing the most impactful variables for effective manipulation poses a significant challenge. To tackle this, the study adopts a factorial experimental design coupled with ANOVA analysis to determine the variables that most significantly affect the process. Based on this analysis, the study suggests process improvement through energy integration. Results, derived from the experimental design and ANOVA analysis, reveal that reactor temperatures play a crucial role in influencing the process's effectiveness. [Display omitted] [ABSTRACT FROM AUTHOR]

• Biomass gasification and CO 2 electrochemical reduction were firstly combined. • Combination of biomass gasification and CO 2 electrochemical reduction achieves profit. • Electricity price is the key indicator for all the combined processes. Combining CO 2 electrochemical reduction (CO 2 R) and biomass gasification for producing methanol (CH 3 OH) is a promising option to increase the carbon efficiency, reduce total production cost (TPC), and realize the utilization of byproducts of CO 2 R system, but its viability has not been studied. In this work, systematic techno-economic assessments for the processes that combined CO 2 R to produce CO/syngas/CH 3 OH with biomass gasification were conducted and compared to stand-alone biomass gasification and CO 2 R processes, to identify the benefits and analyze the commercialization potential of different pathways under current and future conditions. The results demonstrated that the process that combined biomass gasification with CO 2 R to CO represents a viable pathway with a competitive TPC of 0.39 €/kg-CH 3 OH under the current condition. For all the combined cases, electricity usage for CO 2 R accounts for 36–76% of total operating cost, which plays a key role for TPC. Sensitivity analysis confirmed that the process that combined biomass gasification with CO 2 R to CO is sensitive to the price of electricity, while both CO 2 R performance and prices of stack and electricity are important for the processes that combined with CO 2 R to syngas/CH 3 OH. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new method to co-produce of methanol and biochar from bagasse and PW is proposed. • The integrated scenario exhibits the best economic and environmental benefits. • Chongzuo and Laibin have great bagasse development potentials. • Co-production of biochar and electricity is a viable option with limited funds. • The integrated scenario can advance carbon neutrality goals in Guangxi province. The shift from fossil fuels to renewable energy is a crucial strategy to achieve carbon neutrality. However, the methanol industry relies heavily on fossil fuels. Alternative feedstocks, such as biomass and plastics, still face many challenges. Biomass is hydrogen-deficient and cannot achieve a high methanol yield, while plastic gasification consumes too much energy. Accordingly, this research proposed a new method to synergistically co-produce methanol and biochar from bagasse pyrolysis and plastic waste gasification. This innovative approach was assessed using techno-economic analysis and hybrid life-cycle assessment based on sugarcane bagasse resources in Guangxi province as a case study and compared with the other four scenarios. The results indicated that the novel method exhibits huger economic and environmental benefits with a low payback period of 6.32 years and a low global warming potential of −1875.41 kg CO 2 -eq/t. However, the high total capital cost is the primary potential obstacle to widespread promotion. Spatial-temporal analysis shows that Chongzuo and Laibin have the most tremendous methanol production potential and economic and environmental benefits due to their high bagasse production. This study contributes to biomass utilization and plastic waste management by proposing a synergistic process and offers multiple benefits for carbon sequestration, energy security, and waste valorization. [ABSTRACT FROM AUTHOR]

First industrial-scale Power-to-Methanol plants are starting to be deployed in various geographic locations to tackle the problem of high greenhouse gas emissions of the predominantly fossil-based production of methanol. With the aim to speed up the deployment by streamlining their engineering and construction, we explore the potential of reducing the complexity of designs to be distributed across locations with different renewable energy conditions. A multi-objective optimization-based method incorporating a broad process network for early-stage process synthesis is proposed, which by determining the installed capacities of technologies from the chemical production, utility and storage subsystems, identifies alternative designs with different levels of complexity along two dimensions: 1) the number of different technologies used, 2) standardization of designs across different locations. The method was applied to case studies, which paired together design locations with either wind- or solar-dominant renewable resource conditions in the US and Chile for standardization. As per the method, the increases of methanol production costs due to reduced design flexibility, inherently bound to complexity reduction, were quantified and Pareto fronts were constructed. These uncovered the possibility to significantly reduce the complexity of the designs with only small increases of the production costs. By comparing the results of the case studies under different cost and operation scenarios, we characterized general aspects, which need to be considered for such design simplification. One of the main outcomes were the quantified cost-increases due to standardization, which were around 7 and 15 % relative to the specifically designed plants for each location in the US and Chile case studies respectively. A subsequent analysis of the economies of numbers through learning rates reported in academic literature suggested that the proposed standardization, even across extremely different locations, could compensate these cost-increases and be economically beneficial. Yet, more specific data on achievable cost-reductions are needed, requiring more interaction with the industry and further research, for which we highlighted promising directions. [Display omitted] • Method to identify standard and simple design of Power-to-Methanol processes. • Standardization across locations can affect technology selection. • Transfer of the complexity of design into the complexity of fluctuating operation. • Pareto-optimal design with thermal energy storage parabolic troughs, heat pump. • Important to consider the locations, which should share a standard design. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZrO 2 atomic layer deposition was less effective over Ni 5 Ga 3 /SBA-15 substrate. • ZrO 2 deposition was beneficial for formate and methoxy intermediates formation. • The ZrSBANG_6 catalyst followed exclusively the formate route since no CO was detected. The production of methanol through CO 2 hydrogenation holds great promise for efficient CO 2 utilization. The development of catalysts that exclusively favor the formate route is desirable as this enhances methanol selectivity and avoids CO formation. Here, the synthesis of two groups of Ni 5 Ga 3 -ZrO 2 -SBA-15 based materials was studied through the atomic layer deposition (ALD) of ZrO 2. The first group was prepared applying ZrO 2 ALD over a Ni 5 Ga 3 /SBA-15 material and the second group was prepared doing ZrO 2 ALD over a mesoporous silica, Santa Barbara Amorphous (SBA-15), followed by impregnation with Ni 5 Ga 3. Some characterization techniques were employed to assess the effectiveness of the ZrO 2 ALD on both groups. Interestingly, it was observed that ZrO 2 deposition was less effective over the Ni 5 Ga 3 /SBA-15 sample compared to its deposition over pure SBA-15, and through XPS analysis was noticed that ZrO 2 is probably covering part of the Ni 5 Ga 3 alloys. Furthermore, in situ DRIFTS analysis was performed during reaction conditions and revealed that ZrO 2 deposition facilitated the formation of formate and methoxy intermediates in both material groups. The increase in the ZrO 2 ALD cycles increased the formate and methoxy bands and decreased CO-related bands. After 6 cycles, only the ZrSBANG_6 catalyst exclusively followed the formate route, as only formate and methoxy bands were present. [ABSTRACT FROM AUTHOR]