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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]

The present study conceptualizes and simulates a methanol production process through the direct hydrogenation of captured CO2. CuO/ZnO/ZrO2 was employed as the catalyst and Aspen HYSYS was used for the process simulation. Configurational optimization of the process flowsheet was carried out using a step-by-step hierarchical approach. Many alternate flowsheets have resulted, and their capital investment, product cost, and profitability measures were calculated. The discrimination among the competing flowsheets was carried out based on net profit and percent return on investment. The retained flowsheet was further analyzed for optimizing the recycle ratio and evaluating the effect of the price of captured CO2, green H2, natural gas (fuel), and catalyst on the economic performance of the plant. The optimum value of the recycle ratio was computed to be 4.23. Additionally, it was found that the price of H2 is the most important parameter in defining the feasibility and profitability of the process. Mathematical correlations were also developed that relate the profitability and price of the above-mentioned feed materials. [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]

This article presents a computer model for the methanol production from biogas. The stages of autothermal and steam reforming of biogas and the methanol synthesis cycle are considered. A study has been performed on the influence of the composition of biogas and the method of its conversion on the amount of methanol produced. As a result of the computational experiment on the model, the optimal composition of biogas has been determined and the applicability of the methods of autothermal and steam reforming has been assessed. An assessment has been made of reducing the carbon pressure on the environment during the processing of biogas into methanol. [ABSTRACT FROM AUTHOR]

Methanol, the simplest aliphatic molecule of the alcohol family, finds diverse range of applications as an industrial solvent, a precursor for producing other chemicals (e.g., dimethyl ether, acetic acid and formaldehyde), and a potential fuel. There are conventional chemical routes for methanol production such as, steam reforming of natural gas to form syngas, followed by catalytic conversion into methanol; direct catalytic oxidation of methane, or hydrogenation of carbon dioxide. However, these chemical routes are limited by the requirement for expensive catalysts and extreme process conditions, and plausible environmental implications. Alternatively, methanotrophic microorganisms are being explored as biological alternative for methanol production, under milder process conditions, bypassing the requirement for chemical catalysts, and without imposing any adverse environmental impact. Methanotrophs possess inherent metabolic pathways for methanol production via biological methane oxidation or carbon dioxide reduction, thus offering a surplus advantage pertaining to the sequestration of two major greenhouse gases. This review sheds light on the recent advances in methanotrophic methanol production including metabolic pathways, feedstocks, metabolic engineering, and bioprocess engineering approaches. Furthermore, various reactor configurations are discussed in view of the challenges associated with solubility and mass transfer limitations in methanotrophic gas fermentation systems. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions during production is one of the main trends in modern oil and gas chemistry. One of the most realistic possibilities for achieving this is to involve carbon dioxide generated in technological processes as a feedstock for producing gas chemical products. The maximum effect can be achieved in the production of large-scale chemicals, such as syngas, hydrogen, and methanol. We consider such possibilities and present a new combined autothermal process for the joint production of hydrogen and methanol based on non-catalytic matrix conversion of natural gas into syngas, which allows one to almost avoid CO2 emissions. [ABSTRACT FROM AUTHOR]

The urgent global demand for carbon neutrality is met with increasing energy consumption due to economic development, necessitating the adoption of a sustainable energy mix. More than just an essential C1 building block in the chemical industry, methanol production presents a promising solution for utilizing coal with lower carbon emissions. Additionally, it offers a practical means to transport and store excess power for sustainable energy systems with significant fluctuations. In both scenarios, the energy efficiency of methanol production holds great significance as it determines whether the methanol-based approach can be both carbon-neutral and economically viable. From this perspective, the purification process, known as methanol distillation (MD), as the most energy- and carbon-intensive step in methanol production, is of great importance. It plays a pivotal role in determining the competitiveness of methanol applications. Consequently, advanced MD systems (MDS) have garnered substantial interest in recent decades. These efforts have led to significant improvements in the state-of-the-art MDS, making them more efficient than the original designs. However, there is still a long distance from achieving the goal of supporting carbon-neutral energy systems. In this study, we provide a comprehensive review of the iterative development of MDS, spanning from their original configurations to the current competitive advanced processes. As strongly related topics, steady-state design, optimization, and control strategies are also designed. Furthermore, we conduct economic and environmental analyses on configurations commonly used in industry or those reported with considerable efficiency in the literature to identify promising approaches. In conclusion, this review outlines the limitations and challenges in methanol production and explores future opportunities for more sustainable solutions. [Display omitted] • The shift from single-column to multi-column configurations for methanol distillation system (MDS) has been reviewed in detail. • The energy-efficient strategies and process control structures applied in contemporary MDS has been reviewed in detail. • The sustainability of MDS based on steam consumption and CO 2 emissions has been assessed. • Outline the opportunities and limitations in further developments towards efficient and sustainable MD. [ABSTRACT FROM AUTHOR]

The use of supported intermetallic PdxIny nanoparticles as an efficient catalyst for the synthesis of methanol from carbon dioxide was shown. On catalysts with a ratio of Pd : In = 1 : 1–1 : 2 the optimal performance (rMeOH = 65.3 gMeOH kgcat−1 h−1) and methanol selectivity (SMeOH = 49.4%) were achieved. These characteristics are significantly superior to those of the traditional Cu/ZnO/Al2O3 methanol synthesis catalyst. One of the main reasons of the efficiency of Pd-In catalysts is the formation of In-Pd heteroatomic active sites, the structure of which favors a decrease in the chemisorption energy of CO2 molecule. [ABSTRACT FROM AUTHOR]

N-doped ordered mesoporous carbons (NCMK-3) were synthesized using urea and ammonia as nitrogen sources via an incipient wetness impregnation method. To quantify the amount of nitrogen doping and classify the nitrogen bond formations, the XPS technique was used in this study. It was found that urea can increase the nitrogen content up to 2.54% and can classify nitrogen on NCMK-3 into three types: pyridinic-N, pyrrolic-N, and graphitic-N. Subsequently, 15 wt% of Cu–ZnO and 15 wt% of Cu–CeO2 were loaded on NCMK-3 and tested for methanol production from the CO2 hydrogenation reaction. The catalysts' performance was evaluated in a fixed-bed reactor using 0.25 g of catalyst and a CO2/H2 (1/3) mixture at GHSV of 2444 h−1. The results showed that 15 wt% of Cu–ZnO on the nitrogen-doped CMK-3 using urea as a nitrogen source (CZ/NCMK-3U) provided the highest space time yield (STY) of 512 mgMeOH gcat−1 h−1 at the reaction temperature and pressure of 250 °C and 1.5 MPa, respectively. [ABSTRACT FROM AUTHOR]

CuO/ZnO/Al2O3 catalysts are commonly used for the methanol steam reforming reaction. The oxalate precursor of CuO/ZnO/Al2O3 catalysts were prepared via the co-precipitation method using oxalic acid as the precipitator, deionized water and ethanol as the solvent, and microwave radiation and water baths as aging heating methods, respectively. This suggests that ethanol selects the crystalline phase composition of oxalate precursors and limits their growth. Microwave irradiation prompted the isomorphous substitution between Cu2+ of CuC2O4 and Zn2+ of ZnC2O4 in the mother liquid; Zn2+ in ZnC2O4·xH2O was substituted with Cu2+ in CuC2O4, forming the master phase (Cu,Zn)C2O4 in the precursor. Moreover, the solid solution Cu-O-Zn formed after calcination, which exhibited nano-fibriform morphology. It has the characteristics of small CuO grains, a large surface area, and strong synergistic effects between CuO and ZnO, which is conducive to improving the catalytic performance of methanol steam reforming. The conversion rate of methanol reached 91.2%, the space time yield of H2 reached 516.7 mL·g−1·h−1, and the selectivity of CO was only 0.29%. [ABSTRACT FROM AUTHOR]

Gas turbine power cycles are among the most important power plants, operating in higher temperatures. Their principal defect is huge waste heat, leading to lower exergetic performances in addition to higher carbon dioxide (CO 2) emissions. In this regard, the current paper focuses on a new solution to solve these defects appropriately. For this purpose, a new thermal integration model is designed for a multigeneration purpose, which is able to decrease the CO 2 emission intensity below zero (a negative emission solution). The designed model comprises a steam power cycle, a Kalina power cycle, a dual organic Rankine cycle, a water desalination unit plus, and a methanol production unit plus. Thus, the products include electricity, heating, fresh water, and methanol. This system is simulated in the Aspen HYSYS software and is studied from the energy, exergy, economic, and environmental standpoints. According to the results obtained from the thermodynamic analysis, it is demonstrated that the total energy and exergy efficiencies are 49.38% and 66.5%, respectively. Furthermore, the net CO 2 emission intensity of the process is negative and equals − 1.036 kg CO2 /kg MeOH. Eventually, according to the economic evaluation, the methanol production cost equals 0.136 $/kg, which is 90.87% lower than the renewable methanol production method. [ABSTRACT FROM AUTHOR]

In this study, we propose two advanced processes, i.e., advanced syngas-to-methanol (AS2M) and direct CO2-to-methanol (DC2M) processes, for methanol production using waste CO2 and renewable H2 as feedstock. The AS2M process produces methanol from syngas after converting CO2 to CO via reverse water-gas shift and separating CO from a mixture through pressure swing adsorption. In comparison, the DC2M process directly synthesizes methanol from CO2 through direct hydrogenation. Different unit processes and recycles were synthesized to determine the optimal process configurations and operating conditions for maximizing the methanol production rate. The technoeconomic and environmental capabilities of the two proposed processes were analyzed with four evaluation criteria (carbon and energy efficiencies, CO2 reduction, and unit production cost) and compared with conventional CO2-to-methanol processes. A sensitivity analysis for various utilities and H2 supply strategies was performed to evaluate the economic feasibility and environmental benefits of the proposed systems with different design options. Our findings showed that both processes could achieve improved technical, economic, and environmental performances compared to conventional processes. In particular, the DC2M process showed the lowest unit production cost at $1.02/kg because of its simple configuration and mild operating conditions. [ABSTRACT FROM AUTHOR]

The production of renewable energy or biochemicals is gaining more attention to minimize the emissions of greenhouse gases such as methane (CH4) and carbon dioxide for sustainable development. In the present study, the influence of copper (Cu)- and iron (Fe)-based nanoparticles (NPs), such as Cu, Fe3O4, and CuFe2O4, was evaluated during the growth of methanotrophs for inoculum preparation and on the development of a polymeric-matrix-based encapsulation system to enhance methanol production from simulated biogas (CH4 and CO2). The use of simulated biogas feed and the presence of NP-derived inoculums produce a remarkable enhancement in methanol production up to 149% and 167% for Methyloferula stellata and Methylocystis bryophila free-cells-based bioconversion, respectively, compared with the use of pure CH4 as a control feed during the growth stage. Furthermore, these methanotrophs encapsulated within a polymeric matrix and NPs-based systems exhibited high methanol production of up to 156%, with a maximum methanol accumulation of 12.8 mmol/L over free cells. Furthermore, after encapsulation, the methanotrophs improved the stability of residual methanol production and retained up to 62.5-fold higher production potential than free cells under repeated batch reusability of 10 cycles. In the presence of CH4 vectors, methanol production by M. bryophila improved up to 16.4 mmol/L and retained 20% higher recycling stability for methanol production in paraffin oil. These findings suggest that Cu and Fe NPs can be beneficially employed with a polymeric matrix to encapsulate methanotrophs and improve methanol production. [ABSTRACT FROM AUTHOR]

The chemical conversion of carbon dioxide into methanol has the potential to address two major sustainability issues: the economically viable replacement of fossil energy resources and the avoidance of greenhouse gas emissions. However, the chemical stability of carbon dioxide poses a difficult barrier to its conversion, necessitating extreme reaction conditions, resulting in increased energy input and, subsequently, elevated equipment, operation, and environmental costs. This, in turn, could potentially undermine its promising sustainability as a raw material for the chemical and energy industries. This research aims to optimise methanol production from a methanol reactor by using design of experiment (DOE) in Design Expert and Aspen Plus as a reactor simulator. The optimisation process involved eight parameters: five inlet molar flowrates (CO, CO2, H2O, H2, CH3OH) and three reactor conditions (inlet temperature, pressure, and temperature profile). The methanol production in Design Expert was optimised using the Box-Behnken method and a quadratic model. This study used the maximum range for each parameter as the actual industrial data and the minimum range to be 50% below it. The validated Aspen-Plus model was used for methanol production simulation. Response surface methodology (RSM) was used to determine the optimal parameters. This simulation required 120 samples. The optimal parameter values from the RSM were 142.2 kmol/hr of inlet CH3OH, 2250.91 kmol/hr of CO, 1398.3 kmol/hr of CO2, 15.6973 kmol/hr of H20, 19053.7 kmol/hr of H2, 497.883K of reactor inlet temperature, 81.9999 bar of reactor pressure, and 30K for reactor temperature profile with the actual methanol production of 2814.23 kmol/hr. The optimal values were simulated to test the accuracy of the predictive model, and the error was less than 5.2 percent. Overall, the inlet H2 molar flowrate was reduced in optimised conditions, reducing raw material usage and increasing output. [ABSTRACT FROM AUTHOR]

Steam reforming of methanol MSR) is a mobile hydrogen production technology with great application prospect. Reducing the reaction temperature can save a lot of energy. The effects of Pt loading on the phase change of MoCx and its catalytic performance for low-temperature MSR were investigated by fixed-bed catalytic reaction experiment,XRD,TPR, BET, SEM,TEM and XPS. The results show that the introduction of Pt reduces the initial reduction temperature of molybdenum trioxide during carburzing, promotes the formation of a-MoC, and the specific surface area of the sample loaded with Pt is larger. With the increase of Pt loading in Pt/MoCx,the conversion rate of methanol gradually increased. When the catalyst composition was 1. 6Pt/MoCx,the reaction performance was the best:when the reaction temperature was 160 C,n( water) u n( methanol) =3, and the gas space velocity is 4 000 mL/( g x h),the conversion rate of methanol was 92. 1,the C02 selectivity is 96. 8,and the CO content in the tail gas is 0. 28, which is superior to the methanol conversion ( 25. 6 ) of the commercial CuZnAlOx catalyst under the same test conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A strategy to disperse Pd NPs and lack of long-range order nano In 2 O 3 on Al 2 O 3. • One-step coprecipitation method followed by calcination. • In 2 O 3 intrinsic activity in CO 2 hydrogenation to methanol boosted in Pd-In 2 O 3 -Al 2 O 3. • In 2 O 3 loading determines the performance improvement. • Decrease In 2 O 3 to 12 wt% and improve long-term stability by threefold at 30 bar. Pd-In 2 O 3 catalysts are among the most promising alternatives to Cu-ZnO-Al 2 O 3 for synthesis of CH 3 OH from CO 2. However, the intrinsic activity and stability of In 2 O 3 per unit mass should be increased to reduce the content of this scarcely available element and to enhance the catalyst lifetime. Herein, we propose and demonstrate a strategy for obtaining highly dispersed Pd and In 2 O 3 nanoparticles onto an Al 2 O 3 matrix by a one-step coprecipitation followed by calcination and activation. The activity of this catalyst is comparable with that of a Pd-In 2 O 3 catalyst (0.52 vs 0.55 g MeOH h−1 g cat -1 at 300 °C, 30 bar, 40,800 mL h−1 g cat -1) but the In 2 O 3 loading decreases from 98 to 12 wt% while improving the long-term stability by threefold at 30 bar. In the new Pd-In 2 O 3 -Al 2 O 3 system, the intrinsic activity of In 2 O 3 is highly increased both in terms of STY normalized to In specific surface area and In 2 O 3 mass (4.32 vs 0.56 g g MeOH h−1 g In2O3 -1 of a Pd- In 2 O 3 catalyst operating at 300 °C, 30 bar, 40,800 mL h−1 g cat -1).The combination of ex situ and in situ catalyst characterizations during reduction provides insights into the interaction between Pd and In and with the support. The enhanced activity is likely related to the close proximity of Pd and In 2 O 3 , wherein the H 2 splitting activity of Pd promotes, in combination with CO 2 activation over highly dispersed In 2 O 3 particles, facile formation of CH 3 OH. [ABSTRACT FROM AUTHOR]