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The article explores the integration of a methanol production system with a modern combined cycle power plant utilizing oxy-combustion technology, resulting in enhanced efficiency for both systems (synergy effect). The integration involves various components like a 90 MW wind farm, hydrogen generators, and methanol production units. Notably, CO 2 preparation and compression for the methanol reactor within the power plant optimize methanol production and reduce energy consumption in the oxygen separation unit by supplementing oxygen through electrolysis. Utilizing oxygen from electrolysis also decreases energy consumption in the gas turbine's oxidant compressor. Additionally, compressing CO 2 to lower pressures reduces energy consumption in the CCU installation. The article presents a methodology for quantifying energy efficiency for both the methanol production unit and the combined cycle power plant. Integration leads to significant efficiency increases, particularly for low-power generation setups and with greater contributions from renewable energy sources. For instance, in scenarios involving a gas turbine with 7.5 MW capacity, efficiency gains range from 0.8 to nearly 6 percentage points with multiple wind farms. This study is the first of its kind to demonstrate the synergistic advantages of directly integrating an oxy-combined cycle power plant with a methanol production facility. The integration results in heightened efficiency for both the power plant and the methanol production setup, contributing significantly to the advancement of hydrogen technology and the green deal initiative. The unique approach of utilizing hydrogen from electrolysis setups and CO 2 derived from exhaust gases of power plants to generate liquid methanol, a superior energy carrier, is a significant contribution to the existing body of literature. The demonstrated synergistic outcomes of integrating a methanol production facility with combined cycle power plants stem from augmented unit efficiencies, overall installation improvements, and the amelioration of the ecological attributes of the power plant. The innovative character of this research endeavor is underscored by the fact that no existing installation worldwide currently pairs methanol production with a combined cycle power plant. [Display omitted] • Mutual synergy: Methanol system integrated with oxy Combined Cycle Power Plant • Efficiency gains across power plant, methanol unit, and setup • CO 2 prep and compression optimize methanol, reduce Air Separation Unit energy • Oxygen supplementation lowers gas turbine compressor energy • Lower CO 2 mass flow cuts energy use in Carbon dioxide Compression Unit installation [ABSTRACT FROM AUTHOR]

• Evaluation of direct and indirect electrification of methanol production. • Direct electrification implemented through stand-alone heat-pumps. • Indirect electrification implemented by substituting fossil based feedstock. • Indirect electrification has great environmental and economic potential. • Carbon dioxide abatement can reach up to 1.35 kg/kgMeOH if electricity is 100% green. This work aims to explore the electrification of chemical industry taking the production of methanol as a case study. A reference process, with a basis of 400,000 tonne per annum, is first simulated in Aspen Plus to produce methanol via traditional natural gas reforming. As an indirect electrification strategy, a non-conventional carbon dioxide hydrogenation methanol plant is then designed to substitute fossil fuel feedstock. Standalone heat-pumps are implemented as a direct electrification method in both processes at various extents generating different scenarios. It has been found that direct electrification has a small impact on energy consumption in all scenarios. In the reference process, direct electrification can only substitute 7.1 MW of heating, accounting for 7.8% of the total heating. In contrast, the energy structure of the indirectly electrified process is completely changed from the reference process: (1) very high temperature heating is eliminated; (2) electricity consumption is increased from 14.2 to 604.1 MW due to feedstock (hydrogen) synthesis. The renewable energy penetration and electricity price are taken into consideration when financial and environmental assessments are performed. At approximately 88% of renewable penetration, carbon neutrality is achieved in the indirectly electrified process. The net present value of the indirectly electrified process breaks even at an electricity price of 22 €/MWh and exceeds its counterpart reference process at 3–4 €/MWh. This analysis will enable the integration and management of renewable energy for methanol production and will facilitate future studies on the electrification of chemical production. [ABSTRACT FROM AUTHOR]

• A solar-driven biomass gasification based polygeneration system is proposed. • The system mathematical model of off-design evaluations is developed. • The annual thermodynamic performances and transient characteristics are investigated. • Implementing the system economic evaluation and cost sensitive analysis. A new solar-biomass gasification polygeneration system is developed to efficiently utilize renewable energy in this work, with the production of liquid fuel methanol and electricity. In the system, the collected high-temperature concentrated solar energy with a beam-down optical configuration is used to drive biomass gasification, the cotton stalk is selected as feedstock, and the produced syngas is fed into the reactor for methanol synthesis. The un-reacted syngas and the system waste heat are efficiently utilized via the combined cycle to generate electricity. The designed biomass consumption rate and power capacities are 100 ktons/year and 32.7 MW e , respectively. The thermodynamic and economic performances of this polygeneration system are investigated, and the on-design energy efficiency and the exergy efficiency of the system reach to 51.89% and 51.23%, respectively. According to the off-design evaluation within a typical year, the annual production of methanol and electricity are 54.80 ktons and 50.85 GW·h, respectively. Compared with the reference system which consists of a typical methanol synthesis system with biomass-steam gasification and a solar tower power generation system, the annual averaged efficiency of the proposed solar-biomass polygeneration system is increased to 48.35% from 41.09% of the reference system, and the monthly averaged efficiency is varying in the range of 46.65%–49.05%. In addition, the specific biomass consumption rate is reduced by 27.33%, and the levelized cost of methanol is 361.88 $/ton with reasonable economic competitiveness. The polygeneration system achieves competitive thermodynamic and economic potential, and provides an alternative and promising way for efficiently utilizing abundant solar energy and biomass resources. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Photocatalytic CO 2 reduction in OFMR with transparent glass balls is studied. • For single circle and layer model, CH 3 OH concentration increases with ball number. • The closer the distance to fiber and inlet is, the higher the CH 3 OH production is. • CH 3 OH concentration rises with increasing the circle and layer numbers. • 3-circle and 5-layer balls configuration is recommended in the design of OFMR. Abstract Photocatalytic reduction of carbon dioxide to produce methanol is a promising approach to restrain greenhouse gases emissions and mitigate energy shortage, which attracts extensive concerns in recent years. The optical fiber monolith reactor with solid glass balls for photocatalytic carbon dioxide reduction is proposed in this work to increase the product concentration, and the glass balls are transparent and coated with photocatalysts evenly to absorb light. The photocatalytic reduction of carbon dioxide in optical fiber monolith reactor is numerically investigated, by which the effects of glass ball number, location, circle and layer on the production are analyzed. The results show that in the single-circle and single-layer model, the outlet methanol concentration increases with increasing the ball number. The closer to the fiber and reactor inlet the balls keep, the higher the methanol production is. As the circle and layer numbers increase, the methanol concentration also increases. The outlet methanol average concentration of the optical fiber monolith reactor with 3-circle and 5-layer balls gets 11.43% higher than the case without glass balls. [ABSTRACT FROM AUTHOR]

Renewable energy sources for electricity and more efficient processes are needed to decrease greenhouse gas emission rates, in line with the Paris agreement adopted in 2015. Carbon dioxide utilization is emerging as a complementary technology to carbon dioxide capture and storage for reducing greenhouse gas emissions, and as a promising source of competitive advantage for European industry. Current carbon dioxide utilisation technologies are at different stages of maturity, with some being ready to implement immediately. Others are still under research or at a pilot or demonstration phase, requiring further development to reach commercial maturity. Thus, the profitability of such processes under current market conditions is still under evaluation. This study explores the conditions required for an environmentally and economically feasible methanol producing carbon dioxide utilisation system embedded in the energy system. The choice to produce methanol is based on its current mature commercial status and on growing global demand, which makes it an attractive product. The concept proposed considers only one system actor: a wind power producer with a typical operating wind power generation portfolio that invests in a new technology to maximise the total profit. The core of the business model is based on decisions for: (i) selling the wind power in the day-ahead or intraday bidding sessions of the power market or, (ii) producing methanol to be sold to third parties. Several scenarios are tested within the proposed business model to define optimum conditions. Limitations for the economic feasibility of the methanol plant integration into a market with an increasing integration of renewable energy are also highlighted. Results show that producing methanol instead of selling the wind power generated in the market is more profitable when the methanol plant size is three times smaller than a conventional and when power is generated by high speed winds. Under such conditions, the power market energy mix has high amounts of wind power and thus, already a significantly lower carbon dioxide emissions rate. Wind power supplied to the small methanol plant is less than 1% of the total wind energy produced. Furthermore, the wind producer could increase profits by up to 33% by integrating methanol production into their business strategy rather than selling all the energy produced in the power market. [ABSTRACT FROM AUTHOR]

• A data-driven optimization algorithm is developed for reliable PtX design. • Constraint of grid utilization prevents overuse of grid for sustainable production. • The trade-off between variations and means of performance indicators is revealed. • Results offer insights into design decision-making under renewable uncertainty. Designing a reliable power-to-X (PtX) process that uses renewable energy and grid electricity as backup power is challenging due to the uncertain nature of renewables and potential limits on grid usage. To address this challenge, this paper proposes a data-driven, reliability-based optimization approach for designing a grid-assisted PtX process and understanding how the uncertainty of time-series renewable profile affects its design and optimal sizing. This approach uses generative adversarial networks (GANs) to capture the complex patterns of renewables in temporal and spatial dimensions, rather than simply treating uncertainty as a probabilistic range as in conventional methods. The optimization considers both the mean and variance of production cost as objectives, while also taking into account the level of grid energy penetration as a probabilistic constraint through the reliability analysis. A power allocation and performance evaluation model is developed and used in conjunction with the optimization to assess uncertainty propagation through the PtX process and evaluate the impact of renewable uncertainty on process performance. A case study involving the production of methanol on Jeju Island in South Korea demonstrates how the mean and variance of production cost and other performance indicators can be balanced in the reliable design of PtX processes under renewable energy uncertainty, providing insights for decision-making in such situations. [ABSTRACT FROM AUTHOR]

A 3-dimensional non-isothermal simulator comprising a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) and a methanol steam-reforming cell (MSR-C) was developed in Fluent (Ansys™). The simulator takes into account most of the significant physical processes, including the electrochemical reactions and carbon monoxide poisoning effect on the electro-catalytic activity of the FC; it also considers the methanol steam reforming (MSR), water gas shift (WGS) and methanol decomposition (MD) reactions in the MSR-C. The developed model for the integrated MSR-C/HT-PEMFC unit was simulated between 443 K and 473 K and validated with experimental results reported in the literature, showing always a very good agreement. The thermal sustainability of the MSR-C/HT-PEMFC unit was assessed, and the role of the thermal insulation and air intake (cathode) stoichiometry in the thermal equilibrium of the device were analysed. A novel integrated MSR-C/HT-PEM stack with ten cells was proposed and simulated, showing a performance above the reported in the literature for similar devices. The results indicated that the proposed stack operates at currents between 4.5 A (0.1 A cm −2 ) and 54 A (1.2 A cm −2 ) without any external heat source. To minimize the degradation of the components the stack should adapt the operating temperature to the current density. [ABSTRACT FROM AUTHOR]

Flexible multi-generation systems (FMGs) consist of integrated and flexibly operated facilities that provide multiple links between the different sectors of the energy system. The present study treated the design optimization of a conceptual FMG which integrated a methanol-producing biorefinery with an existing combined heat and power (CHP) unit and industrial energy utility supply in the Danish city of Horsens. The objective was to optimize economic performance and minimize total CO 2 emission of the FMG while it was required to meet the local district heating demand plus the thermal utility demand of the butchery. The design optimization considered: Selection, dimensioning, location and integration of processes; operation optimization with respect to both hourly variations in operating conditions over the year as well as expected long term energy system development; and uncertainty analysis considering both investment costs and operating conditions. Applying a previously developed FMG design methodology, scalable models of the considered processes were developed and the system design was optimized with respect to hourly operation over the period 2015–2035. The optimal design with respect to both economic and environmental performance involved a maximum-sized biorefinery located next to local industry rather than in connection with the existing CHP unit. As the local industry energy demands were limited when compared to the biorefinery dimensions considered, process integration synergies were found to be marginal when compared to the economic and environmental impact of the biorefinery for the present case. Assessing the impact of uncertainties on the estimated FMG performances, the net present value (NPV) of the optimal design was estimated to vary within the range 252.5–1471.6 M€ in response to changes of ± 25 % in investment costs and methanol price, and considering two different electricity price scenarios. In addition, a change in the interest rate from 5% to 20% was found to reduce the lower bound of the NPV to 181.3 M€ for reference operating conditions. The results suggest that the applied interest rate and operating conditions, in particular the methanol price, would have a much higher impact on the economic performance of the designs than corresponding uncertainties in investment costs. In addition, the study outcomes emphasize the importance of including systematic uncertainty analysis in the design optimization of FMG concepts. [ABSTRACT FROM AUTHOR]

Both methane (CH 4 ) and carbon dioxide (CO 2 ) are major greenhouse gases (GHGs); hence, effective processes are required for their conversion into useful products. CH 4 is used by a few groups of methanotrophs to produce methanol. However, to achieve economical and sustainable CH 4 reduction strategies, additional strains are needed that can exploit natural CH 4 feed stocks. In this study, we evaluated methanol production by Methylosinus sporium from CH 4 and synthetic gas. The optimum pH, temperature, incubation period, substrate, reaction volume to headspace ratio, and phosphate buffer concentration were determined to be 6.8, 30 °C, 24 h, 50% CH 4 , 1:5, and 100 mM (with 20 mM MgCl 2 [a methanol dehydrogenase inhibitor]), respectively. Optimization of the production conditions and process parameters significantly improved methanol production from 0.86 mM to 5.80 mM. Covalent immobilization of M. sporium on Chitosan significantly improved the stability and reusability for up to 6 cycles of reuse under batch culture conditions. The immobilized cells utilized a synthetic gas mixture containing CH 4 , CO 2 , and hydrogen (at a ratio of 6:3:1) more efficiently than free cells, with a maximum methanol production of 6.12 mM. This is the first report of high methanol production by M. sporium covalently immobilized on a solid support from a synthetic gas mixture. Utilization of cost-effective feedstocks derived from natural resources will be an economical and environmentally friendly way to reduce the harmful effects of GHGs. [ABSTRACT FROM AUTHOR]

Emerging emission-to-liquid (eTL) technologies that produce liquid fuels from CO 2 are a possible solution for both the global issues of greenhouse gas emissions and fossil fuel depletion. Among those technologies, CO 2 hydrogenation and high-temperature CO 2 electrolysis are two promising options suitable for large-scale applications. In this study, two CO 2 -to-methanol conversion processes, i.e., production of methanol by CO 2 hydrogenation and production of methanol based on high-temperature CO 2 electrolysis, are simulated using Aspen HYSYS. With Aspen Energy Analyzer, heat exchanger networks are optimized and minimal energy requirements are determined for the two different processes. The two processes are compared in terms of energy requirement and climate impact. It is found that the methanol production based on CO 2 electrolysis has an energy efficiency of 41%, almost double that of the CO 2 hydrogenation process provided that the required hydrogen is sourced from water electrolysis. The hydrogenation process produces more CO 2 when fossil fuel energy sources are used, but can result in more negative CO 2 emissions with renewable energies. The study reveals that both of the eTL processes can outperform the conventional fossil-fuel-based methanol production process in climate impacts as long as the renewable energy sources are implemented. [ABSTRACT FROM AUTHOR]

• A new layout to indirectly couple solar energy with biomass chemical looping gasification is proposed; • The proposed system can circumvent the fluctuating working condition of CLG and downstream processes; • Efficient thermal recovery of the solid particles is easier to be fulfilled for the proposed system; • The present configuration based methanol synthesis route produces more methanol and electricity, but emits less carbon. A new configuration of solar-assisted biomass chemical looping gasification (CLG), in which solar heat is indirectly absorbed and stored in the form of sensible heat in solid particles (oxygen carrier and support material), was developed (i.e., indirect coupling). A steam Rankine cycle was integrated to further recuperate the thermal energy of the high-temperature solid particles at the outlet of the steam reactor. Compared with the direct solar energy utilization approach, the proposed configuration can circumvent the fluctuating working conditions of the CLG and downstream processes. Additionally, since the solar receiver and reactor are uncoupled, efficient thermal integration of the developed system is relatively easy to achieve. Thermodynamic analysis of the proposed configuration was conducted, and the indirect coupling of solar energy with CLG was investigated. A case study of methanol synthesis was conducted to compare the annual output of the proposed configuration with that of an auto-thermal CLG. Results indicate that the energy and exergy efficiencies of the present configuration were 66.16% and 77.68%, respectively. The optimal solar multiple was 2.8, which corresponds to the thermal energy storage and designed heliostat size of 10 h and 110.74 × 103 m2, respectively. The case study shows that the present configuration-based methanol synthesis route produced more methanol and electricity but emitted less carbon than the auto-thermal CLG-based method. [ABSTRACT FROM AUTHOR]

Highlights: [•] Polygeneration of MeOH and power in recycle and once-through configurations. [•] Integrated systems show better performance than stand-alone. [•] Polygeneration systems can cope with lower catalyst performance. [•] Flexibility of integrated systems shown to be feasible. [ABSTRACT FROM AUTHOR]

Highlights: [•] The integration of a methanol synthesis process in steel plants increases the gas utilization efficiency. [•] Methanol produced by off-gases from steelmaking combined with biomass show competitive production costs versus petrol. [•] The integration of a methanol synthesis process in steel plants may reduce the specific CO2-emissions of the plant. [ABSTRACT FROM AUTHOR]

Abstract: Co-utilization of natural gas and biomass is a successful way to make efficient use of them for chemical production and power generation, for biomass is rich in carbon while natural gas is rich in hydrogen. The present paper therefore proposes a new polygeneration system taking biomass and natural gas as materials for methanol production and power generation. The new polygeneration system can achieve the optimal ratio of H2 to CO for methanol production by adjusting input ratio of natural gas to biomass without any energy penalty. Thus, the suggested system can eliminate CO to H2 shift process and CO2 remove process, which can avoid material and energy destruction; however, those processes are otherwise necessary in individual biomass to methanol plant. Moreover, the new system eliminates the CO2 addition process; however, the addition of CO2 is necessary in individual natural gas to methanol plant, which causes extra energy penalty. This system combined chemical production and power generation together, in order to achieve the cascaded utilization of chemical and physical energy of natural gas and biomass. In a further way, we investigated the key processes, to maximize the utilization of energy and improve system performance. A thermo-chemical process taking biomass and natural gas as co-feedstock is compared with the systems that only taking either biomass or natural gas as resource for methanol production and power generation. The evaluation and calculation of the systems are carried out by help of Aspen Plus process simulator. The evaluation results indicate that, the new polygeneration system can reduce materials input at least 9% compared with individual systems with same output. In a further way, the effect of natural gas to biomass feed ratio on system performance is also investigated. The research results show that, the proposed polygeneration system would be expected to realize efficient utilization of biomass and natural gas, and offer a possibility of developing new technologies for biomass and natural gas based systems. [Copyright &y& Elsevier]

• Techno-economic analysis was performed for renewable methanol synthesis. • Optimum operating conditions were obtained from process simulation results. • Predictive cost analysis was conducted to make methanol production cost attractive. • Renewable H 2 production cost and CO 2 tax credit were considered in this work. With the growing concern about environmental issues including high CO 2 emission, which is the main contributor to global warming resulting in climate change, CO 2 utilization technologies have received much attention. Among diverse technologies, renewable methanol synthesis using H 2 generated from the water electrolysis and the CO 2 captured from various industrial processes as well as the atmosphere has received significant attention. In this context, the technical and economic feasibility analysis of renewable methanol synthesis was conducted in this study. Using a commercial process simulation program, Aspen HYSYS®, parametric studies were conducted to investigate the effects of diverse operating parameters, such as the reaction pressure, temperature, and H 2 /CO 2 ratio, on the technical performance of this process. Under the optimum conditions of 100 bar and 493 K derived from thermodynamic studies, an economic analysis was performed to estimate the unit methanol production costs at different methanol production capacities using itemized cost estimation, sensitivity analysis, and predictive cost analysis. Predictive cost analysis was conducted to determine how the unit methanol production cost could be rendered reasonable compared to the existing one, which indicated that decreasing the renewable H 2 production cost as well as increasing in the CO 2 tax credit for a methanol production capacity of 100 ton per day would make the renewable methanol synthesis an economically feasible process. [ABSTRACT FROM AUTHOR]

• CO 2 impact of using renewable energy (RE) to produce MeOH from CO 2 quantified. • Three sources of electricity and CO 2 emissions accounted for. • RE on grid versus RE for producing MeOH from CO 2 accounted for. • RE on the grid avoids greater CO 2 than RE for producing MeOH from CO 2. • Use RE to produce MeOH from CO 2 only if grid intensity is below 67 gCO 2 /kWh Carbon capture and utilization (CCU) to produce methanol is a beneficial pathway to use carbon dioxide (CO 2) and mitigate climate change. Existing life cycle assessments demonstrate that CCU methanol generates a net CO 2 benefit when the hydrogen (H 2), required for hydrogenating the captured CO 2 , is generated by electrolyzing water using renewable electricity (RE). However, the findings do not account for the environmental opportunity cost when RE can be supplied to the grid to offset CO 2 intensive electricity instead of electrolyzing water, the energy penalty of capturing CO 2 and the scope for technological improvement. This study quantifies the environmental opportunity cost and determines the net CO 2 emissions when CCU methanol offsets the production of conventional methanol across 14 scenarios. The 14 scenarios account for capturing CO 2 from 3 sources (combined and conventional natural gas, and coal power plants) and generating H 2 with electricity from 3 sources (photovoltaics, wind and the grid). The CO 2 avoided by using RE on the grid is greater than that from producing CCU methanol by 660 to 11960 kg CO 2 /ton methanol across the 14 scenarios. Unless the grid CO 2 intensity drops below 67 g CO 2 /kWh, it is environmentally preferable to supply RE to the grid than for use in CCU methanol production. At the thermodynamic limit of CCU methanol production, the grid CO 2 intensity should be lower than 82 g CO 2 /kWh, which is unlikely in the US before 2050. [ABSTRACT FROM AUTHOR]

• A system for solar methanol production by hybridizing natural gas is proposed. • The effect of reaction conditions on methanol yield are analyzed. • The energy efficiency and exergy efficiency of the system are 62% and 65%. • Coupled with a power generation system, the net solar to electricity efficiency is 23%. Liquid sunshine is a concept for converting solar energy into liquid fuel. Methanol is an attractive candidate as the liquid fuel due to the long-period experiences in large-industrial scale of methanol production. Solar driven chemical looping process is considered as a way to produce raw materials of methanol synthesis. To achieve the transformation from solar energy to the chemical energy of liquid fuel, an integrated system based on the solar-driven chemical looping process using methane for methanol production is proposed. During the chemical looping process, solar heat is absorbed by the reaction to convert methane into syngas with a reasonable hydrocarbon ratio. The syngas as raw materials would be sent into a two-tower tandem methanol synthesis sector. The obtained crude methanol would be rectified and stored as the product. A preliminary parameter analysis helps to get the optimal reaction conditions of the chemical looping process, as the reaction temperature of 600 °C, CH 4 -to-NiO ratio of 1.25 and H 2 O-to-CH 4 ratio of 0.7. In addition, the system was simulated and the energy analysis and exergy analysis are examined. The results show that energy efficiency is about 62%, and exergy efficiency is about 65%. In addition, the stored chemical energy in methanol can be released by employing solar energy again. The solar heat at around 250 °C driven methanol cracking process can be further released and coupled with an internal combustion engine for power generation. The net solar to electricity efficiency is evaluated and reaches around 23%. In this study, by solar-driven natural gas chemical looping process coupled with methanol synthesis, we would expect to provide a new pathway for further development of liquid sunshine. [ABSTRACT FROM AUTHOR]

• Conversion of 100 MW wind power to methanol at 50% efficiency. • Feedstock H 2 O and CO 2 are captured from air. • Design of air capture installation and methanol reactor based on experimental work. • 10 MW wind turbines can accommodate the air capture installation in the base tower. • Estimated methanol price: 800 euro per ton. A 100 MW stand-alone wind power to methanol process has been evaluated to determine the capital requirement and power to methanol efficiency. Power available for electrolysis determines the amount of hydrogen produced. The stoichiometric amount of CO 2 – required for the methanol synthesis – is produced using direct air capture. Integration of utilities for CO 2 air capture, hydrogen production from co-harvested water and methanol synthesis is incorporated and capital costs for all process steps are estimated. Power to methanol efficiency is determined to be around 50%. The cost of methanol is around 300€ ton−1 excluding and 800€ ton−1 including wind turbine capital cost. Excluding 300 M€ investment cost for 100 MW of wind turbines, total plant capital cost is around 200 M€. About 45% of the capital cost is reserved for the electrolysers, 50% for the CO 2 air capture installation, and 5% for the methanol synthesis system. The conceptual design and evaluation shows that renewable methanol produced from air captured CO 2 , water and renewable electricity is becoming a realistic option at reasonable costs of 750–800 € ton−1. [ABSTRACT FROM AUTHOR]

• The optimal BtM process has efficiency of 53.3% and a payback time of 4.8 years. • The SOE-BtM increases efficiency to 66.0% and payback time to 11 years. • The waste heat of gasification process 50% less than the state-of-the-art and zero-power export cases. • The payback time can be shorter than 5 years. The purpose of this paper is to assess techno-economically the integration of solid-oxide electrolysis in biomass-to-methanol processes: (1) The hydrogen produced by electrolysis can be used to adjust the composition of syngas from gasification to increase the conversion of carbon in biomass, (2) the oxygen as a byproduct of electrolysis can be used in the gasifier to avoid expensive air separation units, and (3) the overall process can be thermally integrated. Two integration concepts are proposed with different sizing methods of the electrolyzer: (1) the case of full conversion of carbon in biomass, in which a large electrolyzer is driven by the electricity purchased from the grid, and (2) the case of zero power exchange, in which only part of the carbon in biomass is converted reaching self-sufficiency of electricity. The three cases including the state-of-the-art biomass-to-methanol process are investigated to identify (1) possible trade-offs between efficiency and costs, and (2) under which conditions, these concepts become economically viable. With a reference methanol production of 100 kton/year, the results show that there is an optimal design for the state-of-the-art case, which offers an efficiency of 53.3% due to steam cycles and a payback time of 4.8 years. For the integrated concepts, there are sharp trade-offs between the system efficiency and methanol production cost rate. The case of full carbon conversion can reach an energy efficiency of 64.5–66.0% but results in a longer payback time of over 11 years. The case of zero-power exchange can achieve a similar efficiency as the state-of-the-art case with a slightly increased payback time of over 5.5 years. The payback time of the full carbon conversion case can be shorter than 5 years with a reduction in stack cost and electricity price, and an increase in stack lifetime. [ABSTRACT FROM AUTHOR]