Process design and techno-economic-assessment of the sorption enhanced methanol synthesis over zeolite 3A

The current effort towards sustainable methanol production is fostering research into the development of new small-scale processes that can adapt to the decentralized nature of most renewable electricity production sources. The production of methanol from electrolytic H2 and CO2 requires the development of new chemical routes that account for the many limitations present in small-scale applications. Among these, the most relevant is the low pressure (<30 bar) at which H2 is normally delivered from electrolysis. In this context, the exploitation of sorption-enhancement may be of interest as it shifts the thermodynamic equilibrium, requiring lower synthesis pressure. This work delivers a comprehensive model of the sorption-enhanced methanol synthesis process, including both the reaction and the regeneration phase in the simulation. An economic assessment is performed to determine the levelized cost of methanol (LCMeOH) and compare it with that of a benchmark methanol plant. In every scenario analyzed, the configuration with the sorption-enhanced reactor shows better economic performance. Nevertheless, costs related to the production of hydrogen, representing 50.60% of capital expenditures and 76.40% of operational expenditures, make this solution not competitive compared to the traditional, fossil-based production process. As the electricity cost is dominant in the total process costs, the LCMeOH can be reduced by considering the self-production of electricity from photovoltaic panels, decreasing the LCMeOH by 28.71%, settling it at 1785 $/ton. With an increase in the operating hours. it could be possible to achieve an additional reduction by 29,54% of the levelized cost, to 1250 $/ton.