Development of sustainable CO2 conversion processes for the methanol production

Utilization of CO2 feedstock through CO2 conversion for producing valuable chemicals as an alternative to sequestration of the captured CO2 is attracting increasing attention in recent studies. Indeed, the methanol production process via thermochemical CO2 conversion reactions is considered a prime candidate for commercialization. The aim of this study is to examine two different options for a sustainable methanol plant employing the combined reforming and CO2 hydrogenation reactions, respectively. In addition, process improvement strategies for the implementation of the developed processes are also considered. The two methanol plants are developed using Aspen Plus (R), the commercial process simulator. The net CO2 flows and methanol production costs are evaluated using ECON (R) and compared with those of the conventional methanol plant, which uses two-stage reforming. It is verified that the combined reforming process has to be integrated with the existing conventional methanol plant to obtain a reduced CO2 emission as well as lowered production costs. On the other hand, the CO2 hydrogenation based methanol plant could achieve a reduction of net CO2 emission at a reasonable production cost only with utilization of renewable energy resources (hydroelectric power and biomass) for the H-2 feedstock.