Hydrogen (H2) will foster the decarbonization roadmap. H2 faces challenges that hamper its application, storage and transport being the major issues needing reliable and affordable solutions. Its transformation into H2-based green methanol offers a potential alternative. The present research applied a multi-step inter-cooled fixed-bed reactor using a Cu/ZnO/Al2O3 catalyst and fed with biogas-derived syngas of different CO/H2 concentration ratios. The reaction is mainly carried out at 503 K and 5 MPa. Conversions and yields were measured after each of the 4 steps and revealed a total conversion of 97.8%. The catalyst was fully characterized and showed a nano-size structural cell with ultrafine crystallinity. Aspen simulation predictions using the Graaf et al. kinetic expressions accurately fitted the experimental results. The methanol purity exceeded 99.5%. The concept can be readily scaled up by using 3 successive catalytic beds with intercooling. Pilot-plant experiments will be further used to enhance the Technology Readiness Level.
Zhang et al. (Tue,) studied this question.