Drm+Cosorb Process for Syngas Production with High H2/CO Ratio

Dry Reforming of Methane (DRM) refers to the reaction between CH4 and CO2 to produce syngas. However, due to the stoichiometry of the reaction, the H2/CO ratio of the syngas produced is slightly below 1. Life cycle analysis work done by our group [1] indicates that parallel combinations of a DRM unit with a commercial process like Steam Methane Reforming might not result in an appreciable decrease in overall CO₂ emissions or operating costs. Hence, other process combinations were investigated. Out of those processes studied, the DRM+COSORB option gave the best results in terms of reduction of carbon footprint as well as competitive operating costs. The DRM+COSORB process is a stand-alone DRM reformer followed by a CO absorption unit to boost DRM syngas ratio. This process combination has considerable improvement at higher syngas ratios. For a syngas ratio of 2, the DRM+COSORB process would have ~68% reduction in CO₂ emissions and ~21% reduction in operating costs when compared to a Partial Oxidation plant (which utilizes oxygen). Similarly, for a syngas ratio of 3, when compared to an Auto-Thermal Reformer, the reduction in CO₂ emissions is ~72% and reduction in operating costs is ~25%. The current work build on these new targets and by combining information of OPEX and CAPEX of each process and gives more accurate estimates of the economics of each process and their impact on carbon footprint. The proposed DRM+COSORB process will be able to produce high quality syngas, through a stand-alone DRM unit without the need for external hydrogen blending for syngas ratio adjustment. This simulation work of the DRM+COSORB process is one step towards better understanding of this process which has the potential of producing same quality of syngas as commercial processes (H₂/CO ≥ 2) with lower CO₂ emissions and competitive operating costs.

References:

[1] Afzal et al., ACS Sustainable Chem. Eng. 2018, 6, 6, 7532-7544