Synthesis Gas Processes for Methanol Production via CH₄ Reforming with CO₂, H₂O, and O₂

Abstract

A conceptual design for the production of synthesis gas, suitable for methanol production, is presented. We propose the reforming of natural gas with high CO2 content by using H2O or H2O–O2 as coreactants. A thermodynamic analysis for two reforming processes is developed to get adequate operating conditions for the reformer. The flow scheme for the syngas-methanol plant, together with the corresponding mass balances, is presented. A H2 separation process is considered for syngas composition adjustment. The methanol-loop reactor was also included in the analysis to take into account its close relationship with the reformer’s energy balance. For a comparative study, the hypothetical expansion of an existing methanol plant based on steam reforming of natural gas was chosen. A fundamental economic study shows that combined reforming (CO2 + H2O) and tri-reforming (CO2 + H2O + O2) of CH4 are competitive processes, with lower operating and capital costs in comparison with steam reforming.