Simulation of CO2 Conversion into Methanol in Fixed-bed Reactors: Comparison of Isothermal and Adiabatic Configurations

Abstract

CO₂ capture and utilization (CCU) has been widely considered as a potential solution to overcome global warming. Conversion of CO₂ into methanol is an interesting option to transform waste into value-added chemical while also reducing greenhouse gases emissions in the atmosphere. In this paper, utilization of CO₂ into methanol was simulated using Aspen Plus software. The reaction between CO₂ and H₂ to produce methanol and water was carried out in a simulated fixed-bed reactor with Cu/ZnO/Al₂O₃ commercial catalyst, following LHHW (Langmuir – Hinshelwood – Hougen – Watson) kinetic model. Isothermal and adiabatic reactor configurations were compared under similar feed conditions and the concentration profile along the reactor was observed. The result showed that isothermal configuration converted 3.23% more CO₂ and provided 16.34% higher methanol yield compared to the adiabatic reactor. Feed inlet temperature variation was applied and the effect to methanol production on both configurations was studied. The highest methanol yield for adiabatic and isothermal reactor was obtained at 200 ^oC and 240 ^oC respectively.