Experimental and kinetic modelling studies for the design of fixed bed methanol reactor over CuZA catalyst

Abstract

Direct conversion of CO2 via hydrogenation to value-added chemicals is a vital approach for utilising CO2 emitted into the atmosphere. In this paper, a critical analysis of reaction kinetic modelling studies is explored in a fixed bed reactor to improve methanol yield for different H2 to CO2 ratios by simulating a lab-scale reactor for adiabatic and isothermal conditions. The feed inlet temperature and pressure variations are applied to study the effect of both configurations on methanol production. The results show that the isothermal configuration yields 2.76% more methanol yield compared to the adiabatic reactor. The effect of H2 to CO2 molar ratios of 3, 6 and 9 on the performance of the catalyst and the influence of CO and CO2 hydrogenation is investigated with model simulations. The overall methanol yield is increased from 19.03% to 36.41% with increase in H2 to CO2 molar ratio from 3 to 9. Experiments are performed using commercial copper-based catalyst for different temperatures of 210, 230 and 250 °C at a pressure of 40 bar for H2/CO2 of 3 and GHSV of 720 h−1 as well as at optimal temperature of 250 °C and 50 bar with varying H2/CO2 of 3, 6, 9 for 3 g and 6 g catalyst. The maximum methanol yield of 2.53% and space time yield of 13.59 mg/gcat.h is obtained at H2/CO2 ratio of 9.