Design and optimization of CO2 hydrogenation multibed reactors

Abstract

[EN] The use of CO2 towards the production of chemicals can help in the decarbonization of industry, but the transformation of such a stable compound is a challenge. This work uses genetic algorithms for the design of multi bed reactors for the hydrogenation of CO2 towards handy products. Two cases of study were evaluated. The production of biomethane from biogas, where the presence of methane in the feedstock represents an additional challenge to achieve a high conversion, and the production of methanol. The optimization addressed the design, bed sizing and number of beds, and the operating conditions of the feedstock, composition, and temperature profile. The optimal configuration of the biomethanation reactor consists of 2 beds using a H2 to CO2 ratio of 2.75, operating at 15 atm, limiting the T at each bed to 100 K. A lower number of beds is required if a larger Tmax is allowed, improving the reactor conversion. The methanol production reactor is recommended to consist of 6 beds operating at 50 atm, with a feed ratio H2 to CO2 of 3.5, requiring less catalyst than at higher pressure.