Removal of Acid Gases from Biomass-to-Liquid Process Syngas Used as Raw Materials for Fischer-Tropsch Technology

Abstract

Due to the high energy consumption and decreasing oil supply, the alternative energy sources such as biomass and agricultural waste can be considered as the main sources of energy in the future. Currently, one of the technologies to convert such biomass to more valuable products is biomass-to-liquid process. However, acid gases like CO₂ and H₂S are produced as intermediates causing the decrease in product heating values, operational problems, corrosion, and environmental concern. Therefore, the objective of this work is to simulate the absorption process of acid-gas cleaning by using various solutions at different operating conditions in order to meet the requirement. The results show that MDEA has higher performance to remove both gases compared to other chemicals. Furthermore, at 0.9 MPa and 25 °C, the treated gas provides 3.19 vol% CO₂ and 27.7 ppb of H₂S for MEA, 2.13 % CO₂ and 0.02 ppb of H₂S for MDEA and 7.45 % CO₂ and 1.12*10^-6 ppb of H₂S for Selexol. Moreover, the liquid flow rate, solution concentration and effects of temperature and pressure are also investigated for the optimal design of the absorption column.