Analysis of Syngas Production from Catalytic Biogas Reforming and Upgrading

Abstract

The development of alternative and sustainable technologies for the production of liquid biofuels has gained ground worldwide. Biogas is one of the most potential feedstocks to be used and the Fischer-Tropsch (FT) route is one of the most studied processes for the production of these liquid biofuels. In this work, different processes for the conversion of biogas to syngas by catalytic reforming were studied, in order to evaluate the better route to obtain the syngas and its usage as feedstock in FT synthesis. Two steps were analyzed using Aspen Plus V12.1®: 1) biogas upgrading; and 2) catalytic reforming process. Dry reforming (DR) and Bi reforming (BR) were selected for the reforming process assessment. CH4 and CO2 conversions were selected to evaluate the process performance. Results showed that water scrubbing is a better route to perform biogas upgrading, based on the H2S final content and the CH4 recovery. Besides, for the biogas reforming process, all scenarios presented an increase in conversions when the temperature was increased. For bi reforming, which uses biogas and water steam as reactants, a decrease in the molar fraction of H2O contributed to higher CO2 conversion. The BR process with a molar ratio of CH4, CO2, and H2O at 3:2:1, respectively, at elevated temperatures and pressure of 0.1 MPa, showed the most promising combination of results for syngas production, considering environmental and operational factors. The CH4 and CO2 conversions obtained in 900 °C were 96.45% and 98.06%, respectively.