Upgrading of Biogas Generated from Shrimp Processing Effluent Using Vacuum Pressure Swing Adsorption

In this study, a field study was presented on upgrading the biogas generated from shrimp processing wastewater (sfw-biogas) that had H2S of 5000-6000 ppm, CO2 13-32 %, and CH4 68-87 % using the oxidative absorption of H2S in iron-chelated solution in series with vacuum pressure swing adsorption (VPSA). The regeneration of the adsorbent treating sfw-biogas required a shorter evacuation time than that of treating the biogas with a typical composition of 60 % CH4 (t-biogas). The VPSA process treating sfw-biogas required half the evacuation time and 26 % lower energy consumption. However, the methane recovery decreased from 80 % for t-biogas to 65 % for sfw-biogas. The oxidative absorption can reduce the H2S composition in the biogas generated from seafood processing wastewater from above 5000 ppm to 100 ppm, while the four-column eight-step vacuum pressure swing adsorption process can increase the methane content from 87 % to 99 %. image