Techno-economic assessment of biogas plant upgrading by adsorption of hydrogen sulfide on treated sewage-sludge

摘要

Biogas plant upgrading by adsorption of hydrogen sulfide on treated sewage-sludge was technoeconomically assessed. Three different processes were included in the study: the desulfurization of biogas by adsorption, the in-situ regeneration of the adsorbent and its production from sewage-sludge. Biogas plant upgrading was performed for a flow rate of 1000 Nm(3)/h of biogas with a H2S concentration of 2000 ppmv and a breakthrough concentration of 200 ppmv, which is the technical limit value for internal combustion engines. The cost due to the steam required for the in-situ regeneration was evaluated in two different scenarios: as a bought external utility and as an in-situ produced utility, installing an electric or a biogas steam boiler. According to the cash flow analysis carried out, all the options require a similar minimum selling price for the upgraded biogas (about 0.27-0.29 (sic)/Nm(3)), with a cost of the overall desulfurization process between 2.5 and 4.0 c(sic)/Nm(3). (C) 2016 Elsevier Ltd. All rights reserved.