The use of a silicone-based biomembrane for microaerobic H2S removal from biogas

Abstract A lab-scale bio-membrane unit was developed to improve H 2 S removal from biogas through microaeration. Biomembrane separated biogas from air and consisted of a silicone tube covered by microaerobic biofilm. This setup allowed efficient H 2 S removal while minimizing biogas contamination with oxygen and nitrogen. The transport and removal of H 2 S, N 2 , O 2 , CH 4 and CO 2 through bare membrane, wet membrane and biomembrane was investigated. Membrane allowed the transfer of gases through it as long as there was enough driving force to induce it. H 2 S concentration in biogas decreased much faster with the biomembrane. The permeation of gases through the membranes decreased in order: H 2 S > CO 2  > CH 4  > O 2  > N 2 . H 2 S removal efficiency of more than 99% was observed during the continuous experiment. Light yellow deposits on the membrane indicated the possible elemental sulfur formation due to biological oxidation of H 2 S. Thiobacillus thioparus was detected by FISH and PCR-DGGE.