6533b82dfe1ef96bd1291b9a

RESEARCH PRODUCT

Biogas Cleaning by Hydrogen Sulfide Scrubbing and Bio-oxidation of Captured Sulfides

subject

description

Hydrogen sulfide and partially carbon dioxide can be absorbed into alkaline washing liquid with nitrates for upgrading a quality of biogas. Sulfides captured into the washing liquid are consequently biologically oxidized in an anoxic bioreactor by autotrophic denitrifying bacteria. Nitrates in the washing liquid serve as electron acceptors for sulfide bio-oxidation. Washing of hydrogen sulfide from biogas was examined in a lab-scale countercurrent scrubber that was packed with plastic carriers and operated at different biogas and washing liquid flows. The hydrogen sulfide concentration in treated biogas was investigated in the range from 3 to 12.3 g m–3. The influence of the hydrogen sulfide volumetric loading rate on required scrubber wetting Sw was determined. The anoxic bioreactor packed with the same plastic carriers for immobilization of bacteria was operated long term at the sulfide loading rate in the range from 21 g m–3 day–1 during the start-up period to 400 g m–3 day–1 at the end of the operatio...