Biogas desulfurization using autotrophic denitrification process

• Published in: Applied microbiology and biotechnology 2016-01, Vol.100 (2), p.939-948
• Main Authors: Bayrakdar, Alper, Tilahun, Ebrahim, Calli, Baris
• Format: Article
• Language: English
• Subjects: Activated carbon; Analysis; Autotrophic Processes; Biofuels; Biogas; Biomedical and Life Sciences; Bioreactors; Biosynthesis; Biotechnology; Chemical properties; Denitrification; Desulfuration; Desulfurization; Electrons; Environmental Biotechnology; Fixed bed reactors; Hydrogen sulfide; Hydrogen Sulfide - metabolism; Identification and classification; Industrial Waste; Laboratories; Life Sciences; Manure - microbiology; Manures; Microbial Genetics and Genomics; Microbiology; Nitrates; Nitrates - metabolism; Nutrient removal; Observations; Oxidation; Performance evaluation; Poultry manure; Reactors; Sludge; Sodium; Studies; Sulfides - metabolism; Sulfur; Sulfur - deficiency; Sulfur - metabolism; Thiobacillus - metabolism; Waste Disposal, Fluid - methods; Water treatment
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-015-7017-z

The aim of this study was to evaluate the performance of an autotrophic denitrification process for desulfurization of biogas produced from a chicken manure digester. A laboratory scale upflow fixed bed reactor (UFBR) was operated for 105 days and fed with sodium sulfide or H 2 S scrubbed from the biogas and nitrate as electron donor and acceptor, respectively. The S/N ratio (2.5 mol/mol) of the feed solution was kept constant throughout the study. When the UFBR was fed with sodium sulfide solution with an influent pH of 7.7, about 95 % sulfide and 90 % nitrate removal efficiencies were achieved. However, the inlet of the UFBR was clogged several times due to the accumulation of biologically produced elemental sulfur particles and the clogging resulted in operational problems. When the UFBR was fed with the H 2 S absorbed from the biogas and operated with an influent pH of 8–9, around 98 % sulfide and 97 % nitrate removal efficiencies were obtained. In this way, above 95 % of the H 2 S in the biogas was removed as elemental sulfur and the reactor effluent was reused as scrubbing liquid without any clogging problem.