title: Microaerobic desulphurisation unit: a new biological system for the removal of H₂S from biogas.
abstract: A new biotechnology for the removal of H2S from biogas was devised. The desulphurisation conditions present in microaerobic digesters were reproduced inside an external chamber called a microaerobic desulphurisation unit (MDU). A 10 L-unit was inoculated with 1L of digested sludge in order to treat the biogas produced in a pilot digester. During the 128 d of research under such conditions, the average removal efficiency was 94%. The MDU proved to be robust against fluctuations in biogas residence time (57-107 min), inlet H2S concentration (0.17-0.39% v/v), O2/H2S supplied ratio (17.3-1.4 v/v), and temperature (20-35°C). Microbiological analysis confirmed the presence of at least three genera of sulphide-oxidising bacteria. Approximately 60% of all the H2S oxidised was recovered from the bottom of the system in the form of large solid S(0) sheets with 98% w/w of purity. Therefore, this system could become a cost-effective alternative to the conventional biotechniques for biogas desulphurisation.
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Escuela de Ingenierías Industriales, Sede Dr. Mergelina, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Ramos
authors.forename: R
authors.initials: R
authors.lastname: Pérez
authors.forename: M
authors.initials: M
authors.lastname: Fdz-Polanco
mesh_terms: D000332:Aerobiosis; D056804:Biofuels; D019149:Bioreactors; D005240:Feasibility Studies; D006862:Hydrogen Sulfide / Q000302:isolation & purification*; D013696:Temperature
chemical_list: D056804:Biofuels; D006862:Hydrogen Sulfide
keywords: Biogas desulphurisation; Elemental sulphur; Hydrogen sulphide; Microaerobic; Oxygen