Abstract
Hydrogen sulfide (H2S) is one of the main contaminants found in biogas, which is one of the end products of the anaerobic biodegradation of proteins and other sulfur-containing compounds in solid waste. The presence of H2S is one of the factors limiting the valorization of biogas. To valorize biogas, H2S must be removed. This study evaluated the performance of a pilot-scale biotrickling filter system on H2S removal from landfill biogas. The biotrickling filter system, which was packed with stainless-steel pall rings and inoculated with an H2S-oxidizing consortium, was designed to process 1 SCFM of biogas, which corresponds to an empty bed residence time (EBRT) of 3.9 min and was used to determine the removal efficiency of a high concentration of hydrogen sulfide from landfill biogas. The biofiltration system consisted of two biotrickling filters connected in series. Results indicate that the biofiltration system reduced H2S concentration by 94 to 98% without reducing the methane concentration in the outlet biogas. The inlet concentration of hydrogen sulfide, supplied to the two-phase bioreactor, was in the range of 900 to 1500 ppmv, and the air flow rate was 0.1 CFM. The EBRTs of the two biotrickling filters were 3.9 and 0.9 min, respectively. Approximately 50 ± 15.7 ppmv of H2S gas was detected in the outlet gas. The maximum elimination capacity of the biotrickling filter system was found to be 24 g H2S·m-3·h-1, and the removal efficiency was 94 ± 4.4%. During the biological process, the performance of the biotrickling filter was not affected when the pH of the recirculated liquid decreased to 2-3. The overall performance of the biotrickling filter system was described using a modified Michaelis-Menten equation, and the Ks and Vm values for the biosystem were 34.7 ppmv and 20 g H2S·m-3·h-1, respectively.
Highlights
Biogas is one of the end products of the anaerobic digestion process
50 ppmv of H2S gas was detected in the outlet gas
The thiosulfate mineral medium (TMM) containing sulfur-oxidizing bacteria (SOB) was loaded into the lab-scale reactor with sodium bicarbonates being the sole carbon source and thiosulfate being the sole energy source supporting SOB growth
Summary
Biogas is one of the end products of the anaerobic digestion process. This process involves a series of metabolic stages (hydrolysis, acidogenesis, acetogenesis, and methanogenesis), in which a consortium of microorganisms degrades the organic substances in the absence of oxygen. Landfill biogas is a renewable energy consisting mainly of methane The main problems that occur as a result of high H2S concentrations in biogas are (i) damages engines and other equipment due to its corrosive action, and (ii) H2S combustion, which produces sulfur oxides (SOx) and causes emissions of increasing environmental concern (Dumont 2015). H2S in biogas must be removed to avoid treatment facility corrosion, unnecessary production of by-products, and possible public exposure and complaints (Namgung et al 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
