Preliminary Study on Microbial Desulfurization: Targeting for H2S Removal in Biogas in by Bio-scrubber in Biogas Power Plant
Abstract
Bio-desulfurization generally oxidizes sulfide to elemental sulfur in aerobically oxidized by sulfide oxidizing microbes that should be extracted from biogas like biogas power plant which is establish in the area palm oil industry. The source of microbes was screened from various sources like in waste of coal, active sludge of mixing Palm Oil Mill Effluent (POME) – cow manure and spring water. Screening for the potential microbes were conducted by using synthetic chemical reagent as S source. Decomposition of chemicals as S sources, like NaHS or Na2S2O3, has been observed through microbial process where S is separated into elemental Sulphur (S0). The screening firstly conducted in selective media for certain species like Thiobacillus sp. and continues with the addition of an S source to see if the microbes are able to decipher the S to sulfuric acid or S0. However, preference microbe that would be chosen to be applied in bio-scrubber was that capable to decompose the S source into S0.
containing Sulphur separation was done in specific medium containing fertilizer as N source and potatoes dextrose broth as C source. The specific medium was added in artificial solution containing the active sludge to simulate desulfurization. At the starting fermentation, the pH was set between 5 and 6 and monitored daily. Sulphur was detected by the appearance of yellowish sediment at medium, predicted as elemental sulphur. The yellowish was strongly shown by dilution it in toluene. In addition, pH monitoring showed stable during sulfur separation. Further treatment of yellowish sediment has potential to produce by product by separation and purification the elemental Sulphur. Sulfide oxidizing microbes that includes filamentous sulfur microbe, photosynthetic sulfur bacteria and colorless sulfur bacteria, among which some species of the best group can oxidize sulfide to extracellular sulfur, and are the main culture of sulfide oxidation stage. This treated active sludge would be applied at biogas production from POME, especially in CSTR because 1200 ppm H2S containing in biogas cause corrosive to the reactor.
Keywords: desulfurization, H2S removal, biogas, bioscrubber, elemental Sulphur
