MICROBIAL DESULFURIZATION OF LIGNITE

High sulfur containing lignite was investigated for the removal of sul fur content by bacterial cultures using shake flask experiments. The e ffect of bacterial action on unwashed and washed lignites with dilute acid was tested and found that the lignite does not require any pretre atment prior to microbial desulfurization process. Results indicate th at 78 percent removal of the total sulfur is possible by using 5 perce nt lignite slurry concentration within 18 days by mixed cultures of Th iobacillus ferrooxidans and Thiobacillus thiooxidans. The results also show improvement in lignite quality as volatile matter and ash conten t are reduced during microbial desulfurization.