석탄의 무기황인 pyrite를 제거하기 위하여 chemoautotrophic, acidophilic, iron-oxidizing bacterium Thiobacillus ferrooxidans를 사용하였다. 석탄의 미생물 탈황에 사용된 시료는 한양 탄광에서 생산되는 무연탄이다. 석탄 입자의 크기, 농도, 초기 접종농도 및 염의 농도 등 여러 가지 공정 변수들이 탈황속도에 미치는 영향을 조사하였다. 10-70%(w/v)의 석탄 슬러리 농도에서 11-15일 동안에 약 80-98%의 pyritic sulfur를 제거할 수 있었다. 최대 탈황속도는 50%(w/v)의 석탄 슬러리 농도까지 선형적으로 증가하였고, 70%(w/v) 석탄 슬러리에서 1,117 mg pyritic-S/L·day의 높은 탈황속도를 얻었다. 미생물 탈황공정에서의 최적 조업 조건은 70%(w/v)의 석탄 슬러리 농도, 0.42 mm 이하의 석탄 입자와 109 cells/g-pyrite의 접종농도이다.
To remove pyritic sulfur from coal, chemoautotrophic, acidophilic, iron-oxidizing bacterium Thiobacillus ferrooxidans was employed. Coal samples used in all the experiments were an anthracite coal obtained from the Han Yang Mining Company. The effects of various process variables(such as coal pulp density, salt concentration, particle size and initial cell density) on the pyritic sulfur removal rate has been determined. About 80-98% of pyrite(FeS2) in coal could be removed by T. ferrooxidans within 11-15 days in a shake flask. The maximum pyritic sulfur removal rate increases linearly between 10 and 50%(w/v) of the pulp density and reaches a maximum level at 70%(w/v) of pulp density(1,117 mg-S/L·day). The optimum operating conditions are found to be a pulp density of 70%(w/v), particle size less than 0.42 mm, and initial cell concentration of 109 cells/g-pyrite in coal.
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