Microbial desulfurization of coal by Thiobacillus ferrooxidans and thermophilic archaea

Several different microorganisms have been suggested for coal desulfurization. In the present investigation, the thermophilic archaea Acidianus brierleyi (DSM 1651), Sulfolobus acidocaldarius (DSM 639) and Sulfolobus solfataricus (DSM 1616) were compared with the mesophilic bacterium Thiobacillus ferrooxidans (DSM 583) concerning their capability of removing sulfur from coal. The desulfurization rate as well as the amount of sulfur removed by the microorganisms was studied.

Two of the investigated microorganisms, Thiobacillus ferrooxidans and Acidianus brierleyi, were capable of oxidizing pure pyrite as well as oxidizing sulfur in coal. A kinetic analysis was performed assuming first order reactions. The rate constant for oxidation of pure pyrite by A. brierleyi was observed to be higher than for T. ferrooxidans. The values of the rate constants for sulfur removal from coal were comparable for the two microorganisms, but were higher than for oxidation of pure pyrite.     

氧化亚铁硫杆菌在生物脱硫中的运用

目前国内SO2污染形势严峻,相比传统的脱硫技术,生物脱硫技术的反应条件温和、成本低、能耗少、脱硫速率快,具有明显的经济和技术优势,适合在生产实践中推广。氧化亚铁硫杆菌是生物脱硫中运用最广的细菌,本文介绍了该细菌在生物脱硫中的原理及其运用,并展望了生物脱硫技术的前景。     

国外清洁燃料技术进展

介绍了国外清洁燃料的主要质量指标、生产清洁燃料的加氢技术和非加氢技术的进展情况。随着环保法规和清洁燃料标准的日益严格，清洁燃料的生产将是全球需要解决的重要问题。生物脱硫技术是绿色环保技术，具有广阔的应用前景。     

Combined physical/microbial beneficiation of coal using the flood/drain bioreactor

The flood/drain reactor consists of a bed of intermediate-sized coal (roughly 0.5 to 5 mm) periodically fluidized by pumping in a mixed bacterial culture. Metabolic products and coal fines are washed out of the bed, and large pyritic inclusions and other dense mineral matter tends to settle to the base of the bed. Draining the bed then draws in fresh air for subsequent pyrite removal by microorganisms. Experiments on a laboratory-scale bed, 10.2 cm diameter with two 12 × 30 mesh Illinois # 6 coals and a Pittsburgh # 8 coal showed that up to 80% pyrite removal could be achieved in four weeks by this combination of physical separation and microbial activity. Operational problems included removal of fines from the bed during start-up and the appearance of acidophilic protozoa grazing on the pyrite-oxidizing bacteria. Significant improvement in performance is anticipated by eliminating the lag-phase of the sulfur-oxidizing bacteria and optimizing the timing of the flood/drain cycles.