| There is a certain particularity that the occurrence and consumption structure ofenergy in China, coal is the main body of energy consumption, it occupies theimportant position in the national economic and social development. With the miningof coal resources, the reserves of low-sulfur is tapering off gradually, largely using ofhigh-sulfur coal has become inevitable. Coal desulfurization has become the maindevelopment direction of CCT in China. And microbial coal desulfurizationtechnology, with the advantage of low cost, less energy consumption, simpletechnology and easy operation, more and more get the attention of people.This topic, using microbial desulfurization technology and basing on Escherichiacoli as the experimental strains, carried out leaching desulfurization to the coal ofYanzhou mining area. It discussed the effects of d ifferent conditions to thedesulfurization effect.By experiment research, we get the following research achievements:(1) A new efficient desulfurization strain named HS-1was isolated from theCUMT landscape river. The strain was identified as typical Escherichia coil based onphysiological and biochemical identification. The sulfur removal efficiency of HS-1up to38.79%. In order to obtain a more efficient strain, HS-1was induced withultraviolet. Based on the fatality rate, a mutant strain na med HS-1Y was isolated onthe condition of UV power to30w, UV irradiation distance to30cm, irradiation timeto45s.(2) In bioleaching test, the effect of coal slurry, bacterium concentration andleaching time on desulfurization efficiency were observed. By single factor tests andorthogonal test, the optimal technology conditions were as follow: experimentaltemperature to37℃, stirring speed to140r/min, coal mass to2g, coal slurry to200,bacterium quantity to100ml, leaching time to48h; the order of the effect was coalslurry> bacterium concentration> leaching time.(3) Under the optimal desulfurization technology conditions, the desulfurizationeffect of HS-1and HS-1Y was compared. The result showed that the best leachingtime of the two strains was48h, the desulfurization rate was40%and47.27%, thedesulfurization capability of HS-1Y was better than HS-1.(4) Microwave and ultrasonic was used in biodesulfurization of coal. The resultsshowed that desulfurization effect appeared agrad ual upward trend with the extension of pretreatment time. The best pretreatment time of ultrasonic was60min and thedesulfurization rate reached49.39%; The best pretreatment time of microwave was3min and the desulfurization rate reached53.33%. The results of ultrasonic andmicrowave co-pretreatment test showed that the best desulfurization rate could reach55.15%in48h. Ultrasonic and microwave co-pretreatment of the coal could not onlyenhance the effect of microbial desulfurization but also reduce the cycle of thedesulfurization.(5) Mixed HS-1Y by the proportion of1:1with WS-1, WS-1Y and HS-1. Theresults of strains combination test showed that mixed strain HS-1Y+WS-1Y obtainedthe best desulfurization effect. The optimal technology conditions of HS-1Y+WS-1Ywere as follow: coal slurry to200, leaching time to48h,HS-1Y:WS-1Y=3:2. Underthe optimal technology conditions, the desulfurization rate of HS-1Y+WS-1Y couldreach58.18%. |
