Study On Desulphurization Technology Of High Sulfur Coal

The increase severeness of pollution make people bring forward higher demand for the quality of coal increasingly, especially the content of sulfur. The emission of SO2 destroyed our envirionment seriously. Combustion of high sulphur coal is the main track that produce sulfur oxide, and is a great subject of envirionment pollution. The thesis summarized the status quo of present desulphurization technology and discussed biodesulphurization, mixing reagent method and bio-floatation respectively, and try to discuss new desulphurization skill before and after furnace.Systemic experimentations such as mixing reagent method, bio-floatation process, were made on the basis of former achievement in this treatise. The desulphurization reagent for the mixing reagent before combustion is CaO and CaCO₃, CaO/CaCO₃(moL)=2, Ca/S(moL)=2.3,under which condition the best desulfurization rate has been gained. The sulfur percent of coal decreased from 3.9% to 2.41%; the desulfurization rate is 38.2%. The effect of the bio-floatation desulphurization was studied with Rhodopseudomonas spheroids. The result indicated that when pretreatment time is 10minutes, catch time is 10minutes ,froth time is 5 minutes and microbe concentration is 3.63×10¹⁰/mL, the pyrite decrease rate, total desulphurization rate, the percent of ash decrease and percent of caloric value increase is respectively 54.3%, 43.3%, 68.43%, 1.45%, which have provided very valuable theoretical value for the further pilot scale experiment. At last the removal effect of organic sulpur, the percent of ash decrease and percent of caloric value increase was studied with example of several strains of bacteria screened from Dagang oil field, sludge and water. The best bacterium H29 was singled out; its removal rate of organic sulpur is 41.67%; the percent of ash decrease is 38.6%; percent of caloric value increase is 1.44%. Qualitative analysis was made to study the growth traits and offspring of the strain.