Study On Desulphurization Of Flue Gas With Spray Drying Technology

With the development of modern industry,more and more flue gas containing SO2 is sentout from factories resulting in environment pollution and damage to health. So more and moreattention is paid on the researching of desulphurization of flue gas. Now there are mainly threekinds of process to clean SO2 from flue gas:wet process,dry process and semi-dry process.There exists problem of equipment corrosion in wet process ,and the problem is difficult tosolve ,what is more ,the flow of wet process is too long , so its use is limited. Dry process mustgo on with elevated temperature,what is more, efficiency of absorbent utilization was not high,and there exists acid mist that is difficult to deal with,so it is not a satisfactory method either.The semi-dry process gets rid off shortcomings of the two processes mentioned above, so it isinterested widely. experimental research of flue gas desulphurization with spray drying wasdone in this dissertation, the spray drying absorption process was described, a formulationwas reformed and experimentally tested. The chemical pulp for paper manufacture is chiefly made from wood. However,about10% of the chemical pulp produced worldwide is made from non-wood materials,such asbagasse,straw,reed and grass as fiber source. The major part of chemical pulp production fromthese raw materials is produced by soda process, in which raw material together with thecooking liquor is heated to 140~170℃ under pressure and at high alkalinity. The main portionof non-fibrous matter in the raw material is dissolved into the spent cooking liquor--the blackliquor. Sent into the river or lake directly, the black liquor can do great harm to the aquaticcreature as well as soil, so it is very necessary to treat it before released. For a factory with theyield of 17～20 thousand tons a year,it has to spend 22~24 million RMB on treating of liquorusing traditional Silvola recovery method. The burden is too heavy to be accepted by middleand small factories. Considering its properties, black liquor can react with SO2 and produceignosulfonate used as additive of cement, so using black liquor as absorbent in cement flue gasdesulfurization will realize the idea to convert pollution to resource and produce huge socialand economic benefit. So some preliminary experimental research on the application of theblack water as absorbent and additive for absorbent was done in this dissertation, the main work iABSTRACTis listed below : (1) An available model describing process of SO2 absorption was reformed. Since thetraditional rigid sphere model fails to describe the real process very successfully ,it wasreformed in the dissertation . (2) Influence of operating parameters on absorption efficiency was studied. (3) Preliminary investigation of use the black water as absorbent and additive for absorbentwas carried out.