Experimental Study Of Calcium-based Sorbent In The Flue Gas Desulfurization Applications

SO2 is one of the major components of atmospheric pollutants, which causes serious environmental pollution and does great harm to people’s health. Among removing SO2 is pretty difficult to environmental protection,and each year thepollution caused by SO2 will make huge economic losses, so flue gas desulfurization has become one of hot spots in the field of research now. This paper adopts a new method of flue gas desulfurization, and using CaS as calcium base desulfurizer to remove SO2 can not only restore SO2 to elemental sulfur, but also be combined with a chain of chemical technology, which makes CaS rebirth and achieves the cycle of chemical chain reaction.The main research content is as follows:First of all, based on the laws of thermodynamics and the theory of minimum gibbs free energy, we can use HSC Chemistry software for NiS-SO2, FeS-SO2, Na2S-SO2, MgS-SO2, BaS-SO2, CaS-SO2 to do thermodynamic calculation and analysis, and adjust the proportion of SO2 and the desulfurizer for 2:1, then add N2 as a protective gas and find out suitable CaS as desulfurizer by analysis. This process which can achieve the rebirth of CaS from the reaction of CaSO4. CO, H2 has been applied in the chain of chemical technology, so it can realize chemical chain reaction cycles. Using CaS as desulfurizer not only has good activity, high production rate of elemental sulfur and less side effects,and the desulfurizer can be recycled. So this experiment uses CaS as calcium base desulfurizer for the research of flue gas desulfurization.Second, in the fixed-bed reactor calcium base desulfurizer was investigated,which was used to remove SO2, and we also select the suitable reaction conditions, which include that reaction temperature is 200 ℃, the space velocity is 600 h-1, bed height/diameter was 5:2, CaS content was 40%. The CO2 has no effect on calcium base desulfurizer in this experiment, and the desulfurization effect of CaO is below CaS, O2 can provide the reaction heat in flue gas, and it can be combined with part of CaS at the same time, which makes the desulfurization rate reduce, but the decrease is not obvious. There will be a phenomenon of sintering under high temperature in desulfurizer, which makes particle size increase and specific surface area decrease.Besides, this article adopts the model of the retract to describe the reaction between desulfurizer and SO2 well, effects of reaction temperature, SO2 concentration, space velocity on desulfurization reaction, and the reaction process was linear fit, calculated activation energies and other factors, and it also linear the reaction process fitting.