Engineering Study On Flue Gas Desulfurization With Black Liquor Of Straw Pulping Plants

As regards to environmental protection, it's a main issue for the weave industry and straw pulping plants to find effective and cheap process for the flue gas desulfurization(FGD) process and black liquor treatment. Aims to the difficulties in the particle control and desulfurization of flue gas and black liquor treatment of YiBin Grace Group Limited Corporation, the study in this paper put forward and developed a system of integrating SO2 absorption into black liquor with black liquor treatment, in which SO2 in the flue gas could be absorbed by the alkaline in black liquor and COD in black liquor could be declined. Firstly, the study designed a set of E.S.P (electrostatic particle collector) to replace the original wet scrubber particle collector, and then the original wet scrubber particle collector was redesigned into a rotative-stream plate column to absorb SO2 with black liquor. Particle reduction efficiency and operating parameters of the E.S.P were examined during its trial running and the results showed particle reduction efficiency could achieved about 99.5%. Effects of pH value of black liquor and quality ratio of black liquor/calcium carbide on SO2 absorption efficiency were investigated by running the flue gas desulfurization process for a period. The running results showed that SO2 absorption efficiency could be achieved about 87% under the condition of pH value of black liquor being above 12 and quality ratio of black liquor/calcium carbide being 1000:25. The pH value of the flee of the settling process was about 8.0, which meant that it could be reused as supplemental absorption medium. The economy benefit and environmental benefit analysis results showed that compared to original process, the redesigned processcould reduce operating cost by 1000 RMB/d and reduce alkaline waste water 216000t/a, which included COD 523.6t/a. Thus the redesigned process was both a economy benefit process and a environmental benefit process.Based on engineering running data, the study in this paper set base on the application of combing the FGD process with black liquor treatment process.