| Chlorine gas, hydrogen chloride, fog of hydrochloric acid, fog of sulfuric acid and carbon dioxide are produced in electrolyzation unit in chloralkali plant; the effective treatment and recycling of such waste is very important to reduce the pollution and emission of waste gases. In this work, to solve the problems in waste gas processing in electrolyzation unit in chloralkali plant of Xinjiang Zhongtai Chemical Huatai Company, we study the technology modifications of waste gas processing.(1) The technology modifications in the process of recycling waste chlorine gas include substitute of UPVC pipe lines by CPVC, addition of plate heat exchanger, addition of alkali liquid head tank and variable frequency pump. The stability and applicability of the process are improved significantly.(2) The modifications in the process of recycling chlorine gas include addition of check valve in hydrogen chlorine pipe lines, substitute of pack column by spay absorption column and addition of nitrogen gas pipe lines, which solves the problems of emission and explosion of hydrogen chlorine.(3) The absorption units for capturing fogs of sulfuric acid and hydrochloric acid are added, which solves the problems of pollution and corrosion raised by the fogs, and improves the stability and safety in the process.(4) The unit of carbon dioxide capture by alkaline liquids to produce sodium carbonate is added, which realizes the utilization of carbon dioxide, reduces the cost and decreases the emission of carbon dioxide.After the modifications above, the emission of waste gases is decreased or the utilization of waste gases is realized, and the emission meets the national requirement. |
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