氯化氢尾气两段法间歇吸收工艺

采用两段法水吸收对间歇排放的HCl尾气进行处理，在尾气达到环保排放标准的同时，获得有利用价值的盐酸产品。在两段法吸收塔的下段利用大流量稀酸循环吸收，上段用小流量清水吸收。研究表明，下段吸收液温度小于40℃为宜。在小试实验中，下段吸收液盐酸质量分数为1%～15%的条件下，吸收率可达到99.5%以上。在工业装置实验中，HCl的平均吸收率达到97.6%，吸收液循环可得到10%～15%（质量分数）的副产盐酸。

Two-section column batch absorption of tail gas containing hydrogen chloride

This paper studies batch absorption with a two–section column for the treatment of tail gas containing hydrogen chloride (HCl). The operation not only makes the emission of hydrogen chloride meet the environment standard, but also can produce hydrochloric acid as a by–product. In the lower section of the column, dilute hydrochloric acid is recycled at a large flow rate as the absorbent. Fresh water at a smaller flow rate is used in the upper section. The temperature of the absorbent in the lower section should be below 40℃. In a laboratory test column, when the concentration of dilute hydrochloric acid in the lower section is 1%～15%, the rate of absorption for hydrogen chloride was over 99.5 %. In an industrial test column, the average rate of absorption for hydrogen chloride reached 97.6% and the concentration of by–product hydrochloric acid was 10%～15%.