氯化苯生产中的氯化液除FeCl_3新工艺

A new process for removing FeCl_3 from chlorinated solution in chlorobenzene production

通过小试试验确定离子交换树脂脱除氯化液中FeCl_3的可行性,优选出工业化应用最佳树脂型号为SQD-74,树脂运行最佳工艺条件为:吸附温度50℃,交换流量2BV/h,一批氯化液单柱处理量为220BV。用质量分数1%的盐酸顺流对树脂进行脱吸再生,合格后再用去离子水洗涤至出液pH值为2~3,树脂吸附Fe3+能力基本保持不变。对现有水碱洗工艺进行改造,采用一种先进的树脂塔式工艺和连续自动处理装置处理氯化苯生产中酸性氯化液中的FeCl_3,FeCl_3质量分数由(2~5)×10^(-4)降至5×10^(-6)以下,得到的酸性氯化液直接经碱洗、蒸馏后得氯化苯成品。

The feasibility of using ion exchange resin to remove FeC13 from chlorinated solution was confirmed by experiment. Resin SQD -74 was selected to be the best for industrial application. The optimum operation conditions of the resin were as follows ： adsorption temperature 50℃, flow rate 2 BV/ h, single column capacity 220 BV for a batch of chlorinated solution. Then the resin was desorbed and regenerated to the required index by 1% hydrochloric acid flowing in the same direction, followed by washing with deionized water until the pH of effluent was 2 - 3. The Fe3＋ -adsorping capacity of the resin kept unchanged substantially. The original water washing and alkali washing process was transformed. The acidic chlorinated solution formed in chlorobenzene production was treated by an advanced resin tower process and a continuous automatic treatment device. The mass fraction of FeC13 in the chlorinated solution was reduced from （2 -5 ） x 10^-4 to less than 5x10^-6. The obtained acidic chlorinated solution was subjected to alkali washing and distillation to produce finished chlorobenzene product.