Technology for removing ferric trichloride from chlorination liquid generated in chlorobenzene production

Abstract

The invention discloses a technology for removing ferric trichloride from chlorination liquid in chlorobenzene production. The technology comprises the following steps specifically: collecting chlorination liquid generated in chlorobenzene production to a chlorination liquid intermediate tank; introducing the chlorination liquid in the chlorination liquid intermediate tank into a resin adsorption tower from the bottom of the resin adsorption tower, keeping full and soaking for 10-18 hours, discharging the chlorination liquid from the top of the tower, detecting the content of ferric trichloride in the adsorbed chlorination liquid, and when the content of ferric trichloride is larger than 10 ppm, stopping adsorption; using diluted hydrochloric acid to resolve ferric trichloride complexes adsorbed by the resin, and using water to wash the resin adsorption tower till the content of ferric trichloride in the scrubbing solution is smaller than 10 ppm. In the technology, the resin adsorption tower and a continuous automatic processing method are utilized to process ferric trichloride from chlorination liquid in monochlorobenzene production; the chlorination liquid is adsorbed by the resin adsorption tower to remove ferric trichloride from the chlorination liquid for one time, and the content of ferric trichloride in the chlorination liquid during the monochlorobenzene production after the chlorination reaction is reduced from 150-1000 ppm to 0-10 ppm.

Description

technical field [0001] The invention relates to a purification process for the production of chlorinated benzene, in particular to a process for removing impurities of iron trichloride from the chlorinated liquid produced in the production of chlorinated benzene. technical background [0002] Chlorinated benzene is produced by mixing benzene and chlorine gas in a chlorination reactor under the action of an iron catalyst. The acidic chlorination solution after the reaction contains chlorobenzene (monochlorobenzene and a small amount of polychlorobenzene, the content is about 35% ), trace chlorine, dilute hydrochloric acid (content 0.1~0.5%), ferric chloride (content less than 1%) and unreacted benzene (content about 65%). [0003] Due to the high solubility of ferric chloride in water, water washing and alkali washing processes are mainly used to remove ferric chloride and hydrochloric acid in the chlorinated solution, and then refined to obtain benzene monochloride, such as ...

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Problems solved by technology

[0005] There are following problems in the existing water washing and alkali washing treatment methods for removing ferric chloride: the washing process cannot guarantee the complete removal of ferric chloride in the chlorinated solution, so it is necessary to increase the alkali washing process, and a large amount of trichloride-containing The waste acid of iron oxide increases the alkali consumption of alkali washing; the effect of alkali washing directly affects the quality of the chlorinated solution. A large number of benzene series and ferric hydroxide flocculent precipitation bring great difficulty to the wastewater treatment process; the water washing and alkali washing equipment occupy a large area, the process pipeline is long and the operation is complicated, which does not meet the requirements of "energy saving, reducing waste" in the existing production. Consumption and emission reduction" requirements

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