Method for processing methyl iodide-contained combustible gas discharged into torch system by carbonylation compounding device

Abstract

The invention discloses a method for processing a methyl iodide-contained combustible gas discharged into a torch system by a carbonylation compounding device. The methyl iodide-contained combustible gas discharged into the torch system by the carbonylation compounding device enters a torch water seal tank firstly, and then is discharged into the torch system; after being collected, the methyl iodide-contained sewage generated in the torch water seal tank carries out film concentration processing to obtain concentrated methyl iodide wastewater; the concentrated methyl iodide wastewater and acetic anhydride carry out hydration reaction to remove water; and a reactant is used as one part of carbonylation reaction raw materials and returned to a carbonylation compounding system. The invention solves the problem that the methyl iodide wastewater can not be processed by a common environmental protection approach; and by adopting the method, the torch system of the carbonylation compounding device of acetic acid, acetic anhydride, and the like can be provided with the water seal tank which strengthens the safety of the torch system and can save nitrogen.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a process method for treating methyl iodide waste water discharged from torches of carbonylation devices such as acetic acid and acetic anhydride. Background technique [0002] Methyl iodide is widely used as a cocatalyst in carbonylation reactions such as acetic acid and acetic anhydride, which enhances the activity of the catalyst and makes the reaction conditions mild. At present, the torch systems of carbonylation units such as acetic acid and acetic anhydride are usually not equipped with water-sealed tanks. The liquid level is stable and continuous water replenishment is required, so that the iodomethane-containing wastewater is discharged from the flare system. Because methyl iodide is very toxic (highly harmful) and has a low boiling point at atmospheric pressure (42.5°C), conventional biological treatment methods, chemical treatment methods, physical chemica...

AI Technical Summary

Problems solved by technology

Because methyl iodide is very toxic (highly harmful) and has a low boiling point at atmospheric pressure (42.5°C), conventional biological treatment methods, chemical treatment methods, physical chemical treatment methods, physical treatment methods and other organic wastewater treatment methods cannot treat methyl iodide well. waste water

However, the torch system relies on molecular seals and nitrogen filling positive pressure to ensure its safety, which is not very reliable. At the same time, it consumes a lot of nitrogen, and the operating cost is very high.

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