Method and device for preparing vinyl chloride by treating bis(trichloromethyl) carbonate production tail gas through catalytic chlorination process

Abstract

The invention discloses a method and a device for preparing vinyl chloride by treating bis(trichloromethyl) carbonate production tail gas through a catalytic chlorination process. The method comprisesthe following steps: (1) introducing chlorinated tail gas into a cryogenic device, and condensing organic gas in the tail gas into organic liquid drops; (2) introducing the tail gas treated in step (1) into an acid mist trap, trapping organic liquid drops in the tail gas to the bottom of the acid mist trap, introducing the residual tail gas into a preheater and then into a heater, and simultaneously introducing the heated crude hydrogen chloride and hydrogen into a mixer according to a certain volume ratio; (3) introducing the uniformly mixed gas into a fixed bed reactor, and reacting free chlorine in the mixed gas with hydrogen to obtain refined hydrogen chloride gas; and (4) introducing the refined hydrogen chloride gas into a finished product cooler, cooling, introducing the cooled gasinto a hydrogen chloride distribution table, and respectively distributing into a vinyl chloride production device and an acid making absorption tower. The treatment method is simple in process, lowin energy consumption, low in cost, safe, environmentally friendly and suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of chlorination tail gas treatment, in particular to a method for treating chlorination tail gas produced by synthesizing bis(trichloromethyl)carbonate, in particular to a catalytic chlorination method for treating tail gas produced by bis(trichloromethyl)carbonate Process and device for producing vinyl chloride. Background technique [0002] The production process of bis(trichloromethyl) carbonate (abbreviated as BTC) is a chlorination process, and its production process is a substitution reaction of dimethyl carbonate with excess chlorine under the action of ultraviolet light or a catalyst. After the reaction, a large amount of tail gas is produced, and the main component of the tail gas is chlorine gas. [0003] At present, the tail gas treatment method produced by the production of bis(trichloromethyl)carbonate is washing, including two processes of water washing and alkali washing. The hydrogen chlorid...

AI Technical Summary

Problems solved by technology

Generally speaking, 1 ton of tail gas has about 0.96 tons of hydrogen chloride, which is 3 tons of 32% hydrochloric acid when converted into volume fraction, but this hydrochloric acid contains trace organic matter and free chlorine, and the quality is not high, so it is difficult to sell. In addition, due to the production of di(trichloroform Base) The free chlorine content in the tail gas produced by carbonate is low, and a certain amount of acid droplets are entrained in the tail gas after washing, resulting in a particularly low concentration of available chlorine in the solution after alkali washing, making it difficult to sell

Therefore, the tail gas treatment process produced by the traditional production of bis(trichloromethyl)carbonate will produce a large amount of waste acid and high-salt wastewater, causing serious environmental pollution and becoming a bottleneck restricting the development of enterprises; the hydrochloric acid produced by traditional water washing and alkali washing Although sodium hypochlorite and sodium hypochlorite are based chemicals, the units of use are limited, and the pressure on storage and transportation is high. If the industry does not match, there will be a greater safety hazard due to the pressure on the inventory of hydrochloric acid

Images