Method for treating tail gas in process of preparing epichlorohydrin by oxidation method

Abstract

The invention discloses a method for treating tail gas in the process of preparing epichlorohydrin by an oxidation method. The method for treating tail gas comprises the following steps: diluting the tail gas by adding nitrogen, adsorbing oxygen in the tail gas by taking a microporous molecular sieve as an oxygen adsorbent and utilizing a pressure swing adsorption principle, and then recycling chloropropene tail gas with low oxygen content to a reaction system. Therefore, zero emission of tail gas is realized. According to the treatment method, the oxygen content in the tail gas can be controlled within a safe range, it is ensured that the chloropropene concentration in the tail gas is not within an explosion limit range, namely 2.9 v%-11.2 v%, meanwhile, energy consumption is reduced, and recycling of chloropropene is improved to the maximum extent.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to a method for treating tail gas produced in the process of preparing epichlorohydrin by an oxidation method. Background technique [0002] Compared with the traditional production process, the process of preparing epichlorohydrin by reaction-controlled phase transfer catalyst, hydrogen peroxide, and allyl chloride epoxidation reaction is a new green and environmentally friendly process, but the tail gas produced during the reaction process contains nitrogen, oxygen, allyl chloride and Water vapor is a kind of organic waste gas. With the increasing emphasis on environmental protection in recent years, the treatment of organic waste gas has become an important aspect of economic development and environmental protection. [0003] Patent CN103159703B discloses a method for the direct epoxidation of allyl chloride to continuously produce epichlorohydrin, but the tail gas produced ...

AI Technical Summary

Problems solved by technology

[0003] Patent CN103159703B discloses a method for the direct epoxidation of allyl chloride to continuously produce epichlorohydrin, but the tail gas produced by this method is obviously unable to meet the current organic tail gas treatment requirements only by condensing and recovering allyl chloride

[0004] Patent CN105712955B discloses a process flow for the production of epichlorohydrin by epoxidation of allyl chloride. The tail gas produced by the process is recovered by condensation to recover most of the allyl chloride in the tail gas, and then processed by pressurized secondary condensation. The allyl chloride in the tail gas content ≤ 0.5v%, but this method still cannot meet the current organic tail gas treatment requirements

[0005] Patent CN109867585A discloses a process flow for combined treatment of tail gas by condensation and epichlorohydrin absorption tower; the deficiency of this patent: although the problem of excessive chlorine in the tail gas of allyl chloride is solved, the allyl chloride absorbed by epichlorohydrin needs to be refined again. Distillation can be reused, which increases the energy consumption of the new process

[0006] Patent CN111233622B discloses a treatment method for waste gas produced in the process of producing epichlorohydrin by epoxidation of propylene chloride. The method is to control the reaction of phase transfer catalyst, hydrogen peroxide, and epoxidation of propylene chloride to produce waste gas in the process of producing epichlorohydrin. processing; the deficiency of the patent: after the tail gas is processed, it still needs to be discharged and recovered

Images