Oxychlorination reaction system and method based on four-stage reactor

Abstract

The invention provides an oxychlorination reaction system and method based on a four-stage reactor, the oxychlorination reaction system based on the four-stage reactor comprises four oxychlorination reactors, an oxychlorination reaction unit based on the four-stage reactor and a product post-treatment and ethylene circulation unit which are sequentially connected in series, wherein each oxychlorination reactor is a fixed bed reactor, a cooling mechanism is arranged on each oxychlorination reactor, the oxygen pipeline is respectively communicated with each oxychlorination reactor through an oxygen branch pipeline, and the hydrogen chloride pipeline and the ethylene pipeline are communicated with the primary oxychlorination reactor positioned at the head end. The system is low in energy consumption and high in safety coefficient.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to an oxychlorination reaction system and method based on a four-stage reactor. Background technique [0002] The production of vinyl chloride is divided into ethylene method and acetylene method according to raw materials, and mainly includes calcium carbide or natural gas acetylene method, combined method, oxychlorination method and full equilibrium oxychlorination method according to production process. Among them, the ethylene oxychlorination process is an advanced and reasonable production route recognized internationally. Vinyl chloride is directly synthesized from hydrogen chloride, oxygen and ethylene as raw materials. The technical key of the oxychlorination unit is the type of reactor and the source of oxygen. There are two types of reactors: ebullating bed reactor and fixed bed reactor. [0003] When the ebullated bed reactor is used for operation, ethylene, ...

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Problems solved by technology

[0003] When the ebullated bed reactor is used for operation, ethylene, oxygen and hydrogen chloride are simultaneously added to the reactor in a certain proportion. There is an internal cooling coil for heat removal in the ebullated bed reactor, and there is a cyclone separator on the upper part of the reactor to collect the catalyst entrained in the material. , not only will the catalyst be lost in the reactor, but also the catalyst will be easily released into the wastewater, causing environmental pollution

[0004] The catalyst in the fixed bed reactor is fixed, which has little environmental pollution, but the production capacity of a single fixed bed reactor is small. In the prior art, two stages of fixed beds are used in series to improve production capacity, such as the invention with the authorized announcement number CN1067041C The patent "Oxychlorination of ethylene in two-stage fixed-bed reactors" uses two reactors connected in series to produce ethylene dichloride. In this reaction system, oxygen enters the two-stage fixed bed at a ratio of 50%:50%. In the bed reactor, the safety factor is low, and the minimum load of the two-stage reactor system is 30%, which cannot meet the needs of the plant's low-load operation

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