Hydrogen chloride whole reclaiming zero discharging technique and device for PVC producing process

Abstract

The invention discloses a hydrochloride total-recover zero-discharge method in PVC production and a relative equipment, which uses a new absorber as hydrochloride combination adsorption tower, an alcaine desorption equipment and a dilute hydrochloric acid deep desorption equipment as main equipments, uses the combination adsorption tower to absorb the over hydrochloride in the chloroethylene production and uses the alcaine desorption equipment and dilute hydrochloric acid deep desorption equipment to convert into the synthesis gas material of chloroethylene. The invention can directly convert the low-density alcaine generated in traditional method into the synthesis gas material of chloroethylene, to save production cost, avoid environment pollution and simplify hydrochloride recovery, with few equipments, small volume, thereby saving investment.

Description

field of invention [0001] The present invention relates to vinyl chloride production technology and equipment, specifically, a process and equipment for full recovery of excess hydrogen chloride in the PVC production process. Background technique [0002] In the process of synthesizing vinyl chloride by the reaction of acetylene and hydrogen chloride, in order to increase the conversion rate of acetylene, an economical and feasible way is to allow excess hydrogen chloride in the raw material gas. In the actual production process, acetylene and hydrogen chloride are usually controlled to n(C 2 h 2 ): n (HCl) = 1: (1.05-1.10), the excess hydrogen chloride treatment process in the existing vinyl chloride production process is that at first the crude vinyl chloride comes out from the converter, enters the mercury remover and uses active carbon adsorption to mainly contain chlorine and high mercury compounds After the mercury vapor is released, it enters the synthesis gas graph...

AI Technical Summary

Problems solved by technology

[0003] (1) The washing tower must continuously discharge waste water containing dilute acid and vinyl chloride, which not only causes considerable losses, but also pollutes the environment, constitutes a safety hazard, and increases the investment in pollution control;

[0004] (2) Hydrogen chloride cannot be recycled as raw material gas for the synthesis of vinyl chloride, and the by-product produced is low-concentration mercury-containing hydrochloric acid that is difficult to sell directly;

[0005] (3) The process is long, many devices are used, the operation flexibility of the sieve plate column is small, the pressure drop is high, and the process operation control is difficult

[0006] (4) A large amount of hydrogen chloride enters the system during start-up, which can easily cause super high temperature in the process and damage the device;

[0007] (5) The alkali washing tower is not continuously operated, and the lye needs to be replaced regularly, which has a certain impact on the quality of vinyl chloride refining

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