Method for inhibiting polymerization of ethylene in compressor equipment in production process of low-density polyethylene

Abstract

The invention discloses a method for inhibiting polymerization of ethylene in compressor equipment in the production process of low-density polyethylene. According to the method, in a tubular reactor low-density polyethylene production process, a polymerization inhibitor is added into a secondary compressor to prevent ethylene from self-polymerization, pressure drop rise of a cooler and scaling of equipment are effectively avoided, and the polymerization inhibitor can be used as an initiator in a reactor behind the compressor; and the polymerization inhibitor is oxygen or air. The problems that in the production process of high-pressure polyethylene, ethylene raw materials are self-polymerized too early, and a cooler in a secondary compressor is prone to scaling are effectively solved. The method has the advantages that the polymerization inhibition effect is good, operation is easy and convenient, production is not affected, scaling of the compressor cooler can be eliminated on line, and meanwhile the polymerization inhibitor can be efficiently utilized as an initiator of the follow-up procedure without aftertreatment.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for inhibiting polymerization of ethylene in the production process of a low-density polyethylene tubular method. Background technique [0002] As is known in the art, high pressure polyethylene polymerization processes are carried out in autoclaves or tubular reactors, usually using oxygen or organic free radical initiators, especially peroxides, as initiators to obtain low density ethylene polymers (LDPE). Compared with the kettle-type process, the high-pressure tubular-type polyethylene process has the advantages of high conversion rate per pass, low monomer consumption, long production cycle, large production capacity, simple and reliable equipment, etc., so the tubular-type process is widely used in my country more extensive. [0003] The high-pressure tubular process includes compression unit, polymerization unit, separation and gas circulation unit, ex...

AI Technical Summary

Problems solved by technology

[0005] Due to the high pressure of the secondary compressor unit, ethylene self-polymerization may occur. With the extension of the operating time of the device, high-density, high-molecular-weight polymer scaling is easily formed on the inner wall of the intercooler of the secondary compressor, resulting in narrowing of the pipe diameter. , the pressure drop rises, and even the pipeline is blocked; in addition, during the operation of the equipment, the scaling objects will peel off from time to time and enter the pipeline, affecting the reaction

In particular, there is a need for on-line measures to prevent premature self-polymerization and fouling of ethylene in the condenser without stopping the operation, so as to reduce the reduction in production capacity and efficiency caused by regular shutdown and cleaning

Images