METHOD OF PURIFYING RECIRCULATING FLOW OF ETHYLENE WITH VINYL ACETATE FROM LOW-MOLECULAR COPOLYMER, OILS AND OTHER ORGANIC IMPURITIES Russian patent published in 2016 - IPC C08J11/00 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and petrochemical industry, particularly to a method of purifying recirculating flow of ethylene with vinyl acetate from a copolymer, low-molecular weight copolymer, oil and other organic impurities in process of producing copolymers of ethylene with vinyl acetate by high pressure method. Method includes two-step separation of copolymer with reduction of pressure and temperature of recirculating gas flow of high pressure in a first step to values where initial content of low-molecular weight copolymer of ethylene with vinyl acetate, oil and other organic impurities in gas flow does not exceed 0.04 wt%, and low pressure gas flow to second step, cooling gas flow of high pressure in a series of coolers to temperature of 40-45 °C and separation of condensate after each cooler, wherein condensate temperature after each cooler is maintained at a level higher than chilling point thereof by 3-7 °C, cooling and separation of low pressure gas flow to temperature 15-25 °C at pressure 0.13-0.36 MPa and rate of movement of mixture of 2-15 m/s, maintaining temperature of low pressure gas flow after each cooler, except last, equal to or higher than dropping temperature and raising temperature of gas flow prior to feeding it into main process by 3-5 °C.

EFFECT: invention enables to prevent deposition of condensate in pipelines and equipment of first stage of purification and passage therein of gas stream and improved technical and economic parameters of process of producing copolymers.

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