SEPARATION SYSTEM FOR THE RETURN OF HYDROCARBONS FROM THE PROCESS OF SYNTHESIS OF POLYETHYLENE POLYMERS Russian patent published in 2023 - IPC C07C9/18 C08F6/00 C07C7/04 B01D3/00 

FIELD: separation systems.

SUBSTANCE: invention relates to a separation system for separating ethylene, 2-methylbutane and at least one unsubstituted hydrocarbon (C₆-C₁₂) in a multicomponent mixed condensate containing 2-methylbutane, ethylene, fine particles and at least one unsubstituted hydrocarbon (C₆-C₁₂). Said separation system comprises: a supply pipeline having hydraulic communication with a source of multi-component mixed condensate; a stripping column having hydraulic communication with the supply pipeline, containing the upper part, the lower part remote from the upper part, and from three to ten theoretical stages, while the stripping column is configured to obtain a multi-component mixed condensate through the supply pipeline at a temperature in the range from -13 degrees Celsius (°C) up to -5°C and pressure from 340 kilopascals of excess pressure (kPa g) to 420 kPa g, and the specified stripper column is additionally configured to operate at an internal pressure of 200 kPa to 1500 kPa to separate the specified multicomponent mixed condensate into a mixture of components of heavy fractions with at least one unsubstituted hydrocarbon (C₆-C₁₂) and a mixture of light fractions containing medium components and light components. Moreover, the middle components include at least 2-methylbutane, and the light components include at least ethylene, while the upper part of the stripping column is configured to extract a mixture of light fractions, and the lower part of the stripping column is configured to extract a mixture of components of heavy fractions; re-evaporator in hydraulic communication with the stripping column, configured to operate at a temperature of 50°C to 200°C; a condenser in fluid communication with the top of the stripping column, configured to cool the mixture of light ends coming from the top of the stripping column to a temperature of -19°C to 42°C; and a flash chamber comprising a top and a bottom spaced from the top, said flash chamber being in fluid communication with the condenser to produce a cooled light ends mixture from the condenser, the flash chamber being configured to operate at temperatures from 15°C to 70°C and pressure from 240 kPa to 405 kPa to separate the mixture of light fractions into medium components and light components, wherein the upper part of the evaporation chamber is configured to extract the light components of the mixture of light fractions, and the lower part of the evaporation chamber is configured to extract the average components of the mixture of light fractions provided that there is no distillation column between the source of multi-component mixed condensate and the evaporation chamber. The invention also relates to a gas-phase polymerization system and a method for separating ethylene, 2-methylbutane and at least one unsubstituted hydrocarbon (C₆-C₁₂) in a multicomponent mixed condensate containing 2-methylbutane, ethylene, fine particles and at least one unsubstituted hydrocarbon (C₆-C₁₂).

EFFECT: present invention helps to recover and use more olefin monomers and inert condensing agents from off-gases.

10 cl, 2 dwg