FIELD: technological processes.
SUBSTANCE: invention relates to low-temperature separation plants and can be used in gas industry for extraction of hydrocarbons C2+ from natural gas. Installation in version 1 includes drying unit, external cooling circuit in composition of evaporator, compressor, condenser and reducing device, two recuperative heat exchangers, reducing devices, dephlegmator, demethanizer and low-temperature separator. Version 2 includes compressor, refrigerator and additional reducing device. In operation of version 1, high-pressure gas is dried, cooled in a first recuperative heat exchanger, an evaporator and a second recuperative heat exchanger, then, reduced and directed to dephlegmator cooled by low-temperature separation gas, which is then heated in the first recuperative heat exchanger and discharged. During circulation, the external circuit coolant after heating in the evaporator is compressed by a compressor driven by at least one of the expanders, cooled in a condenser and reduced. Dephlegmation gas is reduced and mixed with the methane-containing gas and separated into a gas and a condensate in a low-temperature separator. Reflux is reduced, mixed with condensate and, through a second recovery heat exchanger, into demethanizer, from which methane-containing gas and hydrocarbons C2+ are removed. Operation of version 2 differs by the fact that part of high pressure gas is compressed by compressor actuated by means of at least one of expanders, cooled in refrigerator, second recovery heat exchanger and reduced.
EFFECT: invention increases output of hydrocarbons C2+.
2 cl, 2 dwg
