FIELD: oil and gas industry.
SUBSTANCE: invention relates to low-temperature separation plants and can be used in gas industry for extraction of hydrocarbons C2+ from natural gas. Disclosed is a palnt which includes, in version 1, a drying unit, an external cooling circuit in the evaporator, a compressor, a condenser and a reducing device, two recuperative heat exchangers, reducing devices, a dephlegmator, a weathering unit, a pump, a demethanizer and a low-temperature separator. Alternative 2 of the installation instead of the external cooling circuit equipment includes a compressor, a refrigerator and an additional reducing device. In operation of version 1, high-pressure gas is dried and separated into two streams, first is cooled in first recuperative heat exchanger, and second one – in evaporator and in second recuperative heat exchanger, then flows are combined, 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 coolant of the external circuit 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 methane-containing gas and weathering gas and separated into a low-temperature separator into gas and condensate. Reflux is removed from the dephlegmator, which is reduced, mixed with condensate, separated in a weathering unit on a weathering gas and a residue, which is fed via a second recuperative heat exchanger into a demethanizer, from which methane-containing gas and hydrocarbons C2+ are removed. Operation of version 2 is characterized by that the second high-pressure gas stream is compressed by a compressor driven by at least one of the expanders, cooled in a cooler, a second recuperative heat exchanger and reduced.
EFFECT: high output of hydrocarbons C2+.
2 cl, 2 dwg
