APPARATUS FOR LOW-TEMPERATURE DEPHLEGMATION WITH SEPARATION OF LTDS TO PREPARE NATURAL GAS TO OBTAIN A PROPANE-BUTANE FRACTION

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to low-temperature condensation plants and can be used in gas industry for natural gas preparation. Disclosed is an apparatus which includes an inlet separator, a dephlegmator, a low-temperature separator, a weathering apparatus, a demethanizer, a de-ethanizer, a debutanizer, first and second recuperative heat exchangers and reducing devices. During operation of the plant crude gas is cooled in the first recuperative heat exchanger, divided into condensate and gas, which after cooling in the second recuperative heat exchanger and reduction is subjected to dephlegmation due to cooling with reduced gas of dephlegmation, supplied from the top of the dephlegmator into its heat exchange section and then into low-temperature separator, from which condensate is removed and after heating in second recuperative heat exchanger prepared gas. Condensate is drained from condenser, all condensates are mixed, reduced and separated in weathering unit into gas returned to low-temperature separator, and a residue which is fed into the demethanizer after heating in the first recuperative heat exchanger, where it is separated into methane-containing gas returned to the low-temperature separator, and a residue which, after reduction, is fed into a de-ethanizer, where it is separated into ethane-containing gas returned to the low-temperature separator, and a wide fraction of light hydrocarbons, which is fractionated to obtain a propane-butane fraction and a stable gas condensate.;EFFECT: invention increases output of hydrocarbons C₃₊ and avoid formation of flare gases.;1 cl, 1 dwg