FIELD: gas industry.
SUBSTANCE: invention relates to low-temperature dephlegmation apparatus with rectification LTDR and can be used in gas industry when preparing natural gas. Disclosed is an apparatus for low-temperature dephlegmation with LTDR rectification, which includes an inlet separator, a low-temperature condensation unit in a dephlegmator and a demethanizer, first and second recuperative heat exchangers and reducing devices, as well as debutanization, carbon dioxide removal and refrigeration units. During operation of the plant raw gas is cooled in the first recuperative heat exchanger, separated in the inlet separator into condensate and gas, which after cooling in second recuperative heat exchanger and reduction is supplied to dephlegmator, from bottom of which condensate is removed, and from top is dephlegmation gas, which is reduced and supplied to demethanizer together with reduced condensates of input separation and dephlegmation. A circulating reflux is removed from the middle part of the demethanizer, which is returned to the demethanizer after being heated by the moist gas. From the demethanizer top, after heating in the dephlegmator heat exchange section and the second recuperative heat exchanger, the treated gas is removed, and from the bottom, a demethanised condensate, which is fed into a debutanization unit for separation into products. LNG is withdrawn from demethanizer middle part to be removed after purification from carbon dioxide and cooling in refrigerating machine.
EFFECT: technical result is obtaining LNG and high output of hydrocarbons C2+.
3 cl, 1 dwg
