FIELD: heat exchange.
SUBSTANCE: low-temperature dephlegmation apparatus with rectification LTDR for complex gas treatment and LNG generation, including an inlet separator, a low-temperature condensation unit with reducing devices, comprising first and second recuperative heat exchangers, a refluxer with a heat exchange section, connected by dephlegmation gas supply line equipped with reducing device, with low-temperature separator equipped with prepared natural gas discharge line, and condensate stabilization unit, where the low-temperature separator is a demethanizer with a demethanized condensate feed line and a prepared natural gas discharge line equipped with the first recuperative heat exchanger, at least one of reducing devices is made in the form of an expander, on the dephlegmation gas supply line after the reducing device there is a separator connected to the demethanizer by a residue separation supply line, on which there is a heat exchange section of the refluxer, and with the LNG production unit—by the separation gas supply line, to which the supply line of its part adjoins the separation residue supply line, wherein condensate discharge lines from inlet separator and dephlegmator with reducing devices, as well as demethanised condensate first part supply line, heated in the second recuperative heat exchanger, are connected to the demethanizer, and on the supply line of its second part as the stabilization unit a debutanization unit is installed, equipped with products output lines, further, the LNG production unit includes, in series on the separation gas supply line, a carbon dioxide purification unit, a first recovery heat exchanger, a first compressor, a cooler with external coolant inlet/outlet lines, a drying unit, first and second recuperative heat exchangers, an expander and a separator with an LNG outlet line and a return gas supply line to the prepared natural gas discharge line, on which the second recuperative heat exchanger and the second compressor are located, and first and second compressors are connected to LNG producing unit expander and to at least one of expanders of low-temperature condensation unit by means of kinematic or electric connection.
EFFECT: technical result is obtaining LNG due to addition of installation by LNG production unit, which compressors are connected to at least one of expanders, as well as high output of C2+ hydrocarbons by cooling the dephlegmator with reduced dephlegmation gas and avoiding formation of flare gases.
1 cl, 1 dwg
