FIELD: technological processes.
SUBSTANCE: invention relates to production of gas of low pressure and liquefied hydrocarbon gases and can be used in gas industry. Low-temperature fractionation unit includes a drying unit installed on a high-pressure line, a recuperative heat exchanger, a reducing device and a fractionating column, as well as a fractionation unit equipped with a demethanized condensate feed line and product discharge lines. Top of the fractionating column is connected by a deethanised gas discharge line to a reducing device connected to the upper heat-mass exchange section by a low-pressure gas discharge line. Lower part of the column with the demethanised condensate discharge line is equipped with a lower heat-mass-exchange section located on the bypass of the recuperative heat exchanger. Fractionation unit is equipped with input / output lines as coolant of deethanised gas part extracted between the column and reducing device, or part of low pressure gas withdrawn between the column and recovery heat exchanger. In compliance with second version, separator is additionally installed.
EFFECT: high output of C2+ hydrocarbons and avoiding use of external sources of low-temperature cold.
2 cl, 2 dwg
