UNIT FOR LOW-TEMPERATURE SEPARATION OF HYDROCARBON GAS Russian patent published in 2010 - IPC F25J3/00 

FIELD: process engineering.

SUBSTANCE: invention relates to hydrocarbon gas processing by low-temperature condensation and can be used in oil-and-gas processing industry. Proposed unit comprises hydrocarbon gas feed pipeline, hydrocarbon gas cooler communicated with first fractionating column furnished with branch pipes to discharge residue gas and to feed shower at tope part and branch pipe to feed condensate into second fractionating column. The latter incorporates branch pipes to discharge deethanisation gas phase and to feed shower at top part, as well as branch pipe to discharge liquid phase enriched with heavy hydrocarbons C_3+higher at bottom part. Residue gas discharge branch pipe is communicated with residue gas heat exchanger and, further, with hydrocarbon gas cooler. Deethanisation gas phase discharge branch pipe is communicated with heat exchanger and, further on, with a tank furnished with deethanisation gas phase discharge branch pipe and liquid phase discharge branch pipe communicated with branch pipe feeding shower into second fractionating column. Proposed unit comprises additionally heat exchanger device with heat exchange chamber communicates, in first heat carrier circuit, with bottom part of the first fractionating column and, in second heat carrier circuit, with the tank deethanisation gas phase discharge branch pipe and residue gas heat exchanger.

EFFECT: increased extraction of fraction C_3+higher from hydrocarbon gas.

6 cl, 3 dwg