METHOD OF PROCESSING NATURAL HYDROCARBON GAS Russian patent published in 2016 - IPC F25J3/02 

FIELD: gas industry.

SUBSTANCE: invention relates to extraction of valuable components from natural hydrocarbon gas and can be used in gas processing industry. Method of processing natural hydrocarbon gas, including a system of interconnected first unit for pre-cooling gas flowing through successively installed heat exchanger, propane refrigerator, first stage separator and turbo-expander unit. Second unit for condensing and supercooling gas flowing through heat exchangers, separators, and stripping columns. Third unit for separating ethane and a wide fraction of light hydrocarbons from a prepared gas, cooled in heat exchangers and propane evaporator and entering a demethanizer with outlets for methane-nitrogen-helium mixture from top and bottom liquid from bottom, which is sent to deethanizer with integrated reflux, from top of deethanizer is withdrawn ethane fraction, and from bottom - bottom liquid in form of wide fraction of light hydrocarbons. Fourth unit for production of helium concentrate by cryogenic separation of methane-nitrogen-helium mixture into a methane fraction and helium concentrate. Resulting streams of methane fraction are sent to optional fifth unit for compression, wherein methane fraction is compressed and separated into two streams, first of which is sent to consumers as commercial-grade gas, and second stream is fed to first unit, where it is subjected to deep cooling and fed into third unit completely using as reflux to demethanizer or completely throttling and feeding as a refrigerant in reflux condenser built into a deethanizer or separating into third and fourth streams. Third stream is fed as reflux to demethanizer, and fourth is throttled and fed as a coolant in reflux condenser built into deethanizer.

EFFECT: technical result is increased extraction of ethane from initial natural gas, preservation of helium and increase in energy efficiency of installation.

3 cl, 1 dwg, 3 tbl