A process for purifying a natural gas feed gas stream including methane and hydrocarbons, including step a): cooling the feed gas stream; step b): introducing the cooled stream into a first phase separator vessel in order to produce a liquid stream and a gas stream; step c): separating the gas stream resulting from step b) in a membrane unit from which a methane-enriched permeate stream and one partially condensed residue stream enriched in hydrocarbons exit; step d): introducing the residue stream resulting from step c) into a second phase separator vessel to produce a liquid stream and a gas stream; step e): introducing at least one portion of the liquid stream resulting from step d) into a JT expansion means; step f): heating at least one portion of the expanded by introduction into the heat exchanger used in step a) counter-current to the feed stream.

A high-efficiency low-cost deep-condensation VOCs recovery system uses air as refrigerant. The recovery system includes a gaseous air purification system, an air liquefaction system and a VOCs recovery cold box. The gaseous air purification system includes an air filter, a cold dryer and an air purifier; the air liquefaction system comprises an air compressor, an air storage tank, a turbo-expander and an air precooler. The VOCs recovery cold box includes a VOCs precooler, a VOCs condenser and a gas-liquid separator.

A system used to recycle exhaust gas during olefin polymer production, comprising: a compression cooling mechanism (101); a hydrocarbon membrane separation mechanism (102) and a hydrogen membrane separation mechanism (103), both connected to a first outlet (202) of the compression cooling mechanism; and a deep cooling mechanism (104) connected to a first outlet (208) of the hydrogen membrane separation mechanism. A method used to recycle exhaust gas during olefin polymer production, comprising a compression cooling step, a hydrocarbon membrane separation step, a hydrogen membrane separation step and a deep cooling step.

A process for obtaining a product gas and product LNG having pressure P1 close to the atmospheric pressure from lean LNG, includes: a) branching the lean LNG to obtain a first flow and a second flow; b) cooling the second flow by using a refrigerant; c) branching a liquid flow derived from the cooled second flow to obtain refrigerant LNG and remaining LNG; d) subjecting the remaining LNG to pressure reduction and gas-liquid separation to obtain a gas phase flow and a liquid phase flow (product LNG) having pressure P1; e) subjecting the refrigerant LNG to pressure reduction; f) using a flow from the step e as the refrigerant; g) joining, before or after the step f, the gas phase flow having pressure P1 to a flow from the step e; h) liquefying a flow resulting from the steps f and g by pressure increase and cooling (through heat exchange with the first flow); i) increasing the first flow in pressure before the step h; j) obtaining the product gas by regasifying the first flow after the steps h and i; and k) joining a flow liquefied in the step h to the second flow.

A method for operating a natural gas liquids processing (NGL) system, the system being selectively configured in either an ethane rejection configuration or an ethane recovery configuration, the method comprising, when the NGL system is in the ethane rejection configuration, collecting a reboiler bottom stream that, in the ethane rejection configuration, includes ethane in an amount of less than 5% by volume, and when the NGL system is in the ethane recovery configuration, collecting a reboiler bottom stream that, in the ethane recovery configuration, includes ethane in an amount of at least about 30% by volume.

A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.

A process for purifying a feed gas including methane and heavy hydrocarbons, including: step a): cooling the feed gas in a heat exchanger; step b): introducing the resulting into a first phase separator to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gas stream; step c): separating the gas stream in a membrane from which a methane-enriched permeate stream and a partially condensed residue stream exit; step d): introducing the residue stream from step c) into a second phase separator vessel in order to produce a liquid stream and a gas stream; step e): introducing at least one portion of the gas stream resulting from step d) into a JT expansion means; and step f): heating at least one portion of the expanded stream in the heat exchanger used in step a) counter-current to the feed stream in order to cool the latter.

The invention relates to a method and system of preparing a lean methane-containing gas stream (22), comprising: feeding a hydrocarbon feed stream (10) into a separator (100); withdrawing from the separator (100) a liquid bottom stream (12); passing the liquid bottom stream (12) to a stabilizer column (200); withdrawing from the stabilizer column (200) a stabilized condensate stream (13) enriched in pentane, withdrawing from the stabilizer column (200) a stabilizer overhead stream (14) enriched in ethane, propane and butane; splitting the stabilizer overhead stream (14) according to a split ratio into a main stream portion (15) and a slip stream portion (16), passing the slip stream portion (16) to a fractionation unit (300) to obtain an ethane enriched stream (17) and a bottom stream enriched in propane and butane (18).

A system for sustainable generation of energy, comprising at least one device for converting natural power into useful energy, and at least one internal combustion engine or heat engine. The internal combustion engine or heat engine may be connected to a gas cleaning device for fuel or heat supply. A method for sustainable generation of energy, comprising the steps of generating a first amount of useful energy by converting natural power; and generating a second amount of energy by operating at least one internal combustion engine or heat engine, wherein the internal combustion engine or heat engine is driven by fuel or heat derived from cleaning a waste gas.

A process for purifying a natural gas feed gas stream including methane and hydrocarbons, including step a): cooling the feed gas stream; step b): introducing the cooled stream into a first phase separator vessel in order to produce a liquid stream and a gas stream; step c): separating the gas stream resulting from step b) in a membrane unit from which a methane-enriched permeate stream and one partially condensed residue stream enriched in hydrocarbons exit; step d): introducing the residue stream resulting from step c) into a second phase separator vessel to produce a liquid stream and a gas stream; step e): introducing at least one portion of the liquid stream resulting from step d) into a JT expansion means; step f): heating at least one portion of the expanded by introduction into the heat exchanger used in step a) counter-current to the feed stream.