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.

Methods and systems for removing contaminants, such as water and/or carbon dioxide, from a gas stream, such as a natural gas stream or a flue gas stream. One or more solid-tolerant heat exchangers are employed to chill the gas stream to a temperature at which the contaminants solidify. The solidified contaminants may then be separated and removed from the gas stream. In one or more aspects, the one or more solid-tolerant heat exchangers may include a scraped heat exchanger.

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.

Process for producing biomethane from a biogas stream including methane, carbon dioxide and at least one impurity chosen from ammonia, volatile organic compounds, water, sulfur-based impurities (H.sub.2S) and siloxanes. A biogas stream is dried, the at least one impurity is at least partially removed by solidification and removal of the impurity. The methane and the carbon dioxide contained in the biogas obtained from the second step are separated so as to produce a biomethane stream and a CO.sub.2 stream.

The present invention relates to a method of cooling and separating a hydrocarbon stream: (a) passing an hydrocarbon feed stream (7) through a first cooling and separation stage to provide a methane enriched vapour overhead stream (110) and a methane depleted liquid stream (10); (b) passing the methane depleted liquid stream (10) to a fractionation column (200) to obtain a bottom condensate stream (210), a top stream enriched in C1-C2 (220) and a midstream enriched in C3-C4 (230), (c) cooling the upper part of the fractionation column (201) by a condenser (206), (d) obtaining a split stream (112) from the methane enriched vapour overhead stream (110) and obtaining a cooled split stream (112) by expansion-cooling the split stream (112), (e) providing cooling duty to the top of the fractionation column (201) using the cooled split stream (112).

A thermoacoustic refrigerator includes at least one pair of pulse combustion tubes (10), preferably Rijke tubes, each tube (10) having a pair of spaced-apart Stirling engines (12), coupled together but with no separating membrane therebetween.

A method for cryogenic cooling without fouling is disclosed. The method comprises providing a first cryogenic liquid saturated with a dissolved gas; expanding the first cryogenic liquid into a separation vessel, separating into a vapor, a second cryogenic liquid, and a first solid; drawing the vapor into a heat exchanger and the second cryogenic liquid and the first solid out of the separation vessel; cooling the vapor against a coolant through the heat exchanger, causing the vapor to form a third cryogenic liquid and a second solid, the second solid dissolving in the third cryogenic liquid; and combining the second cryogenic liquid and the first solid with the third cryogenic liquid, producing a final cooled slurry. In this manner, the cryogenic cooling is accomplished without fouling.

A method is disclosed for separating components of a gas. A feed gas stream is cooled in the first vessel. The feed gas stream comprises methane, carbon dioxide, and a secondary component. A first portion of the secondary component condenses, desublimates, or a combination thereof to form a primary stream, resulting in a first depleted gas stream. The first depleted gas stream is cooled in a condensing exchanger such that a first portion of the methane condenses as a first liquid methane stream, resulting in a second depleted gas stream. The second depleted gas stream is cooled in the second vessel such that a first portion of the carbon dioxide desublimates to form a solid product stream, resulting in a third depleted gas stream.