Systems and methods for the enhanced recovery of ethane and heavier hydrocarbons using an absorbing agent. Typical absorbing agents include one or more C3+ alkanes. The systems and methods separate components of a feed gas containing methane and heavier hydrocarbons, which maximizes ethane recovery, without requiring appreciable increases in capital and operating costs, and improves the safety margin with respect to the risk of CO.sub.2 freeze-out.

Method of liquefaction of methane and filling a tank (2) with liquefied methane, said method comprising: a step of liquefaction of the methane comprising an operation of cooling the methane to its saturation temperature, a step of filling the tank with the liquefied methane, a step of reinjection of the vaporized methane into the liquefaction system.

The present invention is a process for removing carbon dioxide from a compressed gas stream including cooling the compressed gas in a first heat exchanger, introducing the cooled gas into a de-sublimating heat exchanger, thereby producing a first solid carbon dioxide stream and a first carbon dioxide poor gas stream, expanding the carbon dioxide poor gas stream, thereby producing a second solid carbon dioxide stream and a second carbon dioxide poor gas stream, combining the first solid carbon dioxide stream and the second solid carbon dioxide stream, thereby producing a combined solid carbon dioxide stream, and indirectly exchanging heat between the combined solid carbon dioxide stream and the compressed gas in the first heat exchanger.

Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

A method of cooling a boil off gas stream from a liquefied cargo (50a) in a floating transportation vessel is described. The method comprises: compressing a boil off gas stream in two or more stages of compression to provide a compressed BOG discharge stream; cooling the compressed BOG discharge stream against one or more first coolant streams to provide a first cooled compressed BOG stream; cooling the first cooled compressed BOG stream against at least one second coolant stream to provide a second cooled compressed BOG stream; providing a vessel fuel stream from the liquefied cargo; using the vessel fuel stream as a coolant stream to cool either the compressed BOG discharge stream, or the first cooled compressed BOG stream, or both said streams.

The present invention relates to a refrigerant composition. According to the invention it is envisioned that the composition comprises comprising an inert gas selected from nitrogen, argon, neon and a mixture thereof, and a mixture of at least two C.sub.1-C.sub.5 hydrocarbons. The present invention further relates to the use of the refrigerant composition in a method for liquefying a gaseous substance, particularly hydrogen or helium.

Provided are an apparatus and method for liquefying natural gas. The apparatus for liquefying natural gas includes a gas compressor configured to receive and compress the natural gas from a natural gas feed stream, a heat exchanging unit configured to cool a high-pressure natural gas passing through the gas compressor through heat exchange, an expansion valve configured to expand the cooled natural gas passing through the heat exchanging unit, a hold-up drum configured to phase-separate a gas-liquid mixture produced by passing through the expansion valve and divide the gas-liquid mixture into a liquefied natural gas and a cryogenic recycle gas having nitrogen content greater than that of the liquefied natural gas so as to discharge the liquefied natural gas and the cryogenic recycle gas, and a bypass line configured to provide the recycle gas discharged from the hold-up drum to the heat exchanging unit.

A method and a system for separating a feed flow which contains at least hydrogen and a hydrocarbon with three or four carbon atoms per molecule, in particular propane, propylene, propadiene, butane, 1-butene, 2-butene, and/or 1,3-butadiene. The condensed feed flow is cooled over multiple cooling steps in at least two heat exchangers and is then separated into a condensate and a residual gas flow after each cooling step. The at least two heat exchangers are operated at least two different temperature levels, wherein a hot heat exchanger is operated at an average temperature level, and a cold heat exchanger is operated at a lower temperature level. An internal refrigerant which is made of a part of one of the condensate flows and a part of one of the residual gas flows, is used to dispense a part of the heat from the cold heat exchanger.

The invention relates to a refrigeration system that in mode 1 prepares a reservoir of cooled refrigerant before flowing unconditioned gas through the system, and in mode 2, continuously cools feed gas with the prepared refrigerant inventory, extracting natural gas liquids (NGLs) comprising predominantly ethane, propane, butane, and condensate and controlled by a control system without needing ramp up time.

Methods and systems for processing natural gas to meet gas pipeline specifications and/or recovering natural gas liquids (NGL). The natural gas is cooled and distilled such that propane and heavier components are produced as a bottoms NGL product, and inerts, methane, ethane, and other lighter portions are produced as a fuel gas grade/quality residue gas product stream. The gas can optionally be treated to remove hydrogen-sulfide and/or carbon dioxide. The NGL product can be split into a marketable propane and butane liquefied petroleum gas (LPG) liquid product and a natural gas condensate product.