Systems and methods for separating a biogas or other gaseous material into its constituent parts, including solid methane and carbon dioxide, using liquid nitrogen in a processing chamber. The individual parts may be extracted from the processing chamber. Separation and extraction can be performed on a mobile processing plant.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.

A process for separating carbon dioxide from a waste gas of a fluid catalytic cracking installation including converting at least a portion of the carbon monoxide of the waste gas into carbon dioxide to form a flow enriched in carbon dioxide, separating at least a portion of the flow enriched in carbon dioxide to form a gas enriched in carbon dioxide and depleted in nitrogen and a gas rich in nitrogen and depleted in carbon dioxide, and at least a portion of the gas enriched in carbon dioxide and depleted in nitrogen is separated by way of separation at a temperature of less than 0° C. to form a fluid rich in carbon dioxide and a fluid depleted in carbon dioxide and sending a gas containing at least 90% oxygen to combustion.

Disclosed is a method for purifying a main gas, in particular helium, from a source gas stream comprising the main gas, a main impurity, in particular nitrogen, and optionally another, secondary impurity, in particular oxygen, the method comprising a step of partial condensation of the gas stream in order to extract therefrom impurities in liquid form, in particular the main impurity, and to produce a gas stream enriched with main gas, characterized in that the method comprises, before the partial condensation step, a step of injecting into the gas stream a compound in which the main impurity of the gas to be treated is soluble and having a saturation vapor pressure lower than the saturation vapor pressure of the main impurity.

A system for separating olefinic hydrocarbon and hydrogen in an effluent fluid stream from a dehydrogenation reactor includes a heat exchanger that receives and partially condenses the effluent fluid stream so that a mixed phase effluent stream is formed. A primary separation device receives and separates the mixed phase effluent stream into a primary vapor stream and a primary liquid product stream. A heat exchanger receives and partially condenses the primary vapor stream so that a mixed phase primary stream is formed. A secondary separation device receives and separates the mixed phase primary stream into a secondary vapor stream and a secondary liquid product stream. A heat exchanger receives and warms the secondary vapor stream to provide refrigeration for partially condensing the effluent fluid stream and a heat exchanger receives and warms the secondary vapor stream to provide refrigeration for partially condensing the primary vapor stream. A mixed refrigerant compression system provides refrigerant to a heat exchanger to provide refrigeration.

A process for purifying a gaseous feed stream of natural gas including methane, CO.sub.2 and heavy hydrocarbons including step a): cooling the gaseous feed stream in a heat exchanger; step b): introducing the cooled stream into a phase-separating chamber to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gaseous stream; step c): separating the gaseous stream obtained from step b) in a first membrane producing at least one CO.sub.2-enriched permeate stream and a residual stream enriched in methane; step d): introducing the residual stream obtained from step c) into a phase-separator to produce a liquid stream and a gaseous stream; step e): heating the gaseous stream obtained from step d) by introducing it into the heat exchanger used in step a) counter-currentwise with the feed stream thereby producing a gaseous stream depleted in CO.sub.2 and enriched in methane.

A combined plant for cryogenic separation and liquefaction of methane and carbon dioxide in a biogas stream, including a mixing means, a compressor, a first exchanger, a distillation column, a second exchanger, a separating means, an expanding means, and a separator vessel. Wherein the mixing means is configured such that the recycle gas is the overhead vapour stream, and the first exchanger and the expanding means are combined.

A method for recovering C2 components in a methane-containing industrial gas includes the steps of (1) cooling a compressed methane-containing industrial gas and performing gas-liquid separation; (2) absorbing C2 components in the gas phase by using an absorbent to obtain an absorption rich liquid; (3) returning the absorption rich liquid to the compression in step (1) or mixing the absorption rich liquid with the liquid phase obtained in step (1) to obtain a mixed liquid, and depressurizing the mixed liquid or the absorption rich liquid; (4) performing methane desorption on the depressurized stream to obtain a rich absorbent, or performing second gas-liquid separation on the depressurized stream, followed by methane desorption on the second liquid phase to obtain a rich absorbent; and (5) desorbing and separating the rich absorbent to obtain a lean absorbent and an enriched gas, and recycling and reusing the lean absorbent.

A heavies removal heat exchanger cools at least a portion of a feed gas stream. A scrubbing section receives the cooled main feed gas stream. A stripping section receives a fluid stream from the scrubbing section. A stripping gas feed expansion device receives a portion of the feed gas stream and is in fluid communication with the stripping section. A side draw vapor line receives a vapor stream from the vapor outlet of the stripping section and is in fluid communication with a reflux stream cooling passage of the heavies removal heat exchanger. A reflux separation device receives fluid from the heavies removal heat exchanger and has a liquid outlet and a vapor outlet. The liquid outlet is in fluid communication with the scrubbing section. A return vapor expansion device receives a vapor stream from the scrubbing section and directs a cooled vapor stream to a return vapor stream warming passage of the heavies removal heat exchanger. The reflux separation device vapor outlet is configured so that fluid passing therethrough joins with fluid that has exited the return vapor expansion device either before or after the fluid that has exited the return vapor expansion device flows through the return vapor stream warming passage of the heavies removal heat exchanger.

In a process for the separation of a mixture containing hydrogen and carbon monoxide to produce gaseous hydrogen, the mixture is cooled down to a temperature below −180° C. and then separated at a temperature below −100° C. to produce a gas enriched in hydrogen and a fluid enriched in carbon monoxide, at least a part of the gas enriched in hydrogen is sent to a pressure swing adsorption separation apparatus operating at a temperature above 0° C. to produce a gas rich in hydrogen at a pressure of at least 20 bars, and at least a part of the gas rich in hydrogen is cooled in the heat exchanger down to a temperature below −100° C., reduced in pressure in a turbine down to a pressure of at least 8 bars and reheated in the heat exchanger to constitute a product rich in hydrogen at a pressure of at least 8 bars.