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.

A process and a plant for purifying a crude gas stream containing sulfur components and hydrocarbons by gas scrubbing using a scrubbing medium which is selective for sulfur components in an absorption column. Heavy hydrocarbons and heavy mercaptans are removed from the crude gas in a lower section of the absorption column and the resulting, loaded scrubbing medium stream is fed separately from the other loaded scrubbing medium streams to a hot regeneration column. A vapor stream enriched in water, hydrocarbons and sulfur components is obtained as overhead product from the hot regeneration column and this stream is cooled to below its dew point and is separated in a gas-liquid-liquid phase separation apparatus. The resulting, organic liquid phase contains heavy hydrocarbons and heavy mercaptans and can thus be discharged from the process or the plant, as a result of which accumulation thereof in the scrubbing medium is prevented.

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 system for recovering natural gas liquid from a source, comprising: a heat exchanger for cooling wellstream fluid directed therethrough; a first separator for receiving the fluid from the heat exchanger for separating liquid and gas; in a first configuration, the gas from the first separator being directed to a turbo-expander for reducing the temperature and pressure of the gas to form a cold fluid; the cold fluid being directed to a second separator for separating liquid and gas; gas from the second separator being directed to the heat exchanger where it flows therethrough for cooling the wellstream fluid; wherein if the turbo-expander is not operating, the first configuration may be a changed to a second configuration to bypass the turbo-expander and direct the gas from the second separator to a Joule-Thomson valve to form the cold fluid.

One or more embodiments relate to a method for removing CO.sub.2 from a gaseous stream containing CO.sub.2 having the steps of contacting the gaseous stream containing CO.sub.2 with a solvent at a first temperature and a first pressure to dissolve said CO.sub.2 in said solvent, where the solvent is made up of at least one ester, and where said at least one ester has two or more alkyl-ester functional groups on a central hydrocarbon chain.

A method to purify a hydrocarbon gas with hydrogen sulfide as an impurity comprises: (a) charging a chamber with a bed of active-metal carbide of a predetermined mesh-size range; (b) conducting the hydrocarbon gas through the bed of active-metal carbide, forming additional hydrocarbon gas by reaction of the active-metal carbide and the hydrogen sulfide; and (c) filtering from the chamber the hydrocarbon gas without the hydrogen sulfide.

Structured adsorbent beds comprising a high cell density substrate, such as greater than about 1040 cpsi, and a coating comprising adsorbent particles, such as DDR and a binder, such as SiO.sub.2 are provided herein. Methods of preparing the structured adsorbent bed and gas separation processes using the structured adsorbent bed are also provided herein.

A solvent and method for removing carbon dioxide from a gaseous mixture flow with high carbon dioxide partial pressures are disclosed. The solvent includes a secondary or tertiary amine, an amine activator, a physical solvent (e.g., thioalkanol), and a carbonate buffer. The solvent contains less than about 60% by weight of water and is in a single liquid phase.

A process is disclosed for the removal of hydrogen sulfide (H.sub.2S) from natural. This process provides for passing a natural gas feedstream comprising H.sub.2S though a regenerable adsorbent media which adsorbs H.sub.2S to provide an H.sub.2S-lean natural gas product and H.sub.2S. The regenerable adsorbent media of the present invention is a tertiary amine functionalized cross-linked macroporous polymeric adsorbent media.

A subsea fluid processing system which receives a wellstream flow. The subsea fluid processing system includes a pressure control device which regulates a pressure of the wellstream flow, a gas-liquid separator unit which receives the wellstream flow downstream of the pressure control device and which provides a liquid stream and a gas stream, a first membrane separator which receives the gas stream and which provides a retentate stream and a permeate stream, a compressor which receives the permeate stream and which provides a compressed permeate stream, and a discharge cooler which receives the compressed permeate stream and which provides a cooled compressed permeate stream for injection into a subsurface reservoir. A density of the cooled compressed permeate stream is higher than a density of the compressed permeate stream.