A treatment process for remediating; contaminants in a mixture of contaminated fluids, including at least one liquid fluid and at least one gaseous fluid, includes the steps of: preparing a treatment composition containing at least 80 volume % of an aqueous solution containing at least one hydroxide compound at a collective concentration of 35-55 weight percent, and at least one organic acid selected from the group consisting of fulvic acid and humic acid at a collective concentration of 0.1-5 wt % of the treatment composition; adding a dosage of the treatment composition to a mixture of contaminated fluids including a liquid portion and a gaseous portion; and allowing the treatment composition to react with the mixture of contaminated fluids for at least 10 minutes. A pH of the treatment composition is at least 12.0

Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands which have high selectivity and stability in the present of gases and vapors including H.sub.2S, H.sub.2O, and CO.sub.2. Methods include capturing one or more of H.sub.2S, H.sub.2O, and CO.sub.2 from fluid compositions, such as natural gas.

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 method for capturing CO.sub.2 from a gas stream using a metal organic framework (MOF) based physisorbent CO.sub.2 concentrator is provided. In the method, MOF material is pretreated, a gas stream is then introduced into the CO.sub.2 concentrator which comprises the pretreated MOF material. CO.sub.2 from the gas stream is captured with the CO.sub.2 concentrator to generate a CO.sub.2-free stream, which is discharged the from the CO.sub.2 concentrator into the atmosphere. Introduction of the gas stream into the CO.sub.2 concentrator is stopped when the pretreated MOF material becomes saturated with CO.sub.2. The CO.sub.2 concentrator with the saturated MOF material is then regenerated by introducing hot air, hot nitrogen, vacuum, or a combination thereof into the CO.sub.2 concentrator thereby generating a CO.sub.2-rich stream. The CO.sub.2-rich stream is diverted for purification and the regenerated CO.sub.2 concentrator is recycled for future capture of CO.sub.2.

Described herein are articles for separating gases. The article includes an amorphous fluorinated copolymer containing, one or more types of fluorinated dioxolane ring monomers, and one or more types of fluorinated non-dioxolane ring monomers, optionally with crosslinking between the fluorinated copolymer chains. The copolymers of fluorinated dioxolane ring monomers and fluorinated non-dioxolane ring monomers show a large differential in the permeability of certain gases compared with other gases. The resulting polymer membranes have superior selectivity and reliability performance in certain gas separations compared with previous compositions known to the art. Methods for making and using the article described are also provided,

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 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 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 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 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.