This disclosure relates to hybrid membranes comprising functionalized fillers within a polymer matrix and methods of using the membranes for gas separation applications, such as removal of hydrogen sulfide (H.sub.2S) and carbon dioxide (CO.sub.2) from natural gas.

The present disclosure relates to systems and methods for separation of sulfurous material(s) from a multi-component feed stream. The systems and methods can comprise contacting the multi-component feed stream with a solvent in a contacting column so that at least a portion of the sulfurous material(s) is transferred from the multi-component feed stream to the solvent. A stream of a substantially purified gas can thus be provided along with a liquid stream comprising at least a majority of the sulfurous material. In particular, the solvent can comprise liquid carbon dioxide, which can be particularly beneficial for removing sulfurous materials from multi-component feed streams.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to a method for producing biomethane that removes impurities from a compressed digester biogas with staged membrane modules of at least two different types, to produce a biomethane having at least 94% CH.sub.4, below 3% of CO.sub.2, and below 4 ppm of H.sub.2S.

The invention provides an absorbent composition comprising an oxide or a carbonate, the oxide or carbonate comprising one or more transition and/or Group 12 metal and a hydrocolloidal polymer and/or a thermal decomposition product thereof. A method of removing materials such as sulphur containing compounds (such as hydrogen sulphide) or mercury is also provided, as is a method of making an absorbent composition.

In a process for the start-up of a hydrodesulfurization section, comprising the steps of providing a natural gas feed, passing the natural gas feed through the waste heat section of a reformer, thereby heating the natural gas feed, and passing the heated natural gas feed through a hydrodesulfurization section, thereby heating the hydrodesulfurization section while producing a desulfurized natural gas stream, a part of the desulfurized natural gas stream is provided as fuel for the reformer, while the remainder of the desulfurized natural gas is recycled to at least one point upstream the waste heat section.

The present invention relates to a biomimetic-hybrid solvent system for simultaneous capture of H.sub.2S and CO.sub.2 from any gaseous composition. The present invention also relates to a process for upgradation of biogas to bio CNG by removing gaseous contaminants, including microbial removal of H.sub.2S, to obtained purified CO.sub.2. The biomimetic-hybrid solvent system contains three components selected from tertiary amine compounds, a functional colloidal fluid, and an enzyme mimic.

Described herein are articles for separating gases. The article includes a selective layer consisting of a crosslinked amorphous fluorinated copolymer containing one or more types of fluorinated ring monomers, with crosslinking between the fluorinated copolymer chains. The crosslinking improves the mechanical properties of the fluoropolymer, thereby permitting use of polymer types which would otherwise be excessively brittle. The resulting crosslinked polymer membranes have superior selectivity and reliability performance compared with previous compositions known to the art. Methods for making and using the article described are also provided.

A regeneration method for a liquefied gas thiol-removing alkaline solution comprising the following steps: performing an oxygenation reaction with respect to a liquefied gas thiol-removing alkaline solution and, at the same time, utilizing a high air-liquid condition to extract a disulfide and a polysulfide into a gas phase, thus completing the separation of the disulfide and the polysulfide from the alkaline solution, and implementing the regeneration of the liquefied gas thiol-removing alkaline solution.

Compositions of and methods for producing a modified polyimide-containing compound with an alkyl or acyl group, one method including selecting and preparing a polyimide-containing compound to undergo a Friedel-Crafts alkylation or acylation reaction; carrying out the Friedel-Crafts alkylation or acylation reaction on the polyimide-containing compound to bond an alkyl group or acyl group to a reactive site on an aromatic compound of the polyimide-containing compound; cleaving the polyimide-containing compound to produce modified monomers comprising the alkyl group or the acyl group; and using the modified monomers in a reaction to produce the modified polyimide-containing compound, wherein the alkyl group or the acyl group is present in the modified polyimide-containing compound.

Polyamines of formula (I), their preparation method and their use in an absorbing solution based on amines in order to selectively eliminate H.sub.2S from a gaseous effluent containing H.sub.2S and CO.sub.2, which polyamines are obtained by a reaction between piperazine and an epihalohydrin or a 1,3-dihalo-2-propanol ##STR00001##