A three-way catalyst article, and its use in an exhaust system for compressed natural gas engines, is disclosed. The catalyst article for treating exhaust gas from compressed natural gas (CNG) engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first zeolite; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium or a combination thereof.

An adsorbent bed, including at least one elementary composite structure that includes adsorbent particles in a polymer matrix, wherein the adsorbent bed has a bed packing, ρ.sub.bed, defined as a volume occupied by the at least one elementary composite structure V.sub.ecs divided by a volume of the adsorbent bed V.sub.bed where ρ.sub.bed is greater than 0.60.

A method for recovering helium from a feed gas mixture comprising helium, carbon dioxide and at least one of methane and nitrogen, and wherein at least a part of the feed gas mixture is subjected to a separation sequence including a membrane-based separation and an adsorption-based separation forming a helium product, wherein the the membrane based separation is performed using a first membrane separation step and a second membrane separation step, the membrane based separation and the separation sequence includes no further membrane separation steps, the adsorption based separation is performed using a pressure swing adsorption step, at least a part of the feed gas mixture is subjected to the first membrane separation step forming a first retentate and a first permeate. A corresponding arrangement is also provided.

The present invention provides an oxidation catalyst composition suitable for at least partial conversion of gaseous hydrocarbon emissions, e.g., methane. The oxidation catalyst composition includes at least one platinum group metal (PGM) component supported onto a porous zirconia-containing material that provides an effect on hydrocarbon conversion activity. The porous zirconia-containing material is at least 90% by weight in the monoclinic phase. Furthermore, the PGM component can comprise at least one platinum group metal in the form of colloidally deposited nanoparticles. The oxidation catalyst composition can be used in the treatment of emissions from lean compressed natural gas engines.

Methods and systems for producing and using multi-layer composite co-polyimide membranes, one method for producing including preparing a microporous or mesoporous membrane support material for coating; applying a sealing layer to the membrane support material to prevent intrusion into the membrane support material of co-polyimide polymer; applying a first permselective co-polyimide layer atop and in contact with the sealing layer; and applying a second permselective co-polyimide layer atop and in contact with the first permselective co-polyimide layer.

A process for removal of unwanted components from a feed gas mixture, wherein a temperature swing adsorption unit comprising at least two adsorption vessels is used, the method comprising cyclically operating the temperature swing adsorption unit in successive operation modes in each of which a different one of the at least two adsorption vessels is operated in an adsorption mode while a further one of the at least two adsorption vessels previously operated in the adsorption mode is operated in a regeneration mode, the adsorption mode comprising forming an adsorption gas stream using a part of the feed gas mixture and passing the adsorption gas stream through the adsorption vessel operated in the adsorption mode, and the regeneration mode comprising passing a regeneration gas stream through the adsorption vessel operated in the regeneration mode, thereby forming the purified gas mixture.

A method to condense and recover CO.sub.2 from CO.sub.2 containing streams. A first step involve providing at more than one heat exchanger, with each heat exchanger having a first flow path for passage of a first fluid and a second flow path for passage of a second fluid. A second step involves passing a stream of very cold natural gas sequentially along the second flow path of each heat exchanger until it is heated for distribution and concurrently passing a CO.sub.2 containing stream sequentially along the first flow path of each heat exchanger, allowing the water vapor portion of the CO.sub.2 containing stream to condense and precipitate on the condensing heat exchangers. A third step involves passing a water vapor free CO.sub.2 containing stream to a cryogenic heat exchanger to condense, precipitate and recover CO.sub.2. This processes results in the recovery of CO.sub.2 and water vapor from CO.sub.2 containing streams using condensing heat exchangers, chiller, compressor, expander and power generator to recover the low value thermal heat available in CO.sub.2 containing waste streams.

The present invention relates to a compressed natural gas combustion and exhaust system comprising: (i) a natural gas combustion engine; and (ii) an exhaust treatment system, the exhaust treatment system comprising a intake for receiving an exhaust gas from the combustion engine and a catalyst article arranged to receive and treat the exhaust gas, wherein the catalyst article comprises: a substrate having at least first and second coatings, the first coating being free from platinum-group-metals and comprising a copper-containing zeolite having the CHA framework-type and the second coating comprising a palladium-containing zeolite, wherein the first coating is arranged to contact the exhaust gas before the second coating. The present invention further relates to a method and a use.

The present invention relates to a catalytic material for treating an exhaust gas produced by a natural gas engine, which catalytic material comprises a molecular sieve and a platinum group metal (PGM) supported on the molecular sieve, wherein the molecular sieve has a framework comprising silicon, oxygen and germanium, and has a content of heteroatom T-atoms of ≤about 0.20 mol %, wherein the germanium is present in an amount of from 15 to 20 mol %. The present invention further relates to a catalyst article and a compressed natural gas combustion and exhaust system.

The present invention relates to a catalytic material for treating an exhaust gas produced by a natural gas engine, which catalytic material comprises a molecular sieve and a platinum group metal (PGM) supported on the molecular sieve, wherein the molecular sieve has a framework comprising silicon, oxygen, titanium and optionally germanium, and has a content of non-titanium heteroatom T-atoms of ≤ about 0.20 mol %, wherein the titanium is present in an amount of from 1 to 3 mol %. The present invention further relates to a catalyst article and to a compressed natural gas combustion and exhaust system.