A gas sensor comprises a gas separation membrane comprising substituted polyacetylene where a substituent group is combined to a double-bonded carbon atom in the backbone chain of the substituted polyacetylene and a sensing element configured to detect gas permeated through the gas separation membrane.

The present invention relates to a method for upgrading biogas generated by a biological process wherein at least carbon dioxide is removed from the bio-gas. More specifically the present invention relates to method for upgrading a biogas comprising a first absorption step wherein the liquid effluent is subjected to a second absorption step and a flash step and the gas streams resulting therefrom are recycled. The present invention also relates a biogas upgrading plant.

When a product gas producing operation is stopped, a purge operation is executed in which steam purge processing and product gas purge processing are sequentially performed. The steam purge is supplying, instead of a source gas, a product gas from a product gas tank to a reformer using a compressor, and supplying a reformed gas from a reforming processing unit to a plurality of adsorption towers, which perform a pressure swing adsorption operation, while the reformer is heated by a heating burner and steam is supplied to the reformer. The product gas purge is supplying the product gas from the product gas tank to the reformer using the compressor, and supplying the product gas from the reforming processing unit to the plurality of adsorption towers, which perform the pressure swing adsorption operation, while the supply of the steam is stopped and the heating of the reformer is maintained.

Provided herein is a methane oxidation catalyst having a support comprising alumina doped with lanthanum and comprising platinum and palladium as active phases. The platinum and palladium are present in the catalyst at an amount effective for producing an exhaust stream from a natural gas vehicle having reduced levels of methane. The catalyst disclosed herein may exhibit improvements in sulfur and water resistance.

Hydrogen purification devices and their components are disclosed. In some embodiments, the devices may include at least one foil-microscreen assembly disposed between and secured to first and second end frames. The at least one foil-microscreen assembly may include at least one hydrogen-selective membrane and at least one microscreen structure including a non-porous planar sheet having a plurality of apertures forming a plurality of fluid passages. The planar sheet may include generally opposed planar surfaces configured to provide support to the permeate side. The plurality of fluid passages may extend between the opposed surfaces. The at least one hydrogen-selective membrane may be metallurgically bonded to the at least one microscreen structure.

An exhaust gas purification catalyst for providing removal performance of methane, which is chemically stable includes a substrate that divides cells through which an exhaust gas flows and a catalyst layer that is provided on a surface of the substrate. The catalyst layer includes a palladium layer containing palladium that extends from a first end part which is an end part on the side of the cells into which an exhaust gas flows to a second end part which is an end part on the side from which an exhaust gas flows out, a platinum layer containing platinum that extends from the second end part to the first end part, and a rhodium layer containing rhodium that is laminated on both the palladium layer and the platinum layer.

A gas separation method including performing a gas separation operation that separates a source gas into a primary-side gas and a secondary-side gas with a membrane of a membrane module. The source gas contains a combustible component. The gas separation operation includes pressurizing the source gas and supplying the source gas to a primary side of the membrane module and depressurizing a secondary side of the membrane module to a pressure lower than an atmospheric pressure. The primary-side gas has a higher concentration of the combustible component than the secondary-side gas, and the gas separation method further includes detecting a composition of the secondary-side gas and stopping the gas separation operation in an instance in which the composition enters a specified range.

An apparatus for collecting a gaseous pollutant from air within a poultry or other concentrated animal feeding enclosure may comprise multiple vertical panel-beds each containing a solid sorbent; a fan to pass the air within the poultry enclosure through the multiple vertical panel-beds and over the solid sorbent; an outlet gate configured to release the solid sorbent from the multiple vertical panel-beds after the fan passes the air over the solid sorbent; a regeneration vessel configured to regenerate the released solid sorbent by recovering the gaseous pollutant from the released solid sorbent; and a conveyor configured to return the regenerated solid sorbent to the multiple vertical panel-beds.

A membrane including a polymer substrate having pore channels and a metal-organic framework disposed on the polymer substrate. Methods of producing the membrane are described. Methods of separating gases using the membrane are also provided.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.