The present invention provides a method for purifying carbon dioxide gas characterized in that carbon dioxide gas containing at least one of 3-methylmercaptopropionaldehyde and acrolein is contacted with activated carbon to remove at least one of the 3-methylmercaptopropionaldehyde and acrolein. The present invention provides also a method for producing methionine comprising the purification step of the recovered carbon dioxide.

The present invention provides a method for purifying carbon dioxide gas characterized in that carbon dioxide gas containing at least one of 3-methylmercaptopropionaldehyde and acrolein is contacted with activated carbon to remove at least one of the 3-methylmercaptopropionaldehyde and acrolein. The present invention provides also a method for producing methionine comprising the purification step of the recovered carbon dioxide.

The present invention provides a catalyst for catalytic reduction of an industrial flue gas SO.sub.2 with CO to prepare sulfur, a method for preparing the same and use thereof. A CeO.sub.2 nanocarrier is prepared by using a hydrothermal method, La and Y are loaded as active components, pre-sulfurization is conducted with 6% of SO.sub.2 and 3% of CO, and finally, the catalyst is prepared. The catalyst has high reactivity and sulfur selectivity and strong stability. The by-product sulfur generated by the reaction is recovered with a solvent CS.sub.2, and the solvent CS.sub.2 is recovered by using a distillation process. The preparation method is low in cost, causes no secondary pollution and is high in sulfur recovery rate. The problem of low sulfur production in China at present is solved.

The invention is directed to a continuous process to treat a hydrogen sulphide comprising gas comprising the following steps: (a) contacting the hydrogen sulphide comprising gas with an aqueous alkaline solution further comprising sulphide oxidising bacteria thereby obtaining a loaded aqueous solution comprising sulphide compounds and sulphide oxidising bacteria. (b) contacting the loaded aqueous solution with an oxygen comprising gas to regenerate the sulphide oxidising bacteria to obtain a liquid effluent comprising regenerated sulphide oxidising bacteria which is partly used as the aqueous alkaline solution in step (a). (c) separating elemental sulphur as prepared by the sulphide oxidising bacteria in steps (a) and (b) from the loaded aqueous solution of step (a) and/or from the liquid effluent of step (b) and wherein the consumption of oxygen in step (b) is measured and wherein the supply of oxygen in step (b) is controlled by the measured consumption of oxygen.

A duct can be configured to receive a denuding gas flow. A solid denuding surface that is connected to a drive system can be configured to move the solid denuding surface within the duct while the solid denuding surface is continuously concentrating one or more gas-phase species from the denuding gas flow on the denuding surface. Also, a denuding gas flow can be passed along a denuding surface to concentrate one or more gas phase species from the denuding gas flow onto the denuding surface with a diffusion denuding action. The denuding surface can be moved while continuing to concentrate the one or more gas phase species from the denuding gas flow onto the denuding surface.

A duct can be configured to receive a denuding gas flow. A solid denuding surface that is connected to a drive system can be configured to move the solid denuding surface within the duct while the solid denuding surface is continuously concentrating one or more gas-phase species from the denuding gas flow on the denuding surface. Also, a denuding gas flow can be passed along a denuding surface to concentrate one or more gas phase species from the denuding gas flow onto the denuding surface with a diffusion denuding action. The denuding surface can be moved while continuing to concentrate the one or more gas phase species from the denuding gas flow onto the denuding surface.

The present invention relates, inter alia, to the use of porous crystalline solids constituted of a metal-organic framework (MOF) for the selective adsorption of aldehyde volatile organic compounds.

The MOF solids of the present invention can be used for the improved purification of dry or humid air, and for the manufacture of regenerable filters for air purification, particularly leak-free regenerable air filters.

The present invention relates, inter alia, to the use of porous crystalline solids constituted of a metal-organic framework (MOF) for the selective adsorption of aldehyde volatile organic compounds.

The MOF solids of the present invention can be used for the improved purification of dry or humid air, and for the manufacture of regenerable filters for air purification, particularly leak-free regenerable air filters.

Sorptive gas separators can employ contactors having various sorbents blended together. The various sorbents used to make a blended sorbent contactor can be selected for their various physical and chemical properties, which will allow operators to customize formulations and structural configurations to obtain optimum performance of sorptive gas separators using blended sorbents.

Sorptive gas separators can employ contactors having various sorbents blended together. The various sorbents used to make a blended sorbent contactor can be selected for their various physical and chemical properties, which will allow operators to customize formulations and structural configurations to obtain optimum performance of sorptive gas separators using blended sorbents.