A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

A passive NO.sub.x adsorber is disclosed. The passive NO.sub.x adsorber is effective to adsorb NO.sub.x at or below a low temperature and release the adsorbed NO.sub.x at temperatures above the low temperature. The passive NO.sub.x adsorber comprises a noble metal and a molecular sieve having an LTL Framework Type. The invention also includes an exhaust system comprising the passive NO.sub.x adsorber, and a method for treating exhaust gas from an internal combustion engine utilizing the passive NO.sub.x adsorber.

A method for preparing a nanoporous silica sol-gel matrix containing at least one amine reactant selected from hydroxylamine, methylhydroxylamine, tertbutylhydroxylamine, methoxyamine, tetraethylenepentamine, dicarboxylic acid dihydrazides, particularly adipic acid dihydrazide, and the salts thereof, said method including the following steps: a) synthesising a gel from tetramethoxysilane or from a mixture of tetramethoxysilane and another organosilicon precursor selected from among phenyltrimethoxysilane, phenyltriethoxysilane, a fluoroalkyltrimethoxysilane, a fluoroalkyltriethoxysilane, a chloroalkylmethoxysilane, a chloroalkylethoxysilane, an alkyltrimethoxysilane, an alkyltriethoxysilane, an aminopropyltriethoxysilane and the mixtures thereof, the synthesis being performed in an aqueous medium at a temperature ranging from 10 to 70° C. in the presence of at least one amine reactant selected from among hydroxylamine, methylhydroxylamine, tertbutylhydroxylamine, methoxyamine, dicarboxylic acid dihydrazides, particularly adipic acid dihydrazide, and the salts thereof; b) drying the gel obtained during step a) so as to obtain a sol-gel matrix containing at least one amine reactant.

The invention relates to the intensification of hydrogen PSA processes through utilization of specifically engineered core-shell composite adsorbents. Different embodiments of core-shell adsorbents can be used with either high or low heat capacity cores, and different adsorbent shells (e.g. activated carbon, zeolite, silica gel, alumina etc.) resulting in higher mass transfer rates and hence sharper mass transfer fronts during the PSA process. The location of the limiting impurity front determines the product purity. Therefore, with sharper impurity fronts, lower height of adsorbent bed is required, and cycle time can be proportionally reduced. Also, thermal swing during the PSA can be reduced by use of such adsorbents. The use of a high heat capacity core to reduce the thermal swing, leads to higher overall working capacity of the adsorbent bed.

An aminated siliceous adsorbent, which is the reaction product of dried acidified rice husk ash having disordered mesopores and an amino silane, wherein amine functional groups are present on an external surface and within the mesopores of the dried acidified rice husk ash, and wherein the aminated siliceous adsorbent has a carbon content of 24 to 30 wt. %, based on a total weight of the aminated siliceous adsorbent. A method of making the aminated siliceous adsorbent and a method of capturing CO.sub.2 from a gas mixture with the aminated siliceous adsorbent.

According to one embodiment, a carbon dioxide adsorption-desorption device including an electrode that includes a porous composite is provided. The porous composite includes an electro-conductive component and a porous material on the electro-conductive component. The porous material has pores of an angstrom size or a nanometer size, and includes a moiety exhibiting redox activity according to electrical response.

One or more embodiments relates to method for generating CHEFS having the steps of generating the CHEFS from a dope. One or more embodiments relates to a method for generating CHEFS having amine functional groups having the steps of generating a dope containing a BIAS with amine groups, at least one polymer, and at least one solvent; and forming CHEFS from the dope, wherein the generated CHEFS have no more than 30% amine loss compared to the BIAS.

A method of forming a gas treatment element for use in a gas treatment apparatus, such as a desiccant dryer, is disclosed. The element is formed by casting a sheet material by phase inversion of a dope mixture including a solvent, an adsorbent material such as a desiccant and a polymer binder. Layers of the sheet material are located adjacent one another and this is most readily achieved by rolling the sheet material to form the gas treatment element.

The present invention relates to novel sulfur-doped carbonaceous porous materials. The present invention also relates to processes for the preparation of these materials and to the use of these materials in applications such as gas adsorption, mercury and gold capture, gas storage and as catalysts or catalyst supports.

A preparation method for the carrier, includes: 1) mixing hydrated alumina with an organic acid to obtain a mixture A; and 2) adding tetraalkylsiloxane to the mixture A, thus obtaining a mixture B; stirring the mixture B in a closed condition; spraying atomized water into the mixture B; and stirring to yield the carrier.