An air-cleaning filter includes a non-woven fabric for dust collection and a non-woven fabric for deodorization having activated carbon particles combined therewith. By adjusting the particle diameter and content of the activated carbon particles and laminating with a non-woven fabric coated with an absorber for other gases, a dust collecting function and a deodorizing function can be imparted at the same time while also creating a structure with a low differential pressure.

A complex malodor removing equipment includes: a neutralizing module which dissolves a portion of malodor-causing substances, in malodorous gas introduced from malodor-producing equipment, in liquid water and removes same, which includes an acidity neutralizing module that introduces an alkaline substance from outside and removes an acidic malodor-causing substance from the malodor-causing substances, and an alkaline neutralizing module that introduces an acidic substance from outside and removes an alkaline malodor-causing substance from the malodor-causing substances, and which connects the acidity neutralizing module and the alkaline neutralizing module; and a balancing module which dissolves the remainder of the malodor-causing substances, in the malodorous gas introduced from the neutralizing module, in water and removes same, which includes an oxidation balancing module that introduces an oxidizing agent from outside and balances the malodor-causing substances, and a reduction balancing module that introduces a reducing agent from outside and balances the malodor-causing substances.

An example article includes a substrate and a coating applied to the substrate. The coating includes a stabilizer and an organic phosphonic acid reactant. In an example article, the coating includes a water-soluble polymer and an organic phosphate or phosphonate reactant. An example coating configured to be applied to a basic gas filter substrate includes a water-soluble polymer and an organic phosphate or phosphonate reactant. An example technique includes applying a coating to a substrate and heating at least the coating to a temperature between about 100? C. and about 275? C. for about 1 minute to about 10 minutes. An example system includes a basic gas filter including a coating, and a sensor configured to sense an optical change in the coating.

An absorbent for selective removal of hydrogen sulfide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I)

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in which R.sub.1 and R.sub.2 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl, with the proviso that at least one R.sub.4 and/or R.sub.5 radical on the carbon atom bonded directly to the nitrogen atom is C.sub.1-4-alkyl or C.sub.1-4-hydroxyalkyl when R.sub.3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H.sub.2S selectivity to be set at pressures of the kind typical in natural gas processing.

Process for treating a gas contaminated by at least one element selected from the group consisting of heavy metals, organic compounds, and combinations thereof, wherein a calcium-phosphate reactant (reagent) particle comprising apatite is brought into contact with the contaminated gas at a temperature of at least 30 C. and preferably at most 1100 C. The metal(s) and/or organic compound(s) to be removed from the contaminated gas may be selected among the list of: Al, Ag, As, Ba, Be, Bi, Ce, Co, Cd, Cu, Cr, Fe, Hf, Hg, La, Li, Mg, Mn, Mo, Ni, Pb, Pd, Rb, Sb, Se, Sn, Sr, Th, Ti, U, V, Y, Zn, Zr, VOC, aromatic compounds, PAHs, dioxins, furans, or any mixture thereof. In such process, an alkaline compound particle comprising sodium bicarbonate, sodium carbonate, sodium sesquicarbonate (trona), quick lime, hydrated lime, lime stone or combinations thereof, may be further brought into contact with the contaminated gas.

A membrane humidifier assembly for fuel cell applications includes a first flow field plate adapted to facilitate flow of a first gas thereto, a second flow field plate adapted to facilitate flow of a second gas thereto, and a polymeric membrane disposed between the first flow field plate and second flow field plate. The polymeric membrane is adapted to permit transfer of water. In order to prevent a perfluorosulfonic acid polymer, humidifier membrane from fouling and having diminished water vapor transport performance, ammonia and cation contaminants must be removed from the ambient gas streams. Suitable cationic and ammonia scavengers include filters comprising polymers functionalized with carboxylic acid groups, phosphonic acid groups, sulfonic acid groups, perfluorosulfonic acid groups or combinations thereof.

An object of the present invention is to obtain a gas adsorbent, a gas adsorption sheet, a filter medium, and an air filter that are excellent in gas component adsorption capacity and excellent in long-term stability of the adsorption capacity and also re-release little odor after being used as an air filter. A main object of the present invention is to provide a gas adsorbent that contains an acid-impregnated activated carbon, a base-impregnated activated carbon, and an aldehyde adsorbent.

Removing waste gas, more particularly carbon dioxide, from a gaseous medium and producing gaseous oxygen, a recovered waste constituent, more particularly solid carbon, heat and electrical power, by means of chemical reaction of waste gas with a metal oxide, more particularly dodecatungstophosphoric acid, immobilized in a porous matrix, more particularly tetraethylorthosilicate sol gel, enclosed in a gas permeable membrane. Regeneration of the metal oxide, more particularly by heating, and reconstitution of the porous matrix containing same by periodic introduction of base materials, and in some cases with externally supplied energy.

The present disclosure relates to a method that includes, in a first zone, contacting an ammonia-rich gas comprising ammonia with an ammonia-lean liquid sorbent resulting in the reversible transfer of at least a portion of the ammonia from the ammonia-rich gas to the ammonia-lean liquid sorbent, thereby forming an ammonia-rich liquid sorbent and an ammonia-lean gas and, in a second zone, removing at least a portion of the ammonia from the ammonia-rich liquid sorbent to form gaseous ammonia and regenerate the ammonia-lean liquid sorbent.