Impregnated filter element, and methods

Abstract

A contaminant-removal filter for removing carbonyl-containing compounds from a gas stream, such as air. Examples of common airborne carbonyl-containing compounds include ketones, including acetone, and aldehydes, including formaldehyde. The filter has a porous or fibrous body that includes a plurality of passages extending from a first, inlet face to a second, outlet face, the passages providing flow paths. The body has a reactant material impregnated throughout the substrate. The reactant material is a sulfite, bisulfite, oxidant, or derivative of ammonia, specifically high molecular weight and stable amines. Strong alkali (basic) materials are particularly suitable for aldehyde removal. The filter is free of any humectants.

Dependencies are inferred from the claim text.