This invention relates to catalysts and more particularly to the catalyst decomposition of one or more oxides of nitrogen present in a gas stream by contacting the gas with a catalyst comprising a compound of the formula A.sub.x B.sub.y, where A is selected from the group consisting of Tl, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Th, and U, B is selected from the group consisting of B, C, N and Si, x has a value 1.ltoreq.x.ltoreq.7 and y has a value 1.ltoreq.y.ltoreq.4.
A method is described for converting formaldehyde to a gaseous product mixture capable of reacting with nitrogen oxide which comprises reacting formaldyhyde with nitrogen in the presence of a catalyst which is capable of promoting the reaction between formaldehyde and nitrogen at a temperature below about 1200.degree. F. The gaseous product mixture obtained in this manner is effective in reducing the nitrogen oxide content of combustion gases by mixing the gaseous product mixture with the combustion gas at temperatures from ambient temperature up to about 2000.degree. F.
A stable liquid suspension composition comprising a liquid carrier, a solid fatty acid or a salt thereof, and a solid particulate is disclosed wherein said liquid carrier is selected from the group consisting of oils, olefins, terpenes, glycols, esters, ethers, alcohols, and combinations of any two or more thereof and said liquid carrier, solid fatty acid or salt thereof, and solid particulate are each present in said composition in a stabilizing amount sufficient to produce a stable liquid suspension. Also disclosed is a stable liquid composition comprising a liquid carrier, an oil-soluble polymer, and a solid particulate wherein said liquid carrier is selected from the group consisting of liquid alkenes, terpenes, esters, and combinations of any two or more thereof and said liquid carrier, oil-soluble polymer, and solid particulate are each present in said composition in a stabilizing amount sufficient to effect the formation of a stable liquid suspension.
A moving fluid containing pollutants including NOx compounds is subjected to a relatively low-power alternating-current dielectric discharge for a relatively long time duration. In this manner, pollutants are oxidized and dissociated while the temperature of the fluid is kept low enough to prevent the formation of new NOx pollutants.
A process is described for reducing the nitrogen content of a post combustion gas which comprises the steps of (A) generating NCO free radicals, and thereafter (B) adding the free radicals to the gas whereby the NCO free radicals react with the nitrogen oxide in the gas to form nitrogen and carbon dioxide. The NCO free radicals may be obtained from a variety of sources such as by the catalytic decomposition of cyanuric acid; the reaction of formaldehyde with nitrogen or nitric oxide; the reaction of carbon monoxide with nitrogen oxide or nitrogen or mixtures thereof; or the reaction of methanol with nitrogen in the presence of a catalyst. The NCO free radicals thus generated are effective for reducing the nitrogen oxide content of combustion gases in accordance with the process of the present invention at temperatures from ambient temperature up to about 2000.degree. F.
