Abatement of Nitrous Oxide Emissions by Low Temperature Catalytic Decomposition

75602-Nitric acid production is currently the largest source of nitrous oxide emissions in the chemical industry. Reductions in these emissions are urgently required because nitrous oxide is both a strong greenhouse gas and an ozone layer depleter. Although measures exist to eliminate nitrous oxide emissions from adipic acid plants, they cannot be applied to eliminate nitrous oxide emissions from nitric acid plants. One candidate method involves the direct catalytic decomposition of nitrous oxide; however, with current state-of-the-art catalysts, temperatures of 400¿C and higher would be required to decompose nitrous oxide in the tail-gases of a nitric acid plant. Unfortunately, in many nitric acid plants, the temperature is well below 400¿C, and preheating would be expensive. Therefore, new catalysts are required that can decompose nitrous oxide at temperatures lower than 400¿C, preferably at 100¿C-200¿C, and at the conditions encountered in nitric acid plants. This project will develop a nitrous oxide abatement technology that can eliminate nitrous oxide emissions from nitric acid plants without the need to pre-heat the waste gas stream. In Phase I, nitrous oxide decomposition catalysts, originally developed for green chemical propulsion for space applications, will be demonstrated to decompose nitrous oxide into nitrogen and oxygen at 200¿C or below, under conditions encountered in nitric acid plants. Commercial Applications and Other Benefits as described by the awardee: The nitrous oxide abatement technology could be retrofitted to existing nitric acid plants and applied to new ones. Adipic acid plants also could be retrofitted to increase efficiency and to reduce the cost of nitrous oxide abatement. The low temperature nitrous oxide decomposition technology also could find application in the removal of nitrous oxide from mobile sources, i.e. automobiles.