A system is provided in which particulates, nitrogen oxides, and sulfur oxides are simultaneously removed from flue gases in a granular bed filter and scrubber with a nitrogen oxide-capturing reducing agent and a bed of sulfur oxide-capturing and particulate-removing material. the spent sulfur oxide-capturing...http://www.google.com.au/patents/US4617175?utm_source=gb-gplus-sharePatent US4617175 - Nitrogen oxide, sulfur oxide, and particulate removal system
