The Babcock & Wilcox Company

Peter V Smith

William Downs

John B Doyle

Paul Chu

Dennis W Johnson

Robert B Myers

Fred C Owens, Ii

Robert Martinelli

A method and apparatus is described for removing acid gases, air toxics and/or other contaminants from a flue gas stream formed during the combustion of fossil fuel, and/or waste materials. The flue gas stream is conditioned immediately downstream of the combustion source with a finely atomized liquid which is preferably water. The water spray decreases the volume of the flue gas and cools the flue gas to condense air toxics or heavy metals on the baghouse fabric filters. Advantageously, this may utilize the alkalinity inherent in the fly ash component of the particulate to assist in the removal of acid gases and/or other contaminants via adsorption. Also, the conditioned gas reduces the flue gas volumetric flow rate and hence the size of the particulate collection device, and the cost of the fabric filter media.

Flue gas conditioning for the removal of acid gases, air toxics and

A method for controlling emissions of a fossil fuel fired boiler including a high temperature fabric filter house with an SCR catalyst situated therein for receiving flue gases along with an injected ammoniacal compound and sorbent. The sorbent reacts with the SO.sub.x while the ammoniacal compound reduces the NO.sub.x in the presence of the SCR catalyst inside the high temperature fabric filter house. Both the SO.sub.x and the particulates are removed upstream of the SCR catalyst to diminish the problems of SO.sub.2 or SO.sub.3 poisoning of the catalyst and erosion and fouling of the catalyst with the fly ash. Since the sulfur oxides and particulates are removed prior to the heat recovery system, the fouling and corrosion potential are substantially decreased thus allowing the heat recovery system to be operated at a lower outlet flue gas temperature which yields an incremental improvement in energy recovery.

SO.sub.x, NO.sub.x and particulate removal system

A method and apparatus for controlling emissions of a fossil fuel fired boiler including a high temperature fabric filter house with an SCR catalyst situated therein for receiving flue gases along with an injected ammoniacal compound and sorbent. The sorbent reacts with the SO.sub.x while the ammoniacal compound reduces the NO.sub.x in the presence of the SCR catalyst inside the high temperature fabric filter house. Both the SO.sub.x and the particulates are removed upstream of the SCR catalyst to diminish the problems of SO.sub.2 or SO.sub.3 poisoning of the catalyst and erosion and fouling of the catalyst with the fly ash. Since the sulfur oxides and particulates are removed prior to the heat recovery system, the fouling and corrosion potential are substantially decreased thus allowing the heat recovery system to be operated at a lower outlet flue gas temperature which yields an incremental improvement in energy recovery.

SO.sub.x , NO.sub.x , and particulate removal system

Improved SO.sub.x, NO.sub.x, and particulate removal system

Growing community of inventors

North Canton, OH, United States of America

Peter V Smith