Abstract:
A method comprises injecting a reductant stream comprising a hydrocarbon reductant and water into an exhaust chamber comprising a nitrogen oxide-containing exhaust stream; contacting a composition comprising the reductant stream and exhaust stream with a catalyst; and decreasing a concentration of the nitrogen oxide in the composition comprising the reductant stream and exhaust stream. An exhaust stream treatment system, comprises an exhaust chamber comprising a catalyst; an exhaust stream comprising a nitrogen oxide; and a reductant stream comprising a hydrocarbon reductant and water.
Abstract:
A catalyst system for the reduction of NOx. is provided. The system comprises a catalyst in a first zone comprising a catalyst support, a catalytic metal comprising gallium, and at least one promoting metal selected from the group consisting of silver, gold, vanadium, zinc, tin, bismuth, cobalt, molybdenum, tungsten, indium and mixtures thereof; a catalyst in the second zone comprising a second catalyst support, a second catalytic metal selected from the group consisting of indium, copper, manganese, tungsten, molybdenum, titanium, vanadium, iron, cerium and mixtures thereof The catalyst system further comprises a gas stream comprising an organic reductant. The catalyst system may further comprise a catalyst in a third zone; the catalyst comprising a third catalyst support and a third catalytic metal selected from the group consisting of platinum, palladium, and mixtures thereof. A method for reducing NOx utilizing the catalyst system is also provided.
Abstract:
A method comprises injecting a reductant stream comprising a hydrocarbon reductant and water into an exhaust chamber comprising a nitrogen oxide-containing exhaust stream; contacting a composition comprising the reductant stream and exhaust stream with a catalyst; and decreasing a concentration of the nitrogen oxide in the composition comprising the reductant stream and exhaust stream. An exhaust stream treatment system, comprises an exhaust chamber comprising a catalyst; an exhaust stream comprising a nitrogen oxide; and a reductant stream comprising a hydrocarbon reductant and water.
Abstract:
A method for preparing hydroxyaromatic compounds brominated in the para-position, such as p-bromophenol, is disclosed. The method yields overall high process selectivity through isomeric equilibration and separation of the brominated products, thereby eliminating the need for high para selectivity in the products of catalytic oxybromination reactions of hydroxyaromatic compounds using oxygen, a bromine source, and an acidic medium in the presence of a metal catalyst. Furthermore, the invention provides an efficient method for recycling the metal catalyst, as well as reagents used in the bromination, to further reactions.