Catalytic reduction of NOx with high activity catalysts with propylene reductant

摘要

Methods and systems are provided for selective catalytic reduction of NOx with a low molecular low molecular weight hydrocarbon, e.g., propylene, as a reductant using a catalyst system including two catalysts. An exhaust stream containing an amount of NOx from a combustion operation is provided. A portion of the exhaust stream and a reductant stream including a low molecular weight hydrocarbon is introduced to a first catalytic reactor, which comprises a first catalyst including alumina loaded with silver. The NOx-reduced exhaust stream from the first catalyst is then directed to a second catalyst including zirconia loaded with at least one metal.

主权项

1. A method for selective catalytic reduction of NOx comprising:
providing an exhaust stream from a combustion operation, the exhaust stream containing an amount of NOx; introducing at least a portion of the exhaust stream and a reductant stream including propylene to a first catalytic reactor comprising a first catalyst including alumina loaded with silver, the reductant stream and the at least a portion of the exhaust stream being introduced to the first catalytic reactor at suitable operating conditions to reduce the amount of NOx in the exhaust stream; and directing the NOx-reduced exhaust stream from the first catalyst to a second catalyst including zirconia loaded with at least one metal.