Patent ID: 8124017

Claim:
A system for regenerative selective catalytic reduction, comprising: a) a catalyst chamber having an inlet, an outlet and defining a flow path between the inlet and the outlet, the catalyst chamber containing a catalyst for reducing NO x in a gas stream passing therethrough; b) a reactant injector in fluid communication with the system for introducing a reactant into the gas stream upstream from the catalyst chamber as the gas stream passes through the system; c) a valve manifold in fluid communication with the inlet and the outlet of the catalyst chamber, wherein the valve manifold is adapted to direct a substantially continuous gas stream through the catalyst chamber from the inlet to the outlet during each cycle of system operation along the same flow direction; d) a first heat exchanger in fluid communication with the valve manifold, wherein the first heat exchanger includes a heater and a vessel including a thermal mass adapted to permit a gas stream to pass therethrough, the first heat exchanger adapted to exchange energy with a gas stream passing therethrough; and e) a second heat exchanger in fluid communication with the valve manifold, wherein the second heat exchanger includes a heater and a vessel including a thermal mass adapted to permit a gas stream to pass therethrough, the second heat exchanger adapted to exchange energy with a gas stream passing therethrough; f) wherein the valve manifold is further adapted to: i) heat a gas stream passing through the system by directing the gas stream through the first heat exchanger, and cool the gas stream by passing the gas stream through the second heat exchanger, during a first system cycle; and ii) heat a gas stream passing through the system by directing the gas stream through the second heat exchanger, and cool the gas stream by passing the gas stream through the first heat exchanger, during a second system cycle.