Systems and methods for high efficiency regenerative selective catalytic reduction
AssigneeBabcock Power Environmental Inc.
InventorsJohn R. Harold, James D. Dougherty
Life of this patent
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Abstract
The invention provides a system for regenerative selective catalytic reduction including a catalyst chamber that contains a catalyst for reducing NOX in a gas stream passing therethrough. The system also includes a reactant injector, first and second heat exchangers, and a valve manifold adapted to direct a substantially continuous gas stream through the heat exchangers and catalyst chamber in such a manner as to flow through the catalyst chamber in the same flow direction during each cycle of the system. The invention also provides a process of regenerative selective catalytic reduction wherein the gas stream through the catalyst chamber flows in the same flow direction during each cycle of the process.
Claims20
A regenerative selective catalytic reduction process, comprising:
- a) providing a gas stream to be treated containing NOX;
- b) introducing a reactant into the gas stream;
- c) directing the gas stream into contact with a catalyst to cause at least some of the NOX contained in the gas stream to be reduced, wherein the gas stream is adapted to flow past the catalyst along the same flow direction throughout the process in a substantially continuous manner wherein:
- i) the gas stream is heated by directing the gas stream through a first heat exchanger, and the gas stream is cooled by directing the gas stream through a second heat exchanger during a first system cycle, and
- ii) the gas stream is heated by directing the gas stream through the second heat exchanger, and the gas stream is cooled by directing the gas stream through the first heat exchanger during a second system cycle.
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 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, 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, 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.
Dependencies are inferred from the claim text.