THERMAL DECOMPOSITION OF UREA IN A SIDESTREAM OF COMBUSTION FLUE GAS USING A REGENERATIVE HEAT EXCHANGER

摘要

This invention relates generally to the treatment of NOx in combustion flue gas. In certain embodiments, the invention relates to the use of a regenerative heat exchanger (RHE) to convert urea to ammonia in a side stream of flue gas. Ammonia and/or other urea decomposition products exit the heat exchanger,- are mixed with the rest of the flue gas, and enter a selective catalytic reduction (SCR) unit for reduction of NOx in the flue gas. The use o an RHE significantly improves the thermal efficiency of the overall process. More particularly in certain embodiments, the regenerative heat exchanger is a dual chamber RHE.