Denitrification and desulfurization of combustion gases. Quarterly technical progress report No. 7, March 18-June 17, 1982

This program was initially designed for developing new and more efficient processes for the removal of SO/sub 2/ and NO/sub x/ from hot combustion gases. For SO/sub 2/ removal, the goal was to develop, on a laboratory scale, the Fe/sub 2/O/sub 3/ catalyzed fluidized bed combustion process. For the NO/sub x/ removal, it was intended to develop a two-step process for NO/sub x/ decomposition to form N/sub 2/, with a low-cost sorbent/catalyst and with no NH/sub 3/ injection. The study on the iron oxide catalyzed sulfation of limestone has been completed. Based on our kinetic (TGA) data, the Lee-Georgakis model predicts that an 1% Fe/sub 2/O/sub 3/ coating on Tymochtee dolomite would reduce the lime requirement by about 30 to 40% for 90% sulfur retention for a typical FBC operation. This new process holds considerable economic promises and is ready and recommended for further pilot-scale development. We have had some success with the sodium ferrite sorbent/catalyst in the two-step NO/sub x/ decomposition process. However, Fe/sub 2/O/sub 3/, which was used as the catalyst for NO decomposition, is not among the best catalysts. Copper oxide is known to be about two orders of magnitude more efficient as Fe/sub 2/O/sub 3/. Andmore » more important, Cu(SO/sub 4/)/sub 2/, which will be formed from CuO in a combustion gas, is as efficient as CuO as a catalyst in NO decomposition. Based on the above reasons, we have been studying CuO containing materials as the sorbent/catalyst. In some of the materials, such as CuO supported in a matrix of a cement and mixed CuO and CaO, have shown that about 40% of the NO originally absorbed can be decomposed into N/sub 2/ in the regeneration step. We are now narrowing down the specific CuO containing sorbent which is best in fulfilling all the aforementioned requirements. 8 figures.« less