Regeneration Of The Sulfured CuO/Al₂O₃ Catalyst-Sorbents

Sulfur dioxide (SO2) and nitrogen oxides (NOx) from flue gas seriously polluted the environment, and the removal of the two pollutants is one of the important subjects for the development of economy and society in China. The regenerable CuO/Al2O3 catalysts show good activities for simultaneous removal of SO2 and NOx, the sulfured catalysts can be regenerated under the reductant gas atmosphere of NH3 and simplified the sulfur recovery process. This technology is considered to be one of the most effective means to remove SO2 and NOx from flue gas, however there still some problem exist in sulfur removal capacity and regeneration.Therefor, the attention of this work is to improve the regeneration of the catalysts and study the effect of the V2O5 on SCR activities and regeneration. A series of CuO/Al2O3 catalysts with different CuO loadings were prepared, regeneration of the catalysts with V2O5 addtive were also studied systematically. The main results are described in the following.(1) The catalysts with different Al2O3 carrier showed differtent SCR activities at 400℃because of the different interaction between the Cu2+ and the Al, O in the Al2O3. It is also found that V2O5 addtives can improve the SCR activities of the catalysts.(2) There are two different kinds of the Cu2+ exist on the suface of the carrier AI2O3, which result in different reduction temperature of the sulfured CuO/Al2O3 catalysts in 5vol%NH3/Ar. One has no interaction with the Al and has lower reduction temperature, another has the stronge interaction with the Al in the carrier Al2O3 and thus exhibite the higher reduction temperature. Thus two reduction peaks appeared during regeneration of the sulfured catalysts.(3) The catalysts prepaired with different Al2O3 have different reduction temperature in 5vol%NH3/Ar due to their suface property which effect the dispersion of CuO and the interaction between Cu2+ and Al. V2O5 addtives can inhibit over reduction of CUSO4 by NH3 in the regeneration process.(4) N2O is found during the regeneration process.