Low N 2 O, NO and SO 2 emissions from circulating fluidized bed boilers

摘要: A new method, reversed staging, for decreasing N 2 O without increasing the emission of other pollutants, NO x and SO , was investigated in 12 MW circulating fluidized bed boiler at Chalmers University Technology. It possible to reduce one fourth (25 ppm), half (about 40 ppm) compared normal staging temperature, significantly affecting sulphur capture efficiency 90%). Air which is normally used boilers means that only a part combustion air, primary added bottom zone, resulting lower oxygen concentration part, while secondary air results more oxidizing conditions upper chamber cyclone. The principal idea reverse top bottom, i.e. decrease increase it part. Such reversal accomplished by adding corresponding an ratio approximately unity. No will be low final cyclone outlet.