木醋调质石灰石用于O2/CO2燃煤同时脱硫脱硝性能

采用管式炉和沉降炉分别研究了O₂/CO₂气氛下燃煤预混和烟气喷入木醋调质石灰石的同时脱硫脱硝性能。结果表明,在温度1 173~1 323 K、钙硫比为2.0的条件下,木醋调质石灰石混煤燃烧脱硫效率91.0%~94.9%、脱硝效率23.5%~30.8%。随着钙硫比的增加,木醋调质石灰石混煤燃烧脱硫脱硝效率增大,适宜的钙硫比为1.5~2.0。相同的燃烧温度和钙硫比,含硫量高的煤预混木醋调质石灰石燃烧获得较高的脱硫、脱硝效率。木醋调质石灰石用于O₂/CO₂燃煤脱硫脱硝性能优于醋酸钙。O₂/CO₂燃煤烟气中喷入木醋调质石灰石、钙硫比为2.0、停留时间为0.8 s、在1 223和1 323 K时获得最大脱硫效率和最大脱硝效率为75.8%和86.6%。在上述条件下将氨气喷入反应区,氨氮比为0.75、温度为1 223和1 323 K时,脱硫效率分别为73.2%和63.9%,脱硝效率分别为93.2%和94.8%。

Performance of simultaneous desulfurization and denitration using limestone modified by wood vinegar in O2/CO2 coal combustion

The performance of simultaneous desulfurization and denitration during coal combustion in O₂/CO₂ atmosphere with premixed and injected limestone modified by wood vinegar (LMWV) was investigated in a tube furnace and a drop tube furnace, respectively. The SO₂ and NO reduction efficiency are 91.0%~94.9% and 23.5%~30.8% respectively during the combustion of coal premixed with LMWV at 1 173 ~ 1 323 K at the Ca/S molar ratio of 2.0. The desulfurization and denitration rates increase with raising the Ca/S molar ratio, and the optimum Ca/S molar ratio is from 1.5 to 2.0. The higher the sulfur content of coal, the greater desulfurization and denitration rates are gained during coal combustion. The performance of desulfurization and denitration with LMWV is better than that with calcium acetate. The maximum desulfurization and denitration rates of 75.8% and 86.6% respectively are gained by injecting LMWV directly into the flue gas of O₂/CO₂ coal combustion at both 1 223 K and 1 323 K and the Ca/S molar ratio of 2.0 with a residence time of 0.8 s. When the ammonia is injected into the reactive zone at NH₃]/NO] molar ratio of 0.75, the desulfurization rates are 73.2% and 63.9%, and the denitration rates are 93.2% and 94.8%, respectively at the combustion temperature of 1 223 K and 1 323 K.