煤焦化过程中颗粒物和二氧化硫的释放

选择山西省某地的四个土焦炉、两个热回收焦炉和两个机焦炉开展焦炉顶空气和烟气中颗粒物和SO2研究。结果显示在正常工作条件下热回收焦炉顶空气中颗粒物和SO2浓度最小,其次是机焦炉,土焦炉顶最高。机焦炉和热回收焦炉顶污染物浓度在出焦和装煤时明显升高。土焦炉烟气中颗粒物排放浓度和排放速率明显高于热回收焦炉和机焦炉;各种炉型烟气中SO2浓度差别较小,排放速率以机焦炉最高;土焦炉的烟尘和二氧化硫吨焦排放量最高,而机焦炉和热回收焦炉由于环保设备的使用显著降低。生产过程污染物释放显示机焦炉和热回收焦炉的颗粒物和SO2释放主要来源于焦化过程和熄焦过程。由吨焦排放量估计炼焦烟尘和二氧化硫对全国的烟尘和二氧化硫排放贡献小于5%,但对山西省的贡献接近15%和30%,控制炼焦污染对当地环境改善具有重要意义。

EMISSIONS OF TSP AND SULFUR DIOXIDE (SO2) FROM COAL COKING PROCESS

Four indigenous beehive coke ovens(IBC),two heat recovery coke ovens(HRC) and two by-product recovery battery coke ovens(BRBC) in Shanxi Province were selected to investigate TSP and SO2 in stack and oventop air.The concentrations of TSP and SO2 in oventop air were lowest from HRC,followed by BRBC,and highest from IBC.They were obviously increased when charging coal and pushing hot coke for HRC and BRBC.In stack gas,the concentrations and emission rate of TSP were higher for IBC than for HRC or BRBC;the emission rate of SO2 was highest for BRBC,though SO2 concentrations from BRBC were comparable to those from IBC and HRC.The emission rates of SO2 and TSP per ton coke produced were highest in IBC,and much lower in HRC and BRBC for the use of dust catcher and desulfurizer.The emission of TSP and SO2 in HRC and BRBC was mainly from coking and quenching processes.The total emission of TSP and SO2 from coke production was also estimated based on the emission per ton coke produced and coke output.The calculation showed that coke production contributions are less than 5% of the total TSP and SO2 emission in China,but as much as 15% and 30% of TSP and SO2 in Shanxi Province,respectively,thus controlling the emission of pollutants from coke production is of great importance for the improvement of local environmental quality.