超低排放典型燃烧源颗粒物及水溶性离子排放水平与特征

研究以自行开发建立的超低排放高湿废气中总颗粒物(total particulate matter,TPM)的直接冷凝采样系统及监测方法,应用于3台北京市超低排放典型燃烧源烟气中颗粒物的排放监测.分析和评估超低排放典型燃烧源排气中颗粒物及其水溶性离子的排放水平与组成特征,探究可过滤颗粒物(filterable parti...

Emission Concentration and Characteristics of Particulate Matter and Water-Soluble Ions in Exhaust Gas of Typical Combustion Sources with Ultra-Low Emission

A self-developed direct condensation sampling system and monitoring method for total particulate matter (TPM) in ultra-low-emission and high-humidity exhaust gas were applied to the emission monitoring of particulate matter in flue gas from three typical combustion sources with ultra-low emissions in Beijing. The emission levels and composition characteristics of particulate matter and water-soluble ions in the exhaust gas of typical combustion sources with ultra-low emissions were analyzed and evaluated. The interaction and influencing factors of filterable particulate matter (FPM) and condensable particulate matter (CPM) and their water-soluble ions were explored. The results showed that the emission concentration of FPM in the exhaust gas of the coal-fired boiler with ultra-low emissions was between 1.04 mg·m^-3 and 1.11 mg·m^-3 in standard smoke oxygen content, and that of TPM was between 3.82 mg·m^-3 and 8.69 mg·m^-3, which all met the national ultra-low emission limit (10 mg·m^-3). However, the TPM emission concentration of the coal-fired power plant exceeded the emission limit of Beijing (5 mg·m^-3). The emission concentrations of CPM and its total water-soluble ions from the coal-fired heating boiler were 3.05 mg·m^-3 and 1.30 mg·m^-3, respectively, which were significantly lower than those of the coal-fired power plant, and were related to the higher load and flue gas temperature of the coal-fired power plant. Furthermore, the emission concentrations of CPM and its total water-soluble ions from the coal-fired power plant boiler were 2.2 to 2.4 times and 1.7 to 2.2 times greater than those of the coal-fired heating boiler, respectively. The emission concentrations of TPM and its total water-soluble ions from the gas power plant were 1.99 mg·m^-3 and 1.44 mg·m^-3, respectively, which were significantly lower than those from the coal-fired boiler. CPM was the main form of particulate matter in the exhaust gas of the combustion source. The contribution of CPM to TPM in the ultra-low-emission boiler flue gas increased significantly, and increased with the increase in the flue gas temperature, ranging from 72.6% to 88.1% for the coal-fired boiler and 93.1% for the gas power plant. Total water-soluble ions made up 66.1% to 94.2% of the CPM. The flue gas temperature had a significant impact on the existing forms, removal efficiencies, and emission concentrations of particulate matter and water-soluble ions. SO₄^2- was the main characteristic water-soluble ion of particulate matter in the coal-fired boiler, and its emission concentration ranged from 0.98 mg·m^-3 to 1.18 mg·m^-3, accounting for 27.7% to 49.6% of the total water-soluble ion emissions, which originated from flue gas desulfurization. F^- was another characteristic water-soluble ion of particulate matter in the coal-fired power plant, and its emission concentration ranged from 1.91 mg·m^-3 to 2.32 mg·m^-3, accounting for 54.4% to 56.1% of the total water-soluble ion emissions, which might have been related to the high F content of fuel coal. NH₄⁺ was the main characteristic water-soluble ion of particulate matter in the gas power plant, and its emission concentration was 0.92 mg·m^-3, accounting for 64.2% of the total water-soluble ion emissions, which originated from the escape of NH₃ in the process of selective catalytic reduction. The emission concentration of NH₄⁺ was significantly higher than that of the coal-fired boiler; this might have been related to the synergistic removal effect of the gas-fired power plant, which lacked other purification facilities.