燃煤机组非常规污染物排放及减排效果研究

Study on unconventional pollutants emission and removal from coal-fired units

采用异丙醇吸收法、安大略法、旋风分离法和EPA Method 202法对3台燃煤机组的SO_(3)、Hg、PM_(2.5)、可凝结颗粒物(CPM)等非常规污染物开展测试,研究超低排放燃煤机组非常规污染物排放水平和脱除效果。结果表明:SO_(3)排放质量浓度为1.91~2.50 mg/m^(3),总脱除效率为87.0%~92.9%,ESP对SO_(3)脱除效率为24.4%~66.4%,FGD为65.9%~70.5%,WESP为52.8%,烟气冷却器为38.1%。Hg主要以Hg^(0)的形式排放,Hg^(T)排放质量浓度为1.06~1.59μg/m^(3),Hg^(T)脱除效率为67.9%~88.7%,其中ESP主要脱除Hg^(p)和Hg^(2+),Hg^(T)脱除效率为24.6%~33.3%,FGD主要脱除Hg^(2+),Hg^(T)脱除效率为52.6%~63.1%,WESP的Hg^(T)脱除效率为59.2%,烟气冷却器Hg^(T)脱除效率为29.2%。PM_(2.5)排放质量浓度为0.99~1.79 mg/m^(3),总脱除效率为99.69%~99.88%,其中ESP对PM_(2.5)的脱除效率为99.00%~99.53%,从FGD入口到烟囱排口PM_(2.5)脱除效率为68.82%~74.02%。CPM排放量占TPM总量的53.7%~83.3%,排放质量浓度为1.65~6.87 mg/m^(3),经烟气冷却及再热后脱除效率为31.53%~77.45%。

The tests were carried out by the isopropyl alcohol absorption method,Ontario method,cyclone separation method and EPA Method 202 method on the non-conventional pollutants such as SO_(3),Hg,PM_(2.5)and condensable particulate matter(CPM)from three coalfired units to study the emission levels and removal effects of non-conventional pollutants from ultra-low emission coal-fired units.The results show that SO_(3)emission concentration is 1.91-2.50 mg/m^(3),total removal efficiency is 87.0%-92.9%,among which the removal efficiency of ESP for SO_(3)is 24.4%-66.4%,FGD is 65.9%-70.5%,WESP is 52.8%,and flue gas cooler is 38.1%.Hg is mainly emitted in the form of Hg^(0),Hg^(T)emission concentration is 1.06-1.59μg/m^(3),Hg^(T)removal efficiency is 67.9%-88.7%,where ESP mainly removes Hg^(p)and Hg^(2+),Hg^(T)removal efficiency is 24.6%-33.3%,FGD mainly removes Hg^(2+),Hg^(T)removal efficiency is 52.6%-63.1%,Hg^(T)removal efficiency of WESP is 59.2%.PM_(2.5)emission concentration is 0.99-1.79 mg/m^(3),the total removal efficiency is 99.69%-99.88%,among which the removal efficiency of ESP for PM_(2.5)is 99.00%-99.53%,and the PM_(2.5)removal efficiency from FGD inlet to stack outlet is 68.82%-74.02%.CPM emissions accounted for 53.7%-83.3%of the total TPM,with emission concentrations of 1.65-6.87 mg/m^(3),and removal efficiencies of 31.53%-77.45%after flue gas cooling and reheating.