在煤和煤矸石燃烧的过程中,许多重金属污染物排放到大气中,从而造成严重的环境问题,因此研究煤燃烧过程中重金属排放的环境效应很有必要。本研究运用ReCiPe2016软件计算了煤矸石和煤在330 MW煤粉炉、50 kW循环流化床和实验室燃烧时As和Pb排放的环境影响值。结果表明当煤在330 MW煤粉炉燃烧的时候,底渣、飞灰、烟气中的As排放对环境的影响值分别是3.28×10-6、2.68×10-5、3.89×10-3,底渣、飞灰、烟气中的Pb排放对环境的影响值分别是8.57×10-6、6.00×10-5、4.83×10-2。底渣中的As和Pb排放对环境的影响比飞灰中低;As和Pb排放到大气对环境的影响比排放到土壤高。另外,当煤在50 kW循环流化床燃烧的时候,飞灰中的As和Pb排放对环境的影响值分别是3.26×10-5和1.28×10-4,底渣中的As和Pb排放对环境的影响值分别是1.16×10-6和1.43×10-5。本文的研究结果还表明当煤矸石在实验室燃烧的时候,随着燃烧温度的升高,As和Pb排放对环境的影响值升高。另外,As和Pb排放到大气对环境的影响占总环境的影响比例比排放到土壤高。此项研究还表明当煤在煤粉炉和循环流化床燃烧的时候,相同工况下Pb排放对环境的影响比As高。这项结果也为运用生命周期影响评价软件预测煤矸石在循环流化床燃烧As和Pb排放的环境影响提供基础数据。

1 Methodology and variable description
2 Result and discussion
2.1 Emission characteristics of As and Pb during coal combustion in the 330 MW pulverized coal boiler
2.1.1 Content and relative mass distribution of As and Pb from the 330 MW pulverized coal boiler
2.1.2 Environmental effects of As and Pb emission during coal combustion in the 330 MW pulverized coal boiler
2.1.3 Migration path comparison of As and Pb during coal combustion in the 330 MW pulverized coal boiler
2.2 Emission characteristics of As and Pb during coal combustion in 50 kW circulated fluidized bed boiler
2.2.1 Content and relative mass distribution of As and Pb from 50 kW circulated fluidized bed boiler
2.2.2 Environmental effects of As and Pb emission during lignite combustion in the 50 kW circulated fluidized bed boiler
2.3 Environmental effects of As and Pb emission during coal gangue combustion in laboratory
2.3.1 Volatilization rates of As and Pb during coal gangue combustion in the laboratory
2.3.2 Environmental effects of As, Pb emission during coal gangue combustion
2.3.3 Migration path comparison of As and Pb during coal gangue combustion in laboratory
3 Conclusions