Emissions of organic hazardous air pollutants during Chinese coal combustion

Abstract

This paper provides a general investigation of the emissions of organic hazardous air pollutants (HAPs) during the combustion of several typical Chinese coals. First, the distribution of four types of HAP, i.e., aliphatics, cyclic hydrocarbons, monoaromatic compounds and PAHs, in the CH 2Cl 2 extracts of six Chinese coals were studied and the influences of the extractive times and coal varieties were also evaluated. Second, the partitioning of these HAPs in the flue gas during coal combustion in a small-scale reactor were investigated, depending on oven temperatures (500 °C, 600 °C, 700 °C, 800 °C, 900 °C) and coal varieties. The behaviors of HAP in the combustion flue gas were compared with those in the CH 2Cl 2 extracts. Finally, combustion was conducted at given conditions in two laboratory-scale reactors: a fluidized bed and a fixed bed. Two coals (Shengmu bituminous coal and Xunhuan anthracite coal) and one coke were considered in this case. The HAP partitioning both in flue gases and in ashes were evaluated and compared between the two combustors.