进出口煤炭环保评估体系的构建及实例分析

Construction of environmental protection assessment system and example analysis for imported and exported coal

为有效化解煤炭贸易技术堡垒,科学评估进出口煤炭的环保性,以华北某电厂燃煤为例,探讨了进出口煤炭环保评估体系的构建方法。选取水、大气、土壤三大环境要素为评估对象,构建了系统层、指标层和指数层的3层指标体系,初步研究了各个系统层的评价分值的计算方法及其权重值的确定方法,并根据三大环境要素的总评价分值对煤炭环保等级进行了划分。实例计算结果表明,该电厂燃煤总评价分值为2.5,环保等级为Ⅴ级,即煤炭对环境的有害影响非常大。

For effectively breaking the coal trade technology barrier, as well as providing scientific assessment on the environmental-friendly properties of the imported and exported coal, the construction method of environmental protection assessment system for imported and exported coal was explored by taking the coal from one of the power plant in North China as sample. Three major environmental factors including air, water and soil have been taken as the assessment objects and a 3-layer indicator system-system layer, indicator layer and index layer was built. The calculation method of the assessment value for each system layer and the determination method of their weights values were studied. The environmental protection grades of the coal were also defined according to the total assessment value of these three environment factors. The calculated results of the sample showed that, the emission concentration of soot （ 60 mg/m^3） exceeded the emission standard （50 mg/m^3, GB 13223-2003）. However, the emission concentration of SO2（220 mg/m^3） was still within the emission standard （400 mg/m^3, GB 13223--2003）. The trace elements in the coal severely bring pollution to the atmosphere. The volatilities of F, Hg, Se, Cl in the coal were strong and all of the pollution indices of F, Hg, Se, Cr, Be were bigger than 3. The leaching rates of the Hg and As in the coal and bottom ash were higher, and the presence of Hg in the coal and bottom ash, whose pollution index was 3.18 and 1.83 respectively polluted the water environment severely The enrichment of Cd and Hg in the soil was considerably significant. In addition, the presence of element Cd with index as high as 5.9 has polluted the solid environment severely. The assessment values of atmospheric system layer, water system layer and solid system layer were 2.27, 2.17 and 4.26 respectively. The total assessment value of the coal in this plant was 2.5 and its environmental protection grade was classified as V, which indicated that the coal did bring great impact to the environment.