关中地区典型煤化工行业VOCs排放系数与特征研究

Study on VOCs emission factor and characteristics of typical coal chemical industry in Guanzhong area

基于关中地区大气挥发性有机物(VOCs)排放清单,选取炼焦和煤制烯烃2个典型企业采集VOCs样品,核算其有组织、无组织排放量,结合工况核算其排放系数,分析其排放特征。结果表明:100万t/a炼焦企业VOCs总排放量为659.17 t/a,吨焦炭排放系数为0.659 kg/t;其VOCs各排放源主要组分分别是焦炉烟囱为乙烯、苯,装煤、出焦地面站为萘、乙烯,焦炉炉体表面为苯、丙烯类,化产区无组织废气为1-己烯、醛类物质,储罐区无组织废气为苯、1-己烯等物质。180万t/a煤制甲醇、60万t/a甲醇制烯烃煤化工企业VOCs总排放量平均为821.08 t/a,其中煤制甲醇过程排放量为692.41 t/a,甲醇制烯烃过程排放量128.67 t/a;煤制甲醇过程中吨甲醇VOCs排放系数为0.385 kg/t,甲醇制烯烃过程中吨烯烃VOCs排放系数为0.215 kg/t;其VOCs各排放源主要组分分别是低温甲醇洗放空气为甲醇,聚丙烯造粒废气为四氢呋喃、烷烃类,硫回收尾气焚烧炉烟气为反-2-丁烯、甲醇等,磨煤工段为丙酮、正丁醛等物质,MTO废水储罐主要为1-己烯,废碱液池主要是甲醇。

Based on the emission list of volatile organic compounds(VOCs)in Guanzhong area,two typical enterprises,coking and coal-to-olefin,were selected to collect VOCs samples,calculating their organized and unorganized emissions.Combined with the working conditions,their emission factors were calculated and emission characteristics were analyzed.The results showed that:the total VOCs emission of 1 million t/a coking enterprise was 659.17 t/a,and the emission factor was 0.659 kg/t coke.The main VOCs compositions from each emission source were ethylene and benzene in coke oven chimney,naphthalene and ethylene in coal charging and coke discharging ground stations,benzene and propylene on the surface of coke oven body.The unorganized waste gas in the chemical production area was mainly 1-hexene and aldehydes,and the unorganized waste gas in the storage tank area was mainly benzene,1-hexene and other substances.The total emission of VOCs in coal chemical enterprises of 1.8 million t/a coal to methanol and 600,000 t/a methanol to olefin was 821.08 t/a on average.Among them,the emission from coal to methanol was 692.41 t/a,and the emission from methanol to olefin was 128.67 t/a,the emission factor of VOCs from coal to methanol was 0.385 kg/t methanol,and that from methanol to olefin was 0.215 kg/t olefin.The main VOCs compositions from each emission source were as follows:the vent gas in rectisol was methanol,the polypropylene granulation waste gas was tetrahydrofuran and alkanes,the flue gas from sulfur recovery tail gas incinerator was trans-2-butene and methanol,acetone and n-butyraldehyde in coal grinding section,mainly 1-hexene in MTO wastewater storage tank,and mainly methanol.