典型钢铁企业挥发性有机物排放量测算及组分特征

选取涵盖钢铁炼制全流程的典型企业，综合采用不同核算方法估算比较了该企业挥发性有机物（VOCs）排放结果；并在此基础之上，通过氟聚化合物气袋、SUMMA罐采样及气相色谱质谱联用仪（GC-FID/MS）分析方法，对烧结、焦化、热轧和冷轧等工序废气中VOCs浓度水平及排放特征进行监测.结果表明，整个厂区VOCs年排放量为430.82t，其中工艺有组织排放占66.0%，储罐18.5%；烧结机头和焦炉推焦排放口VOCs及非甲烷总烃（NMHC）浓度高于其他点位；各工序排放的芳香烃占比较高，其中焦化装煤除尘和焦炉推焦排放口芳香烃占90%以上；烧结工序CS₂占比最高（36.6%），其次为苯和甲苯；焦化工序占比靠前的物种为1，2，4-三甲基苯、邻甲乙苯、1，4-二乙基苯、1，2，3-三甲基苯和1，3，5-三甲基苯等；热轧工序与其他工序有一定区别，车间无组织排放芳香烃和烷烃占比均在35%左右，排放靠前的物种除芳香烃外还有高碳烷烃，如十一烷、十二烷和正丁烷等；冷轧工序有组织和无组织排放主要物种较为类似，均为芳香烃物种，如乙基苯、间/对二甲苯、甲苯、苯和邻二甲苯.不同工艺环节排放物种存在一定差异，但主要以焦化副产物（芳香烃）和烧结燃烧产物（CS₂）为主，建议钢铁行业有针对性地加强浓度高、活性高和毒性大的组分控制.

Emission estimation and component characteristics of volatile organic compounds in typical iron and steel enterprise

This research was performed in a typical steelmaking enterprise, which contained entire process of steel refining. Different methods were applied to estimate the VOCs emission account and the VOCs exhaust concentrations derived from sintering, coking, hot rolling and cold rolling processes were detected by using Teflon/SUMMA canister+GC-FID/MS. The annual VOC emissions from this enterprise were 430.82t in total, 66.0% from controlled emission, and 18.5% from storage tanks. The VOCs concentrations from sintering head and coke pushing outlet were higher than other places. The aromatic hydrocarbons in each process account for a relatively high proportion, which contributed more than 90% in the controlled emission of coking process. The CS₂ exhaust in sintering process was the highest (36.6%), followed by benzene and toluene. The main VOC species in the coking process were 1,2,4-trimethylbenzene, o-ethylbenzene, 1,4-diethylbenzene, 1,2,3-trimethylbenzene and 1,3,5-trimethylbenzene. There were some differences between the hot rolling process and other processes. Aromatics and alkanes emitted from the workshop uncontrolled sources accounted for around 35% respectively. Except the aromatics, high-carbon alkanes such as undecane, dodecane and n-butane were also high emission species. The main VOC species emitted from cold rolling process were similar in controlled and uncontrolled sources, much of them were aromatics, such as ethylbenzene, m-xylene, toluene, benzene and o-xylene. Although, there were some different VOC species detected from different processes, but the main emissions were though coking (aromatic hydrocarbons) and sintering (CS₂). Therefore, we suggested that the high concentration, high activity and high toxicity VOCs should be well controlled in steel manufacturing industry.