1-十六烯烷基化降低煤沥青中毒性多环芳烃含量的研究

Alkylation of 1-hexadecene on Reducing Toxic Polycyclic Aromatic Hydrocarbons Content in Coal-tar Pitch

因含烷基的芳烃特别是被长链烷基取代的芳烃,其潜在毒性显著降低,尝试用傅-克烷基化反应来转化煤沥青中的毒性多环芳烃(PAHs).选用蒽作为多环芳烃模型化合物来研究其烷基化反应条件,从5种烷基化剂和6种催化剂中分别筛选出1-十六烯和磷钨酸,优化反应温度为170℃,反应时间为2h,蒽的转化率达到100%,烷基蒽收率为35.46%.与煤沥青的反应表明:US EPA优先监控的16种多环芳烃总含量降低37.88%,利用Wiles毒性当量因子计算得到苯并[a]芘等量毒性降低率为45.97%.FTIR表征发现,改性后的沥青滤液中多环芳烃发生了烷基取代反应;TG表征说明改性后残渣结焦率上升,热稳定性提高.

Friedel-crafts alkylation was tried to reduce the content of toxic polycyclic aromatic hydrocarbons（PAHs）in coal-tar pitch（CTP）,because the potential toxicity of alkyl aromatic compounds,especially the long chain alkyl substituted aromatics,dropped down dramatically.Anthracene,as a model compound of PAH,was used to investigate the reaction conditions of alkylation.From 5 kinds of alkylation agents and 6 kinds of catalysts,1-hexadecene and phosphotungstic acid are screened in alkylation of anthracene.The optimized reaction conditions are obtained as follows：the reaction temperature is 170 ℃,the reaction time is 2 h,and the anthracene conversion reaches 100%,the alkyl-anthracenes yield is 35.46%.The reaction with CTP shows that the content of the 16 kinds of US EPA priority PAHs is reduced by 37.88%,and the reduction rate of BaP equivalent calculated by Wiles toxic equivalence factor is 45.97%.The filtrate of modified CTP characterized by FTIR shows that PAHs have been substituted by alkyl groups,and TG analysis shows that the coking rate and thermal stability of the modified CTP residue both have gone up synchronously.