Feiyue Gao, Chuncai Zhou, Zihao Wang, Weiwei Zhu, Xin Wang, Guijian Liu
School of Resources and Environmental Engineering, Hefei University of Technology, No. 193, Road Tunxi, Hefei 230009, China.
School of Resources and Environmental Engineering, Hefei University of Technology, No. 193, Road Tunxi, Hefei 230009, China.
J Environ Manage. 2023 Jul 1;337:117679. doi: 10.1016/j.jenvman.2023.117679. Epub 2023 Mar 17.
Coal tar residue (CTR) is acknowledged as hazardous industrial waste with high contents of carbon and toxic polycyclic aromatic hydrocarbons (PAHs). Microwave-assisted extraction for separating tar and residue in CTR was investigated to reduce the content of PAHs. The key operating factors such as solvent type, solvent addition amount, radiation temperature, and radiation time in the extraction process were evaluated. Results showed that extreme extraction performance in the solvent with cyclic structure was attained, and an enhancement in extraction efficiency was achieved in elevated solvent addition amount, radiation temperature, or radiation time in a certain range. The optimized conditions were determined as benzene was chosen as extractant, solvent-solid ratio of 5:1 mL/g, radiation temperature of 75 °C, and radiation time of 10 min. Relative extraction efficiency of CTR and reduction efficiency of 16 priority control PAHs were 28.70% and 92.82%, respectively. According to the characterizations of extracted residue (MCTR) and tar (MCT) under optimum experimental conditions, it is possible to convert them into value-added products (carbon materials, solid fuels, or chemicals). Solid-oil separation via microwave-assisted extraction is a safe and high-valued utilization approach for CTR.
煤焦油残渣（CTR）被认为是一种危险的工业废物，含有高含量的碳和有毒的多环芳烃（PAHs）。为了降低多环芳烃的含量，研究了微波辅助萃取法分离CTR中的焦油和残渣。对萃取过程中的关键操作因素，如溶剂类型、溶剂添加量、辐射温度和辐射时间进行了评估。结果表明，在具有环状结构的溶剂中获得了极佳的萃取性能，在一定范围内增加溶剂添加量、辐射温度或辐射时间可提高萃取效率。确定的优化条件为：选择苯作为萃取剂，溶剂与固体的比例为5:1 mL/g，辐射温度为75℃，辐射时间为10分钟。CTR的相对萃取效率和16种优先控制多环芳烃的降低效率分别为28.70%和92.82%。根据最佳实验条件下萃取残渣（MCTR）和焦油（MCT）的特性，有可能将它们转化为增值产品（碳材料、固体燃料或化学品）。通过微波辅助萃取进行固油分离是一种安全且高价值的CTR利用方法。
