Abstract:

The separation of aromatic and aliphatic hydrocarbons from straight-run naphtha is an important prerequisite for the optimal utilization of resources in the petrochemical industry. Solvent extraction and extractive distillation are commonly used separation methods. But traditional solvents usually have an upper limit of extraction capacity and the separation performance of low concentration aromatics is not ideal. Based on reversible π-complexation reaction, π-complexation extraction can realize the separation of mixtures. Bimetallic halides can directionally complex with aromatics, which breaks the limit of extraction capacity and achieves the purpose of highly selective separation of aromatics. The aromatics complexation extraction performance of a variety of bimetallic halides was investigated. It was found that CuAlCl₄ showed good complexation extraction performance for aromatics. The aromatics selectivity could reach 88.15, which was significantly better than the traditional solvents. The interaction forms and interaction energy between bimetallic halides and hydrocarbons were explored using molecular simulation based on the density functional theory. The results showed that π-complexation is the essential reason for the separation of aromatics. The study indicates that bimetallic halides can separate aromatics from naphtha with high selectivity.

Key words: bimetallic halide, aromatics, alkane, separation, molecular simulation

摘要：

直馏石脑油中芳烃和脂肪烃的分离是石化行业实现资源优化利用的重要前提，溶剂萃取以及萃取精馏是常用的分离手段，但传统溶剂通常存在萃取极限，对低浓度芳烃的分离效果不够理想。π络合萃取是一种基于可逆π络合反应实现混合物分离的技术，双金属卤化物能够定向络合芳烃，打破萃取极限，达到高选择性分离芳烃的目的。实验探究了多种双金属卤化物对芳烃的络合萃取性能，发现双金属卤化物CuAlCl₄具有良好的芳烃络合萃取性能，芳烃选择性可达88.15，明显优于传统溶剂。使用基于密度泛函理论的分子模拟手段探究双金属卤化物与烃类之间的相互作用形式及相互作用能，揭示了π络合作用是实现芳烃分离的本质原因，表明双金属卤化物能够高选择性地分离石脑油中芳烃。

关键词: 双金属卤化物, 芳烃, 烷烃, 分离, 分子模拟