Abstract:

Solvent extraction is widely used in the petrochemical industry, which is a powerful technology for the separation and purification of petroleum and petrochemical products. Ionic liquids, as a new type of separation medium, have attracted great attention in recent years, especially in oil extraction and separation due to their advantages such as designable structure, high chemical and thermal stability, and very low vapor pressure. In this paper, the properties and classification of ionic liquids are introduced firstly. Secondly, according to different separation objectives, the latest progress of ionic liquids in the fields of aromatics separation from saturated hydrocarbons, desulfurization and denitrification, separation of olefins from paraffins is summarized. The existing problems and future development directions of ionic liquids in oil separation are discussed. The chain of cationic sides and polarity are the key factors affecting the extraction efficiency of aromatic hydrocarbons. However, the separation of aromatics form saturated hydrocarbons in the real oils needs further study. Ionic liquids show a strong ability to separate heteroatomic sulfur and nitrogen compounds, but it is difficult to remove basic nitrogen and non-basic nitrogen compounds simultaneously by using the same ionic liquid. The alkalinity of hydrogen bond is a key factor affecting the separation of olefins by ionic liquids. However, most ionic liquids have low selectivity to olefins. According to different separation tasks, it is important to understand the relationship between the structure of ionic liquids and their separation performance at molecular level, and then design new ionic liquids with high separation efficiency and low environmental impact, which will maximize the utilization value of the key components in oil.

Key words: ionic liquids, solvent extraction, separation, aromatics, desulfurization and denitrification, olefins, intermolecular interaction, petroleum

摘要：

溶剂萃取分离技术广泛应用于石油化工领域，为石油石化产品的分离和提纯生产提供了有力的技术支撑。离子液体的结构可设计性、化学稳定性和热稳定性、极低的蒸气压等优点，使其在烃类化合物分离领域受到了研究者广泛关注。本文首先介绍了离子液体的性质及分类，根据分离目标不同，归纳了离子液体在芳烃-饱和烃分离、脱硫脱氮、烯烃-烷烃分离领域取得的最新进展，探讨了离子液体在油品分离领域研究中存在的问题和未来发展方向。文中指出：阳离子烷基侧链和极性是影响其对芳烃萃取效果的关键因素，然而对实际体系芳烃-饱和烃分离还有待进一步研究；离子液体对杂原子含硫含氮化合物均表现出较强的分离能力，但是碱性氮化物和非碱性氮化物不易通过一种离子液体同时脱除；氢键碱性是影响离子液体分离烯烃的关键因素，然而大部分离子液体对烯烃选择性仍然不高。根据不同的分离任务，从分子水平上认识离子液体结构与分离效果的关系，进而设计出兼具高效分离能力和低环境影响的新型离子液体，对提升油品中关键组分的高附加值转化利用具有重要意义。

关键词: 离子液体, 溶剂萃取, 分离, 芳烃, 脱硫脱氮, 烯烃, 分子间相互作用, 石油