Refineries process a number of gas oils such as straight run gas oil (SRGO), light cycle gas oil, coker gas oil and visbreaker gas oil for producing a common gas oil pool to be used as a transportation fuel. Considering stringent sulfur standards, new strategies and design modifications are being evaluated for desulfurization of these gas oils with minimum loss of oil during the desulfurization process. In this review, developments in solvent extractive desulfurization of gas oil have been discussed from both fundamental and applied point of views. Various performance indicators used for solvent evaluation/screening in computational and experimental studies are discussed. Particular emphasis has been given on latest developments in performance evaluation of organic and ionic liquid solvents for desulfurization of SRGO and other gas oils. Various possible designs of solvent recovery section to remove solvent from raffinate and extract phases for solvent recycling have been reviewed. Various potential options for the use of extract as high-quality secondary feedstock or co-products to improve the process economics have been reviewed from technical and economic thoughts. Finally, some research gaps are identified to work upon for stimulating the implementation of extractive desulfurization in industry.

精炼厂处理多种瓦斯油，例如直馏瓦斯油（SRGO），轻循环瓦斯油，焦化瓦斯油和减粘裂化瓦斯油，以生产用作运输燃料的普通瓦斯油池。考虑到严格的硫标准，正在评估这些瓦斯油的脱硫新策略和设计变更，同时在脱硫过程中油的损失最少。在这篇综述中，从基本和应用的观点讨论了瓦斯油的溶剂萃取脱硫的发展。讨论了用于计算和实验研究中溶剂评估/筛选的各种性能指标。特别强调了用于SRGO和其他粗柴油脱硫的有机和离子液体溶剂性能评估的最新进展。审查了溶剂回收段从萃余液和萃取相中除去溶剂的各种可能设计，以回收溶剂。从技术和经济思想出发，已经对使用提取物作为优质次要原料或副产品来改善工艺经济性的各种潜在选择进行了审查。最后，确定了一些研究空白以刺激工业中萃取脱硫的实施。