Sulphur compounds naturally exist in crude oil and in the oil refinery, various fuel fractions distributed according to their boiling points. Diesel is a significant transportation fuel and made up of various refinery streams like straight run gas oil, light cycle oil, coker gas oil, etc. Light cycle oil (LCO) is rich in aromatics especially polyaromatics, e.g., alkylated naphthenes, etc. as well as refractory sulphur compounds e.g., dibenzothiophene etc. It may not be possible to reduce aromatics through hydrogenation and sulphur compounds through hydrodesulphurization. Both are expensive and releases more greenhouse gasses. Hence, alternative methods are gaining importance among which solvent extraction has attracted worldwide attention due to inherent advantages like mild reaction conditions and low cost.
In this article, LCO has been distilled up to and above 250°C fractions. Extraction of LCO 250°C+ fraction with solvents, aqueous NMP and nitro methane have been carried out using various solvent to feed ratio and achieved polyaromatics reduction from 23.0 % to < 5.0 % and low sulphur < 0.3wt%. Thus process avoids hydro treating step for meeting PAH specifications.

中文翻译：

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使用溶剂萃取路线升级轻循环油

硫化合物天然存在于原油和炼油厂中，各种燃料馏分根据其沸点分布。柴油是一种重要的运输燃料，由各种炼油厂物流组成，例如直馏瓦斯油，轻循环油，焦化瓦斯油等。轻循环油（LCO）富含芳烃，尤其是聚芳烃，例如烷基化环烷烃等。以及难处理的硫化合物，例如二苯并噻吩等。可能无法通过加氢还原芳族化合物，而无法通过加氢脱硫还原硫化合物。两者都很昂贵，并且会释放更多的温室气体。因此，替代方法变得越来越重要，其中溶剂提取由于其固有的优点，例如温和的反应条件和低成本而引起了全世界的关注。
在本文中，LCO的馏分高达250°C以上。使用各种溶剂与进料比，已使用溶剂，NMP水溶液和硝基甲烷萃取了250°C +的LCO，并实现了多芳烃从23.0％降低至<5.0％和低硫<0.3wt％的目标。因此该方法避免了满足PAH规格的加氢处理步骤。