Development of Novel Desulfurization and Dmetallization Process for Light and Residue Oils using Photochemical Reaction and Liquid-Liquid Extraction

以轻质油/水两相体系和轻质油/有机极性溶剂两相体系为基础，研究了光化学反应和液-液萃取法对轻质油的深度脱硫工艺。轻质油/水两相系统深度脱硫研究二苯并噻吩（DBT）是轻质油中一种典型的难降解硫化合物，其光化学反应受到萘的抑制。因此，我们开发了一种新的工艺，利用三态光敏剂（二苯甲酮）间接光激发DBT，过氧化氢氧化，然后去除到水相。该工艺特别适用于芳香族化合物含量较低的商品轻质油，光照射48 h （λ > 280 nm）可使硫含量从0.2 wt%降至0.05 wt%。设计了含双氧水回收系统的整体脱硫工艺。轻质油/有机极性溶剂两相体系深度脱硫研究。在该系统中，DBT被提取到乙腈中，并被光氧化成高度极化的硫化合物，而硫化合物不会再次分布到轻油相中。将商品轻质油成功脱硫至0.05 wt%，再脱硫至0.005 wt%。为了改进工艺，引入9,10 -二氰蒽（DCA）进行DBT的电子转移光敏氧化。在改进的工艺中，可以利用可见光（λ > 400 nm）进行脱硫。设计了整体脱硫工艺，并在实验室规模上进行了间歇运行评价，结果表明，商品轻质油深度脱硫成功，硫含量达到0.02 wt%。

Deep desulfurization processes for light oil using photochemical reaction and liquid-liquid extraction, based on light oil/water two-phase system and light oil/organic polar solvent two-phase system, were investigated.1. Deep desulfurization of light oils using light oil/water two-phase system. Photochemical reaction of dibenzothiophene (DBT), a typical refractory sulfur compound in light oil, is suppressed by naphthalene. Thus, a new process was developed, where DBT was photoexcited indirectly by using triplet photosensitizer (benzophenone), oxidized by hydrogen peroxide, and then removed into the water phase. This process was especially applicable for commercial light oils in which aromatic compounds were less contained, and 48-h photoirradiation (λ > 280 nm) brought about a desulfurization from 0.2 wt% sulfur content to 0.05 wt%. An overall desulfurization process, containing recycling system for hydrogen peroxide solution, was designed.2. Deep desulfurization of light oils using light oil/organic apolar solvent two-phase system. In this system, DBT is extracted into acetonitrile and photooxidized to highly polarized sulfur compounds which does not distribute again into the light oil phase. Commercial light oil was successfully desulfurized to 0.05 wt% and then to 0.005 wt% sulfur content. In order to improve the process, 9, 10-dicyanoanthracene (DCA) was introduced for electron-transfer photosensitized oxidation of DBT. In the improved process, visible light (λ > 400 nm) could be utilized for the desulfurization. Overall desulfurization process was designed and evaluated by batch operation in laboratory scale, which showed that the deep desulfurization of commercial light oil to sulfur content of 0.02 wt% was successful.