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

研究了基于轻质油/水两相体系和轻质油/有机极性溶剂两相体系的光化学反应-液-液萃取轻质油深度脱硫工艺.轻质油/水两相体系深度脱硫二苯并噻吩（DBT）是轻质油中典型的难降解硫化物，萘对DBT的光化学反应有抑制作用。因此，开发了一种新的工艺，其中DBT通过使用三重态光敏剂（二苯甲酮）间接地光激发，通过过氧化氢氧化，然后去除到水相中。该工艺特别适用于芳烃含量较少的轻质商品油，48 h光照射（λ > 280 nm）可使硫含量从0.2 wt%降至0.05 wt%。设计了一套完整的脱硫工艺，包括过氧化氢溶液回收系统.轻油/有机非极性溶剂两相体系深度脱硫研究。在该体系中，DBT被萃取到乙腈中，并被光氧化成高度极化的硫化合物，该硫化合物不会再次分布到轻质油相中。工业轻油成功地脱硫到0.05wt%，然后到0.005wt%的硫含量。为了改进该工艺，引入了9，10-二氰基蒽（DCA）用于DBT的电子转移光敏氧化。在改进的工艺中，可见光（λ > 400 nm）可用于脱硫。对脱硫工艺进行了设计，并在实验室条件下进行了间歇操作评价。结果表明，工业轻油深度脱硫至硫含量为0.02wt%是成功的。

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.