新型还原法脱除苯并噻吩有机硫  

Desulfurating Benzothiophene with New Reduction Method

作　　者：郭秀燕[1] 李术元[1] 岳长涛[1] 倪贤明[1] 

机构地区：[1]中国石油大学重质油国家重点实验室,北京102249

出　　处：《应用化学》2006年第9期982-987,共6页Chinese Journal of Applied Chemistry

基　　金：中国石油科技中青年创新基金(04E7030);中国石油大学重油开放基金(2004-0J)

摘　　要：研究了以硼氢化钾为还原剂的新型还原法脱除苯并噻吩有机硫。结果表明,CoC l2.6H2O适宜用量为0.50 g,溶剂CH3OH体积为20 mL,还原剂用量为0.40 g,苯并噻吩的正庚烷溶液硫含量由1.420×10-3g/g下降到1.75×10-4g/g,脱硫率可达88%,反应时间为20 m in,反应过程中温度应控制在15℃以下;气相中不含有H2S,被脱除的S元素保留在固相产物中。可能的反应机理为:在质子溶剂中,CoC l2与KBH4发生反应,生成活性黑色固体硼化钴和H2;还原脱硫过程为加氢脱硫机理,苯并噻吩的还原过程经由直接氢解和加氢2种路径完成;反应过程生成大量的初生态吸附在硼化钴表面并被活化,进一步转化成瞬时中间产物,该瞬时中间产物进攻苯并噻吩的不饱和键,或苯并噻吩通过S原子配位加合到该中间产物上,发生键的断裂反应。A new reductive protocol of desulfurization was developed to desulfurate benzothiophene with KBH4 as reductant. Experimentally, the appropriate masses of CoCl2· 6H2O and KBH4 were 0.50 g and 0.40 g, respectively; the volume of CH3OH was 20 mL, and the sulfur was reduced from 1. 420 × 10^-3 g/g to 1.75 × 10^-4 g/g, the desulfurization percentage was 88% ; the reaction time was 20 min; and temperature should be controled under 15 ℃ ; the sulfur obtained by desulfurating benzothiophene was retained in active cobalt boride formed during the reaction. The proposed mechanism is that the reduction reaction occurred between CoCl2·6H2O and the reductant in protic solvent, then black cobalt boride and H： were formed; the hydrogenation desulfurization mechanism was deduced according the product distribution, and the reduction of benzothio- phene was carried out through both the hy hydrogen was absorbed and activated on the surface of the active solid, and was further transformed into transient intermediateds,which attack the unsaturated bonds of benzothiophene and then led to the cleavage of C-S or C-C bond.

关 键 词：还原脱硫 苯并噻吩 反应条件 反应机理 

分 类 号：O643[理学—物理化学] TE626.2[理学—化学]