银基活性炭对废轮胎热解油的吸附脱硫机理研究

废轮胎经热解制备得到热解油和热解炭，热解炭活化制得活性炭，并利用Ag⁺对活性炭进行改性制得Ag⁺改性活性炭（Ag/AC），将Ag/AC用于热解油的吸附脱硫实验，并利用GC/MS对热解油中的含硫化合物进行了分析。研究结果表明：活性炭吸附脱硫的合适温度和时间分别为20℃和12 h，此时未改性活性炭的脱硫率为15.33%；而Ag/AC的脱硫率提高到了38.6%。GC/MS分析发现热解油中有机硫的主要存在形式为噻吩、2-甲基噻吩、苯并噻吩、二苯并噻吩和4，6-二甲基二苯并噻吩，其中二苯并噻吩（DBT）的GC含量最高，为2.57%。利用原位红外、核磁共振氢谱、ICP-OES和元素分析等检测手段，进一步探究了Ag⁺与二苯并噻吩模型化合物在溶液中的反应机理，研究发现：二苯并噻吩分子上存在S原子和苯环2个反应位点，当Ag⁺加入二苯并噻吩溶液后，Ag⁺与二苯并噻吩分子上的S原子或者苯环发生配位数为1的配位反应生成2种配合物，分子式分别为Ag（D_S）NO₃和Ag（D_C6H6）NO₃。

Adsorption Desulfurization Mechanism of Waste Tire Pyrolysis Oil by Ag+ Based Activated Carbon

Pyrolysis oil and pyrocarbon were prepared from waste tires by pyrolysis. Activated carbon was prepared by activation of pyrocarbon. Ag⁺ modified activated carbon (Ag/AC) was prepared by modifying activated carbon with Ag⁺. Ag/AC was used for adsorption desulfurization of pyrolysis oil. The sulfur compounds in pyrolysis oil were analyzed by GC/MS.The results show that the appropriate temperature and time for adsorption desulfurization of activated carbon were 20 ℃ and 12 h respectively, and the desulfurization rate of unmodified activated carbon was 15.33%, while that of Ag/AC was 38.6%. GC/MS analysis showed that thiophene, 2-methylthiophene, benzothiophene, dibenzothiophene and 4, 6-dimethyldibenzothiophene were the main forms of organic sulfur in the pyrolysis oil, and dibenzothiophene (DBT) had the highest content of 2.57%. The reaction mechanism of Ag⁺ and dibenzothiophene in solution was further explored based on in situ FT-IR, ¹H NMR, ICP-OES and elemental analysis. The results showed that there were two reaction sites on dibenzothiophene molecule: S atom and benzene ring. When Ag⁺ was added into the dibenzothiophene solution, a coordination reaction occured between the Ag⁺ and S atom or the benzene ring on the dibenzothiophene molecule with the coordination number of 1. Two kinds of complexes might be generated during the complexation reaction, and the molecular formulas were Ag(D_S)NO₃ and/or Ag(D_C6H6)NO₃.