【作者】 董振国；

【导师】 王军；

【作者基本信息】 南京工业大学 ， 化学工程， 2005， 硕士

【摘要】 随着环保要求的进一步提高,世界各国对柴油中硫含量的要求越来越严格。目前,催化加氢脱硫（HDS）技术仍是实现柴油低硫化的关键所在,各国学术界和工业界对开发新加氢催化剂及新型加氢反应器技术十分关注。HDS 过程的动力学不仅是研究各种硫化物在催化剂上加氢机理的重要手段、对指导新HDS 催化剂研制有重要意义,而且也是反应器开发和不同操作条件下脱硫率的预测及工艺优化的基础。本论文分别以柴油中难脱除的二苯并噻吩（DBT）为含硫模型化合物、喹啉为含氮模型化合物,在中压滴流床反应装置中研究了工业NiW/Al₂O₃催化剂RN-10上的加氢脱硫和加氢脱氮反应的动力学规律,详细考察了反应温度、氢分压、氢油比、液时空速等工艺条件对加氢反应结果的影响,同时研究了喹啉对DBT的HDS反应的抑制影响。系统探讨了直馏柴油（常二）、DCC柴油、FCC柴油、焦化柴油等四种油品的HDS动力学规律,并分别采用适当的动力学模型对上述几个反应过程得到的实验数据进行拟合。首先以DBT/十氢萘为模型体系,研究DBT 在RN-10 上的加氢反应规律,实验结果表明:当氢分压（>3.1 MPa）和氢油比（>500, v/v）较大时,两者变化对DBT的转化率基本无影响;温度对DBT 的转化率影响较大,提高温度可有效提高DBT的转化率,但随着温度的升高,DBT 转化率的增加趋势逐渐变缓。采用2 级平推流反应动力学模型对不同温度范围的实验数据进行了拟合,求得了表观反应速率常数,结果表明高温区DBT 的HDS 反应的表观活化能明显低于低温区的表观活化能,经检验模型拟合良好。以喹啉为含氮模型化合物的加氢脱氮动力学研究结果表明:反应温度和氢分压对喹啉的脱氮率影响较大,提高温度或增大氢分压均可有效提高喹啉的脱氮率;当氢分压和氢油比较大时,其变化对喹啉的脱氮率基本无影响。采用修正的n （n<1）级反应动力学模型对实验数据进行拟合,得到了反应的表观活化能为180.4 kJ/mol,反应级数为0.83。经检验,模型计算结果与实验结果能较好的吻更多还原

【Abstract】 More and more strict environment legislation limit the content of sulfur in diesel oil all over the world, which attracts attention of both researchers and refiners. Hydrodesulfurization （HDS） is still the key to produce the high quality fuel with low sulfur content. Development of novel catalyst and new reactor systems for HDS plays an important role in fuel hydrotreatment. Studies on kinetics of HDS are helpful to understand the mechanism of HDS over various catalysts, improve the design of HDS reactor, optimize the HDS process, and predict the sulfur content in product. In this thesis the kinetics of HDS of dibenzothiophene （DBT）, as the model compound for S-bearing organics, and the kinetics of hydrodenitrogenation （HDN） of quinoline, as the model compound for N-bearing organics, were studied over the commercial NiW/Al₂O₃ catalyst （RN-10） in a pressured trickle-bed reactor, respectively. The effect of reaction conditions, such as hydrogen partial pressure, reaction temperature, hydrogen/oil ratio and weight hourly space velocity on the catalytic behavior was investigated in detail. The influence of quinoline on HDS of DBT was also studied. HDS of various diesel oils, such as atmospheric distillation diesel, DCC, FCC and coking diesel oil were carried out under various kinds of reaction conditions. Different kinetic models were obtained on the basis of experimental data. The kinetics of HDS of DBT over the RN-10 catalyst was studied. The result showed that the hydrogen pressure and volume ratio of hydrogen/oil exerted little influence on the conversion of DBT at the high level of hydrogen pressures and volume ratios of hydrogen/oil. At low reaction temperatures, the conversion of DBT increased drastically with the increase of reaction temperature up to 330 ℃, while at high reaction temperatures it increased slowly. A kinetic model of HDS was established according to a second-order kinetic model at various reaction temperatures, and the parameters of the model were calculated. The correlation coefficient of the model was above 0.989. The apparent activation energy of the high reaction temperature region was less than that of the low temperature region, which was 13.4 and 121.4 kJ/mol, respectively. The kinetics of HDN of quinoline showed that the conversion of quinoline increased drastically with the increase of reaction temperature, and the hydrogen pressure also had a significant effect on HDN of quinoline. However, at the high hydrogen pressures and high volume ratios of hydrogen/oil, the conversion of quinoline was almost unaltered. Experimental data were fitted by a n-order （n<1） kinetic model at various reaction conditions, and kinetic parameters of the model were calculated. The apparent activation energy of 180.4 kJ/mol and the reaction order of 0.83 were achieved for this reaction. The experimental data were in good agreement with the model ones. In the presence of quinoline, which is considered as an inhibitor in HDS of DBT, the consumption kinetic model equation of DBT was studied at 0.5% （wt）, 1%, and 1.5% concentration of quinoline, respectively. The result showed that quinoline strongly inhibited HDS of DBT. With the increase of concentration of quinoline, the inhibition became strong, but the decreasing rate of DBT conversion reduced when the concentration of quinoline was above 1%. In HDS of DBT, the hydrogenation （HYD） route was inhibited by quinoline more severely than the direct desulfurization （DDS） route. Experimental data were fitted by a pseudo first-order kinetic model with adsorption constant of quinoline, and kinetic parameters of the model were calculated. The experimental data were in good agreement with the model ones. The kinetics of HDS of the four diesel oils, i.e., atmospheric distillation diesel oil, DCC, FCC and coking diesel oil, were investigated under various reaction conditions in detail, such as reaction temperature, pressure, volume ratio of hydrogen/oil and weight hourly space velocity. Experimental data were fitted by a BP artificial neural network kinetic model, and the content of sulfur in product was predicted by BP artificial neural network under other reaction conditions. The model result indicates that the order of oil physical properties influencing HDS of diesel oil is as the following: density > 90% distillation range> content of nitrogen > content of sulfur >viscosity, and the order of reactions conditions influencing HDS of diesel oil is as the following: reaction temperature > weight hourly space velocity > volume ratio of hydrogen/oil > reaction pressure. This model can precisely predict the content of sulfur in diesel oils after HDS.更多还原