氮化物对柴油深度和超深度加氢脱硫的影响Ⅰ.氮化物含量的影响

氮化物和硫化物同时存在于柴油之中。采用硅胶脱除原料中氮化物，得到硫含量相同而氮含量不同的4种柴油原料。为了考察氮化物对加氢脱硫（HDS）的影响，在反应温度350℃、氢分压4．8MPa、液时空速2．0h^-1和氢／油体积比300的条件下，采用工业化的NiW／Al2O3催化剂在小型固定床实验装置上对该4种柴油原料进行加氢脱硫实验。结果表明，在真实油品的复杂体系中，氮化物对加氢脱硫反应有明显的抑制作用，加氢脱硫反应速率随着原料中氮含量的增加而降低。分子模拟计算结果表明，氮化物与硫化物在催化剂活性位上发生竞争吸附，氮化物的吸附能力较强，抑制了加氢脱硫反应。     

加氢脱硫催化剂中活性相单片层与Al-Si载体相互作用规律的分子模拟研究

Molecular mechanics and quantum mechanics simulations,as molecular simulation methods,were performed to investigate the effects of different surfaces,the promoter Co/Ni,the active phase of MoS2 or WS2,the content of Si and other factors on the order of interaction between the MoS2(WS2) single slab and the support surface.The influence of Si content was studied by molecular mechanics,and an advantageous Si content was found.Various surfaces,promoters and active phases also played an important role in the interaction between the support surfaces and active phases,and some significant trends were found out.Quantum mechanics simulation was performed to study the possible effect of electrostatic interaction between the support and the active phase,upon which the calculations suggested that the existence of a favorable Si content was possible.The electronic effects of Co/Ni promoter and the intensity of Co/Mo/Ni/W/Li/Al/Si species bonded to the alumina support were also investigated by quantum mechanics,and it was found that the different electronic effects of Co and Ni might bring forth some obvious influences on the interaction between the support and the active phase.And the results of comparing the intensity of Co/Mo/Ni/W/Li/Al/Si species bonded to the support can also explain the different interaction intensity in various catalyst systems.     

4,6-DMDBT在Co-Mo-S催化剂001表面物理吸附的分子模拟研究

利用分子模拟技术对4,6-二甲基二苯并噻吩（4,6-DMDBT）在Co-Mo-S加氢脱硫催化剂001表面物理吸附构象、吸附位置以及相应的吸附体系能量变化进行了考察;通过分子动力学方法研究了Co含量、温度对吸附强度、小分子扩散性能的影响,发现Co／（Co＋Mo）原子比在25％～28％之间的Co-Mo-S催化剂表面有利于4,6-DMDBT的物理吸附,且升高温度有利于小分子在催化剂边位吸附,从而部分抵消其空间位阻效应;并用量予力学方法研究了小分子与催化剂001表面的静电作用情况。     

氢分子在超深度加氢脱硫催化剂上吸附与解离

 本文应用量子力学计算方法研究了氢分子在超深度脱硫催化剂上吸附解离的化学过程，考察了特定催化剂簇结构模型的不同位置上H2解离的催化活性，发现活性与反应位之间有一定关系，催化剂边位的活性较高；H2在几种不同加氢脱硫催化剂上的反应热及能垒计算结果显示了几种不同催化剂体系对H2吸附解离反应的催化活性不同；对助剂在H2解离活化反应中的间接、直接作用也进行了比较。