Study On Ultra-fine Nickel Supported Catalysts Applied For Producing Odorless Kerosene

Special solvent oil in the type of odorless kerosene (named as odorless kerosene) is one of the most widely used hydrocarbon solvent oil in fine-chemical engineering due to its excellent properties of low toxicity and good stability. Generally, the foreign petroleum hydrocarbon solvent oils are almost no poison and smell because of their lower sulfur and aromatic content compared with the domestic ones. With the access to the WTO and the need of environment protection, the higher quality of this kind of solvent oil will be increasingly demanded. The special green solvent oils with high quality should be developed as soon as possible in our country to meet the strict environment protection laws, and then strengthen our competition in the world. This thesis will be focus on the R&D a new type catalyst suit for kerosene hydrogenation to produce high quality odorless kerosene, which is based on the before research work on the superfine nickel catalyst for benzene hydrogenation. Firstly, the source of smell in kerosene was investigated furtherly, and a reasonable method to determination the PONA content of kerosene was set up. The physical and chemical properties of catalyst precursors were characterized by BET, DTA-TG ,TPR , ICP ,etal techniques. Hydrofining procedures of kerosene were carried out in a fixed-bed semi-micro reactor. Aviation kerosene from Nanjing refinery plant was selected as feedstock and the optimal reaction conditions were obtained. At last, the experiment of narrow distillate cut was conducted to get the knowledge of their properties respectively and their different ability to hydrogenate.The result shows that the effect of dearomation on ZC type catalysts prepared by sol-gel method was deeply influenced by system pressure and LSHV due to their small and narrow pore diameter distribution .On the other hand , the reaction condition on KC catalyst was more moderate than that on ZC because of its proper pore structure . On the selected condition, the performance of dearomation on KC was better than the one of ZC, Whereas the rate of ring-opening is not improved, and its properties of heat resistance and oxygen regeneration are not satisfying. At last, it was found that the MKC type catalyst had the highest performance of dearomation and selective ring-opening in a wide reaction temperature and LSHV range even at low nickel content, due to its good surface properties , various pore distribution and superfine active component high dispersion, which is benefit for lessen the smell of kerosene and improving the quality of product.The performance of hydrodearomatization and ring-opening on the tested catalysts were investigated under the varied conditions. The best catalyst was then selected and the optional reaction condition was obtained. The temperature impulse and 200h life test showed that the selected catalyst (MKC) had higher themal resistance and stability than that of existing commercial catalyst . Under the optimal conditions the main properties of the hydrogenated oil formed was better than the one of ST-1 solvent oil.