Product Name：CK-2 Catalyst for Hydrotreating of Cat-cracker Cycle Oil and Coking Gas Oil
Products：Clean diesel fuels require low sulfur and aromatics, up to now, most developed countries such as the United States, Europe and Japan request use of diesel fuels meeting European IV specification, i. e., the content of sulfur in diesel less than 50g/g. Hydrotreating process is the most effective technology for desulfurization and dearomatization of diesel fuels, meanwhile, the catalysts with high performance is the key technology for production of clean diesel fuels. Right now, common used commercial catalysts for hydrotreating of diesel fuels are Ni, Co, Mo, W sulfides supported on alumina.
CK-2 is a new generation of hydrotreating catalyst for production of clean diesel fuels developed by the Industrial Catalysis Laboratory(ICL) of China University of Petroleum, on the basis of deeply understanding and study on mechanisms of adsorptions and reactions of organic compounds, as well as on catalysis mechanisms of Ni, Co, Mo, W sulfides. Theoretical investigations indicate that the most difficult organic compounds to remove from gas oils are 4 and/or 4,6-alkyl dibenzothiophenes(DBTs). Alkyls in DBTs produce spatial hindrance, embarrassing the approach and adsorption of organic compound molecules on the active site of the catalyst, results low reactivity in hydrotreating of gas oils. Also, it is found from theoretical investigations that the active phases of Ni, Co, Mo, W sulfides for hydrogenation are layered stacks of MoS2 and WS2 nanoparticles, the appropriate stacks of MoS2 and WS2 nanoparticles are favorable to the approach and adsorption of organic compound molecules on the active site, as well as the formation of high active “Type II” active phases. It was found from our researches that the modification of alumina with the appropriate amount of acidic molecular sieve and phosphorus, in one hand, is favorable to increase isomerization activity of NiMo/Al2O3 catalyst, promoting transfer of alkyls in DBTs and reducing spatial hindrance, results the increase of reactivity for hydrodesulfurization. On the other hand, it is favorable to the appropriate stacks of MoS2 and WS2 nanoparticles, also results the increase of reactivity for hydrodesulfurization. It is instruction of above theories, ICL developed the high performance of NiMoP/HUSY-Al2O3 catalyst for the deep hydrotreating of distillate oils, i. e., CK-2 catalyst.
CK-2 catalyst could be applicable to the deep hydrotreating of distillate oils, especially inferior diesels, such as naphthene-base straight-run diesel with higher sufur content, coking diesel, FCC diesel or the mixture of the above diesels. The outflow products can be used as the blending component of high-quality diesel oil.
The catalyst was made up of support and the active components of molybdenum, nickel and phosphorus. The support of the catalyst is prepared by calcinating the mixture of pseudo-boehmite (purity > 70%) acquiring through alkoxy aluminum hydrolysis or carbonization and a small quantity of zeolite after caution exchange.
■The main physical and chemical specifications were indicated as follows:
■Excellent Performance of CK-2 Catalyst:
CK-2 catalyst shows excellent HDS, HDN and HDAr activity in hydrotreating process. Under the operation conditions with temperature 340~360°C, hydrogen pressure 6~8MPa, LHSV 1-2.0 h-1，H2/Oil 500/1 and RFCC light cycle oil as feedstock, the HDS ratio reach 99%, HDN ratio was 92%, the cetane number increment was 12-13 units, and the yield of diesel was more than 98%.
◆Characteristics of CK-2 catalyst：
●Ni-Mo-P supported in the large porous alumina modified with USY molecular sieve;
●Large pore volume and aperture, high specific surface area and crush intensity, low packing density；
●Excellent HDS, HDN and HDAr activities；
●Very suitable for hydrotreating of light cycle cat-cracker oil and coking gas oil；
●60 metric tons of CK-2 has finished successfully；
◆Industrial application of CK-2 catalyst was achieved at April 2009 in a 500,000 tons/year hydrotreating unit for coking gas oil in Dagang Petrochemical Company, Petrochina, successfully. The high HDS, HDN and HDAr activities were verified. The poor coking gas oil was hydrotreated to clean diesel fuels at mild reaction conditions: average bed temperature 330C，hydogen pressure of hydrogen 5.0MPa，LHSV 1.0h-1，H2/oil 300:1.
