This project involves high viscosity index PAO base oil and its preparation method. PAO is an energy-saving, environmentally friendly and high-quality base oil, and is a "priority theme" of the National Development and Reform Commission's "10th Five-Year Plan","Eleventh Five-Year Plan" and "Twelfth Five-Year Plan".
This project adopts catalyst molecular design and structure control methods to adjust the spatial effect and electronic effect of the active center of the Cr catalyst through the volume, electron supply, substituent and ligand compounding technology of P and N-containing ligands to achieve high selectivity and high activity preparation of advanced alpha-olefins; carrier modification and doping technology are used to control the acid strength, active species structure and PAO molecular structure of the catalyst, and the performance of PAO base oil is improved through the synergistic effect of catalyst design and oligomerization process; A high viscosity index PAO base oil with controllable molecular structure, composition and customizable viscosity was prepared.

1. Preparation technology for efficient ethylene oligomerization catalysts. In view of the lack of high selectivity in the preparation of higher alpha-olefins, this technology designed and synthesized new ligands containing P and N. The spatial effects and electronic effects of the active center of the Cr catalyst are adjusted through ligand volume, electron donation, substituent groups and ligand composite technology, revealing the influence laws of the steric hindrance and electronic effects of the active center on the activity and selectivity of the catalyst. Selecting P-and N-containing ligands with large volume, strong electron donating ability, and small steric hindrance of the substituent on N can effectively improve the selectivity of octene-1 of the catalyst; adopting the compound technology of P-and N-containing ligands and its synergistic effect, Improve the selectivity of 1-decene and achieve a technical breakthrough in ethylene oligomerization to prepare higher alpha-olefins.
2. Preparation technology of supported Lewis acid catalyst and control technology of active species. Existing supported catalysts have the defects of low activity, wide oligomer composition distribution, and high dimer content. The project innovatively developed a new method for carrier modification to regulate the structure and composition of active species of catalysts. Through different carrier modification methods, the content and composition of active species Al2O3-O-AlCl2 and (Al2O3-O)2-AlCl of the catalyst can be controlled, thereby increasing the oligomerization conversion rate of 1-decene, reducing the dimer content, and customizing low or medium viscosity PAO, narrowing the composition distribution. The viscosity index is improved, realizing the performance control of PAO base oil.
3. Regulation of oligomer molecular structure and preparation technology of high viscosity index base oil. In order to prepare high-viscosity index base oils and overcome the persistent problems of high PAO branching rate and low viscosity index of base oils due to lack of chemical control over α-olefin isomerization in the prior art, the project prepared AlCl3/γ-Al2O3 catalyst through carrier doping, which effectively improved the molecular structure of the oligomer, reduced the branching rate of the oligomer, and significantly improved VI, KV and catalytic activity. The synergistic effect of carrier modification and doping can further increase the viscosity index and improve the comprehensive properties of PAO base oil.
4. Technology for synthesizing PAO base oil from mixed decenes. In order to improve technical economy and realize comprehensive utilization of mixed decene resources, the project improves PAO performance through the synergistic effect of catalyst design and oligomerization process. A two-component γ-Al2O3 catalyst was developed, which reduced the PAO branching rate and increased the viscosity index; the oligomerization process technology was used to optimize the control means to balance the contradiction between KV and VI, and a synthetic technology for preparing PAO base oil with high viscosity index and low viscosity was developed using mixed decenes as raw material.
   This project applied for 16 domestic and foreign invention patents (1 international invention, 9 authorized China invention patents) and published 27 SCI papers. Application and testing by authoritative departments have proved that this technical series of PAO base oils have high viscosity index and excellent low-temperature flowability. The comprehensive performance reaches or is better than the quality level of PAO base oils of internationally renowned companies. The overall technology reaches the international advanced level, and the main performance reaches the international leading level. Technical achievements have been applied in three large domestic state-owned petrochemical enterprises and private enterprises, and the product quality is stable. They have been applied to many large lubricant production enterprises to replace imports. In the past three years, it has achieved nearly 6.1 billion yuan in new output value, increased tax revenue by 280 million yuan, and profits by 4.2 billion yuan, achieving considerable economic and social benefits.