采用传统溶剂精制生产极高粘度指数（VHVI）基础油是不现实的。合成油如聚a烯烃虽适合于生产VHVI基础油,但价格昂贵。因此,目前许多厂商都选择加氢工艺。 一般加氢裂化采用含氟的催化剂,但80年代报道过连续注氟引起了设备问题。Criterion催化剂公司和Lyon-dell公司先前开发的无氟催化剂,最近又有了新配方,依靠固有酸性而不连续补氟,中试数据表明,其性能与含氟催化剂相当。1995年这种新催化剂用于某润滑油选择加氢裂化装置,运转情况良好。对二段补充精制催化剂也 It is impractical to produce very high viscosity index (VHVI) basestocks using traditional solvent refining. Synthetic oils, such as poly a-olefins, are suitable for the production of VHVI base stocks but are expensive. Therefore, many manufacturers choose hydrogenation process at present. Fluorocarbon catalysts are generally used for hydrocracking, but continuous fluorine injection has caused equipment problems in the 1980s. Fluoride-based catalysts previously developed by Criterion Catalysts and Lyon-dell have recently been redesigned with inherently acidic and non-continuous fluorine-enrichment. Pilot data show comparable performance to fluorinated catalysts. In 1995, this new catalyst was used in a lube oil selective hydrocracking unit and was operating in good condition. On the second paragraph of refined catalyst also