• Superior low temperature performance.
• Long life lubricants and specialty products that work harder to maximize equipment durability.
• Result: money saved through less equipment downtime, higher productivity, lower maintenance costs and reduced wear.

The basis of Petro-Canada's premium performance and environmentally-friendly products is formed from a combination of proprietary additive packages and the unique pure base fluids derived through the patented Hydrotreating (HT) severe hydrocracking/hydroisomerization processes.

Conventional solvent refining of crude oil attempts to remove undesirable components from the feed through solvent extraction. To accomplish this, the crude oil undergoes atmospheric distillation and is then treated in a solvent extraction process, which removes only 70 to 85 per cent of impurities and aromatics. This is followed by solvent dewaxing to improve the low temperature properties. The result is an amber-coloured base oil often referred to as conventional base oil. In some cases, these stocks are further treated in a mild hydrofinishing step, which should not be confused with the severe hydrocracking or HT process employed by Petro-Canada.

In Petro-Canada's HT severe hydrocracking process, the elimination of aromatics and impurities is achieved by chemically reacting the feed stock with hydrogen in the presence of a catalyst, at high temperature (greater than 375 degrees C or 707 degrees F) and pressure (3000 psi). Several different reactions occur in this hydrocracking process, the principal ones being:

• Removal of sulphur, nitrogen and oxygen.
• Conversion of aromatic hydrocarbons to saturated cyclic hydrocarbons.
• Breaking up of heavy molecules to lighter saturated hydrocarbons.

The HT oil is separated by distillation and solvent dewaxed to improve low temperature fluidity and then passed through a second hydrotreater (greater than 200 degrees C or 392 degrees F and 3000 psi) for additional saturation. This final step maximizes base oil stability by further removing traces of aromatic and polar molecules resulting in water-white base oils which are 99.9 per cent pure. The hydrocarbon molecules that are formed are saturated and very stable which makes them ideal for specialty process applications and high performance lubricants.

Petro-Canada's Very High Viscosity Index (VHVI) fluids are made using a variant of the HT process. The solvent dewaxing step (discussed above) is replaced by "hydroisomerization".

This is a complex process that converts the molecular structure of the waxy hydrocarbons into highly desirable isoparaffins. The result is base fluids with enhanced low temperature fluidity and high oxidation stability. Aromatics, sulphur and nitrogen impurities are virtually removed to produce clear base fluids that are 99.9 per cent pure.

Petro-Canada's VHVI base fluids (Very High Viscosity Index) are synthetic and deliver equivalent performance to more expensive PAOs (polyalphaolefins).

• Download the Patented HT Purity Process Technical Data Sheet (PDF, 4 pp., 177 KB). Requires Adobe Acrobat Version 4.0 or later. Download Adobe Acrobat.