The push toward lifetime lubes

Automobiles that never need oil changes? ...Severe-hydrocracked lubricating oils could make all this possible --- at about half the cost of synthetic oils. Conoco's recent $500 million hydrocracking plant turns petroleum crude into Group II and Group III lube oil base stocks. Flow diagrams for solvent refining and hydrocracking. A catalytic dewaxing step follows hydrocracking to convert waxy, straight-chain paraffins to branched-chain paraffins with lower pour points. (1) Remove sulfur, nitrogen, and oxygen impurities from crude oil. (2) Convert aromatic hydrocarbons to cycloparaffins that remain in Group II base stocks. (3) Open ring structure to paraffinic chains in Group III base stocks. Only the carbon atom skeletons are shown — the rest of the four valence bonds of each carbon atom are filled with hydrogen atoms. Makers of most European cars today suggest changing oil every 6,500 to 9,500 miles. Volkswagen and Peugeot plan to extend that figure to 18,000 miles or 24 months for its passenger cars, and Daimler-Benz may debut a "fill-for-life" vehicle by 2010. Key to the success of such initiatives is better quality motor oils. Current synthetic oils let automobiles run 25,000 miles between oil changes or about five times longer than most conventional types. Despite the advantage, their relatively high cost has limited market share to about 3%. But emerging severe hydrocracked oils cost about half as much as synthetics and last just as long. This has major oil companies scurrying to supply the expected boon. What's in it for them: greater efficiencies and a more environmentally friendly, adaptable process. Traditional refineries distill petroleum crude into mineral lubricating oils using a process largely unchanged since the early 1900s. Here, distillation separates hydrocarbon molecules by boiling point and their respective molecular size and viscosity. Added solvents selectively extract aromatics and other impurities such as sulfur, nitrogen, and