Mobil 1: 100% synthetic base stocks? Please settle this.

[SteveS]

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Originally posted by pscholte:

Hard-core oil aficionados will already know that what is generically called "synthetic" motor oil is actually two distinct types: synthetic and hydrocrack.

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Actually there are two ways of making Group III basestocks, severe hydrotreating and hydrocracking.

Severe hydrtreating is where a mineral base oil is hydrotreated to break all the naphthenic and aromatic rings and olefins to form saturated straight chain hydrocarbons. There may be a fraction of this type of Group II oil which has side chains on them, isomers, and these would probably cause a slightly lower VI for this product. I think there is also a varient of this process which Chevron have patented.

Hydrocracking is the process that Shell use, where they take long chain straight chain hydrocarbons (i.e. waxes) and break them down into shorter (lube oil length) straight chain hydrocarbons. This process produces a purer straight chaim oil, as the feedstock is comprised purely of straight chain HCs from the waxes.

Both methods will produce a Group III base oil.

 

[Drstressor]

Sorry, but severe hydrocracking is the only way a base oil can be produced that will meet Group III specs. The product is a mixture of linear and branched hydrocarbon chains. Just like PAO base oils. A base stock composed of pure linear paraffin would have a very low VI and poor lubricant properties.

Hydrotreating generally refers to a milder catalytic treatment with H2 gas than hydrocracking that is used to produce Group II base stocks. Double bonds are saturated and most forms of sulfur becomes volatilized. But there is little molecular rearrangement that is typical of severe hydrocracking. Chevron developed the basic hydrocracking process and licenses the procedure to everyone else who makes Group III base stocks.

 

[Jimbo]

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Hard-core oil aficionados will already know that ..Conventional motor oil is refined crude oil, pumped out of the ground and distilled for use in car engines...

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Also wrong for the last 50 years. Group I is solvent refined.