What could be the minimum Sulfur contents of a mineral based lubricants?

Mansoor,

The sulphur content is largely dependent on the crude oil itelf. The sulphur content in crude from Middle East may differ from crude in Venezuella and so on. Most refineries employ sulphur stripping or desulphurization operations.

Under the new (Group wise)categorisation of Base oils the values of Sulphur permitted are as follows:

1. Group I > 0.03% Sulphur
2. Group II <_ 0.03% Sulphur
3. Group III <_ 0.03% Sulphur

In many cases lubricants are additivated with Sulphur compounds, as in the case of many Metal working and deformation products, in such cases we can observe upto 10% Sulphur. The sulphur in this instance is in a compound form and rarely termed "free suphur." . To enhance performance free suphur is also added to many Metal working or cutting oils.

To answer your question, the base oil Grouping defines the lowest amount of Sulphur % permitted.

Hussam Adeni

Correction please.

In the last post the last sentence should read

" To answer your question, the base oil Grouping defines the "MAXIMUM' amount of Sulphur % permitted." and "not lowest amount."

My apologies to all readers.

Hussam Adeni

In addition of what Hussam already said, Sulphur in oil is also regulated by environmental agencies. For the US is the EPA.
I recommend you verify with your local environmental agency to have a better knowledge of your local maximum levels.

Environmental regulation does not apply to all oils. To my knowledge, EPA does not care how much sulfur is in your turbine oil as long as the oil is contained, and it doesn’t leak out and contaminate water and/or soil.

Arshad,

The minimum Sulfur Content could be Zero ppm if its a highly Hydrofinished product, falling under Group III+ Base Stock.

Jawad

Jawad,

The Zero ppm benchmark is very difficult to sustain.

I have an interesting experience, where a standard hydraulic oil was topped up in place of a Zero zinc (ZZ) hydraulic oil in a Undergroung Mining application. In spite of repeated flushing with Hydraulic ZZ the sample continued to show above 15 ppm zinc.


Hussam Adeni