Re-refining used lube oil 1

[owg]

I am helping a team of students with this subject. We have four questions which you may be able to help us with.

1. What is the maximum allowable sulfur content in the light virgin gas oil and heavy virgin gas oil, i.e. after the lube oil has been re-refined?

2. What is the approximate selling price of the light virgin gas oil, heavy virgin gas oil, naptha and asphalt after they have been re-refined?

3. In general, how much do lube re-refining plants pay for the dirty lube oil?

4. How do the re-refining plants treat their waste water?

I have taken a shot as follows. 1) Base stocks run around 600 ppm sulphur per a current web offering. 3. A re-refiner should be able to charge for picking up waste oil. Any further help would be appreciated.

 

[Keithbowers]

Maximum allowable sulfur contents of lube base stocks are set by API standards. Group I base oils are higher than 300 PPM. Group II base oils are lower than 300 PPM. Groups III through V(hydro-cracked, PAO, and synthetic esters respectively) are also limited to 300 PPM max, but are really near zero.

The selling price of the by-product distillates are a function of location and quality as well as market competetion. A typical factor would be a discount of 0-20% off current spot prices for virgin material of the same quality.

The 'purchase price' for used oil varies from -$0.15/gal to $0.25/ga at the generator. Collected used oil is available in the market for about 70% of the #6 fuel oil price.

Waste water is treated by bio-treating.

 

[owg]

Keithbowers - Thanks for the answers. I will make sure the students are still monitoring this site. HAZOP at

http://www.curryhydrocarbons.ca

 

[25362]

The following may not be of much help, but I felt an obligation to tell it.

There are various ways to re-refine used crankcase oils to virgin base oil quality. Part of the energy consumed in the process is generated from the by-products (contaminants) recovered with the base oils. Thus, pricing of the internal consumed energy units would have to be based on the purchased used oils, not on market values.

Effluents to the environment include not only spent water, but also metals and heavy asphaltic residues, odours, spent clays, acids, etc. depending on the process sequence used.

Depending on the particular location and economics, used oils could be re-refined also to a fuel oil quality level or to cracking feedstock value.