Sir foxtrot08: do we know what happens to the car wash sludge/oily water waste Safety Kleen recovers and collects?
Thank You so far for all of your knowledge and info. It’s very good to have you here
All used oil has some amount of water in it. Moisture happens. But it’s distilled first. The water is boiled off.
From there it goes through a thin wiper film, there are a few neat YouTube videos of the technology. I can find the one I’m familiar with and link it later.
The sludge, remaining water, a lot of the additives, etc. are dropped out. That is often used for bunker fuels and such.
This is an extremely simplified view of it. Given, there are decontamination steps a head of it. Like filtration to remove solids. Then distillation to remove water and solvents. You then also have centrifugal separation to remove glycols off, other products that you can.
After it is processed in this format:
It’s basically VGO at this point in time. The process can end there technically, and it can be sold as feed stock into a normal refinery if the price is right.
From there, you can have a distillation column much like a normal crude refinery. Where you’ll have your different cuts of oil. And finally, it can be hydrotreated into group 2 “plus” base oils.
Better the product in = better the product out. More group 3’s? Or PAOs? Higher VI product out.