There are other byproducts that are created such as gasses and other petrochemicals. The gasses would be burned to generate the heat needed for the process or to generate electricity for the plant, and the other byproducts would be sold.One consideration I didn't mention.
500 Barrels of crude weighs approximately 68.75 ton.
290 ton of rufuse material minus 68.75 tons of oil = 221.25 ton
I'm wondering what that 221.21 ton of waste from the process is...
And how it's going to be disposed of (or used).