I think you Posted into the wrong Forum Topic area, but I shall answer you, and then ask Admin for the Topic to be shifted into the correct Forum area.

Providing the crude oil you intend to use can be heated, filtered, and any water, acids, sludge etc removed from it, and the viscosity is not too high,there is no reason not to add perhaps a proportion of the crude oil into your pre-processing mixture.

The proportion of crude oil able to be added, often depends on the source, as some crudes are very sticky, acidic, or sludgy, while others are almost at the gasoline stage, and can be lit with a match.

Without being on-site, and doing proper tests, that's about the best which can be done for you, at present......

For what purpose? To put sulphur in a fairly clean fuel?

It is my understanding that biodiesel has a toxicity on par with refined sugar of equal volume. Add the crude and you will need a whole new environmental impact statement if you are in the U.S. probably in Europe also. As stated crude comes in a wide range of flavors, most will cause processing dynamics that would take a full time lab to get a reliable product out. Unless the crude is free it would be a can of worms best left to a refinery.

The glycerin that is a sell able byproduct would be contaminated. Your biodiesel would be a petroleum product. The new byproducts are hazardous waste unless you can further refine them and find a competitive market for them.

Possible maybe, economic would be a lot of research and legal work.

Don't mean to shoot holes in your idea but a lot of ramifications to ponder

Brad

Define crude oil please.

used motor oil will improve the cloud point.

commercial sales of such BIO would be problematic as UV & SS point out.