It is possible to convert the waste oil to diesel using the right pressure, temperature, and catalyst. It isn't distillation in that case, I mean it still gets distilled but to get diesel from motor oil you have to crack some of the heavier hydrocarbons in a reactor. This is a pressure vessel with the air pumped out, containing the oil, platic, rubber, wood, fat, crap, algae, sugar, you name it, and a catalyst like nickel, or iron. The catalyst is chosen to make more or less of certain hydrocarbons, depending on what you want. Without the catalyst it can still be done at highr pressure and temps. There's cracking where you break heavy oil into lighter oil, and there's the opposite where you form them from methane or carbon monoxide and hydrogen. One reaction breaks water down and forms methane by reacting it with red hot coal. Another one makes methanol from methane. Methanol It gets crazier too, the Chinese have made a cataylst to form alcohol from co2. Eventually we will be able to make more fuel than we use and pump it underground. Then we can control the earth's temperature like it has a thermostat, and we can all still feel good driving a giant fuel guzzling vehicle.
