The bags are first converted to crude oil by the pyrolysis process, part of which involves heating the bags in an oxygen-free chamber. This method has been in use by other research teams, but the team from University of Illinois expanded on the technique by fractioning the crude oil into different petroleum products, which allowed them to then produce products such as natural gas, gasoline, waxes and lubricating oils. 

The team was able to create a diesel mixture that complied with national standards and performed better than ultra-low-sulfur diesel, and found that they could mix the plastic-derived diesel with both regular diesel and biodiesel with no compatibility problems.