http://www.digitaljournal.com/news/environment/plastic-shopping-bags-used-to-make-diesel/article/378411

Plastic shopping bags used to make diesel

Posted Mar 26, 2014 by Tim Sandle
Plastic shopping bags can be converted into diesel, natural gas and other useful petroleum products, according to a new study. Furthermore, the by-product can be blended with existing ultra-low-sulfur diesels and biodiesels.
A plastic bag in Toronto
A plastic bag in Toronto
To turn waste plastic bags into a usable fuel requires a process that involves heating the bags in an oxygen-free chamber (a process called pyrolysis). This involves the simultaneous change of chemical composition and physical phase, and is irreversible. The word is coined from the Greek-derived elements pyro "fire" and lysis "separating." The next step of the process involves a form of distillation which extracts the diesel like material that was used to manufacture the bags in the first place and re-converts it back into fuel.
By fractionating the crude oil into different petroleum products and testing the diesel fractions, the researchers were able to manufacture fuels that complied with national standards for ultra-low-sulfur diesel and biodiesel fuels. The resulting product had an equivalent energy content, a higher cetane number (a measure of the combustion quality of diesel requiring compression ignition) and better lubricity than ultra-low-sulfur diesel
The research was carried out at the Illinois Sustainable Technology Center, a division of the Prairie Research Institute at the University of Illinois. The findings have been published in the journal Fuel Processing Technology. The paper is titled “Production, characterization and fuel properties of alternative diesel fuel from pyrolysis of waste plastic grocery bags.”