From plastic bag to petroleum product
Billions of plastic bags end up in landfill. A potential source of carbon fibre and carbon nanotubes, researchers have provided another reason not to throw the bags away by converting them into a range of petroleum products.
Researchers at the Illinois Sustainable Technology Center (ISTC) at the University of Illinois used a process known as pyrolysis, which involves heating the plastic bags in an oxygen-free chamber. Although this technique has been used by other research teams to convert plastic bags back into crude oil, the University of Illinois team went a step further and fractionated the crude oil into different petroleum products.
In this way, the researchers were able to produce natural gas, naphtha, petrol, waxes, and lubricating oils, such as engine oil and hydraulic oil. They also produced diesel which they mixed in a 30% blend with conventional diesel and found no compatibility problems with the biodiesel.
"It's perfect," said Brajendra Kumar Sharma. “We can just use it as a drop-in fuel in ultra-low-sulphur diesel without the need for any changes”.
The researcher says that the conversion process also produces significantly more energy than it uses. "You can get only 50 to 55 percent fuel from the distillation of petroleum crude oil," he said. "But since this plastic is made from petroleum in the first place, we can recover almost 80 percent fuel from it through distillation."