Chemistry

Plastic Bags Efficiently Recycled Into Diesel Fuel

March 20, 2014 | by Lisa Winter

Photo credit: Kate Ter Haar

An estimated 500 billion - 1 trillion plastic shopping bags are used worldwide each year. The EPA estimates that 13% of these get recycled, and the rest of them are sent to the landfill. Well, they are at least meant for the landfill. Because plastic bags are light and catch the wind incredibly easily, many get blown around very easily, ending up in trees and waterways.

Are stray plastic bags really a problem? I’d say yes, considering bags have been discovered at both the North and South Poles, and neither area is particularly known for having an extensive selection of local grocery stores. Not only do the bags look ugly, but they pose a tremendous risk to wildlife; particularly marine animals. Plastic bags get mistaken for jellyfish, and turtles who try to eat them end up choking. Even if the plastic bags get broken into small bits, animals are unable to digest them and it ends up building up and killing the animals.

Many major cities are posing a ban on plastic bags as a way to combat the pollution caused by stray shopping bags (along with the energy required to produce them) but they aren’t widespread enough to put a big dent on the problem. A group of researchers from the University of Illinois have developed a new way to convert plastic bags into useable diesel that can be used in a variety of applications, ranging from candle wax to jet fuel. The results of this new method have been detailed in the journal Fuel Processing Technology

When petroleum crude oil is distilled, only about 55% of it ends up as fuel. Using the new technique with petroleum-based plastic shopping bags, the researchers were able to convert about 80% of it into useable fuel. This is not the first time that researchers have tried to recycle shopping bags into fuel, but this approach goes a bit further. The oil was treated in different ways in order to produce biodiesel or ultra-low-sulfur diesel fuel that is more environmentally friendly. The biodiesel created from plastic bags was combined with regular diesel in order to see if it would work. Even with the 30% of the blend coming from recycled bags, the fuel worked just fine. 

There is currently no information about what it would take to get this technology applied on a larger scale. In addition to creating a larger facility to process the plastic bags, the recycling rate would need to be increased dramatically in order to significantly alleviate the demand for ecologically-responsible diesel fuel. 

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