Turning Plastic waste into Fuel
A team of researchers have developed a relatively low-temperature process to convert certain kinds of plastic waste into liquid fuel as a way to re-use discarded plastic bags and other products. The common plastic – low-density polyethylene (LDPE) is used to make many types of container, medical and laboratory equipment, computer components and plastic bags.
Chemist Achyut Kumar Panda of Centurion University of Technology and Management Odisha is working with chemical engineer Raghubansh Kumar Singh of the National Institute of Technology, Odisha, to develop a commercially viable technology for efficiently rendering LDPE into a liquid fuel.
In their approach, the team heats the plastic waste to between 400 and 500 degrees Celsius over a kaolin catalyst (a clay mineral). This causes the plastic’s long chain polymer chains to break apart in a process known as thermo-catalytic degradation. This releases large quantities of much smaller, 10 to 16 carbon atoms long molecules, mainly paraffins and olefins, which are chemically very similar to conventional petrochemical fuels.
The team optimised the reaction at 450 degrees Celsius with efficiency of 70 percent. Which means for every kilogram of waste plastic this process can produce 700 grams of liquid fuel. The by-products were combustible gases and wax.
The study has been published in the International Journal of Environment and Waste Management. If implemented on a large enough scale it can reduce pressures on landfill as well as ameliorating the effects of dwindling oil supplies in a world with increasing demands on petrochemicals for fuel.