Transforming plastic grocery bags into sustainable fuel would go a long way in solving the problem of getting rid of more than 300 million tons of plastic waste produced annually. Plastic waste can cause serious environmental issues as it is not easy to eliminate it.
This leads to most of the plastic waste ending up either in landfills or the ocean. Here the situation gets worse as the plastic breaks down into microplastics which are consumed by fish and other marine life leading to indigestion and affecting the marine ecosystems.
According to the Journal of Renewable and Sustainable Energy, researchers from California State Polytechnic University, using catalytic pyrolysis to turn plastic wastes into a valuable fuel source.
Pyrolysis – thermochemical decomposition of carbon-based matter in the absence of oxygen.
The researchers were able to recycle plastic and upgrade plastic into other products or convert it into a vapor with heat. This met a catalyst and turned into the desired fuel-like product. The pyrolytic process transforms primary organic waste into a sustainable fuel or another valuable chemical.
Author Mingheng Li said, “The innovative part of the experiment is the catalyst. The catalyst is critical to this particular pyrolysis process because it only requires one step to get to the desired fuel product at relatively mild temperatures.”
The researchers managed to prepare a catalyst by dipping a zeolite substrate in an aqueous solution containing nickel and tungsten and drying it in an oven at 500 degrees Celsius. Later the synthesized catalyst is used in conjunction with a lab-designed, single-stage pyrolytic reactor. It runs at a set point of 360C to break down a mixture of plastic grocery bags.
A similar procedure can be used to process other wastes, such as manure, municipal solid waste, and used engine oil, to make usable energy products.
Li added, “This pyrolysis process serves as a definitive step in reducing reliance on fossil-based fuels.”
The researchers’ studies suggest the pyrolysis product is similar to a standard diesel fuel product via gas chromatographic analysis. It is a type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition.
Going forward, the team will work to explain the cracking mechanism that occurs on the surface of the catalyst. In addition, they will try to optimize diesel fuel production from various mixed plastic wastes.