A combined team of researchers from the Chinese Academy of Sciences and University of California has found a way to degrade ordinary plastics in a way that allows for fuel to be created from plastic trash. In their paper published in the journal Science Advances, the team describes their technique and their hopes for scaling it up to allow for it to be used in actually reducing plastic trash.
Most people know that modern life is filled with plastics, from packaging, to bags and soda bottles—the world has been inundated with them since they became a cheaper alternative to many other products.
Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as post consumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment.