Solving the problem of plastic waste is a global challenge. Currently, only a small percentage of mixed consumer plastics are recycled, with the majority ending up in landfills or incinerated. Conventional recycling methods can be costly and inefficient, leading to the need for alternative solutions.
Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have developed a new catalytic recycling process that has the potential to revolutionize the recycling of mixed plastics. Using a carefully designed organocatalyst, the process selectively deconstructs multiple polymers in mixed plastics into individual monomers, which can be reused to create new plastic products.
The new catalyst offers several advantages over traditional recycling methods. It generates significantly fewer greenhouse gases, requires less energy input, and reduces fossil fuel consumption. By using recycled monomers instead of first-use monomers made from fossil fuels, the process could help reduce annual energy consumption by billions of barrels of oil.
The organocatalyst developed by the ORNL researchers has shown remarkable effectiveness in deconstructing various polymers commonly found in plastic products. It can efficiently break down materials such as polycarbonates, polyurethanes, polyethylene terephthalates, and polyamides, which make up a substantial portion of global plastic production.
The process also offers environmental benefits by replacing harsh chemicals used in traditional recycling methods. It is selective, thermally stable, nonvolatile, and has low flammability. Additionally, it can be used to deconstruct multicomponent plastics, including composites and multilayer packaging.
To confirm the effectiveness of the deconstruction process, the researchers used small-angle neutron scattering at ORNL’s Spallation Neutron Source. This method allowed them to characterize the structure of the deconstructed monomers at different levels of detail.
The organocatalyst deconstructs the plastics at different temperatures, allowing for the sequential recovery of individual monomers. The monomers are then extracted in reusable form, while other materials, such as additives and associated materials, remain intact and can be recovered separately.
The potential of this new catalytic recycling process is significant. If implemented on a global scale, it could greatly reduce plastic waste and the environmental impact of plastic production. By closing the loop on plastic recycling and promoting the use of recycled monomers, we can move towards a more sustainable future.
Source: Oak Ridge National Laboratory
– Organocatalyst: A compound comprised of small organic molecules that facilitate organic chemical transformations.
– Monomers: Molecules that react with other monomer molecules to form a polymer.
Source: Oak Ridge National Laboratory.