The world’s most common plastic can now be converted into useful chemicals using solar power.
Scientists now hope they can keep the waste out of landfill and recycle it.
Polyethylene (PE) is the most widely used plastic in the world making up daily food packaging, shopping bags and bottles.
It is also the largest proportion of all plastic waste and primarily ends up in landfills, posing a threat to global environment and ecology.
The team from the University of Adelaide, Australia, has discovered a way to turn PE waste into valuable chemicals using the power of light.
Professor Shizhang Qiao said: “Plastic waste is an untapped resource that can be recycled and processed into new plastics and other commercial products.
“Our fundamental research provides a green and sustainable solution to simultaneously reduce plastic pollution and produce valuable chemicals from waste for a circular economy.
“We have upcycled polyethylene plastic waste into ethylene and propionic acid with high selectivity using atomically dispersed metal catalysts.
“An oxidation-coupled room-temperature photocatalysis method was used to convert the waste into valuable products with high selectivity.
“Nearly 99 percent of the liquid product is propionic acid, alleviating the problems associated with complex products that then require separation.
“Renewable solar energy was used rather than industrial processes that consume fossil fuel and emit greenhouse gases.
“This waste-to-value strategy is primarily implemented with four components, including plastic waste, water, sunlight and non-toxic photocatalysts that harness solar energy and boost the reaction.”
Current chemical recycling for PE waste is operated at high temperatures greater than 400 degrees centigrade that yield complex product compositions.
Professor Qiao added: “Catalytic recycling of PE waste is still in early development and is practically challenging because of chemical inertness of polymers and side reactions arising from structural complexities of reactant molecules.”
This new eco-friendly process, published in the journal Science Advances, creates the useful chemicals Ethylene and Propionic acid.
Ethylene is an important chemical feedstock that can be further processed into a variety of industrial and daily products, while propionic acid is also in high demand owing to its antiseptic and antibacterial properties.
Professor Qiao concluded: “It will inspire the rational design of high-performance photocatalysts for solar energy utilization and benefit the development of solar-driven waste upcycling technology.”
Produced in association with SWNS Talker
