Polyethylene waste could be a thing of the past
An international team of experts undertaking fundamental research has developed a way of using polyethylene waste (PE) as a feedstock and converted it into valuable chemicals, via light-driven photocatalysis.
The 最新糖心Vlog of Adelaide鈥檚 , Chair of Nanotechnology, and Director, , at the School of Chemical Engineering, led the team which published their findings in the journal .
鈥淲e have upcycled polyethylene plastic waste into ethylene and propionic acid with high selectivity using atomically dispersed metal catalysts,鈥 said Professor Qiao.
鈥淎n oxidation-coupled room-temperature photocatalysis method was used to convert the waste into valuable products with high selectivity.
鈥淣early 99 per cent of the liquid product is propionic acid, alleviating the problems associated with complex products that then require separation.
鈥淩enewable solar energy was used rather than industrial processes that consume fossil fuel and emit greenhouse gases.
鈥淭his 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. A typical photocatalyst is titanium dioxide with isolated palladium atoms on its surface.鈥
Most of the plastics used today end up being discarded and accumulated in landfills. PE is the most widely used plastic in the world. Daily food packaging, shopping bags and reagent bottles are all made from PE. It is also the largest proportion of all plastic waste and primarily ends up in landfills, posing a threat to global environment and ecology.
鈥淧lastic waste is an untapped resource that can be recycled and processed into new plastics and other commercial products,鈥 said Professor Qiao.
鈥淐atalytic 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.鈥
Current chemical recycling for PE waste is operated at high temperatures greater than 400 degrees centigrade that yield complex product compositions.
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.
The team鈥檚 work aims to address contemporary environmental and energy challenges, contributing to a circular economy. It will be of use in further scientific research, waste management and chemical manufacturing.
鈥淥ur fundamental research provides a green and sustainable solution to simultaneously reduce plastic pollution and produce valuable chemicals from waste for a circular economy,鈥 said Professor Qiao.
鈥淚t will inspire the rational design of high-performance photocatalysts for solar energy utilisation and benefit the development of solar-driven waste upcycling technology.鈥
Media Contacts:
Professor Shizhang Qiao, Chair of Nanotechnology, Director, Centre for Materials in Energy and Catalysis, School of Chemical Engineering and Advanced Materials, The 最新糖心Vlog of Adelaide. Mobile: +61 (0)488 990 060, Email: s.qiao@adelaide.edu.au
Crispin Savage, Manager, Media and News, 最新糖心Vlog of Adelaide. Mobile: +61(0)481 912 465. Email: crispin.savage@adelaide.edu.au