School of Engineering

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Transforming plastic wastes into valuable resources

Research led by Dr Anh Phan and colleagues employed a new form of advanced pyrolysis using cold plasma to recover useful chemicals for industry from waste plastics.

Up to 55 times more ethylene, one of the most widely used chemicals for industrial products in the world, was recovered from waste high density polyethylene (HDPE) compared to conventional pyrolysis.

Pyrolysis decomposes materials at high temperatures in an inert atmosphere. It converts plastic to small amounts of gas and wax/liquid for energy. But with cold plasma pyrolysis, we can recover monomer - ie ethylene, hydrogen, methane and other useful chemicals - from waste materials directly rather than generating energy alone.

Waste plastics such as plastic bags and milk and bleach bottles were used as the feedstock for the process, which requires little energy to run. Electricity for generating the cold plasma could be sourced from renewables, with the chemical products used as a form of energy storage.

The work comes in the wake of increasing global concern around plastic wastes entering the land, air, sea, and food web resulting in large scale environmental contamination. The sheer scale of plastic production and disposal makes it perhaps one of the greatest challenges industry, government and society currently faces, especially in regards to sustainability.  

The UK is currently struggling to meet its 50% household recycling target for 2020, and the research demonstrates a possible way forward in valorising plastics in a circular economy, working towards SDG 12: Sustainable Consumption and Production.

Dr Anh Phan, Lecturer in Chemical Engineering, said: “We should be treating plastics as an important part of the circular economy. The technology developed highlights the value of plastic materials in preventing them from going to waste and polluting the environment.

There are a variety of uses for these materials that we currently waste that needs to be brought to the attention of industry, government and consumers”.

An article by Dr Anh Phan about the research is featured in The Conversation.

Read the study:


Dr Anh Phan: Lecturer in Chemical Engineering

published on: 20 September 2018