Turning soft plastic waste into a resource

Challenge

Plastic waste is a global environmental challenge, but some plastics are particularly difficult to recycle.

Polyolefins account for around 43 per cent of plastics used in Australia and are heavily represented in the waste stream because they are commonly used in short-life products such as soft plastic packaging. 

Many soft plastics cannot be mechanically recycled because they are contaminated or made from complex multilayer films. As a result, significant quantities are sent to landfill rather than being recovered and reused.

The challenge is to find economically and technically viable ways to recover value from these difficult-to-recycle materials.

Solution

CQUniversity researchers are working on pyrolysis process optimisation and control system development to improve the quality and value of products generated from waste plastics.

Pyrolysis is a thermochemical process in which plastic waste is heated—typically at temperatures of around 300–900°C or higher—with little or no oxygen. This breaks the plastic down into energy-containing products including:

• oil
• char
• syngas (synthetic gas). 

The CQUniversity team is developing reactor models to optimise process efficiency, with the aim of improving both the yield and value of the resulting oil.

Impact

Diverting plastic from landfill

The research aims to provide technical support for the diversion of large quantities of soft waste plastics from landfill, helping address one of the most difficult parts of Australia's plastics waste stream. 

Recovering value from waste

Rather than treating difficult-to-recycle plastic as waste with no further use, pyrolysis creates an opportunity to recover valuable products from it.

The research is focused on improving the efficiency, yield and quality of these products, helping maximise the value recovered from end-of-life plastics. 

Supporting a circular plastics economy

The ability to convert problematic soft plastics into oils that can be used to make new polyolefins could contribute to a more circular approach to plastics and keeping materials in productive use rather than sending them directly to landfill. 

Connecting research with industry

The project demonstrates CQUniversity's role in collaborative research aimed at solving a major environmental and industrial challenge. Through the SPW CRC, researchers are working with partners to move technological solutions towards practical application.