Cold plasma pyrolysis: making plastics ‘circular’

Cold plasma pyrolysis: making plastics 'circular'
©iStock/FluxFactory

Developing green energy and finding a way to reduce plastic waste and integrate plastics into the circular economy are two of the major challenges the EU currently faces. A recent study may have found a solution to both of these problems: cold plasma pyrolysis.

Finding technology that can regenerate and give new life to plastics is imperative to a circular mode of operation; rather than wasting plastics the new research published in Green Chemistry: Issue 8 has put cold plasma pyrolysis into the mix of solutions.

Plastic waste has been at the centre of many discussions and debates into protecting the environment, circular economy, marine conservation and now also for use as a green energy source. In the EU it is estimated that 31% of plastics end up in landfill and plastic waste makes up 10-13% of municipal solid waste.

What is cold plasma pyrolysis?

The first question that this new research has raised is probably: what is cold plasma pyrolysis and how can it turn plastics into valuable materials? The first answer to this is understanding pyrolysis itself. Pyrolysis is the process of thermal decomposition of organic materials; the optimum environment is between 400-650°C with limited oxygen. Pyrolysis is generally used for the creation of energy, electricity or fuels.

The researchers of the study claim that incorporating cold plasma into the system could be even more beneficial in helping to recover other chemicals and materials; hydrogen, methane and ethylene.

Hydrogen and methane are commonly known for their potential as alternative clean fuels. In regard to ethylene, it is the basic foundation of most plastics globally, this means that recovering more ethylene from plastics will allow for the creation of a range of materials using regenerated ethylene – as it is used to produce everyday objects, such as plastic bottles and piping.

How cold plasma pyrolysis can recover plastic waste

The recent study by Royal Society of Chemistry in Green Chemistry: Issue 8 tested the effectiveness of cold plasma pyrolysis by using plastics bags, milk and beach bottles – all of which were collected by a local recycling facility in Newcastle, UK.

The research found that by using cold plasma pyrolysis compared to conventional pyrolysis, 55 times more ethylene was recovered from high density polyethene (HDPE). The research concluded that the cold plasma process of pyrolysis allowed for around 24% of plastic weight to be converted from HDPE directly into valuable products.

This new research could revolutionise the way we deal with plastics waste in the EU and has the potential to close the plastic production loop.

2 COMMENTS

  1. This is a clever idea to recycle waste plastic materials by the integration of conventional pyrolysis and cold plasma (also called non-equilibrium plasma , non-thermal plasma, or silent plasma) technologies.

  2. So has anyone, business or government setup a plant and trialled this idea??
    In Australia, we have a recycling crisis and yet not one mention of a solution.
    If this is actually possible, then why isn’t someone ‘selling’ the idea so it takes off??
    Whats the setup costs?… What are the negatives ??
    Come on world, surely there are solutions out there?? if not, we need to start inventing…

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