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ENVIRONMENT – If we can’t recycle it, why not turn waste plastic into fuel?

Could this be used for fuel?

By MUXINA KONAROVA
The University of Queensland

AUSTRALIA’S recycling crisis needs us to look into waste management options beyond just recycling and landfilling. Some of our waste, like paper or organic matter, can be composted. Some, like glass, metal and rigid plastics, can be recycled. But we have no immediate solution for non-recyclable plastic waste except landfill.

At a meeting last year, federal and state environment ministers endorsed an ambitious target to make all Australian packaging recyclable, compostable or reusable by 2025. But the ministers also showed support for processes to turn our waste into energy, although they did not specifically discuss plastic waste as an energy source.

The 100 per cent goal could easily be achieved if all packaging were made of paper or wood-based materials. But realistically, plastic will continue to dominate our packaging, especially for food, because it is moisture-proof, airtight, and hygienic.

Most rigid plastic products can only be recycled a few times before they lose their original properties and become non-recyclable. Even in European countries with strict waste management strategies, only 31 per cent of plastic waste is recycled.

Worldwide plastic production is predicted to increase by 3.8 per cent every year until 2030. Flexible, non-recyclable plastic materials are used in an increasing range of applications like packaging, 3D printing, and construction.

We need to expand our range of options for keeping this plastic waste out of landfills. One potential approach is “plastic to energy,” which unlocks the chemical energy stored in waste plastic and uses it to create fuel.

How plastic to energy works

Plastic is made from refined crude oil. Its price and production are dictated by the petrochemical industry and the availability of oil. As oil is a finite natural resource, the most sustainable option would be to reduce crude-oil consumption by recycling the plastic and recovering as much of the raw material as possible.

There are two types of recycling: mechanical and chemical. Mechanical recycling involves sorting, cleaning and shredding plastic to make pellets, which can then be fashioned into other products. This approach works very well if plastic wastes are sorted according to their chemical composition.

Chemical recycling, in contrast, turns the plastic into an energy carrier or feedstock for fuels. There are two different processes by which this can be done: gasification and pyrolysis.

Gasification involves heating the waste plastic with air or steam, to produce a valuable industrial gas mixture called “synthesis gas”, or syngas. This can then be used to produce diesel and petrol, or burned directly in boilers to generate electricity.

In pyrolysis, plastic waste is heated in the absence of oxygen, which produces mixture of oil similar to crude oil. This can be further refined into transportation fuels.

One of the advantages of plastic waste-to-fuel is that plastic doesn’t have to be separated into different types.

Gasification and pyrolysis are completely different processes to simply incinerating the plastic. The main goal of incineration is simply to destroy the waste, thus keeping it out of landfill. The heat released from incineration might be used to produce steam to drive a turbine and generate electricity, but this is only a by-product.

Gasification and pyrolysis can produce electricity or fuels, and provide more flexible ways of storing energy than incineration. They also have much lower emissions of sulfur and nitrogen oxides than incineration.

Currently, incineration plants are viewed as an alternative energy supply source and a modern way of driving a circular economy, particularly in Japan, South Korea and China, where land is valuable and energy resources are scarce. In other countries, although waste incineration is common practice, the debate around human health impacts, supply issues and fuel trade incentives remains unresolved.

Can we embrace plastic to waste?

Gasification of plastic waste needs significant initial financing. It requires pre-treatment, cleanup facilities, gas separation units, and advanced control systems. Pyrolysis units, on the other hand, can be modular and be installed to process as little as 10,000 tonnes per year – a relatively small amount in waste management terms. Plastic pyrolysis plants have already been built in the UK, Japan and the United States.

As pyrolysis and gasification technologies can only process plastics, many councils do not see major advantages in using them. But by taking only a specific waste stream, they encourage better waste sorting and help to reduce the flow of mixed waste and plastic litter.

Australia has invested a serious amount of funding into research, particularly in waste conversion. It has a solid industrialised infrastructure and a highly skilled workforce. The current recycling crisis offers an opportunity to explore some innovative ways of turning our waste into valuable products.

There are direct job opportunities in plastic conversion plants, and indirect jobs around installation, maintenance and distribution of energy and fuels. We might even see jobs in R&D to explore other waste conversion technologies.

In the meantime, the plastic we send to landfill is damaging our environment and harming wildlife. That needs to change, and Australia should consider plastic waste-to-energy as part of that change.The Conversation

Muxina Konarova is an Advanced Queensland Research Fellow at The University of Queensland. This article was first published in The Conversation on May 18, 2018 and is republished under a Creative Commons license. Read the original article. In view of the renewed interest in Kamloops in banning single-use plastics, and seeing the retweet of an article about plastic being three times cheaper than wood for powering factories in Asia, I thought the Conversation story would be of interest. In my view, we need to pay more attention to the potential for using gasification and pyrolysis to cleanly create energy from disposable materials.

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About Mel Rothenburger (6877 Articles)
ArmchairMayor.ca is a forum about Kamloops and the world. It has more than one million views. Mel Rothenburger is the former Editor of The Daily News in Kamloops, B.C. (retiring in 2012), and past mayor of Kamloops (1999-2005). At ArmchairMayor.ca he is the publisher, editor, news editor, city editor, reporter, webmaster, and just about anything else you can think of. He is grateful for the contributions of several local columnists. This blog doesn't require a subscription but gratefully accepts donations to help defray costs.

6 Comments on ENVIRONMENT – If we can’t recycle it, why not turn waste plastic into fuel?

  1. Why not refuse to allow plastics to be produced if they can’t be recycled. I think industry would figure out a way to recycle if it was the only option.

    • Tony Brumell // January 23, 2019 at 11:40 AM // Reply

      There are very few plastice that can’t be recycled.It’s all a matter of profit.Check out the article I mention in mty previous comment on “Plastic to oil “This is not the whole answer but it may be a start.Also there is a company in Kelowna that can use virtually all plastic to produce benches and planks. The city of Kamloops use these benches in riverside pk.

  2. Tony Brumell // January 21, 2019 at 11:41 AM // Reply

    Gasification and pyrolysis do return some of the plastics into usable fuel.This may be better than putting it in the landfill but there are still waste products (what they are I do not know ) that have to be disposed of.While some of the toxic volatiles in the plastics are eliminated, some are not..It makes me think that plastic that is in an anarobic landfill may be just as sequestered as carbon in unburned wood is.The plastic in landfills does not break down for a very long time.and as such may have very little impact on any environment for many hundreds of years,Maybe we can find a safe replacement by then .Don’t forget that burning any carbon based fuel will release that carbon into the atmosphere and cannot be considered carbon neutral.This ia a falicy perpetrated on the public by vested interests.
    The product of gasification (Syngas ) is burned in ICE engines and does contribute to the carbon ffotprint just as any fossil fuel does.

  3. Taking some of the money used to prop up the oil and gas industry and use it for serious research into “turning the tide” against pollution in general and against plastic pollution in particular would seem to make much sense.
    And related, by some accounts the liability for cleaning up decommissioned oil and gas wells is many times multiple the actual amount of money set aside by the industry.

  4. Bronwen Scott // January 21, 2019 at 5:13 AM // Reply

    Burning plastic creates toxic volatile compounds, some of which can travel in the atmosphere hundreds of miles, which is why Inuit women’s breast milk has high levels of such compounds as hexachlorobenzene, listed by WHO as one of the world’s 10 most toxic pollutants. Basic science tells us that matter does not disappear–it is merely transformed. Further, once an incinerator is built, a need for a continuous supply of waste is generated. If our species and many others are to survive, we need to radically change our ways, which includes not manufacturing unrecyclable and non-reusable plastics.

    • Mel Rothenburger // January 21, 2019 at 7:41 AM // Reply

      There’s a big difference between an incinerator and a gasifier, is there not? ie. with a gasifier there is no combustion.

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