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

Could this be turned into fuel, instead of just more plastic?
Shutterstock.com

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 month, 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.

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The 100% 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% of plastic waste is recycled.

Worldwide plastic production is predicted to increase by 3.8% 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 landfill. 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 mixtures 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.
Author provided

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 Australia 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.

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The recycling crisis in Australia: easy solutions to a hard problem

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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.

Muxina Konarova, Advanced Queensland Research Fellow, The University of Queensland

This article was originally published on The Conversation. Read the original article.

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Good signage in national parks can save lives. Here’s how to do it right

Young men and overseas tourists are particularly at risk.
flickr/andrea castelli, CC BY-SA

Pascal Scherrer, Southern Cross University and Betty Weiler, Southern Cross University

Every time we hear of the tragic death of a visitor in one of Australia’s spectacular national parks, there is cause for reflection on how we communicate safety messages in nature.

Our study, published in the Journal of Outdoor Recreation and Tourism, reviewed some of the signs in national parks in Queensland and Victoria; we also interviewed rangers and park managers.

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Our national parks need visitors to survive

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Outdoor recreation inherently comes with risk but there are ways to reduce it without wrapping people up in cotton wool.

One of the simplest ways is to critically examine the way we design safety signs to ensure that visitors actually read them, connect with the message, and accept that this warning does really apply to them.

Our findings help to show why and how particular signs are effective at communicating safety messages – and what not to do.

To be effective a sign should, among other things:

• be easy to notice
• be easy to understand
• use colours that stand out from the background
• include languages other than English
• include graphics and the traditional “no” symbol of a red circle with a line through it
• avoid crowding too many messages into one spot.

Young men and international tourists at risk

Millions of visitors access and enjoy Australia’s vast network of protected areas safely every year.

Park managers want locals and tourists to visit natural areas – it is good for health and well-being, the economy and society. Visitors to parks are also more likely to support national parks. Effective communication of safety information for visitors to national parks is essential, particularly where the potential consequences of mishaps are severe.

Visitor ignoring warning sign to ‘get a better shot’.
Author supplied

We know from previous research that certain groups, such as young men and international tourists, are particularly at risk – too often with tragic and sometimes expensive consequences.

Some park agencies are actively targeting high-risk groups at specific sites, as this example shows.

A signed aimed at high-risk visitor group (18-30 year old males) and complementing traditional approaches to safety signage.
Author supplied

The focus is to tell the story of past tragedies to get across the message that the risk is real and relevant to them.

Of course, risk is part of the attraction for some park-goers. But every visitor needs to know what is appropriate and inappropriate behaviour, and how to take responsibility for their own safety.

Thinking carefully about how we design signs to get safety messages across effectively is an important part of managing risk in national parks and natural areas generally.

Making signs noticeable and easy to comprehend

Based on our analysis of research findings both within and outside park settings, we developed checklists to help park managers assess how effectively their signs communicate risk to national park visitors.

We tested these “best practice principles” checklists at several sites with two Australian national parks agencies. The process proved valuable in strengthening current safety sign policy and practice.

For example, the following sign meets the criteria for being “noticeable” and “easy to comprehend”.

This is an exemplary sign.
QPWS

Limit the number of messages per sign

Park authorities often need to communicate a lot of information at once to park goers. However, this can be done by using clever graphics and limiting the number of messages per sign. It’s also important to put warning signs close to the risky site, not simply warning people when they enter the park.

The example below shows how having multiple signs grouped together can make it hard for users to get the key messages, even if they are driving at low speed. It is all too easy to drive past and ignore the signs altogether.

Information overload.
Author supplied

Our study also highlights that good safety signs can support and complement the dedication and personal responsibility of frontline park staff. Serious incidents can have a direct effect on staff personally, and on the reputation of certain sites, particularly in the eyes of local emergency service workers.

Safety signage will be more effective if embedded in a coordinated risk-management system.

Activities in nature will always carry some risks and some people will choose to engage in unsafe activities despite knowing better. Accidents will continue to occur.

That said, our best practice principles for signage help park managers to do the best they can to make visitors fully aware of the risks while preserving the integrity of the natural site.

They also have direct applications to other nature-based visitor sites. Signs can help address issues such as the recent incidents with kangaroos at Morisset Hospital near Sydney, where visitors were feeding the animals carrots to get a close-up picture.

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Tweet all about it – people in parks feel more positive

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What we still need to know

We have a poor understanding of what makes different types of people (such as those with different cultural backgrounds and experience levels, or people responding to peer pressure) misunderstand or ignore safety warnings.

Best practice signage is already in place at many high-risk park sites. As park visitation continues to increase and visitor profiles change, we need more research on what can help persuade at-risk visitors to read and act on safety messages.

It is time to invest in targeted research on this issue, including trialling and evaluating more innovative and persuasive communication techniques.

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This article and research was co-authored by Rob Saunders, an independent consultant focused on park and recreation strategy, planning and effective communication.

Pascal Scherrer, Senior Lecturer, School of Business and Tourism, Southern Cross University and Betty Weiler, Professor, School of Business and Tourism, Southern Cross University

This article was originally published on The Conversation. Read the original article.