Waste Management Review speaks with Molectra Technologies’ John Dobozy about his unique approach to tyre recycling and the development of several niche products for wide ranging customers and markets.
A critical first step to accelerating off-the-road tyre resource recovery has been completed, with the release of a new report commissioned by Tyre Stewardship Australia.
While the Australian tyre recycling conversation has traditionally focused on passenger and truck tyres, the disposal and recycling of off-the-road (OTR) tyres is largely uncharted territory.
OTR disposal and recycling is particularly challenging in the mining sector, where their size, construction and remote location makes material processing onerous.
To get an accurate picture of OTR, Tyre Stewardship Australia (TSA) engaged Randell Environmental Consulting for a research project. Working with Brock Baker Environmental consulting, the firms completed an analysis of the consumption and fate of OTR tyres.
The analysis was borne from the recommendations of a previous report that same year which identified the need to better understand OTR tyre consumption and fate.
This was given the estimated recovery rate in 2018-19 was a mere 11 per cent, compared to 89 per cent recovery within the passenger and truck sector. The remaining 89 per cent of OTR tyres were not recovered, with an assumed 81 per cent disposed onsite at mining, farming or similar sites.
The report covers the agriculture, aviation, construction, manufacturing and trade and mining sectors. In breaking down the findings, the mining sector had the highest OTR generation in 2018-19 at 68,000 (58 per cent), followed by agriculture at 31,400 (27 per cent) and the other sectors. Combining all the sectors collectively, the five-year average for OTR generation is around 119,000.
Importantly, the report is an entry point to facilitate more informed discussions and does not look to provide the answers to improved used mining tyre recovery.
Lina Goodman, TSA CEO, says stakeholder interviews and visits will inform further information-gathering.
“OTR tyres have been left off the discourse for a while. This is largely because the opportunities to manage them from a resource recovery perspective haven’t been there, or were limited. We’re now starting to see that change,” Lina says.
“While OTR research has traditionally focused on the mining sector, this report tells us there are other parts of OTR that are just as important like agriculture and construction.
“What’s significant is they may be a little bit simpler to manage than the large earthmoving tyres on mining sites.”
WHAT HAPPENED TO THE TYRES?
Australia’s used OTR tyres are subject to a range of different fates possible, including retreading for reuse, civil engineering, turned into processed rubber products, pyrolysis, stockpiles, landfill and exported overseas.
The report’s authors consulted with state and territory regulators and the used tyre recycling industry to understand the fate of these tyres.
Around 93 per cent of used OTR tyres within the mining sector, or 63,300 tonnes, went to onsite disposal.
Industry consultation finds that while repair of large mining tyres is a well-established practice, retreading of OTRs is not practised in Australia except in aviation, where retreading is a normal practice.
Civil engineering is not a significant fate either, with an uptake of around 1200 tonnes of used OTR tyres used in the construction of retaining walls or similar.
Notably, illegal stockpiling, excluding onsite disposal of OTRs was not common in 2018-19, with only 2300 tonnes. Likewise landfilling is unlikely (at 4000 tonnes) and pyrolysis and crumb, granules and buffing is rare.
An estimated 14,400 tonnes of used OTR tyres were exported overseas for processing in 2018-19, with 2500 tonnes of this from the aviation sector. The remaining 12,000 tonnes is believed to be from the construction and manufacturing sectors and sectioned into manageable sized pieces for export.
FUTURE AND EXISTING PRACTICES
After consultation with key mining jurisdictions (WA, QLD, NSW and NT), environment protection agencies and the waste industry, the report highlighted the various storage practices which differ from state to state.
Onsite disposal has been the historical practice as there hasn’t been alternatives. The report points out that mining companies should expect the current practice to cease.
A key point is that only a few of Australia’s used tyre processors are currently able to receive large mining OTR tyres.
Moreover, the report estimates the collection cost of large mining tyres can fall anywhere between $300 to $770 per tonne, with indicative processing per tonne a further $300 to $800 per tonne depending on the recovery outcomes.
All jurisdictions consulted allowed onsite tyre disposal but the requirements were nuanced.
For example, WA permits used mining tyres to be disposed onsite in designated areas defined in the mining site environmental licence. Conversely, Queensland had no limits on quantities or location for onsite storage and disposal, but specific projects had their own requirements. Consultation with EPA NSW staff found that mining tyres were allowed by EPA to be stored and disposed onsite with no limits on quantities or location.
QLD, NSW and WA are all reviewing the current practise of allowing onsite disposal and the QLD Government has raised the issue with the Minerals Council of Australia.
Other areas such as converting mining OTRs into crumbed rubber and steel or tyre-derived fuel are technically feasible, but energy intensive.
Recovery by pyrolysis remains an emerging option, with several sites in Australia targeting used mining tyres as a primary feedstock. This includes the Pearl Global facility and Tytec Recycling as examples which are all based in Queensland.
“The good news is there is a lot of interest from organisations to invest in providing solutions for the sector,” Lina says.
As for the critical next steps? An OTR working group is already underway comprising the earthmoving sector, tyre companies and government.
To improve Australian OTR recovery, the report proposes a range of options to consider. This covers continued collaborative discussions via the working group and OTR manufacturers contributing to the scheme with an aim of expediting the solutions.
Additionally, State and Federal Government intervention is also proposed with a regulatory framework to support these activities.
The framework should work in tandem with OTR sector moving towards the cessation of onsite disposal in all jurisdictions. Recyclers could then support that by developing onshore energy markets for tyre-derived fuel recovery.
Lina says all of these factors, in addition to a roadmap coming in 2020 from the working group, will be critical to achieving change.
Tyre Stewardship Australia has partnered with Snap Send Solve to enable simple public reporting of local tyre stockpiles or dumping hotspots.
Snap Send Solve is a digital platform that facilitates the identification of local issues such as illegal waste dumping and broken infrastructure.
Snap Send Solve CEO Danny Gorog said users capture photos on their smartphones, and the app notifies relevant authorities.
“Now users can easily report not just rubbish, but more specifically dumped or stockpiled waste tyres,” Mr Gorog said.
“The reports will be provided to the relevant council for resolution, as well as Tyre Stewardship Australia, who will monitor hotspots and communicate directly with tyre retailers, state and local authorities to stamp out poor behaviour.”
Tyre Stewardship Australia CEO Lina Goodman said the free smartphone app will help monitor where waste tyres are being dumped or stockpiled.
“If you see some dumped waste tyres or what you suspect is a stockpile, simply snap a photo and send a report using the app,” Ms Goodman said.
“The appropriate authority can then be alerted, and the problem can be solved.”
Ms Goodman said 10 per cent of the almost 56 million tyres discarded annually in Australia are domestically recycled.
“The rest are either exported overseas or disposed to landfill, stockpiled and illegally dumped,” Ms Goodman said.
“Understanding how we can work together to ‘stop the stockpile’ that is generated by illegal operators is the first step in finding sustainable end outcomes for a greater number of used tyres in Australia.”
According to Ms Goodman, there are currently up to nine major known stockpiles around the country, which cost an estimated $5 million each to clean up.
City of Port Phillip Victoria Mayor Dick Gross said he welcomed the addition of tyres as a new category on the app.
“This means we can gain a better understanding of where the hot spots are and thus deal with the dumped or stockpiled tyres faster,” Mr Gross said.
The Australian Road Research Board (ARRB) is recommending further research into the use of passenger vehicle tyres in bitumen production.
ARRB Senior Professional Leader Guy Hand said Victoria’s Transport Department, formerly VicRoads, engaged ARRB to undertake a literature review on the subject.
“Using more end-of-life tyres in road construction is a known way to curb significant environmental challenge for Australia. The question is, how do we make that happen?,” Mr Hand said.
“One possibility is to engage the use of end-of-life car tyres.”
Most crumb rubber repurposed into Australian road construction currently comes from end-of-life truck tyres.
According to Mr Hand, truck tyres are predominantly composed of natural rubber, whereas car tyres contain a high proportion of synthetic rubber, as well as a nylon component.
“It is not well understood whether synthetic rubber will behave in bitumen in the same nature that natural rubber does,” Mr Hand said.
“No data from an Australian context is available to establish the compatibility and performance of synthetic rubber in bitumen.”
Mr Hand said the key objective of the review is to understand the current specifications of crumb rubber sourced by other road agencies, and the market availability and processing requirements of passenger vehicle tyres.
ARRB were additionally asked to identify the benefits and limitations of using passenger vehicle tyre crumb rubber as a road material in asphalt and sprayed seals.
“There are also barriers for recycling car tyres to be considered, such as economic, environmental and processing challenges,” Mr Hand said.
“With the Victorian Government’s focus on increasing the use of recycled materials in road construction, this literature review will help inform all stakeholders on the issues associated with the use of passenger vehicle tyres in bitumen.”
Eight members of Tyre Stewardship Australia are taking their role as tyre manufacturers a step further by working towards a circular economy future.
The Australian Council of Recycling (ACOR) and the Australian Tyre Recyclers Association (ATRA) have announced a partnership as part of ACOR’s new national divisional structure.
Under the new structure ATRA Executive Officer Rob Kelman will serves as Executive Director of the new tyre recycling and container deposit scheme divisions.
“The used tyre recycling sector is maturing alongside the rest of the recycling industry in Australia and this amalgamation is testament to its important role in the industrial and manufacturing sector.
“There will be a continued focus on ATRA’s approach to industry audits and accreditation, but it will also bring much more accountability in terms of our exports,” Mr Kelman said.
ATRA members recycle more than 20 million used tyre units per annum, representing 95 per cent of Australia’s used tyre recycling activity.
ACOR President Peter Tamblyn said the partnership would help promote industry leading practices in tyre recycling and drive the sustainability of the used tyre recycling sector.
“Industry leaders and companies have agreed that working together under the one banner will help bring a focus to the issues and projects that matter and to necessary policy reform.
“The recycling industry employs 50,000 people across Australia and is worth around $20 billion to the Australian economy, and this shows us further maturing,” Mr Tamblyn said.
A trial last year saw Equine Air paving product installed on 550 square meters of Pakenham Racing Club Tynong approach track.
The product was manufactured as part of a Tyre Stewardship and Flexiroc partnership, using over 3000 equivalent passenger units, or 27 tonnes of recycled rubber.
Results from the trail were positive with riders reporting less concussive force and reduced potential for horse industry.
The unique geotechnical profile design allows the product to be placed over problematic ground conditions and drain quickly after rainfall.
Tyre Stewardship Market Development Manager Liam O’Keefe said the product is one of many developments for the company, as it seeks to grow valuable markets for recycled tyre-derived material.
“Equine Air is one of a new generation of products in the paving and surfacing industry that not only deliver better on-site outcomes but also offer a major beneficial end-use of tyre-derived material.
“The work that Tyre Stewardship Australia, and our project partners, have been undertaking in this space is certain to deliver major practical and environmental dividends in the future,” he said.
Tyre Stewardship Australia’s other new products include new mixes of crumbed rubber asphalt, permeable paving and artificial playing surfaces.
Equine Air suites a wide range of applications such as synthetic fibre tracks, sand tracks, horse walks and mounting yards.
Tyre Stewardship Australia hopes the successful trial will influence other racing tracks to use the material, creating long-term potential for the use of rubber granulate.
Around 850 used tyres have been recycled to pave a 335 metre stretch of road as part of a crumbed rubber asphalt trial in the City of Mitcham, South Australia.
The asphalt trial is funded by Tyre Stewardship Australia to support research and development into ways of improving local markets for tyre-derived products.
- Numurkah tyre stockpile to be cleaned up
- Redesigning the wheel: Tyre Stewardship Australia
- Tyre pyrolysis and gasification report to inform industry
A specific warm mix of dense-graded crumb rubber modified asphalt was used on the trial, which has been laboratory tested and found to be suitable for use in challenging underlying soil conditions, such as reactive clay.
The test will focus on a range of performance factors including cracking, rutting, moisture retention and general durability. The results of the test are expected to increase the specification of such roads across Australia.
If successful, the trail aims to contribute to doubling the use of recycled tyre rubber in Australia’s roads, leading to an increase in the percentage of annual used tyres consumed from around five per cent to 10 per cent.
Australia generates around 56 million end-of-life tyres each year, however only around 10 per cent of that volume is recycled domestically in all uses. Crumbed rubber asphalt and rubberised road surface spray seals can provide a potentially benefit of increasing recycling rates and improving roads.
City of Mitcham Mayor Heather Holmes-Ross said there was not only a sustainability dividend, as the asphalt will also have the potential to directly lower maintenance costs as it is less prone to cracking and rutting.
“We are trialling the crumb rubber asphalt because of the significant environmental benefits as well as the opportunity to improve the quality and life of road pavements, particularly in areas of reactive clay soils,” Ms Holmes-Ross said.
Acting CEO of Tyre Stewardship Australia Steve Clifford congratulated the council for conducting the test.
“The work done in South Australia will play an important role in creating valuable domestic recycling outcomes for end-of-life tyres. Outcomes that can also deliver new green jobs,” Mr Clifford said.
Ongoing testing is scheduled to run for two years, with results monitored on a regular basis to assess the key performance parameters.
Tyre Stewardship Australia (TSA) has expanded to include a Demonstration and Infrastructure stream to grow the end market for tyre-derived products.
The new project stream will support projects that offer significant domestic use of tyre-derived products and demonstrate their benefits and viability to potential end users and product specifiers.
- Creating new value: Tyre Stewardship Australia
- JAX Tyres commits to TSA Accreditation
- The road ahead: Tyre Stewardship Australia
A minimum 1:1 funding criterion is required for all projects, with a minimum funding level of $50,000 excluding GST and maximum of $300,000 excluding GST, however considerations will be given for larger or smaller project cash contribution on a dollar for dollar basis if the case can be made for the achievement of greater outcomes.
Applications will be assessed most favourably if a project consumes high volumes of Australian tyre-derived products and are considered innovative by TSA. Projects that can demonstrate a strong correlation between the delivery of the project and ongoing consumption of tyre derived products will also be strongly considered.
Projects must have collaborative partnerships between industry, research bodies and end users such as councils, road authorities, manufacturers or civil engineering and construction companies to demonstrate a realistic market application.
One example is the testing performed by state road authorities of the application of the newly released Australian Asphalt Pavement Association national specifications for crumbed rubber containing asphalt.
Other projects include the University of Melbourne’s trial to develop an optimum blend of permeable paving that uses recycled tyres to create footpaths, bike paths, carparks and low volume traffic roads which also can provide water to nearby trees.
The expanded funding stream does not allow funding of recycling infrastructure, seed funding for new ventures, clean-up of stockpiles or for feasibility studies.
TSA has already committed more than $3 million in support of research and development projects that focus on finding new domestic uses for tyre derived products.
For more information and to apply, click here.
To inform the industry on the use of tyres in thermal processing plants, Tyre Stewardship Australia (TSA) has released a report into the effectiveness of both pyrolysis and gasification.
The Tyre Pyrolysis and Gasification Technologies – A brief Guide for Government and Industry report looks at the global history of operating plants and considers the economic and end-product market factors that are critical to the commercial viability of recycling technologies in the Australian market.
- Lomwest build wall of used tyres in WA
- JAX Tyres commits to TSA Accreditation
- ACCC re-authorises Tyre Stewardship Scheme
High temperature thermal processing can create oil, synthetic gas, carbon black and steel, while also providing a way of handling a waste stream that can have potential environmental or health problems if stockpiled.
TSA Market Development Manager Liam O’Keefe said the motivation of the guide was to provide the industry thought leadership on both emerging technologies as possible recycling solutions and to better inform government and businesses considering investment in such technologies.
“Obviously, TSA is interested in any technology that can sensitively recycle almost 100% of a waste tyre, but we must be aware of the prevailing market conditions, investment costs and competitive pressures that play a role in establishing the economic sustainability of such projects,” Mr O’Keefe said.
“We believe the guide, by providing a high level of consultation, analysis and technical and economic detail, will be an aid to decision making around proposed facilities.
“No one technology will meet the waste tyre environmental challenge on its own. The best result with such immense global resource recovery and management challenges usually comes from a combination of options, offering the flexibility to adjust to future conditions and developing market demands.”
The report can be downloaded here, with a full report on thermal tyre processing technologies by request from TSA.