Introduction
In pursuing a cleaner environment and a regenerative, circular economy, the recycling and reuse of materials play a vital role. One such material that has gained significant attention is scrap tyres. These discarded tyres can pose environmental hazards and occupy valuable landfill space if not properly managed. However, innovative technologies, such as Tyre Derived Fuel (TDF), provide a sustainable solution to address these challenges. In this article, we will explore the concept of tire-derived fuel, its applications in various industries, and the environmental benefits it offers.
The Growing Need for Tyre Recycling
The ever-increasing number of vehicles on the road has led to a corresponding rise in the volume of used tyres, creating both a waste management challenge and an opportunity for resource recovery. Approximately 51 million equivalent passenger units of end-of-life tyres are generated annually in Australia. The disposal of these tyres in landfills not only contributes to land pollution and human health impacts but also represents a loss of valuable resources that could be recycled or recovered. Tyre recycling offers a sustainable alternative by extracting value from used tyres, effectively diverting them from landfills.
Tyre Derived Fuel: An Alternative Energy Resource
Among the promising avenues in tyre recycling, Tyre Derived Fuel (TDF) stands out as a renewable energy source. Shredding tyres produce TDF and are often mixed with other fuels like wood, coal, or chemical waste to supplement industrial processes. It serves as a substitute for finite fossil fuels in applications such as cement kilns, electricity generation, and industrial process heat. Over 80% of Australia’s recycled used tyres are exported as TDF to South East Asia, where it replaces coal in cement kilns and power generation facilities.
The use of TDF as an alternative fuel delivers a trifecta of environmental benefits. It reduces our dependence on finite fossil fuel resources, conserving natural reserves. TDF combustion generates fewer greenhouse gas emissions than traditional fossil fuels. In fact – for every tonne of TDF replacing black coal, one tonne of CO2 is saved, making it a potent ally in the fight against climate change. Furthermore, TDF significantly reduces the volume of waste tyres destined for landfills, addressing the waste management challenge associated with end-of-life tyres.
Applications of Tyre Derived Fuel
Tyre Derived Fuel finds applications across various industries, providing a sustainable alternative to fossil fuels:
- Cement Kilns: Approximately 46% of TDF is used in cement manufacturing facilities. It is burned in kilns to produce gypsum for concrete mix. Cement kilns are an ideal fit for TDF, as they can burn both the rubber and the wire content, eliminating the need for wire removal and reducing processing costs.
- Pulp and Paper Mills: TDF can be blended with wood chips in pulp and paper mills to create a hotter and drier fire, enhancing efficiency. The ash produced in this process contains lower levels of toxic heavy metals than coal ash, benefiting farmers.
- Electric Utilities: Electric utility companies can use TDF as an alternative fuel in their boilers to increase burning temperatures and reduce nitrate emissions, providing a sustainable option for energy production.
- Dedicated Tire to Energy Facilities: These specialised facilities, like the one in Sterling, Connecticut, burn whole tyres directly, producing energy sold to local utilities. While initial construction costs can be high, these facilities offer an efficient and environmentally friendly solution for tyre waste management.
Environmental Benefits of Tyre Derived Fuel
While the environmental impact of TDF remains a topic of debate, several key findings shed light on its implications:
- TDF combustion produces energy comparable to burning petroleum and 25% more energy than burning coal, making it a more efficient fuel option.
- The ash produced from TDF combustion contains lower levels of toxic heavy metals than coal ash, reducing the environmental impact of waste disposal.
- TDF combustion produces fewer greenhouse gas emissions compared to traditional fossil fuels, contributing to climate change mitigation.
Processing TDF into Crumb and Powder
In addition to its use as a fuel, TDF can be further processed into crumb and powder forms for various applications. Crumb rubber is produced by shredding and grinding TDF into small particles, which can be used in applications such as paving, rubber mats, and athletic tracks. Powdered TDF can be used as a filler in rubber products, reducing the need for virgin materials and enhancing the sustainability of rubber manufacturing. These processing methods open up new avenues for TDF utilisation, promoting a more circular and sustainable approach to tyre recycling.
Advancements in Pyrolysis Technology
Pyrolysis, a chemical recycling process, has emerged as a game-changing technology in tyre recycling. It involves the thermal decomposition of tyres in an oxygen-free environment to produce valuable by-products. Pyrolysis offers the opportunity to convert end-of-life tyres into high-value chemicals, materials, and fuels, contributing to a circular economy. Ongoing research and development in pyrolysis technology pave the way for widespread adoption and optimisation in various regions.
Realising the Potential of Tyre Derived Fuel
Although Tyre Derived Fuel (TDF) has found its way into various Australian applications over the last decade, the untapped potential awaits optimal resource recovery. Acknowledging the promising prospects of TDF in achieving economic and sustainable results is crucial. It’s worth highlighting that the financial feasibility of tyre recycling initiatives ideally has a minimum throughput of approximately 3 tonnes per hour. Additionally, it’s noteworthy that while unprocessed EOL tyres were prohibited in 2021, TDF (in sizes under 150 mm) remains an exportable form of tyre waste. This ensures the continuity of export partnerships and creates new opportunities.
By integrating TDF into industrial processes, we can boost resource recovery and play a pivotal role in reducing Australia’s greenhouse gas emissions.
Conclusion
In conclusion, tyre recycling, with a primary focus on Tyre Derived Fuel (TDF), offers a sustainable solution to the challenges posed by end-of-life tyres. TDF serves as a renewable energy source, reducing greenhouse gas emissions, conserving finite resources, and diverting waste from landfills. With advancements in pyrolysis technology and ongoing industry initiatives, the tyre recycling sector is poised for a greener and more sustainable future. Embracing tyre recycling and TDF can help us contribute to a world that is environmentally conscious, resource-efficient, and circular.
For more information on TDF Recycling, contact Waste Initiatives at info@wasteinitiatives.com.