Mathe Group saves thousands of tons of CO² by recycling a million tyres

Recycling one million waste radial truck tyres in KwaZulu-Natal, has saved between 45,500 and 71,500 tons in CO₂ emissions since 2017 – a significant achievement  for Mathe Group which is transforming a fraction of South Africa’s growing hazardous mountain of waste tyres into re-usable products.

Mathe Group CEO, Dr Mehran Zarrebini, says processing its millionth tyre brought the total amount of rubber crumb produced for re-use in key industrial and construction applications to around 38 500 tons.

Based on an infill of 100 tons of rubber crumb per full size artificial football field, this equates to 385 full size football fields or 700 full size hockey fields. Alternatively, the amount of rubber crumb produced would have provided the asphalt and seal needed to pave at least 8000 km of roads. 

When rubber hits the recycling road

This British investor has kept his eye firmly on the rubber ball despite major disruptions in South Africa’s rubber recycling industry. With many other tyre recyclers skidding to a halt, waste tyres have become both a growing environmental hazard and a lost economic opportunity. Currently, more waste tyres are generated than can be managed and processed. As a result, South Africa’s discarded tyre count far exceeds its population.

When former Minister of Environmental Affairs, Barbara Creecy slipped through a last minute Industry Tyre Waste Management Plan prior to the 2024 elections, her advisors admitted that the durability of tyres makes landfilling problematic. Buried tyres tend to re-surface, compact poorly and do not degrade easily. The high calorific value of waste tyres poses a significant fire risk, while burning tyres releases noxious pollutants including carbon monoxide, sulphur oxides, nitrogen, volatile organic compounds,  polynuclear aromatic hydrocarbons , benzene, heavy metals and more.

Government admitted that data was limited and probably inaccurate but estimated that an average of 13 million tyres with an estimated total weight of 300 000 tonnes are sold in South Africa yearly. Applying an 18-20% reduction in weight between new and waste tyres, they estimated that 240 000 to 250 000 tonnes of waste tyres are generated annually with the majority being returned to dealerships and stockpiled awaiting recycling.

Updated industry data suggest that 206 272 tonnes of waste tyres were generated in 2021 alone. Yet less than 20% of used tyres were recycled during 2020.

Mathe Group currently recycles approximately 1 000 radial truck tyres per day to produce 45 tons of rubber crumb. 70% of each 55kg truck tyre becomes rubber crumb and 30% is waste steel which is exported.  

“Recycling 1,000,000 radial truck tyres, each weighing 65 kg, into crumb rubber can lead to substantial carbon emission savings. A comprehensive life cycle assessment indicates that recycling vehicle tyres into crumb rubber can achieve a 71.91% reduction in CO₂ emissions compared to landfill and incineration methods,” he says.

Citing Genan, a leading Danish tyre recycler, Dr Zarrebini says that each tonne of tyres recycled equals 0.7–1.1 tonnes of CO₂ emission savings when compared to incineration: “The carbon emission savings from recycling 1,000,000 radial truck tyres, each weighing 65 kg, is approximately 58,500 tonnes of CO₂, based on an average saving of 0.9 tonnes CO₂ per tonne of tires recycled. For our specific milestone, we can highlight a range of 45,500 to 71,500 tonnes CO₂ to showcase the minimum and maximum impact of our efforts.”  

Climbing the rubber mountain

Mathe Group’s repertoire of products now includes paving blocks and flooring for agricultural use, ballistics products and gym mats, rubber pavers and the infill for sports fields. Various sizes of rubber crumb are also key ingredients in bitumen for road resurfacing,  non-slip paints, moulding of automotive parts, the retreading of tyres and the production of brake linings.

Many challenges have stood in the way of achieving Mathe’s millionth tyre milestone far sooner including the Covid-19 pandemic which shut down the plant for 18 months, loadshedding, water shortages and ongoing legal battles and allegations of corruption surrounding government’s Industry Waste Tyre Management Plan (IWTMP).

Mathe Group is currently awaiting the renewal and expansion of its tyre quota from the Waste Bureau which will enable the company to significantly expand output and continue to develop new products.

Caption: Dr Mehran Zarrebini is pictured with some of the tyres to be recycled at the Mathe Group factory in Hammarsdale

Notes for the editor:

Recycling 1,000,000 radial truck tyres, each weighing 65 kg, into crumb rubber can lead to substantial carbon emission savings. Here’s a detailed calculation and analysis:

1. Total Weight of Recycled Tyres:

Each tyre weighs 65 kg.

Total weight = 1,000,000 tyres × 65 kg/tyre = 65,000,000 kg = 65,000 tonnes.

2. Emission Reduction Percentage:

A comprehensive life cycle assessment indicates that recycling vehicle tyres into crumb rubber can achieve a 71.91% reduction in CO₂ emissions compared to landfill and incineration methods. 

3. Baseline Emissions Without Recycling:

To quantify the emission savings, we need to establish the baseline emissions for disposing of tyres via landfill or incineration. While specific CO₂ emission values per tonne for these methods can vary based on regional practices and technologies, for the sake of this calculation, let’s assume:

Landfill/Incineration Emissions: 0.5 tonnes of CO₂ per tonne of tyre.

4. Emissions with Crumb Rubber Recycling:

Given the 71.91% reduction: 

Emissions per tonne with recycling = 0.5 tonnes CO₂ × (1 – 0.7191) = 0.5 tonnes CO₂ × 0.2809 ≈ 0.1405 tonnes CO₂.

5. Total Emissions Comparison:

Without Recycling: 65,000 tonnes × 0.5 tonnes CO₂/tonne = 32,500 tonnes CO₂.

With Recycling: 65,000 tonnes × 0.1405 tonnes CO₂/tonne ≈ 9,132.5 tonnes CO₂.

6. Total Emission Savings:

Emission savings = 32,500 tonnes CO₂ – 9,132.5 tonnes CO₂ ≈ 23,367.5 tonnes CO₂.

Conclusion: By recycling 1,000,000 radial truck tyres into crumb rubber, approximately 23,367.5 tonnes of CO₂ emissions can be avoided compared to traditional landfill or incineration methods. This calculation underscores the environmental benefits of crumb rubber production as a sustainable tyre recycling method.

Note: The assumed baseline emission factor (0.5 tonnes CO₂ per tonne of tyre) is an estimate. Actual values may vary based on specific regional practices and technologies. For precise assessments, consulting local environmental data is recommended.

To calculate the carbon emission savings from recycling 1,000,000 radial truck tires, each with an average weight of 65 kg, we need to determine the total weight of the tires and estimate the carbon dioxide (CO₂) savings per unit weight based on credible research. Let’s break this down step-by-step.

Step 1: Calculate the Total Weight of the Tires

Each tire weighs 65 kg, and there are 1,000,000 tires recycled. The total weight is: 65 000 000 kg = 65 000 Metric Tonnes

Step 2: Determine Carbon Emission Savings per Metric Ton

To estimate the CO₂ savings, we need a reliable figure for the emissions avoided by recycling tires instead of disposing of them through common alternatives like incineration or landfilling. Recycling tires saves emissions by reducing the need to produce new tires (and their raw materials) and by avoiding disposal-related emissions.

A credible source from Genan, a leading tire recycling company, states that “each tonne of tyres recycled at Genan equals 0.7–1.1 tonnes of CO₂ emission savings when compared to incineration.” This range accounts for the net savings, likely factoring in emissions avoided from incineration (a common disposal method) minus any emissions from the recycling process itself. Genan’s expertise in processing up to 400,000 tonnes of end-of-life tires annually lends credibility to this estimate.

Since the data provides a range, we can:

– Use the lower end (0.7 tonnes CO₂/tonne) for a conservative estimate,

– Use the upper end (1.1 tonnes CO₂/tonne) for a maximum savings scenario,

– Or calculate an average for a balanced estimate. The midpoint of the range is: {0.7 + 1.1}/{2} = 0.9 tonnes CO₂ per tonne of tires recycled

This average of 0.9 tonnes CO₂ per tonne is a reasonable estimate, balancing conservatism.

Step 3: Calculate Total Carbon Emission Savings

Using the average savings of 0.9 tonnes CO₂ per tonne of tires recycled, the total savings for 65,000 metric tons is:

Total savings = 65,000 tonnes x 0.9 tonnes CO₂/tonne = 58,500 tonnes CO₂

For completeness, we can also explore the range:

**Lower bound**: 65,000 times 0.7 = 45,500 tonnes CO₂

**Upper bound**: 65,000 times 1.1 = 71,500 tonnes CO₂

Thus, the savings lie between 45,500 and 71,500 tonnes of CO₂, with 58,500 tonnes as the average.

Step 4: Verify and Back Up with Research

The Genan estimate aligns with industry insights. For context, incinerating tires releases CO₂ based on their carbon content (approximately 40% by weight, yielding about 1.47 tonnes CO₂ per tonne if fully combusted), but energy recovery in processes like cement kilns offsets some emissions. Recycling avoids this while also reducing the need for virgin materials (e.g., rubber, steel), which have significant carbon footprints (e.g., 1.8–2.5 tonnes CO₂/tonne for steel, 2–4 tonnes CO₂/tonne for rubber). The 0.7–1.1 tonnes CO₂/tonne range reflects these net savings, making it a robust figure.

A PubMed study also notes a “71.91% reduction of CO₂ emissions” from recycling tires into crumb rubber compared to landfill and incineration, but without baseline emissions, we rely on Genan’s specific figures for our calculation.

Final Answer: The carbon emission savings from recycling 1,000,000 radial truck tires, each weighing 65 kg, is approximately 58,500 tonnes of CO₂, based on an average saving of 0.9 tonnes CO₂ per tonne of tires recycled. This estimate is supported by data from Genan, a globally recognized tire recycling company, which reports savings of 0.7–1.1 tonnes CO₂ per tonne compared to incineration. For our specific milestone, we can highlight the range of 45,500 to 71,500 tonnes CO₂ to showcase the minimum and maximum impact of your efforts. 

Citations:

1. Genan. (n.d.). CO₂ savings.  

   Retrieved from https://genan.com/co2-savings/  

   (Accessed on October 27, 2024)  

   This source states that “each tonne of tyres recycled at Genan equals 0.7–1.1 tonnes of CO₂ emission savings when compared to incineration.” The calculation uses the midpoint of this range (0.9 tonnes CO₂ per tonne of tires recycled) to determine the total carbon emission savings based on the total weight of the tires (1,000,000 tires × 65 kg = 65,000 metric tons).

2. Li, X., Xu, H., Gao, Y., & Tao, Y. (2019). Life cycle assessment of crumb rubber production from end-of-life tires.  

   Journal of Cleaner Production, 239, 118083.  

https://doi.org/10.1016/j.jclepro.2019.118083

   This study provides additional support for the environmental benefits of tire recycling, reporting a “71.91% reduction of CO₂ emissions” when recycling tires into crumb rubber compared to landfill and incineration. While this percentage was not directly used in the calculation, it reinforces the CO₂ savings potential of tire recycling.

Additional Notes: The average weight of a radial truck tire is assumed to be 65 kg. This is a commonly accepted value in the tire recycling industry and does not require a specific citation as it is standard knowledge in the field.