Driven by both decarbonisation targets and the circular economy agenda, producing TDF (tyre-derived fuel) from waste tyres has become a mainstream route for energy-intensive sectors such as cement, power generation, and steelmaking to reduce both costs and emissions. At the core of TDF quality, throughput, and project economics lies one decisive factor: a refined shredding and pre-treatment system.

With circular shredding technology at its core, HARDEN is redefining tyre recycling, enabling “black waste” to be reliably transformed into premium TDF fuel with a calorific value of around 8,000 kcal/kg, clean combustion performance, and stable energy output.

1. TDF Alternative Fuel: The Regenerative Destination of End-of-Life Tyres

TDF (tyre-derived fuel) is a standardised rubber fuel produced through shredding, contaminant removal, and screening. It offers three irreplaceable advantages:

High calorific value – Comparable to coal and superior to lignite, with stable combustion efficiency
Low emissions – Co-processing results in lower SOx and NOx emissions, supporting corporate decarbonisation targets
Strong economics – Replacing coal significantly reduces fuel costs while allowing companies to monetise waste treatment and benefit from policy incentives

Up to 70% of TDF quality is determined by shredding and pre-treatment. Non-uniform particle size, residual steel wire or fibre contamination directly lead to blockages, accelerated wear, calorific fluctuations and potential emission exceedances. Without precision shredding, high-quality TDF is unattainable.

Traditional single-stage shredding lines can only produce low-grade fuel and fail to meet the strict requirements of cement kilns or power plants for uniform particle size, high purity and continuous feeding.

Competition in TDF is fundamentally competition in pre-treatment technology.

2. Technical Backbone: Circular Shredding Pre-treatment System

As a contributor to domestic alternative-fuel standards and with more than a decade of expertise in solid-waste shredding, Harden has developed a complete tyre-to-TDF processing line centred on circular shredding technology. The system enables direct feeding, multi-stage shredding, closed-loop screening, and uniform discharge.

Core Process: Two-Stage Shredding + Recirculating Screening

Primary twin-shaft shredding
Low-speed, high-torque alloy-steel cutters shear whole tyres, including truck tyres, without bead removal, reducing them directly to roughly 100 mm pieces.

Recirculating screening
Multi-angle dynamic disc screens or star screens ensure precise classification. Oversized material is automatically returned to the shredding chamber, forming a closed-loop system.

Secondary precision shredding
Rubber chips are consistently reduced to the standard TDF size of approximately 50 mm, achieving ≥95% uniformity in output.

Circular Shredding Technology: Three Core Values

No pre-treatment required – Whole tyres can be fed directly, reducing labour, improving safety and increasing efficiency
Exceptional particle consistency – Continuous recirculation ensures highly uniform TDF for more complete combustion
High throughput and long service life – Line capacity of 7–12 tonnes per hour, with wear-resistant tooling and stable continuous operation

3. Why Circular Shredding Is the Optimal Solution for TDF

For environmental outcomes: near-complete resource recovery and elimination of “black pollution.”
For operators: coal substitution delivers cost savings, emission reductions, and waste-treatment revenue simultaneously
For equipment owners: modular design, compact footprint, easy maintenance, and upgrade compatibility

In the global shift towards alternative fuels, precision shredding pre-treatment is not a supporting step — it is the strategic value centre of the TDF supply chain.

End-of-life tyres are not the end of the story; they are the starting point of green energy.
The foundation of TDF lies in pre-treatment, the foundation of pre-treatment lies in precision shredding, and the foundation of shredding lies in circular technology.

Through technological innovation, Harden is tackling the challenge of tyre waste, giving end-of-life tyres a new life via circular shredding pre-treatment systems. This supports industrial resource recovery, low-carbon energy transition and economic optimisation, providing robust equipment solutions for achieving decarbonisation targets.