Tire-derived fuel (TDF) has been used in cement kilns, paper mills, and industrial boilers for decades. It's not a new technology — it's a proven, cost-effective energy source that competes directly with coal and other solid fuels. Here's how TDF stacks up against traditional fuels and what industrial buyers should know before switching or supplementing.
What Is TDF?
Tire-derived fuel is waste tire material that has been shredded into chips — ranging from 152.4mm (6") down to 44.45mm (1¾") — for use as a supplemental or primary fuel in high-temperature industrial processes. Our standard TDF chip size range is 152.4mm (6") down to 44.45mm (1¾"), which covers the specifications required by most cement kilns. TDF can also be processed into smaller sizes for specific applications.
TDF vs. Coal: Key Comparisons
| Property | TDF (152.4mm–44.45mm Chips) | Bituminous Coal |
|---|---|---|
| BTU value (per lb) | 13,000–16,000 BTU | 11,000–14,000 BTU |
| Sulfur content | 1.2–1.5% | 0.5–4% |
| Ash content | ~4–6% | 8–12% |
| Steel content | ~15% (recoverable) | None |
| Moisture content | Low (2–5%) | Variable (5–20%) |
| Consistency | Uniform chip size | Variable particle size |
| Supply reliability | Steady, local supply | Subject to market pricing |
Why TDF Has a Higher BTU Value Than Coal
Tire rubber is essentially a hydrocarbon polymer — chemically similar to petroleum. This gives TDF a higher energy content per pound than most coals. A typical passenger tire contains approximately 25 lbs of rubber, which yields roughly 325,000–400,000 BTU when combusted. For cement kilns operating at 2,600°F+, TDF provides the high-temperature combustion profile needed for clinker production.
Emissions: What the Data Shows
TDF combustion in cement kilns is regulated under EPA's National Emission Standards for Hazardous Air Pollutants (NESHAP) for Portland Cement Manufacturing. Key findings from EPA and industry studies:
- At substitution rates up to 20–25% of total fuel, TDF does not significantly increase emissions of most regulated pollutants
- NOx emissions may increase slightly at higher TDF substitution rates
- SO₂ emissions depend on the sulfur content of both the TDF and the primary fuel
- The steel in TDF is captured in the cement clinker — it does not become airborne emissions
- Mercury emissions from TDF are generally lower than from coal
Facilities using TDF must comply with Benzene NESHAP and applicable state air quality permits. Eco Tire Solutions provides full compliance documentation with every TDF shipment.
Cost Advantages of TDF
TDF is typically priced at a discount to coal on a BTU-equivalent basis, for several reasons:
- Tire recyclers need to move volume — they're motivated sellers
- TDF supply is local and not subject to global commodity price swings
- Some states offer tipping fee revenue to TDF suppliers, further reducing buyer cost
- Long-term supply agreements can lock in pricing stability that coal cannot offer
Logistics & Handling
TDF chips are typically delivered by:
- Bulk walking floor trailer: 20–25 tons per load, most common for cement kilns
- Roll-off container: 10–15 tons, for smaller facilities or trial shipments
- Pneumatic trailer: For facilities with pneumatic unloading systems
TDF chips store well outdoors — they don't degrade significantly in weather. Standard pile storage with drainage is sufficient. No special handling equipment is required beyond what most industrial fuel facilities already have.
TDF Supply for Industrial Buyers
We supply 152.4mm (6") down to 44.45mm (1¾") TDF chips to cement kilns, paper mills, and industrial boilers across the Southeast. Full documentation, consistent spec, reliable delivery.