India's secondary steel sector — comprising re-rolling mills, induction furnaces, and heat treatment units — is concentrated in industrial clusters across Gujarat (Bhavnagar, Rajkot, Surat), Maharashtra (Pune, Nashik), and Rajasthan (Bhilwara). These units use massive quantities of coal and furnace oil for their reheating furnaces and annealing ovens. Biomass pellets are gaining traction as a cost-effective, GPCB-compliant alternative.
Applications in Steel & Metal Processing
Biomass pellets are suitable for several thermal processes in the secondary steel sector:
- Reheating furnaces: Steel billets and blooms are heated to 1100–1250°C before rolling. Biomass pellets with 4400+ Kcal/kg GCV can achieve these temperatures in modified grate-fired furnaces.
- Annealing ovens: Wire, sheet, and strip annealing at 700–900°C is an ideal application for biomass — the temperature range is easily achievable with controlled combustion.
- Foundry cupola preheating: Pre-drying of molds and ladle preheating can be done with biomass burner systems.
- Process steam for surface treatment: Pickling, galvanizing, and powder coating lines use steam — biomass-fired boilers serve this load efficiently.
Technical Considerations for High-Temperature Applications
For reheating furnaces targeting above 1000°C, biomass pellets are typically used in a modified pusher furnace or walking beam furnace with a biomass gasifier or staged combustion burner. Direct grate firing of pellets is suitable up to 900°C. Above this threshold, gasification-based biomass systems are required — a one-time capital investment of ₹15–₹40 lakh for typical 5–15 TPH furnace sizes.
Cost Impact for a 10 TPH Re-rolling Mill
| Parameter | Coal | BBI Biomass Pellets |
|---|---|---|
| Monthly fuel consumption | 120 MT | 105 MT (higher GCV) |
| Cost per kg | ₹12.50 | ₹10.50 (contract) |
| Monthly fuel cost | ₹15,00,000 | ₹11,02,500 |
| Ash disposal | ₹1,20,000 (30% ash) | ₹12,600 (2% ash) |
| Total monthly saving | ₹4,04,900 (25.3%) | |
GPCB Compliance for Metal Industry Units
Steel and metal processing units in Gujarat are classified as Red Category under GPCB. Stack emission norms for particulate matter (≤150 mg/Nm³) and SO₂ (≤200 mg/Nm³) are frequently violated by coal-fired furnaces. Biomass pellets with <0.1% sulfur and <2% ash dramatically reduce both PM and SO₂ emissions, helping units pass GPCB stack tests and avoid closure notices.
Contact BBI for a metal industry-specific supply proposal and technical consultation.