Every BBI biomass pellet begins not in a factory, but in Gujarat's farmlands. The cotton fields of Ahmedabad district, the groundnut farms of Saurashtra, the mustard fields of North Gujarat — these are the true origins of our fuel. The journey from agricultural residue to certified industrial fuel involves five precise manufacturing steps, each designed to maximise the GCV while minimising ash and moisture.
Step 1: Raw Material Sourcing and Quality Screening
BBI procures agricultural residues directly from farmer cooperatives and aggregators across Gujarat. Our procurement team evaluates each feedstock source for three parameters before purchasing: baseline GCV, ash content, and moisture level. Only feedstocks meeting our minimum incoming quality standards are accepted into the production chain.
Primary raw materials:
- Cotton stalks and husks: GCV 4000–4200 Kcal/kg, very low ash
- Groundnut shells: GCV 4200–4400 Kcal/kg, excellent combustion characteristics
- Mustard stalks: GCV 4100–4300 Kcal/kg, low sulphur
- Sawdust and wood waste: GCV 4200–4500 Kcal/kg, ultra-low ash
Step 2: Pre-Processing — Shredding and Grinding
Raw agricultural residue arrives in large volumes and irregular sizes. Industrial hammer mills and shredders reduce the material to a uniform particle size of 3–5mm. Consistent particle size is critical for uniform die extrusion in the pellet press. This step also removes large contaminants (rocks, soil clumps) through vibrating screens.
Step 3: Drying — Achieving <10% Moisture
This is arguably the most important step. Incoming biomass can have 20–35% moisture. Our rotary drum dryers use controlled heat to reduce this to strictly below 10%, usually targeting 8–9%. The drying step directly determines the final pellet's GCV — higher moisture means lower effective heat output. We maintain detailed batch records of pre-drying and post-drying moisture for quality documentation.
Step 4: High-Pressure Extrusion — Pellet Formation
Dried, ground biomass is fed into our ring-die pellet presses under high pressure (100–150 MPa) and moderate temperature. The combination of pressure and heat causes the natural lignin in the biomass to act as a binding agent, forming dense cylindrical pellets without any chemical binder or additive. This is critical — it means our pellets are 100% natural, with no artificial chemicals introduced into the fuel.
Pellets exit the die at 6mm or 8mm diameter and 15–40mm length, cooled immediately by counterflow air to harden the outer surface.
Step 5: Quality Testing and Dispatch
Each production batch undergoes final quality sampling. Samples from the batch are tested in our in-house lab for GCV, moisture, ash content, sulphur, and bulk density. Batches meeting all specification parameters are cleared for dispatch with a Certificate of Analysis. Sub-standard batches are reprocessed or rejected.
"Our manufacturing philosophy is simple: every pellet that leaves our facility must perform exactly as the customer expects — every single time."— BBI Quality Assurance Team, Ahmedabad
To tour our facility or request a production sample, contact BBI's manufacturing team.