15–30% (15–30% moisture)
Also known as: pellet moisture range
The residual moisture content for pelletized digestate — low enough for stable storage and transport without spoilage or significant nutrient loss.
Last updated
Beyond definitions
Planning to start a CBG business?
Get the full business understanding — capex, regulations, machinery, vendor questions, and risk checks before you commit capital.
What is 15–30%?
15–30% is the residual moisture range for composted but unpelletised digestate, or for pellets in their final form — both representing materials stable enough for storage in 50 kg woven bags for 6–12 months without microbial spoilage, fungal growth, or significant nitrogen loss. Below 15% moisture, the material is essentially dust and inhibits microbial respiration; above 30%, moulds and yeasts grow within 4–8 weeks and the bag swells, splits, or develops off-odours.
The 15–30% range emerges from drying economics. Pushing moisture from 30% down to 15% takes roughly 150–200 kg of water removal per tonne of dry solids — at 800–1,200 kcal per kg of water evaporated, that is 120,000–240,000 kcal of thermal energy, or roughly ₹150–300 per tonne of dried product at Indian fuel prices. Pushing further from 15% to 10% (sometimes done for export-grade pellets) doubles the marginal energy cost because the remaining moisture is chemically bound rather than free water. Most Indian CBG plants land at 18–25% moisture in their finished bagged FOM as the cost-optimal point.
The 15–30% range also matters for FCO 1985 compliance. The 2021 amendment specifies a maximum 25% moisture for solid Fermented Organic Manure sold in bags, with 12% maximum for granulated/pelletised FOM. Batches exceeding the limit are rejected by the State Agriculture Department lab during routine sampling, which means plant operators target 20–22% as a safety margin against measurement variability and monsoon-season moisture pickup. Storage warehouses in Indian CBG plants therefore include forced-ventilation systems, raised pallets, and moisture-barrier polypropylene bags to maintain the 15–30% range from production until last-mile delivery.
- Residual moisture for composted, dried, or pelletised digestate — the stable storage window.
- Below 15%: dust and microbial inhibition. Above 30%: mould, spoilage, and bag failure.
- FCO 1985 caps solid FOM at 25% moisture, granulated FOM at 12%.
- Drying cost rises non-linearly below 15% — most plants land at 18–25% as the cost optimum.
Common questions about 15–30%
Plain-English answers to what people most often ask.
How is pellet moisture reduced from digestate to 15–30%?
What happens if pellets are stored at above 30% moisture?
Want the full picture, not just the term?
Adhāra Viveka gives you structured clarity on capital-intensive recycling and renewable-energy sectors — before you commit money or engage vendors.