Example: 100 tons/day of fresh Napier.
Example: 20% DM means 20 tons DM in 100 tons fresh Napier.
Enter the actual dry matter added from paddy straw, corn stover or another dry feedstock.
Used to calculate the physical tons/day of dry feedstock required.
Example: 200 tons fresh Napier per acre per year.
Number of days the plant is supplied with Napier.
1. Dry Matter Substitution
The added dry matter is assumed to replace an equal amount of dry matter that would otherwise come from Napier.
20.00
Original Napier DM
tons/day
tons/day
5.00
Added Dry Matter
tons/day
tons/day
15.00
DM Still Required
from Napier
from Napier
5.56
Physical Dry Feedstock
tons/day
tons/day
75.00
New Napier Requirement
tons/day
tons/day
25.00
Napier Saved
tons/day
tons/day
25.0%
Reduction in Fresh Napier Requirement
2. Napier Land Requirement
Land is calculated using annual fresh Napier production per acre.
182.50
Original Napier Land
acres
acres
136.88
New Napier Land
acres
acres
45.63
Land Saved
acres
acres
25.0%
Reduction in Napier Cultivation Land
3. Quick Comparison
See how different quantities of added dry matter affect Napier requirement.
| Added DM (tons/day) |
Napier Required (tons/day) |
Napier Saved (tons/day) |
Land Required (acres) |
Land Saved (acres) |
|---|
Calculation logic:
Original Napier DM = Fresh Napier × Napier DM%
DM required from Napier after substitution = Original Napier DM − Added DM
New Napier requirement = DM required from Napier ÷ Napier DM%
Napier land requirement = Annual Napier requirement ÷ Napier production per acre per year
Original Napier DM = Fresh Napier × Napier DM%
DM required from Napier after substitution = Original Napier DM − Added DM
New Napier requirement = DM required from Napier ÷ Napier DM%
Napier land requirement = Annual Napier requirement ÷ Napier production per acre per year
Example: 100 tons/day Napier at 20% DM supplies 20 tons DM/day.
If 5 tons DM/day is supplied by dry paddy straw or corn stover, only 15 tons DM/day needs to come from Napier.
At 20% Napier DM, the new Napier requirement is therefore 75 tons/day — a 25% reduction.
At 200 tons/acre/year, land requirement falls from 182.5 acres to 136.88 acres.
Important: This is a dry-matter substitution calculator. It does not assume that all feedstocks produce the same methane. For Bio-CNG project design, the final feed mix should also be checked using actual TS, VS, BMP, digestibility, C:N ratio and digester operating conditions.
Important: This is a dry-matter substitution calculator. It does not assume that all feedstocks produce the same methane. For Bio-CNG project design, the final feed mix should also be checked using actual TS, VS, BMP, digestibility, C:N ratio and digester operating conditions.