Whole Farm > Weight & Measurements
Written October, 2008
File C6-88
Biomass measurements and conversions
1 pound of switchgrass = 7,341 Btu
1 pound of bagasse = 6,065 Btu
1 pound of rice hulls = 6,575 Btu
1 pound of poultry litter = 6,187 Btu
1 cord of stacked wood = 4 feet x 4 feet x 8 feet
1 cord of stacked wood = 128 cubic feet
1 cord of stacked wood weighs about 1.2 short tons
1 cord of stacked wood weighs about 1,090 kilograms
1 metric ton of wood = 1.4 cubic meters (solid wood)
1 ton of wood fuel (bone dry) = 18 to 22 gigajoules – HHV *
1 pound of wood fuel (bone dry) = 7,600 to 9,600 Btu – HHV *
1 ton of wood fuel (air dry – 20% moist.) = about 15 gigajoules
1 pound of wood fuel (air dry – 20% moist.) = about 6,400 Btu
1 ton of agricultural residue (varying moist.) = 10 to 17 gigajoules
1 pound of agricultural residue (varying moist.) = 4,300 to 7,300 Btu
1 metric ton of charcoal = 30 gigajoules
1 pound of charcoal = 12,800 Btus
* Energy contents are expressed as either High (gross) Heating Value (HHV) or Lower (net) Heating Value (LHV). LHV is closest to the actual energy yield in most cases. HHV (including condensation of combustion products) is greater by between 5% (in the case of coal) and 10% (for natural gas), depending mainly on the hydrogen content of the fuel. For most biomass feed-stocks this difference appears to be 6-7%. The appropriateness of using LHV or HHV when comparing fuels, calculating thermal efficiencies, etc. really depends upon the application. For stationary combustion where exhaust gases are cooled before discharging (e.g. power stations), HHV is more appropriate. Where no attempt is made to extract useful work from hot exhaust gases (e.g. motor vehicles), the LHV is more suitable. In practice, many European publications report LHV, whereas North American publications use HHV
References
Biomass Energy Datebook, U.S. Department of Energy
BP Conversion Factors
ConvertIt
Energy Information Administration
Energy Information Administration - Energy Kids Page
Fuel Consumption Converter – Unit Converter
Wikipedia
Don Hofstrand, retired extension value added agriculture specialist, agdm@iastate.edu
