What is the calorifc value of wood?

The calorific value of a fuel expresses the amount of energy released during the complete combustion of a mass unit of a fuel.

The moisture content of wood changes the calorific value of the latter by lowering it. Part of the energy released during the combustion process is spent in water evaporation and is consequently not available for any wished-for thermal use.

Water evaporation involves the “consumption” of 2.44 MJ per kilo of water. It is thereby possible to distinguish between the following:

Net calorific value (NVC):                    

The water released is treated as a vapour, i.e. the thermal energy required to vaporize the water (latent heat of vaporization of water at 25°C) has been subtracted.

Gross calorific value (GVC):                

The water in the combustion products is treated as liquid. When not specified, “calorific value” is to be intended as net calorific value.

The oven-dry calorific value (NCV0) of wood of different wood species varies within a very narrow interval, from 18.5 to 19 MJ/Kg. In conifers it is 2% higher than in broad-leaved. This difference is due especially to the higher lignin content and partly also to the higher resin, wax and oil content present in conifers. Compared to cellulose (17.2-17.5 MJ/kg) and hemicellulose (16 MJ/kg), lignin has a higher NCV0 (26-27 MJ/kg). Some variability in the anhydrous calorific value is also due to the slight variability in hydrogen (H) content and to the comparatively much wider variability in ash contents.

However, when taking into account agricultural biofuels as well, the oven-dry calorific value varies within a 16.5 to 19 MJ/Kg interval. The NCV0 of wood fuels is on average 9% higher than that of herbaceous plants.

Energy content for various biomass (dry weight basis

Below you will find an overview of selected raw materials. 

Are you struggling to figure out what the calorific value for your raw material is, don't hesitate to contact us.

Download the full list here.

Raw Material KJ/Kg (KiloJoule/Kg) Lower calorific values KJ/Kg (KiloJoule/Kg) Higher calorific values Btu/Kg (British thermal unit/kg)Lower calorific values Btu/Kg (British thermal unit/kg)Higher calorific values
Softwood 17500 21100 16590 20003
Hardwood 18600 20700 17633 19624
Oak 17400 18800 16495 17822
Birch wood 18700 20100 17728 19055
Pine wood 19500 20800 18486 19718
Douglas pine wood 19700 21000 18676 19908
Spruce wood 18500 19800 17538 18770
Cherry wood 17900 19100 16969 18107
Cypress wood 21500 23000 20382 21804
Elm wood 19000 20500 18012 19434
Eucaluptus wood 18300 19600 17348 18581
Maple wood 18700 20000 17728 18960
Larch wood 18700 20100 17728 19055
Poplar wood 19400 20800 18391 19718
Teak wood 18900 20200 17917 19150
Coconut trunk wood 16600 17800 15737 16874
Willow wood 17300 18600 16400 17633
Hardwood bark 18300 19600 17348 18581
Oak bark 18300 19300 17348 18296
Pine bark 19700 21000 18676 19908
Spruce bark 19100 20300 18107 19244
Cedar bark 19800 21100 18770 20003
Douglas fir bark 20800 22100 19718 20951
Eucaluptus bark 17300 18500 16400 17538
Miscantus/Napier grass 17800 19100 16874 18107
Switchgrass 16800 19100 15926 18107
Bamboo 19000 19800 18012 18770
Alfalfa 17030 18500 16144 17538
Lucerne 17700 19000 16780 18012
Cotton gin trash 15200 1600 14410 15452
Cotton stalks 17000 18300 16116 17348
Flax 17800 18800 16874 17822
Hemp 16500 17600 15642 16685
Jute stick 17800 19400 16874 18391
Grass 17000 18100 16116 17159
Hay 16200 18300 15358 17348
Corn stalks/stover 16800 18500 15926 17538
Suger cane bagasse 17700 19400 16780 18391
Wheat straw 15000 18900 14220 17917
Rice straw 13500 14800 12798 14030
Rice husk 14200 15400 13462 14599
Solbjergvej 19
DK-9574 Baelum
Tel: +45 9833 7400

CVR: DK21483974
Stay in touch
STAY UPDATED
Sign up for our newsletter
Newsletter form (EN)