Heating value
The heating value is an indication of the amount of energy that a certain fuel contains. When calculating the heating value, one often assumes that the fuel is completely dry and that the ash is not included in the calculation. You are then talking about heating value on a dry and ash free basis (daf).
Heating value is usually described in megajouoles per kilogram of fuel, shortened… to MJ/kg or in gigajoules per ton (GJ/t). The fuel weight is stated inclusive of water content, which is why it is important to know the percentage of moisture that the stated heating value refers to. In practice it is the heating value and the water content of the fuel that is of most importance.
Wood has a heating value on a dry basis of 19.0 MJ/kg. If the water content is estimated at 7 % the heating value of wood pellets can roughly be calculated as
19.0 - (0.2145 * 7) = 17.5 MJ/kg
Heating value is usually described in megajouoles per kilogram of fuel, shortened… to MJ/kg or in gigajoules per ton (GJ/t). The fuel weight is stated inclusive of water content, which is why it is important to know the percentage of moisture that the stated heating value refers to. In practice it is the heating value and the water content of the fuel that is of most importance.
Wood has a heating value on a dry basis of 19.0 MJ/kg. If the water content is estimated at 7 % the heating value of wood pellets can roughly be calculated as
19.0 - (0.2145 * 7) = 17.5 MJ/kg