Typical calorific values of fuels

 

Biomass type	kJ/kg	Kcal/kg	ash (%)
Pine	22300	5330	1.31
Poplar	20750	4959	0.65
Fir	19950	4768	0.25
Oak	19420	4642	1.52
Wheat Straw	17510	4185	8.9
Charcoal
Oak Char	24670	5896	17.9
Redwood Char	28350	6776	2.3
Coal
Bituminous	12000-20000	2868-4780	3.3-11.7
Anthracite	26000-33000	6214-7887	9.7-20.2

Energy from woodfuel changes with varying moisture content. Wight Heat wood briquettes are made from kiln dried wood and have a moisture content of 1 – 2% when bagged. Bio-fuel briquette products depend on their strength and durability, besides their thermal characteristics. Data from MaxTon Industries Ltd 2022.