Heating Value
Heating value, also known as calorific value, is a measure of the amount of energy released when a fuel is completely combusted. It indicates the energy content of a fuel and is typically expressed in units such as megajoules per kilogram (MJ/kg. There are two types of heating values:
- Higher Heating Value (HHV): Also known as the gross calorific value, HHV includes the total energy released during combustion, including the latent heat of vaporization of water vapor formed from the combustion of hydrogen in the fuel and the moisture content of the fuel Therefore, in order to get the HHV out of a fuel, the water in the flue gas must be “reclaimed” in the form of a liquid.
- Lower Heating Value (LHV): Also known as the net calorific value, LHV excludes the energy contained in the water vapor, representing the actual usable energy in practical applications where water vapor remains in the gaseous state.
Understanding the heating value of a fuel is essential for evaluating its efficiency and suitability for different energy production processes, such as heating, electricity generation, or industrial use.
Most biomass combustion systems release the moisture in the flue gas as a gas; therefore, they can only reclaim the LHV of the fuel. There are also some advanced systems in the market which allow for the condensing of the water in the flue gases; these systems can achieve higher efficiencies, since the HHV of the fuel can be reclaimed.
« Back to Glossary Index
