Biomass combustion simply means burning organic material. Throughout history people have used this basic technology to create heat and, now, to generate power through steam. The combustion process begins by heating fuel above its ignition temperature in the presence of oxygen. Under the influence of heat, the chemical bonds of the fuel are split. Once these bonds have split, molecules of the fuel turn to a gaseous state and burn. Complete combustion results in four products – heat, water vapour, ash and carbon dioxide.
Incomplete combustion occurs when not enough oxygen is present and the burning gases are partially cooled below the ignition temperature. The flue gases then contain burnable components or carbon monoxide, soot and creosote. Since these by products are pollutants that harm our environment, measures have to be taken to prevent the formation of them. Modern day biomass combustion technology utilizes high quality air filtration systems to minimize particulate matter that is released into the atmosphere. The emissions are so clean that biomass plants today operate without visible smoke emissions from the flue stack.
A wide range of materials can be burned effectively. These include:
• Wood – roundwood, harvest residues (tops and branches), sawdust and shavings from sawmills, urban and municipal waste (tree removal and trimmings, wood pallets, construction waste)
• Agricultural residues - corn stover, oat husks, etc.
• Purpose grown crops – Switchgrass, Miscanthus, Poplar, Willow, etc.
Combustion BIC Factsheet
An Introduction to Biomass Heating