Burning for household heating and cooking remains the most common use of wood in the world. In the United States, this use of wood is less common; however, wood is our most important biomass energy source because it is used to provide much of the energy for the wood products industry.
Burning wood does have the potential to release pollutants such as carbon monoxide and particulate matter to the air. Wood combustion also releases stored (“sequestered”) carbon as carbon dioxide, the main greenhouse gas. However, wood is a better fuel than most alternatives for a number of reasons.
Wood is relatively low in sulphur and nitrogen, compared with coal for example. Sulphur and nitrogen oxides are pollutants of concern. Burning wood correctly can greatly reduce or eliminate pollutants such as CO and particulate matter. In the home, this can mean burning dry wood in a hot fire with an EPA-approved stove. In commercial operations, there are various scrubbing technologies that are available. Finally, wood fuel is considered to be ‘carbon neutral’; the carbon released from burning wood does not make a net contribution to climate change because it was recently absorbed from the atmosphere by the living tree. This is different from fossil fuels that have been carbon sinks for millions of years and would continue to store that carbon if left undisturbed.
For the above reasons, when wood is used instead of other materials for fuel, it can result in less pollution. A recent study confirmed this and provides a ‘calculator’ that can be used to estimate how much better wood fuel is. Details of the study and the calculator can be found at http://www.orcaa.org/woody-biomass-emissions-study/ .
In summary, wood is an important and good fuel. Its attributes include low cost, widespread availability, adaptability to large or small-scale applications and its low pollution production compared with common alternatives.