Biomass heating system

Biomass heating systems generate heat from biomass.The systems fall under the categories of: The use of biomass in heating systems is beneficial because it uses agricultural, forest, urban and industrial residues and waste to produce heat and/or electricity with less effect on the environment than fossil fuels. This type of energy production has a limited long-term effect on the environment because the carbon in biomass is part of the natural carbon cycle; while the carbon in fossil fuels is not, and permanently adds carbon to the environment when burned for fuel (carbon footprint). Historically, before the use of fossil fuels in significant quantities, biomass in the form of wood fuel provided most of humanity's heating. Forest Health Because forest based biomass is typically derived from wood that has lower commercial value, forest biomass is typically harvested as a byproduct of other timber harvest operations. Biomass heating provides markets for lower value wood, which enables healthy and profitable forest management. In New England as of 2017, one of the greatest threats to forest health is conversion from forest to agriculture and development. Harvard Forest scientists reported in 2017, that 65 acres of forest were being lost per day by conversion. By providing markets for low grade wood, the value of forests is enhanced, which makes conversion to housing or agriculture less likely. On a large scale, the use of agricultural biomass removes agricultural land from food production, reduces the carbon sequestration capacity of forests that are not managed sustainably, and extracts nutrients from the soil. Combustion of biomass creates air pollutants and adds significant quantities of carbon to the atmosphere that may not be returned to the soil for many decades. The time delay between when biomass is burned and the time when carbon is pulled from the atmosphere as a plant or tree grows to replace it is known as carbon debt. The concept of carbon debt is subject to debate. Actual carbon impacts may be subject to philosophy, scale of harvest, land type, biomass type (grass, maize, new wood, waste wood, algae, for example), soil type, and other factors. Using biomass as a fuel produces air pollution in the form of carbon monoxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants, in some cases at levels above those from traditional fuel sources such as coal or natural gas. Black carbon – a pollutant created by incomplete combustion of fossil fuels, biofuels, and biomass – is possibly the second largest contributor to global warming. In 2009 a Swedish study of the giant brown haze that periodically covers large areas in South Asia determined that it had been principally produced by biomass burning, and to a lesser extent by fossil-fuel burning. Researchers measured a significant concentration of 14C, which is associated with recent plant life rather than with fossil fuels. Modern biomass burning appliances dramatically reduce harmful emissions with advanced technology such as oxygen trim systems. On combustion, the carbon from biomass is released into the atmosphere as carbon dioxide (CO2). The amount of carbon stored in dry wood is approximately 50% by weight. When from agricultural sources, plant matter used as a fuel can be replaced by planting for new growth. When the biomass is from forests, the time to recapture the carbon stored is generally longer, and the carbon storage capacity of the forest may be reduced overall if destructive forestry techniques are employed. The forest biomass-is-carbon-neutral proposal put forward in the early 1990s has been superseded by more recent science that recognizes that mature, intact forests sequester carbon more effectively than cut-over areas. When a tree’s carbon is released into the atmosphere in a single pulse, it contributes to climate change much more than woodland timber rotting slowly over decades. Some studies indicate that 'even after 50 years the forest has not recovered to its initial carbon storage' and 'the optimal strategy is likely to be protection of the standing forest'. Other studies show that carbon storage is dependent upon the forest and the use of the harvested biomass. Forests are often managed for multiple aged trees with more frequent, smaller harvests of mature trees. These forests interact with carbon differently than mature forests that are clear-cut. Also, the more efficient the conversion of wood to energy, the less wood that is used and shorter the carbon cycle will be.