Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 202

Biomass plays a unique role in the dynamics of carbon flow in the biosphere. Carbon is biologically cycled when plants such as soybean crops convert atmospheric carbon dioxide to carbon-based compounds through photosynthesis. This carbon is eventually returned to the atmosphere as organisms consume the biological carbon compounds and respire. Biomass-derived fuels reduce the net atmospheric carbon in two ways.

First, they participate in the relatively rapid biological cycling of carbon to the atmosphere (via engine tailpipe emissions) and from the atmosphere (via photosynthesis). Second, they displace fossil fuels. Fossil fuel combustion releases carbon that took millions of years to be removed from the atmosphere; combustion of biomass fuels participates in a process that allows carbon dioxide to be rapidly recycled to fuel. The net effect of shifting from fossil fuels to biomass-derived fuels is thus to reduce the amount of carbon dioxide in the atmosphere.

Because of the differences in the dynamics of fossil carbon flow and biomass carbon flow to and from the atmosphere, biomass carbon is often accounted for separately from carbon derived from fossil fuels.

See also: Biomass, Biomass – Pyrolysis.