. Gasification of biomass
Gasification is a form of pyrolysis, carried out at high
temperatures in order to optimize the gas production. The
resulting gas, known as producer gas, is a mixture of carbon
monoxide, hydrogen and methane, together with carbon
dioxide and nitrogen.
Biomass gasification technologies have historically been
based upon partial oxidation or partial combustion principles,
resulting in the production of a hot, dirty, low
calorific value gas that must be directly ducted into boilers
or dryers. In addition to limiting applications and often
compounding environmental problems, these technologies
are an inefficient source of usable energy.
Biomass gasification is the latest generation of biomass
energy conversion processes, and is being used to improve
the efficiency, and to reduce the investment costs of biomass
electricity generation through the use gas turbine technology.
High efficiencies (up to about 50%) are achievable
using combined-cycle gas turbine systems, where waste
gases from the gas turbine are recovered to produce steam
for use in a steam turbine. Economic studies show that
biomass suffocation plants can be as economical as
conventional coal-fired plants.