How is biomass converted to energy?

There are three primary ways to convert biomass to energy:

• thermal —The oldest and most common way is to burn biomass to create heat. This can be used directly for heating, cooking and industrial processes, or indirectly to generate electricity. At biomass power plants, biomass is burned in a boiler to produce high-pressure steam, which, in turn drives a turbine to generate electricity.
  
  
• thermochemical —By heating (but not burning) plant matter, it is possible to break down biomass into gases, liquids and solids, which can be further processed into gas and liquid fuels like methane and alcohol. Biomass reactors heat biomass in a low-oxygen environment to produce a fuel gas (mostly methane), which can then fuel steam generators, combustion turbines, combined cycle technologies or fuel cells.
  
  
• biochemical —Adding bacteria, yeasts and enzymes to biomass liquids causes biomass materials to ferment and change into alcohol. A similar process is used to turn agricultural products into ethanol (grain alcohol), which is then mixed with gasoline to make an ethanol-gasoline blend. And when bacteria are used to break down biomass, methane is produced and can be captured from landfills and sewage treatment plants to produce fuel for heat and power.