Biomass is organic material that comes from plants and animals, and it is a renewable source of energy. It contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. When biomass is burned, the chemical energy in biomass is released as heat. Biomass can be burned directly or converted to liquid biofuels or biogas that can be burned as fuels.
Examples of biomass and their uses for energy
Wood and wood processing wastes—burned to heat buildings, to produce process heat in industry, and to generate electricity
Agricultural crops and waste materials—burned as a fuel or converted to liquid biofuels
Food, yard, and wood waste in garbage—burned to generate electricity in power plants or converted to biogas in landfills
Animal manure and human sewage—converted to biogas, which can be burned as a fuel
Biofuels are clean burning, biodegradable and made from renewable plant-based resources. They have been around since the early 1900s but often disregarded in favor of large petroleum deposits that turned into cheap gasoline and diesel to power cars and boats. Biofuels have been gaining more attention in recent decades as a potential solution to carbon dioxide emissions and global warming. In addition to being a fuel for transportation, biofuel converts to other useful forms of energy, including methane gas and heat for homes and cooking. Ethanol is typically added to the gasoline you use in your car, so you may be more familiar with biofuel than you thought.
First-generation or conventional biofuels are biofuels made from food crops grown on arable land.
Second-generation biofuels are fuels manufactured from various types of biomass. Biomass is a wide-ranging term meaning any source of organic carbon that is renewed rapidly as part of the carbon cycle. Biomass is derived from plant materials, but can also include animal materials.
Third-generation biofuels using algae as a biofuels source. The oil-rich algae can then be extracted from the system and processed into biofuels, with the dried remainder further reprocessed to create ethanol.
Fourth-generation biofuels are made using non-arable land. Unlike third-generation biofuels, they do not require the destruction of biomass. This class of biofuels includes electrofuels and photobiological solar fuels. Some of these fuels are carbon-neutral.
Biofuels Basics. Switch Energy Alliance, www.switchon.org
Where Biofuels are Found
Algae can be grown. Fermenting starch or sugar crops such as sugarcane, barley, rice, corn, potatoes, sorghum, sunflower, sugar beets, wheat, and other grains, or even cornstalks, fruit and vegetable waste, make ethanol. Biodiesel mixes cooking grease, vegetable oil, or animal fat with alcohol.