BIOFUELS

The organic material produced by plants and their derivatives is called biomass. It includes forest crops and residues, energy crops, and animal manure. It reacts with oxygen in combustion and natural metabolic process to release heat. The material may be transformed by chemical and biological processes to produce intermediate biofuels such as methane gas, ethanol, or charcoal solid. Sugarcane, poplar, eucalyptus, animal, and human waste include biomass which are used as biofuels.

Biofuel production is economical if the production process uses materials as by-products. They are available at low cost. Some examples are waste from animal enclosures, offcuts and trimmings from sawmills, municipal sewage, rice husk and straw, wheat straw, shells from coconuts, and straw from cereal crops. The main dangers of extensive use of biomass fuel are deforestation, soil erosion, and displacement of food crops by fuel crops.