Second generation bio fuels can be derived from the lignocellulosic plants. These fuels use components such as lignin, cellulose and hemi cellulose. These bio fuels can be manufactured from various types of biomass. Second generation bio fuel technologies have been developed because technologies used to manufacture first generation bio fuels have important limitations.

Following are the sources form which second generation bio fuels can be prepared:

Energy Crops:
Energy crop is a plant grown at low cost and low maintenance. It is used to make bio fuels which in turn are combusted to generate heat or electricity. Energy crops can be categorized in to two types, one is woody and the other is herbaceous. Examples of energy crops are wheat straw, Miscanthus, willow and short rotation coppice poplar.

Black Liquor:
Black liquor is the aqueous solution of lignin residues, hemicellulose, and the inorganic chemicals used in the Kraft process. The black liquor contains more than half of the energy content of the wood fed into the digester. The organic matter in the black liquor is made up of water/alkali soluble degradation components from the wood. Tall oil is an important byproduct separated from the black liquor with skimming before going to the evaporators. This is gasified with green house gas reduction potential to produce syn gas for further synthesis.

Green Waste:
Green waste is a biodegradable waste that is made up of grass or flower cuttings, hedge trimmings along with domestic and commercial food waste and this waste is used to produce bio fuels by using different methods.

The following are the various sources from which bio fuels are extracted. These are very eco friendly options for fuel use.