|
About
|
- Biofuels are classified into different generations based on the strategy adopted to derive energy from biomass.
- Accordingly, there are 4 generations of biofuels.
|
|
1st generation (Mostly edible source)
|
- Biofuels derived from edible source.
- Includes both starch-based ethanol and biodiesel (made from edible vegetable oil)
- Sugarcane, corn, and other starch-based crops (sugar beets, rice, wheat, potatoes)
- Oilseeds include rape-seed, sunflower seed, soybeans, palm seeds, rice bran etc.
- Non-edible source Jatropha in India
|
|
2nd generation (cellulosic biofuel)
|
- Non-edible feedstocks like grasses, leaves etc
- Ligno-cellulosic: Mostly wood
- Agricultural waste including rice husk, corn stalks etc.
|
|
3rd generation (mostly algal biomass-based)
|
Biofuels from high-photosynthetic efficiency organisms like algae.
- Feed-stock include:
- Macro-algaeMicro-algae
- Aquatic plants (water hyacinth)
- While most plants are very inefficient in photosynthesis (only 0.5% of sunlight is captured), algae have very high photosynthetic efficiency capable of growing very fast capturing the CO2 from atmosphere.
- Algae extracts large amounts of the carbon dioxide to feed their growth and very little is left to emit to the open air.
- The so grown algae can be used as input for producing both ethanol and biodiesel.
Advantages
- Fastest photosynthesis
- Do not need arable land
- CO2 sequestration (CO2 source can be coal-based power plants too, see section on Direct capture under CCUS technologies)
- Lipids (can be used for biodiesel) and protein source (single-cell protein source)
|