1. Plant Oils:
- Vegetable oils: Seeds and fruits of various plants, such as soybeans, sunflowers, rapeseed (canola), and palm trees, are processed to extract oils. These oils can be refined and directly used as biodiesel in diesel engines or blended with petroleum diesel.
2. Grains:
- Corn: Corn kernels can be fermented and processed to produce ethanol, also known as grain alcohol. Corn-based ethanol is widely used as a biofuel additive or alternative to gasoline.
3. Sugar Crops:
- Sugarcane: Sugarcane juice contains high concentrations of sucrose, which can be fermented and distilled to produce ethanol. Ethanol from sugarcane is a prevalent biofuel in Brazil.
- Sugar beet: Sugar beets also contain sucrose and can be used for ethanol production.
4. Lignocellulosic Biomass:
- Wood: Forest residues, such as wood chips and sawdust, can be broken down through various processes, such as gasification or enzymatic hydrolysis, to produce syngas or bio-oil. These products can be refined into biofuels like ethanol, butanol, or biodiesel.
- Agricultural residues: Crop leftovers like corn stover, wheat straw, and bagasse (dry sugarcane stalks) are abundant sources of lignocellulosic biomass. These residues can be converted into biofuels using similar processes as wood.
- Grasses and dedicated energy crops: Certain fast-growing grasses, like switchgrass, miscanthus, and energy cane, can be cultivated specifically for biofuel production.
5. Algae:
- Microalgae: Some species of microalgae have high lipid content and can be used to produce biodiesel through lipid extraction and conversion processes.
6. Waste:
- Animal fats: Animal fats and oils from meat processing and rendering industries can be converted into biodiesel.
- Food waste: Food leftovers and municipal organic waste can undergo anaerobic digestion to produce biogas, a mixture of methane and carbon dioxide that can be used as fuel.
These are some of the primary sources of biomass for biofuel production, but there is ongoing research and development to explore additional feedstocks and improve the efficiency of conversion processes.
