Biofuel refers to fuel produced from organic matter as a renewable resource, as opposed to fossil fuel, which, although also made from organic matter, was done so many millions of years ago, and is considered a non-renewable resource.
The biofuel industry is one of the largest renewable energy industries in the world mainly because, unlike other renewable energy technologies, it can easily fit into the existing liquid fuel system that already exists for fossil fuels. As such, biofuels can be used as fossil fuel substitutes or as additives to a fossil fuel. This means they can be used for combustion engines in the global transportation industry, e.g., cars, boats, buses, trucks, etc. Biofuels can also be used for heating and cooking.
Biofuels have four classifications. These are (from Wikipedia):
- First generation biofuels
- Green diesel
- Vegetable oil
- Solid biofuels
- Second generation biofuels
- Waste biomass
- The stalks of wheat, corn and wood
- Special-energy-or-biomass crops (e.g. Miscanthus).
- Cellulosic biofuels
- Fischer-Tropsch diesel
- Biohydrogen diesel
- Mixed alcohols
- Wood diesel
- Third generation biofuels
- Fourth generation biofuels
- Green gasoline
- Green diesel
- Green aviation fuel
Biofuels are considered carbon neutral. To understand this classification and why they differ from fossil fuels it is important to understand the biological carbon cycle (see Carbon Capture article this web site). In simplest terms, all organic life on earth is based on carbon. For plants this means that in order to grow they must extract carbon from the environment and store it in their plant structure. Carbon in this organic form can be burned as a fuel. For a biofuel this means that all the carbon (CO2) that is released back into the atmosphere, when it is burned, was originally extracted from the atmosphere in the first place, and so there is no net gain or loss of CO2. For a fossil fuel this is different because, even though it consists of organic plant matter, it was created many millions of years ago and so has not been part of the atmosphere or the carbon cycle for all that time. When fossil fuels are burned they increase the amount of CO2 in the atmosphere beyond what is normal for our time period, and this, as an unnatural condition, contributes to global warming.
Even though biofuels have the benefits of working efficiently with the existing fossil fuel system and of being carbon neutral, they are not without certain problems that some consider significant. These problems center around the production of biofuels, where, like agricultural food crops, they need large amounts of land to grow the required crops. Using land to grow biofuel crops creates the following conditions:
- Traditional food crop land is replaced for biofuel crops
- Less food production negatively affects food resources and prices, particularly in poorer regions
- Ultimately this can negatively affect prices for global agricultural commodities
- Valuable forest areas are turned into biofuel crop lands, i.e., deforestation
- This impacts soil erosion and water resources
Beyond these issues, using biofuel still contributes to CO2 emissions because it involves a CO2 emitting combustion process.
Beneficial Uses For Biofuels
Two areas where creating biofuels is a clear advantage over not creating them are in the areas of energy from waste (see Power Stations article this web site) and bio carbon capture (see Carbon Capture article this web site).