There are good and bad sides to biofuels, as Jane Goodall points out. I will explore this in detail in a series of articles that express my opinion and cite scientific reports or discussions. First, a bullet-point summary of key points is given below.
Much of the good/bad duality of biofuels has to do with the following questions:
- where do the biofuels come from?
- what are we destroying in order to generate biofuels?
- what are we consuming in order to generate biofuels?
- what are we failing to produce in order to generate biofuels?
- Many (most) of the crops being planted for biofuels are destined to generate biodiesel, not bioethanol.
- Some plants grown for fuel are intended to produce a type of diesel called straight vegetable oil (SVO).
- SVOs contain a number of impurities, at least as far as fuel oil is concerned. Even water is an impurity here.
- Just as an example, you only have to press the oil out of the olives to remove it.
- Peanut oil and practical coconut oil can be also be collected mechanically, like pressing olives.
- SVO can be used in a compatible diesel engine.
- The properties of SVO, such as the high viscosity of soybean oil, or the impurities in SVO, may cause problems.
- Waste vegetable oil (WVO), typically used cooking oil, is another impure oil that can be used as liquid fuel.
- Biodiesel is more pure than SVO or WVO (if made properly). It is made by chemically splitting animal fat or vegetable oil into two parts, followed by purification.
- The standard chemical reaction to make biodiesel uses alcohol (methanol or ethanol) and a catalyst.
- This reaction, called transesterification, generates fatty acid esters and the byproduct known as glycerol.
- One example that seems to me to have little or no downside is the generation of biodiesel from fish oil:
- Fish oil is already generated by the fishing industry.
- Fish oil is potential waste that already exists and may not be used as efficiently as possible.
- Fish oil conversion to biodiesel still needs to be pushed forward by invention and commercial development.
- Another example of a method that exhibits great potential is the conversion of all of a plant’s dried matter (known as biomass) into biodiesel:
- Plant oils are only about 10% of total plant biomass in most cases
- Using all the biomass to generate biodiesel captures much more of the value of a plant, and the energy that went into growing it, than using only plant oil does
- Cellulose and lignins are components of typical biomass and are hard to convert into liquid fuel, compared to oils
© James K. Bashkin, 2007
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