Biofuels: The Facts
1. Why Biofuel? Cars and buses, trains and motorcycles, ships and tractors, cranes and planes. Whatever the type of vehicle they all have an engine, and for decades nearly all engines have been of two main types, gasoline combustion engines and diesel combustion engines. The engine that runs on gasoline (also called petrol or benzene) has been the favourite because it runs quieter than the diesel engine and it can go faster. But gasoline comes from oil and oil has become too expensive, so everyone is looking for alternative fuels. Enter biofuels!.
2. So why don’t we all turn to diesel combustion engines? Unfortunately, diesel fuel also comes from oil, so its price isn’t much different to the price of gasoline. The other thing is that oil is what they call a fossil fuel, it comes from dead plant life and is formed deep in the ground; when we burn it in either a gasoline engine or a diesel engine, it doesn’t just get us from A to B, it also produces a gas called CO2 which causes global warming. So we are trying to get away from diesel fuel and gasoline fuel because both are harmful.
3. What’s the difference between fossil oil and biofuel? There are several differences. The first is that biofuel comes from living plants which during their lifetime absorb and store CO2, as all plants do. So they serve a dual purpose, they keep CO2 from going up into the atmosphere and they also generate material for fuel. The trouble with oil is that being underground it doesn’t absorb C02 at all, it is dead and buried. Oil serves a single purpose only; it acts as a fuel and when it does that it emits CO2. Oil is part of the problem, not part of the solution to global warming. Biofuels are also a part of the problem because they too produce C02 on combustion, but they offset that by being absorbers and keepers of CO2 in their plant lifetime.
4. What are the other differences? The other big difference is the amount of C02 and other harmful stuff that they produce on combustion. Measuring this can get a bit complicated because a litre of gasoline won’t take you so far as a litre of diesel, and a litre of your average biofuel won’t take you as far as a litre of gasoline. This sort of thing has to be taken into account in order to make valid comparisons for CO2 and other emissions. Suffice it to say here, biofuels are less harmful per kilometre and that is why some environmentalists like biofuels.
5. What plants do biofuel come from? Broadly speaking, biofuel derives from two broad ranges of plant life: (A) dry organic material like cereal grain, corn, cassava or sugar cane, and (B) oil-producing plants and trees like soybean, oil palm and jatropha.
6. What processes are used to produce biofuel? Broadly speaking there are two types of process. Both processes are as old as the hills. The first one involves fermenting dried plant material with yeast to produce ethyl alcohol or Ethanol; the second one involves extracting oil from plant material or its fruit to make Biodiesel fuel. Whether its alcohol or oil, both can be burned in a combustion engine.
Usually the Ethanol is blended with gasoline to produce Gasohol, an alternative fuel for use in automobiles. and the plant oil is blended with fossil oil to make Biodiesel, an alternative fuel for use in diesel engines which are often found in agricultural vehicles, buses, ships and lorries, and also in automobiles.
7. What crops or plants are used to produce oil-based biofuel (Biodiesel)? It depends on the climate and the soil. In Malaysia and Indonesia, the oil-palm tree grows well and oil is extracted from its fruit to make palm oil for BioDiesel. A relatively unknown tree called Jatropha also does well in hot climates and is beginning to be grown more extensively in Asia. It produces a bean that when heated and crushed produces an oil for Biodiesel fuel.
In cooler climates, such as in the UK, rape-seed is grown for its oil. In the USA, soy-bean oil production has grown rapidly.
A newly-developing source is algae; this can be “grown” in a saline solution and when compressed it produces an oil that can be used to make Biodiesel fuel. This source of vegetable oil could produce excellent results once the techniques for production have been perfected.
But from whichever source they come, when these oils are heated, their viscocity is reduced, and they can be burned directly in a diesel engine in an agricultural vehicle or they can be chemically processed to produce a fuel called Biodiesel (yes, biodiesel is just a type of biofuel) for diesel-engine automobiles, buses, ships, agricultural vehicles.
8. What plants and stuff is used to produce alcohol-based biofuels? Crops that are high in sugar or starch content are used to produce alcohol using the process of yeast fermentation. Sugar cane is grown extensively in many hot countries, most notably in Brazil which is the world’s second largest producer of Ethanol in the world. Cassava (tapioca), sugar beet and sweet sorghum contain plenty of sugar and are also good for the production of Ethanol. Thailand is aiming to grow a lot more sugar to boost production of Ethanol.
The USA is the world’s biggest producer of Ethanol and it mostly uses corn as the feedstock. But whether it’s sugar cane or corn, sorghum or maize, it is all being harvested for fermentation to produce alcohol, ethyl alcohol, Ethanol, whatever you like to call it.
9. I keep hearing this word feedstock. What is feedstock? Feedstock is a buzzword used by industrialists and biofuel chemists to make the rest of us feel stupid! Actually, feedstock is jusdt another word for raw material. So, for example we can say that the fruit of the oil palm is the feedstock of palm oil, or corn is a feedstock for Ethanol. Or we could say of anything which is the prime source of biofuel that it is the feedstock of that particular type of fuel. The word feedstock is used to describe the raw material for any industrial process, not just biofuels.
10. What are the main primary biofuels today? Ethanol (also known as Bio-Ethanol) and Biodiesel are the two main ones. Ethanol (usually referred to as “E” fuel) is the name given to the alcohol produced from sugar, grain, cassava etc and is usually mixed with gasoline to produce a blend named E something or other, like E10 to denote 10 percent Ethanol, or E85 to denote 85 percent Ethanol.
Contrary to popular belief, Biodiesel (usually referred to as “B” fuel) contains no petroleum diesel or fossil fuel of any description. It is not a blend of petroleum diesel and vegetable oil, it is a thoroughbred refined vegetable oil. However, in cold climates it is invariably mixed with fossil oil to prevent it from freezing.
11. Does Ethanol give the same mileage as gasoline? No it doesn’t. The energy content of Ethanol is only about two-thirds of the equivalent amount of gasoline. Most new cars nowadays are designed to run on Gasohol (a blend of gasoline and ethanol). In Thailand, Gasohol can be found in thousands of filling stations throughout the country. Some stations don’t sell gasoline (petrol, benzene, call it what you like) at all, they have gone over completely to Gasohol and Biodiesel.
Gasohol comes in several blends ranging from E10 (10 percent Ethanol) to E85 (85 percent Ethanol). Obviously, the more E there is in the blend, the lower will be the mileage per litre because of its lower energy content.
With modification, combustion engines can run on 100-percent Ethanol. And with even less modification, they can use E-85. The major automobile manufacturers in Thailand now produce flexible fuel vehicles (FFVs) that are already set to use blends of up to 85 percent Ethanol. Even old cars with engines that have never been modified can use E10.
12. Is Biodiesel less damaging to the environment than Gasohol? In most cases yes. In hot climates where the temperature never falls below zero, Biodiesel can be used in its pure form i.e. 100 percent vegetable oil or B100. But in colder climates where the temperature falls below zero, Biodiesel is blended with petroleum diesel (fossil oil) and we all know what fossil fuels are doing to the planet.
13. What is Cellulosic Ethanol? When people talk about 2nd generation biofuels they are referring to Ethanol derived from cellulose, by which they mean corn fibre, corn cobs, switch grass and similar materials, as opposed to the usual source or feedstock today, namely cereal grain or sugar cane. Cellulosic Ethanol is expected to replace 1st generation Ethanol. but it cannot be successfully commercialized until cost-effective and sustainable systems have been developed to produce, harvest, store and handle the feedstock. The Americans in particular are working on this but it hasn’t really happened yet.
14. Is Methanol a Biofuel? If it is produced from wood or trash or some other carbon-based material methanol can be classified as a biofuel. But most methanol nowadays is produced synthetically and is therefore not a biofuel. Although methanol is the favourite fuel in drag-racing it is toxic and has been banned in some parts of the world. Detractors of methanol believe it may be carcinogenic.
15. What are the benefits of biofuels? Biofuel-plant designers, corn growers, bio-refinery suppliers, oil-palm producers, distributors and a host of others with a vested interest say the use of biofuels (a) reduces toxic emissions (car fumes) (b) reduces the build-up of greenhouse gases (CO2) (c) improves energy security by reducing a country’s dependence on imported oil, and (d) gives work to domestic agriculture. They also point out that biofuels come from renewable sources.
16. What do detractors say about biofuels? Most environmentalists have changed their minds about bio-fuels. They say that (a) massive areas of peatlands and wetlands have been drained and whole forests have been cleared to make way for plantations of oil-palm and other sources of biofuel (b) the energy used by machines and people to grow crops and process them for biofuels produces more CO2 than it saves. The early enthusiasm for bio-fuels is wearing off, largely because of their capacity to bring deforestation and dewetlandisation in their wake.
17. Are Biofuels the answer to Global Warming? No they are not. Biofuel combustion emits less CO2 than gasoline combustion, but it still emits plenty of CO2. Yes, biofuel derives from plant life and plant life absorbs and stores carbon, but all too often this plant life is being cultivated where wetland, peatland and prime forest with old trees used to be. Anything that does that is retrograde. Malaysia and Indonesia are cited as being among the world’s two worst offenders for draining wetlands and clearing forests to make way for oil-palm cultivation. Brazil, the world’s second-biggest producer of Ethanol (after the USA) has also played a significant part in deforestation on a massive scale.
18. Do Biofuels have a future? Not in the long-term they don’t, and the jury is still out on whether they are beneficial in the short term. 1st generation Ethanol may soon give way to 2nd generation Ethanol based on cellulose. But the fact is that biofuels of all kinds produce CO2 on combustion. In the very near future, perhaps within 10 years, all fuels that emit C02 are likely to be banned.
In the meantime, “B” fuels (Biodiesel) are preferable to today’s E fuels (Ethanol) but only if they have been produced from certified plantations, using low-tech production methods with no mechanisation. At the present time there is no such certification. If you know the farmer or the plantation, and you know that he isn’t using heavy machinery that emits loads of C02, and that his crops are not growing on what was previously peatland or wetlands, his Biodiesel could be a good option for the time being. But sooner or later, and the sooner the better, we have to use non-carbon sources for our fuel.
(August 2008)