Composed by Galina Vitkova
Biofuels belong to the most quickly developing branches of renewable energy sources, mainly due to oil price spikes and the need for increasing energy security. There are two main sorts of biofuels: bioethanol and biodiesel.
Bioethanol (also called biogasoline or simply ethanol) is an alcohol made by fermenting the sugar components of plant materials It is made mostly from sugar and starch crops. Technological process for producing ethanol requires as a rool a significant amount of energy (often unsustainable fossil fuel). Making ethanol from the sugar cane is less energy-consuming.
Ethanol can be used as a fuel for vehicles in its pure form, but it is usually added to a gasoline to increase octane and improve vehicle emissions. Most existing car petrol engines can run on blends of up to 15% bioethanol with petroleum/gasoline.Many car manufacturers are now producing flexible-fuel vehicles (FFV’s), which can safely run on any combination of bioethanol and petrol.
Bioethanol is widely used in the USA and in Brazil – see the table below:
Fuel ethanol(thousand tonnes equivalent oil)
Share of total
|USA||17 460||41.3 %||50.2 %|
|Brasilia||13 549||20.0 %||38.2 %|
|Europe||1337||50.8 %||3.8 %|
|Total world||34 800||30.9 %||100 %|
The expanded table with the similar content could be found in Renewables are becoming more and more popular based on REN21 Interactive Map (beta-version).
Green diesel (biodiesel) is the most common biofuel used in Europe. It is a liquid similar in composition to fossil/mineral diesel. Feedstocks for biodiesel include animal fats, vegetable oils, soy, flax, sunflower, palm oil, hemp and many others. Pure biodiesel (B100) is the lowest emission diesel fuel.
Biodiesel can be used in any diesel engine when mixed with mineral diesel. The majority of vehicle manufacturers recommend to add up to 15% biodiesel blended with mineral diesel. Many current diesel engines are made to be able to run on B100 without altering the engine itself.
Since biodiesel is an effective solvent and cleans residues deposited by mineral diesel, engine filters may need to be replaced more often because the biofuel dissolves old deposits in the fuel tank and pipes. In many European countries, a 5% biodiesel blend is widely used and is available at thousands of gas stations. Biodiesel is safe to handle and transport (e.g. it has a high flashpoint of about 300 F (148 C) whereas petroleum diesel fuel has a flashpoint of 125 F (52 C)).
The structure of the USA buofuels resources is depicted on the chart below:
Second-generation biofuels production processes use non-food crops and do not divert food away from the animal or human food chain. These include waste biomass, the stalks of wheat, corn, wood, and special-energy-or-biomass crops (e.g. Miscanthus). Many second generation biofuels are under development such as biohydrogen, biomethanol, biohydrogen diesel, mixed alcohols, wood diesel etc.. For example, producing ethanol from cellulose is a difficult technical problem to solve. So in cellulosic ethanol laboratories, various experimental processes are being developed to simulate natural enzymatic digestive processes, typical for animals, to make ethanol fuel.
Scientists also work on experimental organisms using recombinant DNA genetic engineering (see also Genetics for common people) to increase biofuel potential. A technology to use industrial waste gases from steel mills as a feedstock for producing ethanol has been developed in New Zealand.
Third generation biofuel is a biofuel from algae. Algae are low-input, high-yield source biofuels. Based on laboratory experiments, it claimed that Algae can produces up to 30 times more energy per acre than land crops such as soybeans, but these yields have yet to be produced commercially. With the higher prices of fossil fuels, there is much interest in farming algae.
Wikipedia, the free encyclopedia – http://en.wikipedia.org
REN21 Interactive Map (beta-version) – http://www.ren21.net/map/
P S : You can find a lot of absorbing information about biofuels made of sugar cane on the blog http://sugarcaneblog.com
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