Ethanol as an alternative fuel

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The top five producers and users of ethanol in 2005 were Brazil producing 4.35 billion gallons per year, The United States producing 4.3 billions gallons per year, China producing 530 million gallons per year, The European Union producing 250 millions gallons per year and India producing 80 million gallons per year. Brazil and The United States account for about 90 per cent of all ethanol production, although in the last few year the United States production of ethanol has grown to about 4.6 billion gallons per year and are now widely consider the world's largest producer of ethanol.

The advantages of ethanol use are:

  • The fuel can utilise existing distribution outlets. Other fuel sources such as hydrogen would require the creation of distribution networks and technology with accompanying establishment costs
  • It is a renewable resource and so would reduce the use of non-renewable materials.
  • It could reduce green house gas emissions if solar energy was used to distil it from aqueous solutions.
  • It reduces dependence on imported oil and the influence of the oil cartels that currently control oil production and price. This reduced dependence on imported oil also protects consumers from the economic variations that are caused by the political and social events in oil producing countries

While it is very unlikely that ethanol will ever replace the world's main energy source, it will reduce the total amount of oil the country would need to import.


  • There are claims that the production and distribution of ethanol as an alternative motor vehicle fuel source will in fact increase greenhouse gas emissions over those generated by conventional fuels.
  • Large areas of agricultural land would need to be used to grow suitable crops, leading to soil erosion, deforestation fertiliser run off and salinity. There is just not enough land to produce the crops needed for ethanol to become a major alternative fuel, with crops at the moment only sustaining about 1 per cent of the worlds transport fuel. There is also a worry that the land needed for ethanol production will compete with food production.
  • The disposal of the large amounts of smelly waste fermentation liquors after removal of ethanol would present major environmental problems.
  • There is a cost involved in making ethanol is nearly twice as much as the cost of making gasoline. There is also a cost involved in modifying vehicles to use ethanol or methanol.
  • Ethanol also has smaller energy density than gasoline, taking about 1.5 times more ethanol than gasoline to travel the same distance. However with new technologies the advancements in ethanol engines are improving every year.
  • Although ethanol does reduce the toxicity of the car exhaust, it can also be corrosive. Ethanol can absorb water and dirt easily and if those contaminants are not filtered out successfully that can damage the inside of the engine block.

The politics that surround the increased use of ethanol in Australia are uncertain. The major political parties have a clear policy position on this initiative at either State or Federal level. There is even debate within the minor political groups that usually defend the environment as to the long term benefits and consequences of increased ethanol consumption. With conflicting claims and a lack of clear evidence, a cautious approach has been adopted by politicians.

At State Government level, it is the NSW Government that has principally supported the introduction of ethanol. It has been suggested that the NSW Labor governments' position has been influence by donations from major ethanol producers and even the Rudd Federal Labor government is critical of a number of aspect of NSW expansion of ethanol production.

Against this background, the NSW Government has consistently refer to the greenhouse benefits of ethanol as one of the reasons for its decision to require that 10% of all fuel sold is to be ethanol (E10) by 2011. There are claims that the long term uses of ethanol are as equally damaging to the environment as conventional fuels. For consumers acceptance of this alternative fuel source is as much about the price at which it will be delivered at the petrol pump, as it is about the environmental motivations.

Fermentation and distillation have been used to produce ethanol for centuries, making it one of the earliest organic compounds to be obtained in nearly pure form. Fermentation is a process in which glucose is broken down to ethanol and carbon dioxide by the action of enzymes present in yeast. These enzymes act as biological catalysts, which first convert the starch or sucrose in the mixture into glucose and or fructose. Finally enzymes will convert the glucose and or fructose into ethanol and carbon dioxide. Yeast can produce ethanol contents up to 15 per cent. If the alcohol concentrations were above this level the yeast would be killed and further fermentation would be stopped. To further produce higher alcohol content, up to 95 per cent fractional distillation or even to 100 per cent more elaborate distillation procedures of the liquid are then needed. Plant materials suitable for fermentation must have a high concentration of simple sugars (sucrose, glucose and fructose). Starchy grains like corn, tubers like potatoes and fruits like grapes with high simple sugar contents are most commonly used.

Cellulose and starch are biopolymers which are formed by condensation polymerisation of glucose monomers. Cellulosic ethanol is produced from woods, grasses and non-edible parts of the plants. There are two ways of producing ethanol from cellulose; gasification or cellulolysis processes. Gasification transforms raw lignocelluloses materials which are composed of cellulose, hemi cellulose or lignin into gaseous carbon monoxide and hydrogen. These gases can then be converted into ethanol by fermentation and distillation. Cellulolysis processes use hydrolysis, which is where enzymes are used to break up the complex cellulose structures of lignocelluloses materials into simple sugars which then followed by fermentation and distillation can be changed into ethanol.



Hannah, You have most of the information needed to get good marked however you would be sitting at a 70-80% mark.

Things that need fixing,

It is easy to get the information and stick it in to answer the question, the hard part is to interpret the information and produce a flowing read, so for you have only written you information on an answering question basis that is basic and simple in a way that once you had addressed that particular question you move on to the next creating a stuttered read. This assignment ideally should be submitted as an essay, using the Intro to start the purpose of the paper, the body to discuss all the questions in a collaborative fashion so you are looking at presenting a paper with facts that relate to one another, eg tie in the political stuff with you ads and disads, back up statements using information sourced for 2 different areas rather than once so you argument is stronger, and conclude summing up the information from a slightly personal perspective relying heavily on the info you have gathered and analysed all through the paper. it doesn't need to be massive amounts of info, just succinct flowing and accurate as well as addressing the questions and tieing into the marking criteria. eg when answering the question, have a look at the outcomes being assess and see what is required to get a full mark. couple more things, it is great to have statistics in there but even better when these are presented in a suitable graph, as it's much harder to get you info across when its stats without aid of a graph. it also shows analysis of info and data, while also making the paper look more presentable and easier to read.

Images, tables (eg advantages and disadvantages) and graphs make it read so much better don't take long and are easy marks. you may show a comparison diagram of the production of ethanol from cellulose and also from glucose to discuss to the differences, etc, an equation is good here.

Also don't just answer the question with raw information, interpret the info and discuss it, whilst also making corrections such as changing figures to the metric system, eg gallons to litres, gasoline to Petrol, small things that may not seem much, but to a marker shows you have thoroughly check over and also changed things to suit the country's systems.

Overall there isn't much changing to do to the info you have just re-writing it in a fashion that reads (essay) and shows you have interpreted it.

Don't forget to use other sourced of info other than the internet. a good spot to look is Google books, which is essentially a book and not the internet.