Stage 2 Chemistry Issues Investigation
Topic: What are the difference between E10and other types of fuels?
Introduction
Over millions of years ago, remains of ancient marine organisms, algae and plants which lived in shallow areas within the ocean have produced mixed organic materials which include petroleum or as many may call it the ‘black gold’. This organic mixture has created many wars through out the human history, but we’re not going to get into the depth of that as this isn’t a historic debate, this howeveris solely a chemistry issues investigation, so the chemistry nature of the topic will only be researched. For over 8 months,I have been using the UPULP (98 octane rating) car fuel thinking that it is the better alternative by using an old logic, which goes by “You get what you pay for”. Additionally, I had always over-heard people discussing about how the UPULP not only cleans the engine and makes the engine run smoother but also gives the car higher performance ratings. As there are lots and lots of people within Australia who use UPULP (it is not to be criticized whether they actually know the chemical differences or not) it is for the best to find out what the differences between these fuels are.
Chemical Background
Ethanol (refer to figure a)is a highly flammable liquid, which surrounds two carbons, 4 hydrogen and anoxygen molecule, which is then bonded with another hydrogen. The boiling point of ethanol is 78.3°C and its melting point is -114. The density of ethanol is 789.00 kg/m³. Ethanol is classified as an alcohol (which is self-explanatory due to its ‘ol’ prefix).Octane (refer to figure b) contains 8 carbons alongside with 18 hydrogen molecules. The boiling point of octane is measured at 125°C and its melting point is -57. Octane (114.23 g/mol) weighs higher than ethanol (56.06 g/mol). Evidently, the bigger the carbon chain, the higher the melting point as more energy is required to break the bonds contained within1. All fuels are mainly composed of mostly octane. Different types of fuels come different types of octane ratings. With E10, 90% octane is present alongside with 10% ethanol, with UPULP 2% ethanol is present alongside with 98% octane.
Octane and ethanol are both classified as hydrocarbons. Hydrocarbons combust by reacting with oxygen to create carbon dioxide and water plus energy.
(Ethanol)
C2H5OH + 3O2à2CO2 + 3H2O+ Energy (1386 kJ mol-1)
(Octane)
C8H18+ 25/2O2à8CO2 + 9H2O + Energy (5460 kJ mol-1)
As it can be seen, octane produces almost four times the amount of energy that ethanol produces. Hence why the octane to ethanol ratio is always higher.
SocialIssues
Pros
As ethanol can be extracted from plants, it can become very useful when it comes to renewable fuel. This also further helps with the reduction of the Greenhouse gas emissions. Sulphur content of the fuel are also reduced when ethanol is used.
Cons
Conclusion
References
1http://www.masterorganicchemistry.com/2010/10/25/3-trends-that-affect-boiling-points/
