Ethanol – Why not

8/3/2019 Ethanol – Why not

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Why we should useEthanol to replace petrol in

motor vehicles.

By Amelia, Anastasia andSoracha.

Ethanol – Whynot?



Suitability for Road Transport The largest single use of ethanol is as a fuel, and

mostly as a biofuel additive for petrol.

Only ethanol from fermentation is a renewableenergy resource, therefore ethanol from crude oilis less suitable as a fuel.

Ethanol has a high octane number (129) so it isuseful in improving cold-starting and increasingthe octane number of fuels it is added to.



Ethanol: Availability and Cost of

SupplyEthanol can be made from ordinary crops like sugar cane, potato, corn,cassava and maize. Therefore in theory the availability of ethanol should beendless as its feedstock's are from renewable sources. However, at themoment there are some concerns about food prices, the large amount of arableland needed for crops and its energy and pollution balance of its production,

that might limit its availability

The most commonly used ethanol for fuel is E85. E85 is an alternativetransportation fuel composed of 85% ethanol and 15% gasoline. However, it isnot available to all countries. Countries who produce their own ethanol, likeBrazil and India, have all the means to produce E85. So since they don’t import

ethanol, they can blend it with ethanol in any mixture that their vehicles need.Whereas in countries like Nigeria and the Philippines, the ethanol is importedand therefore E85 is not available.Therefore it is not available to the whole world. For those countries who cannotproduce ethanol, this fuel is not available to them because the cost ofproducing it will be greater than the regular gasoline. And since gasoline and

ethanol are imported the cost of E85 will be much higher.



Energy Density

Energy density is “the amount of energy per

mass.”

This means that the greater the value the morebeneficial the source is.

The energy density of ethanol is 26.8 MJ/kg.

This is a relatively low energy density in

comparison to, for example, methanol andbiodiesel.



Can existing engine technology bereadily adapted to use ethanol? Most modern cars with any diesel generated engine, are capable of

running with a blend from 10% up to 15% ethanol mixed intogasoline (E10-E15). With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85%(E85).

For example, the manufacturer Scania adapted its engines to run onethanol. Their latest diesel-ethanol engine achieves the sameefficiency as a corresponding engine running on diesel.

However, almost all pre 1994 vehicles and many later vehicles havefuel lines that are not compatible with biodiesel. This is because

their rubber fuel system components, such as hoses and pumpseals gradually get degraded with the use of biodiesel. Also,biodiesel can liberate deposits mounted up on pipes and tank wallsfrom previous traditional diesel fuel, thus primarily causing fuel filterclogs when used for the first time. Therefore we would have tochange this to enable using biodiesel without damage.



Storage and Distribution Ethanol is in a liquid state at

room temperature, therefore it isrelatively easy to store andcontain.

However, no water is allowed to

mix with the ethanol in the tanksand micron-filters have to beinstalled to ensure this doesn’thappen.

Distributing ethanol is

predominantly done by rail ortruck.

Ethanol pipelines would be anideal solution, but due it’s solventproperties the pipes would bevery expensive as constantmonitoring and specialised pipes



Ethanol: The effect on theenvironment

Ethanol and Greenhouse Gas EmissionsEthanol, blended with gasoline, actually turns out to increase theformation of potent greenhouse gases more than gasoline does byitself. As far back as 1997, the U.S. Government Accountability Officedetermined that the ethanol production process produces relativelymore nitrous oxide and other potent greenhouse gases than does

gasoline. In contrast, the greenhouse gases released during theconventional gasoline fuel cycle contain relatively more of the lesspowerful type, mostly, carbon dioxide.

Ethanol and Air Pollution

Although the U.S. Environmental Protection Agency (EPA)claims that a net decrease in greenhouse gas emissions isfrom using ethanol, they recognize that ethanol use is aproblem for conventional air pollutants. Ethanol use,according to the EPA, will increase the emission of chemicalsthat lead to the production of ozone, one of the nation's most

challenging local air pollutants.



Ethanol and Fresh Water ConsumptionIt takes a lot of fresh water to produce ethanol.

Petroleum refining consumes 1 to 2.5 gallons of water per gallon of refinedproduct.

Scientists estimate that refining a gallon of corn ethanol today requires thirty-fivegallons of water. However, that is not all. They also estimate that three times asmuch water is needed to grow the corn that yields a gallon of ethanol. That bringsthe total to 140 gallons of water per gallon of corn ethanol produced.

Ethanol and Water PollutionCorn, requires more fertilizers and pesticides than other food or biofuel crops.These fertilisers contain pesticides that contaminate water nearby. E.g. pesticidecontamination is highest in the corn belt in America, and nitrogen fertilizer thatruns off from corn already has the highest agricultural impact on the MississippiRiver.

Overall, the more corn raised for ethanol means more fertilizers, pesticides, andherbicides in waterways, which means more low-oxygen "dead zones" fromfertilizer runoff and therefore more local shortages in water for drinking andirrigation.

Ethanol and Land Consumption

In order to meet consumption needs of ethanol, billions of acres dedicated tocultivatin corn onl for ethanol would be necessar . Therefore this would take



Safety...

Ethanol is actually one of the safest of liquid fuels

Neat ethanol is more difficult to ignite than petroland diesel fuel in open spaces. Some of thereasons for that is:

Lower vapour pressure compared with petrol

Lower vapour density and higher diffusioncoefficient compared with petrol

Safer in contact with hot surface Neat ethanol represents – due to fuel properties –

the highest risk for ignition (fire and explosion) inclosed spaces.

Ethanol – Why not

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