Ethanol as a fuel

Marina89 · 30 Oct 2009, 12:41 PM

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I was just wondering, other than that it is renewable and undergoes complete combustion, what is another advantage of using ethanol as a fuel? I was going to use 'carbon neutral' but I've just been told that it's incorrect.

Any help would be much appreciated =) Thanks

Aerath · 30 Oct 2009, 12:55 PM

Carbon dioxide neutral is correct (I think). It's cause the amount of moles of CO2 liberated from combustion and fermentation is reabsorbed when plants perform photosynthesis.

Marina89 · 30 Oct 2009, 1:48 PM

Yeah theoretically it's right but it actually doesn't take into account the carbon dioxide that is used in photosynthesis to produce the glucose

6CO2 + 6H2O -> C6H12O6 + 6O2

so there is actually more carbon dioxide used than is produced

Marina89 · 30 Oct 2009, 2:05 PM

Ok wait I do get what you're saying.. so it's sorta assumed that all of the CO2 released during fermentation and combustion of ethanol is going to be absorbed during photosynthesis

clintmyster · 30 Oct 2009, 2:15 PM

I've been marked wrong in exams for saying carbon neutral because you need to consider the energy requirements in transportation as well as combustion.

Another advantage would be that the fuel combusts more cleanly and evenly due to the oxygen atom. Octane has toxic additives like MTBE added that is harmful for the environment. For more info, check chem contexts on it. I suppose also it would create more areas of employment, particularly for people struggling the economic crisis but that might be pushing it xD

Other than that 3 adv and 3-5 of the following disadvantages would be enough.
Talk about the infastructure issues, less energy produced per gram or mole of ethanol as opposed to octane, issues with agricultural land needing to be sacrificed, herbicides + insecticides sprayed which degrade soil quality and can run off into lakes and streams harming marine life.

annabackwards · 30 Oct 2009, 2:19 PM

It does have the potential to be greenhouse neutral, but correctly fossil fuels would still need to be used in the distillation of ethanol and harvesting/planting of glucose rich plants so it actually isn't greehhouse neutral.

Another advantage would that is burns cleaner than traditional fuels such as petroleum and countries could rely on internal agricultural output to produce fuel instead of oil exports.

EDIT: already mentioned by clintmyster.

Marina89 · 30 Oct 2009, 4:26 PM

Thanks guys, that helps a lot!!

carlytse621 · 31 Oct 2009, 3:16 AM

- Job creation in new fermentation plants and other processes
- Regional economic growth in rural areas
- Biodegradable

mrhorseham · 31 Oct 2009, 10:05 AM

just say it has potential of reducing greenhouse gas emissions if solar/wind energy is used in its production.

jp92 · 31 Oct 2009, 1:51 PM

ethanol as a fuel would result in decrease in the reliance on crude oil for fuel which allows the minimal crude oil remains to be used for the petrochemical industry.

MrMMMan · 31 Oct 2009, 2:39 PM

Ethanol is also more reliable in that it can be produced from petroleum cracking as well as fermentation.

MMEB · 1 Nov 2009, 11:56 AM

Ethanol has a lower boiling point than petrol. What does that mean in terms of an advantage/disadvantage of its use as an alternative fuel??

harry4 · 1 Nov 2009, 11:59 AM

i suppose less energy would be used in combustion

brenton1987 · 1 Nov 2009, 5:54 PM

A couple more points for you all

Octane is immiscible in water and less dense so in the event of a spill it will form a distinct layer on top of water allowing for easy clean up. Where as ethanol is miscible in water so the result will be a toxic alcohol solution which cannot be cleaned. Disadvantage of ethanol.

Octane vaporises more easily than ethanol. In confinement octane vapour will collect creating an explosive hazard. Ethanol will stay as a liquid. Advantage for ethanol.

Octane has a much larger enthalpy of combustion so more energy will be obtained per unit volume from octance rather than ethanol. Disadvantage of ethanol.

chuboy · 1 Nov 2009, 6:27 PM

Some engines (and car owners) disagree with ethanol fuel making it hard to mandate - issues with warranties, engine repairs, etc.

Increased fuel consumption when using ethanol.

Stock for ethanol may eventually compete with food supplies, particularly in third world countries where returns from SUV-driving soccer moms outweigh those from starving African villagers.

Consider agricultural consequences of raping the land for ethanol stock.

30 Oct 2009, 12:41 PM	#1 (permalink)
Marina89 Junior Member HSC: 2009 Gender: Female Join Date: Mar 2009 Posts: 46 Last Activity: 11 Nov 2009, 10:48 PM	Ethanol as a fuel You can hide this advertisement by registering. I was just wondering, other than that it is renewable and undergoes complete combustion, what is another advantage of using ethanol as a fuel? I was going to use 'carbon neutral' but I've just been told that it's incorrect. Any help would be much appreciated =) Thanks __________________ Advanced English Maths 2 unit Chemistry Business Studies I.P.T Last edited by Marina89; 30 Oct 2009 at 12:41 PM. Reason: typo

30 Oct 2009, 12:55 PM	#2 (permalink)
Aerath Prophet 9 <3 HSC: 2009 Gender: Male Location: Sydney Join Date: May 2007 Posts: 4,546 Last Activity: Today, 6:43 AM	Re: Ethanol as a fuel Carbon dioxide neutral is correct (I think). It's cause the amount of moles of CO2 liberated from combustion and fermentation is reabsorbed when plants perform photosynthesis. __________________

30 Oct 2009, 1:48 PM	#3 (permalink)
Marina89 Junior Member HSC: 2009 Gender: Female Join Date: Mar 2009 Posts: 46 Last Activity: 11 Nov 2009, 10:48 PM	Re: Ethanol as a fuel Yeah theoretically it's right but it actually doesn't take into account the carbon dioxide that is used in photosynthesis to produce the glucose 6CO2 + 6H2O -> C6H12O6 + 6O2 so there is actually more carbon dioxide used than is produced __________________ Advanced English Maths 2 unit Chemistry Business Studies I.P.T Last edited by Marina89; 30 Oct 2009 at 1:51 PM. Reason: if you look at the fermentation equation and the combustion of ethanol as well you'll see what I mean

30 Oct 2009, 2:05 PM	#4 (permalink)
Marina89 Junior Member HSC: 2009 Gender: Female Join Date: Mar 2009 Posts: 46 Last Activity: 11 Nov 2009, 10:48 PM	Re: Ethanol as a fuel Ok wait I do get what you're saying.. so it's sorta assumed that all of the CO2 released during fermentation and combustion of ethanol is going to be absorbed during photosynthesis __________________ Advanced English Maths 2 unit Chemistry Business Studies I.P.T

30 Oct 2009, 2:15 PM	#5 (permalink)
clintmyster Prophet 9 FTW HSC: 2009 Gender: Male Join Date: Nov 2007 Posts: 814 Last Activity: Today, 9:52 AM Blog Entries: 1	Re: Ethanol as a fuel I've been marked wrong in exams for saying carbon neutral because you need to consider the energy requirements in transportation as well as combustion. Another advantage would be that the fuel combusts more cleanly and evenly due to the oxygen atom. Octane has toxic additives like MTBE added that is harmful for the environment. For more info, check chem contexts on it. I suppose also it would create more areas of employment, particularly for people struggling the economic crisis but that might be pushing it xD Other than that 3 adv and 3-5 of the following disadvantages would be enough. Talk about the infastructure issues, less energy produced per gram or mole of ethanol as opposed to octane, issues with agricultural land needing to be sacrificed, herbicides + insecticides sprayed which degrade soil quality and can run off into lakes and streams harming marine life. __________________ Need some extra help with l subjects like Physics, Maths and English? Looking to excel in the 2010 HSC? Click here! ----------------------------------------- AIMS: UAI 98.5+ MBBS ----------------------------------------- 2009 Girraweener n proud Subjects Mathematics Extn 1: Mathematics Extn 2: Chemistry: Physics: Ancient History: English:

30 Oct 2009, 2:19 PM	#6 (permalink)
annabackwards <3 Prophet 9 AyyyTAR Hater HSC: 2009 Gender: Female Location: Sydney Join Date: Jun 2008 Posts: 3,288 Last Activity: Today, 2:45 PM	Re: Ethanol as a fuel It does have the potential to be greenhouse neutral, but correctly fossil fuels would still need to be used in the distillation of ethanol and harvesting/planting of glucose rich plants so it actually isn't greehhouse neutral. Another advantage would that is burns cleaner than traditional fuels such as petroleum and countries could rely on internal agricultural output to produce fuel instead of oil exports. EDIT: already mentioned by clintmyster. __________________ Courses: Extension 1 + 2 maths, Chemistry, Physics, Modern History and Advanced English UAI aim: 99+ Click the user bars to join the groups of the era Want a friendly tutor with experience and plenty of resources? Click here, but hurry as there's only one slot left!

30 Oct 2009, 4:26 PM	#7 (permalink)
Marina89 Junior Member HSC: 2009 Gender: Female Join Date: Mar 2009 Posts: 46 Last Activity: 11 Nov 2009, 10:48 PM	Re: Ethanol as a fuel Thanks guys, that helps a lot!! __________________ Advanced English Maths 2 unit Chemistry Business Studies I.P.T

31 Oct 2009, 3:16 AM	#8 (permalink)
carlytse621 Member HSC: 2009 Gender: Female Location: just right next to you -0- Join Date: Feb 2008 Posts: 177 Last Activity: Today, 2:44 PM	Re: Ethanol as a fuel - Job creation in new fermentation plants and other processes - Regional economic growth in rural areas - Biodegradable

31 Oct 2009, 10:05 AM	#9 (permalink)
mrhorseham Junior Member HSC: 2009 Gender: Male Join Date: Oct 2009 Posts: 27 Last Activity: 20 Nov 2009, 10:15 PM	Re: Ethanol as a fuel just say it has potential of reducing greenhouse gas emissions if solar/wind energy is used in its production.

31 Oct 2009, 1:51 PM	#10 (permalink)
jp92 New Member HSC: 2010 Gender: Male Join Date: Sep 2008 Posts: 6 Last Activity: Yesterday, 6:06 PM	Re: Ethanol as a fuel ethanol as a fuel would result in decrease in the reliance on crude oil for fuel which allows the minimal crude oil remains to be used for the petrochemical industry.

31 Oct 2009, 2:39 PM	#11 (permalink)
MrMMMan New Member HSC: 2009 Gender: Male Join Date: Oct 2009 Posts: 23 Last Activity: 12 Nov 2009, 9:48 PM	Re: Ethanol as a fuel Ethanol is also more reliable in that it can be produced from petroleum cracking as well as fermentation.

1 Nov 2009, 11:56 AM	#12 (permalink)
MMEB New Member HSC: 2009 Gender: Female Join Date: May 2009 Posts: 2 Last Activity: 1 Nov 2009, 9:55 PM	Re: Ethanol as a fuel Ethanol has a lower boiling point than petrol. What does that mean in terms of an advantage/disadvantage of its use as an alternative fuel??

1 Nov 2009, 11:59 AM	#13 (permalink)
harry4 Member HSC: 2009 Gender: Male Join Date: Sep 2008 Posts: 139 Last Activity: 15 Nov 2009, 4:21 PM	Re: Ethanol as a fuel i suppose less energy would be used in combustion __________________ Subjects- Maths Ext 2 (1/2) Maths Ext 1 (1/12) English Advanced (1/55) Chemistry (1/12) Physics (1/9)

1 Nov 2009, 5:54 PM	#14 (permalink)
brenton1987 Senior Member HSC: 2005 Gender: Male Location: Newcastle Join Date: Jun 2004 Posts: 246 Last Activity: Yesterday, 11:11 PM	Re: Ethanol as a fuel A couple more points for you all Octane is immiscible in water and less dense so in the event of a spill it will form a distinct layer on top of water allowing for easy clean up. Where as ethanol is miscible in water so the result will be a toxic alcohol solution which cannot be cleaned. Disadvantage of ethanol. Octane vaporises more easily than ethanol. In confinement octane vapour will collect creating an explosive hazard. Ethanol will stay as a liquid. Advantage for ethanol. Octane has a much larger enthalpy of combustion so more energy will be obtained per unit volume from octance rather than ethanol. Disadvantage of ethanol.

1 Nov 2009, 6:27 PM	#15 (permalink)
chuboy Assistant Member HSC: 2009 Gender: Male Location: Northern NSW Join Date: May 2009 Posts: 98 Last Activity: Today, 12:42 PM	Re: Ethanol as a fuel Some engines (and car owners) disagree with ethanol fuel making it hard to mandate - issues with warranties, engine repairs, etc. Increased fuel consumption when using ethanol. Stock for ethanol may eventually compete with food supplies, particularly in third world countries where returns from SUV-driving soccer moms outweigh those from starving African villagers. Consider agricultural consequences of raping the land for ethanol stock. __________________ 2009 HSC: AdvEng, Ext2 Math, Chem, Physics, Music1

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