Ethanol as an alternative fuel (1 Viewer)

[bobbybrownsenior]

Can anyone explain what this statement means towards me pls?
"Ethanol is advocated as being 'greenhouse neutral' as the CO2 liberate when it is burnt, is used in its synthesis. This means ethanol has the potential to reduce greenhouse gas emissions"

 

[aanthnnyyy]

CO2 is a non-pollutant unlike CO and part of the carbon cycle. Ethanol is said to reduce greenhouse gas emissions- but I'm pretty sure this hasn't been 100% proven. Nevertheless it is a more sustainable and ecologically friendlier gas to burn as it is obtained from fermenting glucose (sustainable method). Note when obtaining from ethene still not as sustainable since it is still extracted from fossil fuels (before hydrating ethene)

 

[Drsoccerball]

CO2 is a non-pollutant unlike CO and part of the carbon cycle. Ethanol is said to reduce greenhouse gas emissions- but I'm pretty sure this hasn't been 100% proven. Nevertheless it is a more sustainable and ecologically friendlier gas to burn as it is obtained from fermenting glucose (sustainable method). Note when obtaining from ethene still not as sustainable since it is still extracted from fossil fuels (before hydrating ethene)

You didn't answer the question. When ethanol is produced it consists of cellulose being crushed and used. when it is used as fuel it produces carbon dioxide and water. This carbon dioxide is then again used by the plants for photosynthesis resulting in a zero gain feedback loop.

 

[el_manu]

You didn't answer the question. When ethanol is produced it consists of cellulose being crushed and used. when it is used as fuel it produces carbon dioxide and water. This carbon dioxide is then again used by the plants for photosynthesis resulting in a zero gain feedback loop.

Yes. So ethanol can be classified as 'carbon neutral' fuel on the surface.

Photosynthesis: 6CO2(g) + 6H2O(l) --> C6H12O6(aq) + 6O2(g)

Fermentation: C6H12O6(aq) --> 2C2H5OH(aq) + 2CO2(g)

Overall result: 4CO2(g) + 6H2O(l) --> 2C2H5OH(aq)) + 6O2(g)

When ethanol is used as a fuel it undergoes combustion:
2C2H5OH(aq) + 6O2(g) --> 4CO2(g) + 6H2O(l)
This combustion reaction is the reverse of the overall synthesis reaction and so using ethanol appears carbon neutral.