Ethanol (=alcohol) added to gasoline

  • Thread starter Thread starter Ulysees
  • Start date Start date
  • Tags Tags
    Ethanol Gasoline
Click For Summary

Discussion Overview

The discussion revolves around the presence of ethanol as an additive in gasoline, particularly in the United States, and inquiries about purifying ethanol to high concentrations. Participants explore the implications of ethanol in fuel, its historical context, and practical considerations for obtaining high-purity ethanol.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • Some participants assert that gasoline in the United States can contain up to 5% ethanol, questioning the accuracy of this information.
  • There are discussions about the process of purifying ethanol, with some suggesting simple distillation, while noting the difficulty in achieving concentrations above 90% due to ethanol's hygroscopic nature.
  • One participant mentions that ethanol is added to gasoline to increase its octane rating, serving as a replacement for previously used additives like MTBE and tetra-ethyl lead, which have toxic properties.
  • Another participant references the requirement for 10% ethanol in gasoline in the U.S. and speculates about future infrastructure developments for higher ethanol blends like E85.
  • Participants discuss the availability of high-purity ethanol, with some suggesting that local liquor stores may carry 98% ethanol, while others challenge this claim based on regional availability and the nature of ethanol's azeotropic behavior.

Areas of Agreement / Disagreement

Participants express varying views on the accuracy of ethanol content in gasoline and the implications of its use. There is no clear consensus on the best methods for purifying ethanol or the availability of high-purity ethanol in different regions.

Contextual Notes

Participants note limitations regarding the availability of high-purity ethanol and the challenges associated with distillation methods, including the formation of azeotropes that complicate achieving concentrations above 96%.

Ulysees
Messages
515
Reaction score
0
1. Incredibly it appears that in the United States gasoline may have ethanol in it as an additive. Up to 5% can be ethanol in the fuel sold there. Does anyone know if this is accurate?

2. How do I purify ethanol (=alcohol) to 99%?

3. Where do I buy 99.9% pure ethanol?
 
Engineering news on Phys.org
Gasoline is a mixture of all sorts of hydrocarbons typically around 5-8 C long so a bit of ethanol isn't going to make a lot of difference.

You can purify ethanol by simple distillation although it's hard to get above 90% because ethanol readily absorbs water from the air.

You can buy high purity ethanol from the normal lab supply companies, sigma-aldritch etc but it isn't going to be high purity for long once you open the bottle.
 
There's nothing particularly shocking about oil companies adding ethanol to the fuel you buy. More curiously, incentive/legislation is made such that bio-ethanol is added to pump fuel in many countries, which is understandably controversial.
 
Ulysees said:
Incredibly it appears that in the United States gasoline may have ethanol in it as an additive. Up to 5% can be ethanol in the fuel sold there. Does anyone know if this is accurate?

In modern days, Ethanol is being added to gasoline to raise its effective Octane number. It is basically a replacement for MTBE and tetra-ethyl lead. tetra-ethyl lead was originally used for raising a fuel's resistance to spark knock, followed by MTBE which didn't contain lead, but turns out to be carcinogenic. Basically, Ethanol is one of the only additives that can be used with gasoline that is easy to manufacture and does not have heavily toxic or carcinogenic effects like tetra-ethyl lead or MTBE. Still, I think that many toxic properties of gasoline additives such as MTBE are blown far out of proportion.

http://en.wikipedia.org/wiki/Tetra-ethyl_lead

http://en.wikipedia.org/wiki/MTBE
 
Ulysees said:
1. Incredibly it appears that in the United States gasoline may have ethanol in it as an additive. Up to 5% can be ethanol in the fuel sold there. Does anyone know if this is accurate?

2. How do I purify ethanol (=alcohol) to 99%?

3. Where do I buy 99.9% pure ethanol?

Your local liquor store has pure grain alcohol which is 98% alcohol.

On the other note, with the United States requiring 10% ethanol in gasoline, it is setting up the infrastructure to switch to E85 in the distant future.
 
sirzerp said:
Your local liquor store has pure grain alcohol which is 98% alcohol.
That would be a special liquor store. Alcohol forms an azeotrope at lower concentrations, so stuff above 96% is going to be hard to find. The usual methods for getting higher concentrations are discussed in fuel distillation sites.

http://running_on_alcohol.tripod.com/
 
sirzerp said:
Your local liquor store has pure grain alcohol which is 98% alcohol.

Not in Ohio you won't. Kentucky on the other hand...:devil:
 
Lightest diesel engine known to man

Sorry, wrong thread, ignore this.
 

Similar threads

  • · Replies 131 ·
5
Replies
131
Views
11K
  • · Replies 27 ·
Replies
27
Views
17K
  • · Replies 7 ·
Replies
7
Views
6K
  • · Replies 1 ·
Replies
1
Views
11K
  • · Replies 9 ·
Replies
9
Views
9K
Replies
3
Views
7K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
6K
Replies
31
Views
7K