Why is Ethanol such a polarizing topic?

[Frank Lee]

All I know is, I dropped the gas tank on my '92 to replace the fuel pump; I've been running lots of straight E85 through it and it looked as new and clean as a whistle as the day it was made.

Yeah, I know- replacing the pump. Well it's 22 years old and who knows if the pump would have failed if it had never been exposed to a single drop of ethanol in that time.

Also, I just completed a trip with the F150 pulling the flatbed; filled with straight E85 for $2.41/g then topped off with regular close to home. Got 16 mpg, which is just as good as I could hope for with E10 yet saved over $1/g.

[Allch Chcar]

Theoretically RedDevil, until it phase separates.

I recall a Wankel Rotary engine being developed for a flying car that was being tested with 80% Ethanol and 20% water. Their reasoning was that it allowed the engines to generate more power with a cheaper fuel. Wankel Rotaries are especially prone to detonation. Since water has the phenomenal quality of increasing detonation resistance but with lower energy density. 160 proof has about half the energy density of Gasoline yet costs a fraction of high octane fuel.

Water doesn't mix with Gasoline, so testing with 10-15% Alcohol is risky by nature. Ethanol is all that's holding it together and will sink if enough water is present. My preference is going to be testing with over 70% Ethanol content and a combination of water and Gasoline. That would require testing on FFVs to compensate for the much higher volume requirements. Ideally I would take some 160 proof add some gasoline and tune it by hand or laptop.

I had to put Regular Gasoline in the van with prices being what they are. $3.25 for Gasoline vs $2.89 for E85. For that tight of a spread, I kept driving.

[RedDevil]

Yup, I dig that.
I even doubt I'd continue tanking hE15 if they didn't give it away like they do
I have no reliable data as both my MID and the fuel pump gauge are off. Yet I think it might just make a tiny difference in fuel efficiency, like 1 or 2 % adverse compared to the regular stuff. As it is only 2 cents per liter cheaper than regular (@ lowest discount action prices) which is close to 2 euro's per liter, say $10 a gallon) it is probably not worth it, except for the random polar bear maybe.

[freebeard]

What's this then?

http://inhabitat.com/tag/isobutanol/

[RedDevil]

Isobutanol does indeed have a higher energy density than ethanol, but it is also less volatile. Not sure if it can be used as is.
One factual untruth in the article:

The researchers can produce 1.88 grams of isobutanol per liter of fluid, the highest concentration recorded to date for transforming plant material into biofuel.

Yeast can produce up to 120 grams of ethanol per liter (15% volume).
Sunflower seeds, linseed etc. contain almost pure biodiesel.
I guess the original quote had more premisses, like "using gentech on previously unproductive organisms".

Imagine the cost of distilling purish isobutanol from a less than 0.2 % mixture.
It will need a lot of time and effort to become practical.
Nevertheless, this is a promising development.

[freebeard]

Sunflower seeds, linseed etc. contain almost pure biodiesel.

No love for hemp oil?

Removing the water is the hard part of many things. The Thermal Depolymerization process uses flash evaporation
[Thermal depolymerization - Wikipedia, the free encyclopedia

The 'factual untruth' says specifically, isobutanol.

[RedDevil]

It says 'biofuel'... it may be true for isobutanol, but biofuel can mean anything of (recent) organic origin.

Maybe they can make the isobutanol bind to somethhing or form polymers; then they probably can be filtered out efficiently.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

No love for hemp oil?

I'm not a pothead, but I wouldn't be unfavorable to hemp-based biofuels. Also, after extracting the textile fibers from the weed, some cellulosic leftovers could be used for ethanol production. In Europe there are some THC-free varieties of cannabis, used for industrial purposes. It's worth to note that cannabis was never forbidden in China, and is widely used for industrial purposes and even to reinforce concrete in buildings.

[freebeard]

Are you familiar with Al Capp's Shmoon?

Cannabis is like that. It can be optimized for flowers, seeds, or stalk, each with it's own uses, plural. Medicine, fuel or paper are only examples.

[Occasionally6]

Originally Posted by Allch Chcar

Wankel Rotaries are especially prone to detonation.

I think you have that backwards. The high surface area to volume ratio and that the combustion chamber is constantly moving into a new, cool, part of the engine means that Wankels are less prone to detonation than piston engines. This is one reason why they have promise - if any ICE does - for running on H2

The consequences of detonation in a Wankel may well be worse than it occurring in a piston engine.

Originally Posted by RedDevil

Isobutanol does indeed have a higher energy density than ethanol, but it is also less volatile. Not sure if it can be used as is.
One factual untruth in the article:
Yeast can produce up to 120 grams of ethanol per liter (15% volume).
Sunflower seeds, linseed etc. contain almost pure biodiesel.
I guess the original quote had more premisses, like "using gentech on previously unproductive organisms".

Imagine the cost of distilling purish isobutanol from a less than 0.2 % mixture.
It will need a lot of time and effort to become practical.
Nevertheless, this is a promising development.

Isobutanol can be used as is in an ICE designed for use with gasoline. (It might be better in an ICE designed for use with it though.)

One problem with isobutanol is that the biological pathway that generates it means less of the energy theoretically available in the feedstock ends up in the fuel than with ethanol.

The gain is in that the isobutanol is easier to separate from the water based fermentation broth than is ethanol.

Those are the things that are considered when figuring out the economics of a biotech research effort to produce fuels (or anything else): What is the maximum theoretical yield and what is the value of the product? If even the theoretical yield is too low, there's no point in trying to figure out how to get (close) to it.

If you are looking at growing/manufacturing/extracting a biofuel you have to consider the yield - potential and realized - at each stage:

Seed crops for biodiesel have good yield (and easy extraction) from the seed but poor yield per acre because the seeds are such a small fraction of the total biomass of the plant.

You also have to consider that to make biodiesel that is compatible with current engines, there is an interesterification step, to swap the glycerol with a small chain alcohol (MeOH usually but it can be EtOH), required.

Anything that can use cellulose (even better with lignin) is potentially good because that is what makes up most of all terrestrial plants.

At the processing/fermentation step, you are looking for the efficiency with which the fermenting organism can convert the feedstock to the product, the concentration at which the fermentation ceases and the speed of fermentation (you might not run it to completion if it slows down with increasing product concentration). The latter two are because of the capital cost of the fermentation vessels, not just the extraction costs.

Yeast, consuming 6 Carbon sugars, are pretty much the best option at the moment, which, regardless of subsidies, is why that is the predominant biofuel.

Algae look good because there's not much "extra" organism that has to be grown, avoiding diversion of resources in the organism away from the desired product(s) and extraction requires little energy.