Jan 20, 2009 at 4:23 pm #1233391
So I've been playing with my new FeatherFire XL the last couple days, and have come up with a few questions and observations.
Everclear is only available at 75.5% in Michigan, not 95%. I used ~22ml to boil a pint of tap water with the stove throttled way down (in my kitchen). With the stove fully opened I then boiled a pint (after whole system had throroughly cooled) using ~18ml of 75% Everclear. My Ti-Tri is on the way… but still, I expected better fuel economy with the stove "simmer" setting. Any insight?
Second question: I've found mention that even pure grain alcohol (ethanol/ethyl alcohol/etc) releases formaldehyde in combustion. Is that true? If so, is there a fuel that doesn't release toxins when you burn it? By extension, I have access to 2 kinds of industrial ethanol, one of which is spectroscopic, totally pure unadulterated (though still petrochemically based, I think?) 199.99 proof. Would burning ~100% etoh be roughly 25% more fuel efficient than burning my 75% everclear? And further, even though that spectroscopic stuff is probably petrol based, would it ultimately release any more toxins than the everclear?
Thanks!Jan 20, 2009 at 7:12 pm #1471656
> Would burning ~100% etoh be roughly 25% more fuel efficient than burning my 75% everclear?
Weight for weight it should be more efficient. But we have found that the size of the flame and the size of the pot can be confounding factors here as well.
I think an article on water/alcohol blends is in preparation, but it is some months away.
CheersJan 21, 2009 at 11:24 am #1471775
My experience echos Roger's comments. Even though 100% ethanol SHOULD have more energy in it than methanol, and 100% SHOULD be 33% more efficient than 75%, I find it doesn't burn as well when used straight. Watering it down does help some, but not sure just how much water is optimal. Methanol is so cheap that it's a moot point for me.
Not sure about the toxins. Incomplete combustion would, at the very least, release ethaonl fumes which are definitely a toxin. I presume CO would also be floating around?Jan 21, 2009 at 11:34 am #1471778
Be sweet if you could water it down with cola.Jan 21, 2009 at 5:51 pm #1471881
Hmmm, dehydrated cola?Jan 22, 2009 at 9:19 am #1472011
@magillagorillaLocale: Southwest Ohio
I can get the 190 proof Everclear here. I hike it in as a beverage. I figure in a pintch I can use it for fuel. I've never tried it in a stove. For one thing it's expensive for fuel. On another note, I don't think I could bring myself to just burning it. If it brought it for fuel I'd likely end up drinking all of my fuel and eating cold meals.
I think you are correct on the 99.99 percent stuff. They add some nasty chemicals to it in order to extract the last 5 percent of water.
I hope someone invents powdered cola soon. Hopefully it comes with powdered fizz and powdered ice.
Once again, I have posted a comment which added nothing to the conversation.Jan 22, 2009 at 12:47 pm #1472070
Thanks so far, guys-
I guess even if I carried the ~100%, I could water it down with water in camp and save a little fuel weight that way.
I'm not so sure about the powdered cola, but I have seen powdered beer… use a straw for bubbles?
If anyone has some insight on products of combustion I'd really appreciate it. Cheers-Mar 17, 2009 at 10:31 am #1486320
A professor of mine in my chemical engineering course work said that benzene (a carcinogen) was used to extract the last bit of water to make ~100% ethanol leaving trace amounts behind. I don't think there would be any health issue using this for burning if you can get ahold of it but for drinking it's not a good idea.
On a side note this professor was telling how he was in charge of purchasing the alcohol for the parties at his dorm when he was in college in the 50's. He didn't know better at the time and purchased 50 gallon drums of industrial 100% ethanol and they mixed it with punch. He's currently over 80 and seems to be in good shape so I wouldn't get too terribly worried about it.Mar 17, 2009 at 12:12 pm #1486349
"I can get the 190 proof Everclear here. I hike it in as a beverage."
That's not a beverage, that's a drug. A beverage should at least taste nice ;)
RE: drinking 99.99% ethanol, bad idea thanks to the traces of benzene. Better to go with the 95% stuff. I find ethanol leaves some soot behind that I don't get with methanol, and the 95% stuff doesn't burn as efficiently as methanol in my experience, but the difference is pretty small.Mar 17, 2009 at 1:01 pm #1486373
@redleaderLocale: Luxury-Light Luke on the Llano Azul
I tried burning 151 proof (75.5%) Everclear in various stoves. It didn" work as well as the denatured alcohol from the paint store.Mar 17, 2009 at 2:41 pm #1486412
> ethanol fumes which are definitely a toxin.
Yeah, so no sniffing your cognac!
Methanol is toxic in that sense; ethanol is … well … not so toxic :-)
> I presume CO would also be floating around?
Some. See the alcohol section of the CO series at
The 95% Everclear would make a good fuel; the 75% Everclear will work in some stoves. Good fuels…
But beware: 'denatured alcohol' in the USA can legally have horrendous nasties in it. Tinny found bleach in his.
Technical Reviews on this coming soon.
CheersMar 17, 2009 at 3:18 pm #1486434
Regarding "powdered cola": try Nuun's Kona Kola – it comes in tablet form and dissolves much like AlkaSeltzer leaving a fizzy cola-ish drink. It's available next to all of the sports drink mixes in little white tubes.
Honestly, I wasn't impressed as a straight cola replacement, but it might work well for drink mixes.
Ice already comes in powdered form and can often be found on the trail if you hike in the right spots :)Mar 17, 2009 at 3:54 pm #1486450
"Yeah, so no sniffing your cognac!"
Definitely not if you are a tea-totalling health nut.Mar 17, 2009 at 5:58 pm #1486498
"and the 95% stuff doesn't burn as efficiently as methanol in my experience, but the difference is pretty small."
It seems that you would get a lot less energy from burning methanol than ethanol. 2 less C-H bonds to oxidize. Do you find any noticeable difference in the field?Mar 17, 2009 at 9:52 pm #1486591
> It seems that you would get a lot less energy from burning methanol than ethanol.
> 2 less C-H bonds to oxidize. Do you find any noticeable difference in the field?
Dead right. Technical article on this coming soon.
CheersMar 18, 2009 at 7:54 pm #1486958
" Technical article on this coming soon."
I'll be watching for that one, Roger. I'm particularly interested in the effect on combustion, if any, of the 5% of H2O that Everclear contains. Minimal, I'd guess, but I'm no expert.
TomMar 18, 2009 at 10:57 pm #1487028
> the effect on combustion, if any, of the 5% of H2O that Everclear contains.
That was the bit that surprised me too. A bit of water seems to be a 'good thing'.
CheersMar 19, 2009 at 8:30 am #1487082
I've been playing with samples of ethanol and other alcohols obtained from a friend. Best stuff I've found so far was of course the stuff that we can't really get, 95% + ethanol (that grade of Everclear isn't legal in my state). A couple drops of water helped a little, but not enough to matter to me. I've been routinely using 13ml of ~95% etoh to boil a pint with my caldera cone.Mar 19, 2009 at 12:45 pm #1487171
"That was the bit that surprised me too. A bit of water seems to be a 'good thing'."
Would that have to do with hydrogen combustion(re-oxidation) from the fraction of H2O that dissociates as the temperature in the stove rises? My chemistry is very rusty, but I seem to vaguely recall that heat applied to water will cause it to dissociate into 2H + O. Hydrogen does not remain elemental very long in the presence of oxygen, and its re-oxidation would release heat. A partial recapture of heat released by the original oxidation of the ethanol, sort of an after burner effect? Or am I totally out in left field here?Mar 19, 2009 at 2:12 pm #1487196
The left hand giveth, and the right hand grabbeth …
If the water molecule dissociates it sucks energy out of the flame; when it recombines it liberates the same amount of energy. There is no net profit.
The effect of adding water seems to be more along the lines of limiting the rate of burning of the alcohol. This has two benefits I think. One is that less of the flame goes up the side of the pot to be wasted. The other is a bit more subtle, and has to do with the limited rate oxygen can diffuse into the flame from the periphery. By slowing combustion in the flame, the water prevents soot from forming so easily.
Much more in the articles.
CheersMar 19, 2009 at 3:23 pm #1487234
"There is no net profit."
I'm with you there, Roger. The 2nd Law rules. My line of reasoning was that the energy involved was that which was not absorbed by the pot surface and would be lost up the side of the pot. By re-oxidizing the H the heat would be re-released and possibly be partially absorbed by the pot surface . A timing issue. Speculative, to be sure. I was just wondering out loud. Your response just triggered another speculative idea: If the H2O dissociates, you have an embedded source of oxygen not reliant on diffusion from the periphery. Possible?Mar 19, 2009 at 4:07 pm #1487250
@redmonkLocale: Greater California Ecosystem
I don't think it is from water dissociating, but from a change in the vapor pressure of the alcohol.
Since only the vapor is flammable, and it is burned with the oxygen in it's environment, I think the difference boils down to the stoichiometry of the reaction. If there is too much alcohol vapor, the amount of oxygen will be insufficient to ensure complete combustion, leaving soot. Unburned substrates will remain, reducing the efficiency of the stove.
If there is enough alcohol vapor to sustain the reaction, and there is oxygen in excess, the alcohol will combust completely and cleanly.Mar 19, 2009 at 4:34 pm #1487257
" and it is burned with the oxygen in it's environment".
That's the point I was trying to make: The O from dissociated H2O could provide more O in the environment. Pure speculation, I admit. The follow on question in that line is would the free O oxidize free H or go to work on the
ethanol, or both?Mar 19, 2009 at 6:59 pm #1487314
Cameron has it in a nutshell (imho).
CheersApr 20, 2011 at 12:30 pm #1727107
@foundLocale: Sacramento, CA
Can anyone confirm that 151-proof Everclear burns "well enough"? We can't get 190-proof in California.
You must be logged in to reply to this topic.