Is Ethanol Worth It? (for alcohol stoves)

[mrclean417]

You mean, in his example, the Ethanol was more efficient with his stove at those temperatures. At lower temperatures Methanol may be the way to go and in some instances a totally different stove will be needed. To go to extremes you won't be using Kerosene or Gasoline in the same stove that you're using two closely propertied versions of alcohol.

[mrclean417]

I like to think that if things aren't quite clear I can make them totally confusing in a simple paragraph.

It's not much but its what I do.

[hikin_jim]

Do you have data showing that it requires measurably more methanol than ethanol to boil the same amount of water?

With my two Caldera Cone set ups, I was getting a boil with 18ml of high ethanol content alcohol and 24ml with HEET (99% methanol). That's a ratio of 1:1.6 if I'm doing my math correctly. When put in terms of weight, it takes about 5 additional grams of methanol to do the same amount of cooking.

HJ

[hikin_jim]

...there is something you need to remember about fuels - operation is more important than efficiency. Methanol's lower vapor pressure makes it a much better choice for cold weather. And unless you are measuring the flue gasses, you have no idea whether or not your particular stove uses methanol efficiently.

Ethanol has a higher heat content per gram than methanol. The results from my testing seem to reflect the physical characteristics of the fuels used. I suppose if one were to be really rigorous, one would conduct such tests with a cross section of the alcohol stoves out there.

I've only done ethanol vs. methanol tests of the type described on my blog with Caldera Cones, however, my experience with my DIY stoves, while I wasn't writing down fuel consumption numbers and such was about the same.

HJ

[hikin_jim]

Let me clear something up: The downside to open burners is that you can't control boil off. Methanol's lower vapor pressure, which makes it easier to use in cold weather, also means that it boils easier than ethanol. And more can boil off than can burn. You can smell the unburned alcohol and you can see it collect on the bottom of a cold pan. You could probably setup a condenser (think moonshine still) and extract the unburned alcohol out of the exhaust.

Probably the better way to conduct your test would be to try it in the cold and with different burners. You really need at least two data points to draw any conclusions.

Ah, I see what you're driving at.

YES, in certain temperature ranges, the two alcohols tested will have very different burn characteristics. Particularly as it gets cold, methanol will be the more practical fuel. Practical considerations of course outweigh any theoretical advantage.


HJ

[hikin_jim]

I like to think that if things aren't quite clear I can make them totally confusing in a simple paragraph.

It's not much but its what I do.

We appreciate your sharing your gift with us. lol

HJ

[Camping Dave]

Oops, I meant to write $16 per gallon. HEET, and my local Quik-E-Mart and gas station, is about $2.50 per bottle. What are they, 12 oz, so roughly 11 bottles per gallon?

[dla]

I like to think that if things aren't quite clear I can make them totally confusing in a simple paragraph.

It's not much but its what I do.

Thanks - I was having a brain fart when I was rushing to knock out a post. This board doesn't allow us freebies to edit, so I followed one dumb post, with another and another....

[dla]

Ethanol has a higher heat content per gram than methanol. The results from my testing seem to reflect the physical characteristics of the fuels used. I suppose if one were to be really rigorous, one would conduct such tests with a cross section of the alcohol stoves out there.

I've only done ethanol vs. methanol tests of the type described on my blog with Caldera Cones, however, my experience with my DIY stoves, while I wasn't writing down fuel consumption numbers and such was about the same.

HJ

You really can't judge the efficiency based on the btu/gal. The useful metrics are (a)the BTU/hr generated, (b) the amount of fuel used, (c) ambient conditions and (d) burner type. I know that Iditarod racers are fond of Heet powered burners, and I doubt many folks will encounter worse conditions. But Parks brand Denatured (90% ethanol) would be a better choice in the summer. Operation over a wide temp range is the reason why SLX brand denatured, advertised as stove fuel, is a 50/50 mix of methanol/ethanol.

To me, the worst case is when the temps are in the 20's, there's a little wind blowing, my fingers are cold and I want lunch and a cup of coffee. What I've discovered is that the lowly alcohol stove, (my fave is the Trangia), works pretty good.

[kayak karl]

if your on the trail denatured will be the easiest to get. heet second. other stuff will be hard to find.

[hikin_jim]

if your on the trail denatured will be the easiest to get. heet second. other stuff will be hard to find.

Interesting. I would have thought HEET would be easiest to find since gas stations will frequently carry it.

I guess though that a lot of gas stations are going to stop carrying it now that gasoline contains something like 10% ethanol. Kind of makes the HEET redundant.

I guess denatured is available from paint and hardware stores. Even fairly small towns should have a general store that might carry either HEET or some brand of denatured alcohol.

HJ

[hikin_jim]

You really can't judge the efficiency based on the btu/gal. The useful metrics are (a)the BTU/hr generated, (b) the amount of fuel used, (c) ambient conditions and (d) burner type. I know that Iditarod racers are fond of Heet powered burners, and I doubt many folks will encounter worse conditions. But Parks brand Denatured (90% ethanol) would be a better choice in the summer. Operation over a wide temp range is the reason why SLX brand denatured, advertised as stove fuel, is a 50/50 mix of methanol/ethanol.

To me, the worst case is when the temps are in the 20's, there's a little wind blowing, my fingers are cold and I want lunch and a cup of coffee. What I've discovered is that the lowly alcohol stove, (my fave is the Trangia), works pretty good.

Efficiency shmiffiency! I think we'd all agree that a stove's got to work. In cold weather, methanol is your go-to alcohol fuel. The fact that ethanol has more potential heat is of little solace if you can't reasonably cook dinner.

The tests I did were at about 50F/10C (a little colder in the morning when I started, a little warmer in the afternoon when the clouds broke up). The results I got should be relevant for people hiking in weather around those temperatures or warmer.

HJ

[Wise Old Owl]

ok where do we get ethanol? - without blowing us up!

[hikin_jim]

Relax, WOO, it's not explosive. Now, what happens to your personality after you drink it, now that might be explosive.

It's pretty tough to get high concentration ethanol unless you want to pay the $$$'s for Everclear. Sunnyside denatured alcohol and Klean Strip Green denatured alcohol have good ethanol content and are more reasonably priced.

HJ

[Rasty]

Hmmm...I love the smell of burnt hair in the morning!

A few years ago a gave myself a 400,000btu hair cut (eye lashes & eye brows also) lighting a commercial LP broiler. Kind of looked like a cross between Friar Tuck and Uncle Fester. Cooking professionally I have burned everything from my foot to my eyeball.

[ALLEGHENY]

Good discussion. Thanks for all you do. When I read in the companion that a place sells ethanol by the ounce, what are they charging?

[Bearbait]

Guys be very careful handling Methanol. If Methanol finds it's way into your body, cuts on your hands, inhalation, contamination with food or drink, it will never leave you. Your body can not process out this chemical. Continued exposure over time can cause blindness, cataracts, and liver damage. That said, I use it all the time, but I am very careful not to expose myself while handling it and I never carry it in or near my pots and food bag.

[hikin_jim]

Are you sure about that? My understanding is that the problem with methanol is not so much that it doesn't break down but rather what it breaks down in to: formaldehyde and formic acid. It's the break down components that cause the neurological damage as I understand it.

But I guess the way it screws you up isn't too important. What's important to know is that methanol is toxic and due care is necessary. As long as you're reasonable careful and DON'T DRINK THE STUFF, you should be OK.

HJ

[Bearbait]

I work with thousands of gallons of this stuff at the Chemical Plant where I work. It will not break down.

[dla]

Are you sure about that? My understanding is that the problem with methanol is not so much that it doesn't break down but rather what it breaks down in to: formaldehyde and formic acid. It's the break down components that cause the neurological damage as I understand it.

But I guess the way it screws you up isn't too important. What's important to know is that methanol is toxic and due care is necessary. As long as you're reasonable careful and DON'T DRINK THE STUFF, you should be OK.

HJ

Methanol will absorb through your skin. Look up the MSDS on the stuff. It will not break down safely in the body. In fact, the standard treatment is to flood the victim's system with ethanol so that the liver can't break down the methanol into toxic products.