Why Isn’t There an UL Alcohol Type Stove that Bruns White Gas?

Several years ago, one of the big companies (I think it was MSR) had a prototype non pressurized white gas type stove that used a ceramic filter that somehow created pressure via capillary action as the gas burned. The military was given some to try out with their fuel. But it never made it into the market; what I heard was that they had problems with the filter getting clogged. I had such high hopes when I first heard about it, but it never came to be. I think that Hikin' Jim has one of the prototypes and brought it to the GGG a year or two back, but I missed seeing it.

Tony, I'd rephrase your Q as, "Why can't I put white gas in an alcohol-type UL stove?" Which also begs the question, "What happens if you use alcohol in a WG stove?"

I've got a few theories (WG has a much lower flash point suggesting a more dangerous situation), but I don't know because I've never tried it. Maybe I should put on my nomex tomorrow and try it out.

Clearly, pressurized stoves can pre-mix the vaporized fuel and air, resulting in more complete combustion, higher temperatures, and greater fuel efficiency.

Clearly, unpressurized stoves can be much, much lighter.

But if you accepted lower efficiency, could you use the more widely available WG or mo-gas in a very UL set up while retaining your eyebrows? I don't know.

I'm curious to know what happens when you try to burn gasoline in a "pressurized" alcohol stove like a penny stove?

Obviously, this has been tried before and doesn't work well, but can anyone tell me why it fails? Does it not get enough air? Does it explode? Is it just really inefficient? What's the hang up?

White Gas needs a heck of a lot less pressure than alcohol. The vapour pressures are too different. Yes, a few pressurized stoves will burn 180 proof alcohol with modifications. This makes them unsuitable for burning WG…lots of dirty yellow flames. You need to replace the jet minimally, often something with a preheat coil, not a single line, is needed, too. The jet supplies small, vaporized fuel ammounts in lots of air. This is the same as a canister jet mixing large amounts of air. Genrally, the heavier the fuel, the more heat is needed to get it going. So, methane,ethane,butane and propane are easy. Alcohols evaporate to form this gas. As does pentane, hexane, septane, octane, etc… Generally WG contains almost NO octane. Alcohol is partially combusted already, if you will allow this anology. It does not have the same energy, but has many of the same characteristics as hydrocarbons, but only about 1/2 as much energy.

The SVEA 123 series was the most popular stove out there with no pump. A regular alcohol stove produces about 1000BTU. On low, the SVEA can *just* hit that. Depending on ambient temps, between 8-15g/l have been reached leaving this stove as efficient as any. Nobody likes to carry the 19oz, though. The cup weighs another 2+oz. This will burn acetone, benzene, regular unleaded and some other stuff besides WG. Though WG is the optimal fuel for it. Acetone burns too hot and will trip the saftey after 10 minutes. Auto gas will burn slow.

Zelphs stoves do not burn efficiently using WG. Most of the fuel is simply wasted so this is no real savings due to inneficiency.

Methanol/ethanol are uasy to combust because they do not require a lot of air mixing. So, in small unpressurized stoves, they work fine. Do a search on line for "alcohol coil" stoves, way too many to list. The so-called pressurized stoves we usually see are th ones like the penny stove et al. These are not true presurized stoves. Note that the coil stoves are somewhat dangerous, many are simply capped off with no saftey valves to relieve excess pressure in case of a blockage. Not recommended except for experimentation under controlled circumstances. Unless you are a good machinist, I would not fool with these. There are some nice ones out there, though. No moving parts, except maybe a valve, makes these attractive from a maintenece stand point.

Most of the work on stoves has been done. The fuels have chemical charateristics which *must* be allowed for. It is difficult to change the way a manufacturor thinks about the stoves. They do little active research. Capilary Action (old technology) was developed by MSR and makes the "disk" stoves for the military, though it is difficult to get them to admit it. It runs on JP4, not WG, I believe, though it may burn it. (CLEAN, CLEAN fuel.) Presurized fuel through a bunch of these makes them rather explosive, think BIG fireball. Not available for the camper, generally.

"Like tossing a match into a bucket of gasoline on a really cold morning. Nothing.
Gasoline vapor though, BOOM."

Things must be slow in Humbolt County.

–B.G.–

Yeah, I was out in the garage again on Saturday playing with my stoves, thinking too of some simple stove. Svea 123, Optimus 8/8R's. Self pressurizing, but heavy for UL bping, unless you go retro. My penny stove yesterday was actually way faster than the modified Starlyte, but by the time you add the weight of the priming fuel to it, took more fuel. Fun to experiment.
Duane

This one is for David Thomas and Roger:

Venom Super Stove using HEET in the "Red" bottle.

http://www.youtube.com/watch?v=1gqWJvYtcTA

Now Roger and David tell us why the Venom Super Stoves can burn these fuels.

Tony,

Passive white gas stoves can be built (been there, done that). In my opinion, these are some of the things that I observed:

1) Refueling – WG typically isn't sold in small volumes so what do you do with the excess?
2) I worry enough about people using alcohol incorrectly. WG is way worse
3) While fuel efficient, it burned slow in my system
4) I thought that it stank, not sure what other people found

At the end of the day I dropped developing a WG gas stove because 1) I didn't think the benefits outweighed the negatives and 2) the thought of offering a WG gas stove to the general public raised the concerns about the overall safety. These are my opinions, I am sure others will have a different point of view.

Best regards,

Jon

What I really wanted to work on for a UL cooking system is an unpressurized stove that ran on calcium carbide. Just carry the DRY pellets in a water proof container

>"I think that I am on my way to developing a stove fetish now."

Tony, it is only a fetish in comparison to someone with a single stove.

Compared to Hiking Jim, you have only a mild kink about stoves.

>"What I really wanted to work on for a UL cooking system is an unpressurized stove that ran on calcium carbide."

Shooting from the hip, I think you're not going to have as good energy to weight as with a hydrocarbon fuel. Off to check references. . . .

Making acetylene:

CaC2 + 2 H2O → C2H2 + Ca(OH)2

You carry in 40+12+12=64 grams of carbide to make 12+12+1+1 = 26 grams of acetylene. So a pound of carbide gives you 0.41 pounds of acetylene with a gross heat of combustion of 21,500 BTU/lb for a total of 8,734 BTU per pound of carbide you schlepped in.

That's like wood.

Versus propane-butane-hexane-etc all in the range of 20,000 to 19,000 BTU/pound. So you are carrying over twice the weight of carbide as butane AND you need some way to convert carbide to acetylene in a controlled manner.

Play with it if you like, it's a great little science experiment. But no way will you be finding some lighter alternative.

Back in the day before LED bulbs; carbide had a place for weight-efficient lighting (I was a moderately serious caver for a number of years). And rather than bring a WG Coleman lantern equivalent to a 100-watt bulb (but bulky, many pounds, and fragile) for large group BP trips; I'd bring a brass carbide lantern equivalent to about a 20-25 watt incandescent bulb in a soda-can size and at about 8 ounces. Directing it at the kitchen area allowed 4-10 people to work on dinner, read a book, etc.

"Bob Gross you know very well I have not offered a stove for sale that would be dangerous. How you handle your fuel depends on the danger involved."

Well, Dan, I didn't know that, but I would have hoped that to be correct. Due to the added dangers of white gas, that is why you have a complete set of user instructions and a legal disclaimer printed on the outside of any burner that you sell that might be used that way with white gas. You do, don't you? I thought that your lawyer was better than Jon's lawyer.

–B.G.–