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Pack stoves come in a variety of flavors, consuming white gas, denatured alcohol, propane, wood, gels, unleaded, kerosene... etc.

Given the assumption that I will be carrying all the fuel I need (no wood collecting), and that all stoves weigh the same (big assumption, but for the sake of the discussion, lets try it...) which one provides the highest heat-output per gram of fuel?

If we consider the weight of non-reusable containers, does that significantly change things?

Is any one significantly bulkier?

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The hydrocarbons are going to dominate in this category. Gasoline, diesel, and kerosene, and diesel are all nearly the same in terms of energy content by mass and volume, and are significantly higher than everything except propane:

http://en.wikipedia.org/wiki/Energy_density#Common_energy_densities

Those fuels contain an enormous amount of energy, that's why we use them to power so much stuff. Gasoline has nearly double the energy content per mass as coal.

Propane is also a hydrocarbon, and it has similar per-mass performance as the other liquids. However, because it is LP gas, it's not quite as dense as Gasoline, plus you require the sturdy metal container to contain the gas pressure.

So bottom line: If you need as much heating power as you can get, get a liquid fuel stove, and burn white gas or motor fuel.

  • This assumes that the efficiency of the different stoves is the same. Like Peter says, the Jetboil is supposed to be more efficient. Also, with white gas you lose a little every time you light it while you wait for the fuel tubes to heat up. Also, altitude and cold weather affect propane and gas stoves differently. I'm not sure how it balances out. – xpda Feb 12 '12 at 2:33
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    The efficiency of all fuels with a similarly built stove are similar. I don't know if jetboil makes a liquid fuel version, but there is no physical reason you couldn't. Better heat exchangers are independent of fuel used. – whatsisname Feb 26 '12 at 21:44
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There is also the question of heat exchange. How much of the generated heat will end up in the water/food, and how much will go into the surrounding air. I use a Jetboil for this reason. It has a heat exchanger at the bottom of the "pot" to absorb as much of the heat as possible. It also has neoprene insulation to maintain the heat. This is so effective that you can hold your hands around the bottom of the pot without burning them, try that on a regular stove...

Another alternative is the MSR reactor. It has a similar construction although it's a bit more expensive.

This means that you will have to bring less fuel in total since you will use it more effectively. A 100g gas canister is usually more than enough for a weekend of cooking for two. The gas is also, in my opinion, by far the easiest fuel to use. No soot, no preheating, no risk of spilling on hands or food.

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I found this PDF from UNESCO

It would seem ethanol (denatured alcohol) is top of the list, but petrol is pretty good and probably more cost-effective. The both have similar densities (about 0.7 kg/l). No data on white gas, but given the chemical content of it, I shouldn't think it's too far off petrol. However, as Zoul points out in the comment below - ethanol releases its energy slower, so it isn't all that useful.

Another consideration is soot - petrol can leave a fair bit of soot, and dirties up your jets. Ethanol burns a lot cleaner (denatured alcohol may soot up some more, because of the additives).

Personally - I use an omni-fuel burner which could burn propane, butane, white gas, petrol and kerosene. Most of the time, I use Coleman's fuel (a type of white gas). I found one litre of that would easily last me three days of breakfasts, dinners and cups of tea.

I also think ethanol burners are pretty dangerous - they're prone to being kicked over and spreading burning fuel, and the flame burns clear.

Update: an alternative to liquid/gas burners are hexamine fuel blocks - they're what I used to get when in the Territorial Army, and one block will boil a pint of water and last for several minutes (great for boil-in-the-bags and leaving a water for a brew). They're pretty light-weight, and the burner is simply a foldable tin stand (saving weight from a liquid/gas burner).

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    Mountaineering: FOTH (p. 66 in the seventh edition) says that alcohol is a poor choice because of its low heat output (= longer cooking time). No personal experience. – zoul Jan 25 '12 at 11:10
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    thinking about it - I agree that ethanol releases heat slower, I've seen ethanol burners take longer than gas and kerosene. I guess that energy content is not the same as rate of release... – HorusKol Jan 25 '12 at 11:28
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As you are asking for a stove I'm assuming what you are really interested in is actually cooking/warming up water or food, and not simply the energy density of the fuel. (Btw, for fuel naming, see also How are camping fuels named in different languages and geographies?)

Multiple factors play into this:

  • Energy density of your fuel
  • Container you (need to) carry your fuel in
  • Heating efficiency of the stove + windshield + pans setup
  • Weight of your stove + pans

For the energy density: you can look this up easily on a table such as e.g. here on Wiki. Propane / Gasoline / Diesel will be about as high as you can get, but the differences are minor. I'd say unless you're going for treks longer than one week fuel weight itself will not be a very major issue, so optimising here will have little effect.

Some fuels require more elaborate (read: heavy) containers. Propane for example you'll only be able to carry in a pressurised gas container of fixed size. Apart from the containers weight itself this also means that you can't really 'tailor' the amount of Propane you'll bring with you... Compare this to ethanol, for example, which you can fill into a small plastic bottle (of the right type) to exactly the amount you will need for your trip.

Probably most important is the efficiency of the stove you'll bring. Some stoves have enormous power output, but without properly sized windshields, good pans (and lids!) etc. you'll mostly be heating the environment. Some stoves are simple and of lower power, but come with fully integrated and very efficient windshields and lids (e.g. the ones by Trangia). The efficiency of your setup can also vary greatly with the ambient temperature, your altitude and prevailing winds, so there is no single best answer here.

Of course the weight of stove, pans and fuel overall is mostly what you're interested in eventually, as this is what you'll carry on your back. As always there are trade-offs: more efficient stove setup means less fuel needed, but the more efficient stoves tend to be bulkier/heavier. Longer trips will require you to plan for more cooking, i.e. more fuel, which means that fuel weight/efficiency is of higher importance. On very short trips a minimal overall weight might be reached by a simple but inefficient stove - when only cooking once or twice you might not care if you use twice the amount of fuel.

  • The extreme low weight /low efficiency option is probably hexamine (or the same stove used with solid alcohol, which is cleaner). It's also compact. It has its uses if you just need boiling water for drinks and dehydrated meals /noodles but forget cooking a proper meal on it. – Chris H May 6 at 7:25
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There are many things to consider. Do you cook in your tent or outside? That matters, because the more time it takes you to warm up whatever, the more heat you're going to waste. That's not too important if you're cooking in your tent and need that heat anyway.

Hydrogen would be nice, I guess, particularly if you needed to keep things cold in addition to heating things up, as you could release the gas through your cooler before sending it to your heater.

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