Originally Posted by
cyccommute
You can't burn a lower heat content fuel at twice the rate and transfer heat faster by just making the pool of fuel larger. First, the fuel has a specific amount of heat per mass. If it has less heat per mass, you have to burn more of it to transfer that heat. If you make a large pool of it, you just lose more of the heat to the surroundings. You also have mass transport problems with larger pools of fuel. The yellow flame of your picture and the sooted bottom of the pot indicate that you aren't burning the fuel efficiently because the fuel isn't getting enough oxygen.
There are natural laws that you simply can't violate which dictate how much heat a substance has and how fast that heat can be delivered. You can't break them or even bend them. You may think you have bent them but you really haven't. You are likely comparing caulk to cheese by doing a poorly controlled experiment. You can compare the fuels and the heating rates but you need to use equipment that is the same or at least similar enough to give you a meaningful comparison.
Let's not wander off into silly territory. Sticking to the point of liquid fuels used for camp stoves, there is definitely a difference in the energy transfer between ethanol and kerosene and the equipment used to burn the fuel. For example, kerosene used in a Trangia would provide more heat than ethanol because it has a higher amount of energy to give up. In an open burn situation, however, the amount of oxygen getting to the fuel would be limited and it would burn cool. It would produce lots of unburned carbon which is an indication energy loss. Pressurize it, atomize the fuel and efficiently mix it with oxygen and you can capture nearly all of the energy the fuel has to offer.
On the other hand, if you were to do the same with ethanol, i.e. pressurize it, atomize it and efficiently mix it with oxygen, you would see a gain in capturing energy but there isn't as much to gain as hydrocarbon fuels. Your fuel is partially oxidized and therefore doesn't has as much energy to give up.
I hate to break this to you, but most of the alcohol fuels you are likely to use, outside of something like Everclear, are produced from petroleum. Drinking ethanol is made by biological processes and has been for millennia. But commercially produced ethanol that is use in denatured ethanol is made through refining and cracking and treating oil.
You are assuming that the stoves project their heat from only the burning pool. They don't, as was explained to you earlier.
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In Australia (we don't just talk about the US in these forums), bioethanol is produced from organic products including sorghum and sugar cane. Petroleum is not used as the base. It never has been, as far as I am aware -- the plant would be readily identifiable as there are only a handful of petroleum refineries in the country, and Caltex seems likely to close one soon.
Certainly the chemical plant in Alberta that Machka worked for that dealt with ethylene used its gas and oil supplies to produce plastics. Nope, no ethanol there, either.
I also did a google search that stated that only 5% of the world's production of ethanol came from the petroleum source in 2003.
Then, Wikipedia (the go-to for all discussions like this, eh?) stated that the TCX Technology was invented by Celanese and was launched in only 2010. Celanese expects to produce from three new plants (two in China, one in Texas) 300 million gallons of TCX ethanol by 2016. There was no mention of volume petroleum production in Brazil or Argentina, which have high ethanol usage, but there was some mention of exports from the Middle East of some petroleum-based ethanol.
The other methods of obtaining ethanol from petrochemical feedstocks are virtually obsolete, with Lyondell-Basell Industries being the only company to still use one of them. The article said that petroleum ethanol was used only as an industrial feedstock.
Methylated spirits also is not taxed in the same way as gasoline, and therefore the production and make-up of methylated spirits is tightly controlled by various governments.
So where does the rest of the petroleum-based ethanol that you allude to come from?
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The shortcomings of alcohol stoves have been mentioned time and again, not only in this thread, but in previous ones where you have slapped down posters with all sorts of theory... and that's just what it has been, because you admitted in this thread that you haven't done enough practical research to provide a realistic and balanced critique of the equipment and fuel source.
But ultimately, the same defence you use for the integrity of your chosen stove applies here -- it's up to the user to beware the issues and to act appropriately.
By the way, I was in an outdoor supplier at the Grand Canyon today and looked at the Whisperlite stove (complex and I can understand how it can go wrong), the Jetboil (a bulky package if the jug is included, and you still have to buy the plastic base to create any sort of stability, plus tote around the cannisters), the PocketRocket (which I am already familiar with because I own one), and the fuel cannister to power the Jetboil and
PR (and those weigh a fair bit). Then I looked at the can of denatured alcohol and thought, yep, even here you can get something to power your Trangia.