[Stoves] Jatropha and its future

Sun Aug 7 23:35:46 CDT 2011

Dear Roger

The glycerine-as-fuel is interesting. There is a lot of glycerine produced
in the oil pumping business - it sticks to the inside of the pipes. What
happen to it these days? Vaseline was developed to get rid of it at a
profit!

If it is cheap (might not be) it can be 'canned' like ethanol gel. Ethanol
does not have a very high heat content (hence the poor mileage cars
currently get compared with real gasoline). Watered-down ethanol is pretty
crummy. James Robinson at the SeTAR Centre has seem some at 18 MJ/Litre or
even less. Prof Philip Lloyd was running a stove on a fuel that had so much
water in it, it was condensing on the underside of the pot and dripped so
much it extinguished the fire!! Ha ha!

So what is the heat content of glycerine? How much does it cost? Where does
it come from? Is there much available? What is the melting temperature? 

Philip: what is the vapour pressure and so on? Have you ever tried burning
it? [Philip reads this list.]

Most alcohol burning stoves are terrible - that is my biased assessment.
They are usually choked to death near the evaporation zone and have very
short flame spaces, followed by too much air supply, yielding a smelly burn
- smelling like partly burned gel compound. We test quite a number of them.
There is a belief that if the fuel is ethanol, the emissions are inherently
low, which is not true. The emissions are potentially low because the fuel
is usually pretty good, but emissions are produced by the stove+fuel
combination. If the burner is poorly constructed, it's gonna smell.

You know those little pots of flame under the vegetables at the restaurant
buffet? Terrible combustion efficiency. Lotsa CO.

Regards

Crispin

From: stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Fireside
Hearth
Sent: 08 August 2011 00:20
To: stoves at lists.bioenergylists.org
Subject: Re: [Stoves] Jatropha and its future

    Thank you Crispin....

             These are all great ideas! Do you have any gut level sense of
what downsides there could be with regard to emission? would I find these to
be "fairly clean" fuel options? The glycerine did produce a scent/smoke free
burn once temperatures got high enough, however getting there was both
smelly and irritating. My delivery system I believe will need to advance to
(possibly) a fuel injector, unless something less complicated (oil drip) can
be thought up with any reliability. I actually started this project as a
pellet stove with a simple 12 volt auger and timing block system. I could go
back to that to push grains, seeds, or pitts....even dung! The electrical
demand would be covered by solar, and at some time I wish to experiment
further with thermocoupling the stove for a truly off grid, self powered
pellet stove. I am saving these posts which get me thinking so once my
current project is underway I can revisit them. With the level of expertise
represented here many  things are exciting possibilities......this is one
e-mail I will save for the near future and look for more information on as I
develop new ideas. Thank you very much.
Roger  

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