Stirlingengineforum.com

What is a good alternative fuel to run your stirling engine on? I know solar energy is a favorite but not very practical. My favorite at the moment is wood gasification. Burns really clean and is renewable. It doesn't need to be wood. You can use nut shells, corn stalks etc. People try to use it in internal combustion engines but they just cant burn it clean enough.

In New Zealand and probably other countries, during WW2, what was known as producer gas was used for cars with varying success when petrol was rationed. I don't know that it was very economical, but better than nothing. I think this may be the wood gas that you are talking of. Ian S C

Ian SC
That is the gas .It doesn't work all that well in an internal combustion engine, creosote build up. But using a burner like a propane gas stove uses, it burns very clean. Even burning the creosote.

For a Stirling Engine you can get away with fairly raw gas, ie., unrefined, where as an IC engine needs it reasonably clean. I have from time to time wondered about the compost heap, and as we don't have reticulated sewerage, each house has a septic tank to treat effluent, both these are gas sources. Ian S C

Ian SC
Those are great ideas. What if you used the compost as a preheater(140f) and the methane as the heater?

I know that sewerage can be converted into a viable fuel, The sewerage works in Christchurch NZ(my nearest city) use the fuel to run a large diesel (marine type) engine to generate electricity, and to run all their vehicles. Some cities are using gas from land fills/ rubbish dumps. Ian S C

I made one of those little coke can methanol gas burners that worked pretty well with ethanol...



And then filled it with chop fat (it needed a charcoal wick and a lot of preheating to get it going...



But probably one of the easiest would be old deep frying oil from a restaurant. They have to pay to get it removed so it's free, and your Stirling engine will smell delicious.

With the deep fryer oil, all you need is a wick, so depending on the size you want you could go with a spirit lamp or a hurricane lamp, or all the way up to a kerosene heater. All those should work, To go go bigger than that, I'd look at very porous fire bricks (a ceramic material that looks like a loaf of bread with the crust cut off) as a wick because I think it would get too hot for normal wick if you went really big. Charcoal works well as a wick as well. Just put some vegetable oil into a bowl and drop a lump of charcoal into it as a test.

Slightly interesting fact - cooking two lamb chops creates enough fat to cook two more. :)

120
I love those pop can ethanol stoves. I thought of having an air lock on a fermenter ,run that tube to a pop can ethanol stove. You would heat the bottom of the fermenter till the mash was 170f. At this point you would have a prestill. The ethanol would be pressurized gas to run the stove. You can get up to 20 percent ethanol .A five gallon fermenter would give you a long burn time. Then use this to heat your stirling engine.

Alternatively you could do a beer can stove that uses alcohol? http://vimeo.com/tomallen/how-to-make-an-alcohol-stove

There's a book titled "How I built a 5-HP stirling engine" by Lockwood. Its about how he and his team built a stirling engine that was fueled by rice husks from the rice they were milling. They ended up needing about 28%-38% of the husks to keep the engine running.

Make ethanol from lawn clippings, then turn the solid remains into solid pellets as used in pellet fires, it all burns, or you could just dehydrate the clippings, and compress that into pellets, almost make lawn mowing seem worth while. Other vegetation could be used. Ian S C

My lawnmower at present is a goat. She is a little rough on the edging but works out in the long haul.

Your goat is also dropping potential fuel where ever she wanders, part procesed bio fuel. A whole web site could be (probably is)dedicated to this subject

fullofhotair
If you could plug your goats output into some kind of convoluted set-up with pipes and stuff
then that might make a Stirling Engine with approximately a 1gp (goat power) of output (don’t ask me how many watts or GTU's that might be).


vamoose

fullofhotair wrote:120
I love those pop can ethanol stoves. I thought of having an air lock on a fermenter ,run that tube to a pop can ethanol stove. You would heat the bottom of the fermenter till the mash was 170f. At this point you would have a prestill. The ethanol would be pressurized gas to run the stove. You can get up to 20 percent ethanol .A five gallon fermenter would give you a long burn time. Then use this to heat your stirling engine.

That's a very cool idea.

I think a lot of the gas from your wort is CO2, so that might be a problem. Fire hates that stuff :)

But I think ethanol rises and I know CO2 sinks (you can pour it out of a jug to put out a candle as if it were a liquid) so there's a pretty good chance you could make a simple gravity based separator.

Now I have to go and do a stack of research and experements.

[PsudoSarcasm] Thanks a lot. [/PsudoSarcasm]

I think everyone should be provided with a free grad student to do experiments for you (unless of course you are a grad student :) )

Master.Elodin wrote:Alternatively you could do a beer can stove that uses alcohol? http://vimeo.com/tomallen/how-to-make-an-alcohol-stove

There's a book titled "How I built a 5-HP stirling engine" by Lockwood. Its about how he and his team built a stirling engine that was fueled by rice husks from the rice they were milling. They ended up needing about 28%-38% of the husks to keep the engine running.

Nice method to make a stove!

One of the most difficult bits to do when you make those pop can stoves is to fit the top into the bottom (because they are exactly the same size). I spent ages crushing the rims before I realised you can stretch them with an unopened can, because they are under pressure and as a result, slightly larger in diameter. But that video uses spaced dents rather than holes to jet the vapour. The dents make one end much smaller than the other.

Genius!