A friend of mine asked me if it were possible to buy a small diesel engine, that ran on bio-fuel, so he could use it as a practical demonstration of alternative energy sources from fossil fuels to his 13-15yrs old students.  As a reader of Model Engineer Workshop I suggested to him that I could request some information from that world of expertise.  My initial searches of the WWW info has caused me to believe that maybe, apart from model aircraft engines, such beasts are not readily available or maybe not even a practical alternative.  We would both like to promote alternative fuels to our students but are struggling to find classroom examples on a scale of our beloved Wilesco steam engine to show them it can be done.

Any ideas????

The energy requirements to sustain our (my?) indulgent standard of living is the question of the millenium, so much of our current food production is underwritten by it, and if it collapses so does our food, hard to contemplate.  We have 10% alcohol fuel that I buy for my 4WD, knowing that the lower octane rating means I save very little as I have to use more to do the same work.  However I buy it as I like to support an alternative where possible to give the energy power brokers a message (mind you a very weak one seeing they make nearly the same amount of money no matter what I choose).

The Stirling engine is a good lead and I will follow that one up.  It certainly has some excellent thermodynamic messages in the use of fuel to source heat energy.  PLus we can source them easily in OZ.

Your collection of diesels Ian asounds impressive especially seeing you have already achived the goal of the biofuel alternative if necessary.

I have found 10cc diesel model aeroplane motors discussed on the WWW but no source found to buy one as yet.

Well done Ian, I hope the bike conversion goes well.  It is a neat project to do.

The alcohol idea sounds good as well Gordon, but another coincidence I am happy home brewer of beer.  Rather than try, and waste, that fine product, can we use methylated alcohol (plus oil) on a small two stroke for example?  If so we could get an old trimmer motor, and run it on alcohol.  Obvioulsy if wear was a problem it would not matter too much as we would be only using for very short “demo” periods, a matter of minutes.  I think foorm memory the carby need a bigger venturi, but again this is to maintain power, we just want to ge the thing to run.

Thanks for all yurt comments suggestions so far.  Wardy

Now that sounds about as good as we will get Gordon.   Though when I explained to my teaching friend I had researched it amongst you kind folk and had an alcohol suggestion, he told me it was not quite what he was after.  He wanted to do the whole “waste chip oil to diesel” chemical process, and the chemistry was as important as the motor and bio-fuel bit.  Unless anybody has an alternative suggestion that is diesel based, I think we probably have gone as far as we can for the moment, or is there any hope for an alternative?

 

I certainly won’t be giving any beer to him for distilling down to fuel, far too valuable!!  

 

Thanks for all you kind assistance so far, Wardy.

I believe you are right about using the chip fat as a direct diesel fuel.  I have seen a bloke do the full diesel chemistry for a small Toyota 4cyl van.  He used various chemicals and scrubbing processes (from memory) to create a diesel he could use in his van with very few modifications.  He was planning on swapping to the direct use of the chip oil as the by products from the chemical process were mounting up and pretty well unusable commercially (how much hand cream does the world need?).  The straight oil burning would maximise the energy returns and only have the gaseous and particle emissions to worry about.  The problem as I understand it with the chip oil (fat?) is it solidifying when not being used and then  having to get it molten before it can be passed through the “normal diesel” fuel lines etc   His conversion relied on passing fossil diesel fuel through at the end of a run to give it a clean start next time it was used.

 

The use of food sources for energy is a hard question and is probably a more likely source of international conflict eventually than anything else.  A bit chemistry I can handle, solutions to these problems are out of my league.

 

The Stirling engine does sound good.  I will research that for my own benefit even if my chemistry teacher friend is not keen on that angle.