Author Topic: Ethanol fuel in 6/1  (Read 14078 times)

phaedrus

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Re: Ethanol fuel in 6/1
« Reply #30 on: February 22, 2007, 08:14:07 PM »
Ditto! Welcome aboard Ed!


He wrote: "I have a 6/1 indirect injected engine and am considering running straight ethanol (160 to 190 proof).  Is this possible and what are the ill effects if any?  If it is possible what would need to be done to make it happen? Thanks for the input.  Ed"

Ethanol is highly hydroscopic and it's reasonable that the less than pure nature as defined by the proofs Ed gives is due to water contamination. What Ed proposes is to run on a solution of ethanol and water. Alcohols in general, and ethanol in particular, especially in combination with atmospheric oxygen and water, are corrosive to metals, and also tend to promote electrolytic corrosion. While it is, no doubt, possible to engineer away from problems associated with these qualities, it's a tough road to take and quite likely not a "best path".

In combustion the alcohol-water solution would, I think, exhibit knock due to the rapid expansion. Yes, diesels can and do knock. Much effort in design goes into minimizing this tendency.

So, Ed, it looks to me like an undesirable path to explore.

A solution of ethanol and water will not dissolve in diesel oil - so mixing your alcohol with fuel oil is not realistic. If you had pure ethanol it would mix, but even a small amount of water would cause the alcohol to come out of solution, even after the fact. Water's ubiquitous, eg not a good idea.

But let's go further. What about estrification, which is obliquely referred to above? You'd need oil for this. The alcohol you've defined, assuming that the low proofs are due to water, cannot be estrified. If it were methanol, maybe, but ethanol has to be very dry for esterfication into so-called bio-diesel. It is possible to dry alcohols, in particular one can dry ethanol, but you're going to have to learn a bit of chemistry - and it's costly in terms of time and money. You could, with considerable effort and oil, make your ethanol into bio-diesel, and that would work.

And even further, evaporating your ethanol-water solution into the intake air of your 6-1 (running on diesel oil) ought to, if you limit the "fumigation" to a natural evaporative rate, give you some efficiency increase and realize the latent energy of the alcohol fraction without damage to the engine. That would work. And, if I had drums of watery ethanol, that's what I'd do with it. Some people might just drink it though, depends... Anyway "fumigation is simple, cheap, and gets watts out of the alcohol.

Carburetting the alcohol, eg adding it to the intake air as a vapor in proportion to air volume, as is done in a gasoline engine, would be hard to govern - you wouldn't want to throttle the diesel intake. But "carburetting" in proportion to the rack-position might well work. Diesels, even at full power, seldom burn even half the oxygen available. My guess is that you could go to 10% alcohol in terms of the BTU of the two fuels. While experience might let you get near the 75% level Bob posits, I would be surprized at that. Of course, you'd still have the corrosive problems associated with alcohols and water...

Best of luck, Ed, let us all know how this turns out, keep us posted.

if ya don't ask permission they can't deny it...

mobile_bob

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Re: Ethanol fuel in 6/1
« Reply #31 on: February 22, 2007, 08:56:26 PM »
some info on dual fuel operation on ethanol

http://www.saeindia.org/saeconference/ethanolreview.htm

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info