Removing Ethanol from Gas?

-----Original Message-----
From: Jim Macklin [mailto Posted At: Wednesday, August 09, 2006 8:32 PM
Posted To: rec.aviation.piloting
Conversation: Removing Ethanol from Gas?
Subject: Removing Ethanol from Gas?

Avgas and mogas are rated/tested by different methods and
standards.


Some have been posting about using 92 or 93 octane mogas and removing
the Ethanol to get to the 90 or so octane for the old 80/87 engines. If
the testing and rating is different between mogas and avgas, is there a
conversion chart or algorithm somewhere so that we at least start with
the right stuff before we try to remove the ethanol?

"Jim Carter" wrote:

Some have been posting about using 92 or 93 octane mogas and removing
the Ethanol to get to the 90 or so octane for the old 80/87 engines. If
the testing and rating is different between mogas and avgas, is there a
conversion chart or algorithm somewhere so that we at least start with
the right stuff before we try to remove the ethanol?

They are close. Here's a link to an article that seems to sum up the
octane business in layman's terms:

http://www.prime-mover.org/Engines/G...es/octane.html

The biggest issue is the reduction in power. You can regain the power by
rejetting the carb or injectors and assuring sufficient intake airflow, but
then the fuel flow is much higher.....and your range is poor.

The fuel system might need modification to insure all components are
compatible with ethanol. One example is: the O-rings in your fuel tank
selector might not tolerate ethanol, swelling and making the fuel selector
tight or even locked in one position.

Regards,
John Severyn
@KLVK


"Jay Honeck" wrote in message
ups.com...
The adding of ethanol to gasoline has made the auto-gas STC unusable
for many aircraft owners, nationwide. So far, we're okay (in Iowa,
which is pretty funny) and are able to purchase untainted mogas -- but
the long-range situation seems untenable. We, as a nation, are
inexorably being forced toward the addition of alcohol into ALL
gasoline, so it seems...

On the Cherokee 235 user's group, there is a guy who's been
successfully using ethanol-gas in his aircraft. It's ruined his
fiberglass tip tanks, but he apparently expected this to happen.
Otherwise, the engine is running fine, or so he reports. (Personally,
I think he's crazy, ruining tip tanks that run close to $4K *apiece*,
but that's just me...)

His experience has led to a more interesting (to me) discussion about
the possibility of REMOVING ethanol from gasoline. Several ideas have
been postulated (evaporation; heating; adding water), but none of them
sound particularly safe or easy.

Any chemists out there? Anyone know a way to remove the ethanol from
mogas, so that we may safely use it in our aircraft?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On Wed, 09 Aug 2006 22:01:21 -0500, James Robinson
wrote:

"Jim Carter" wrote:

Some have been posting about using 92 or 93 octane mogas and removing
the Ethanol to get to the 90 or so octane for the old 80/87 engines. If
the testing and rating is different between mogas and avgas, is there a
conversion chart or algorithm somewhere so that we at least start with
the right stuff before we try to remove the ethanol?

They are close. Here's a link to an article that seems to sum up the
octane business in layman's terms:

http://www.prime-mover.org/Engines/G...es/octane.html

Well, it says the lower number (aviation lean) for aviation fuel will
be within one or two digits of the "motor octane" (MOR) on the gas
station pump. But US pumps don't tell you the MOR, they tell you the
anti-knock index (AKI), or (MON + RON)/2. As a rule of thumb the MOR
is 5 less than the AKI. (And the research octane number RON is 5 more
than the AKI.)

Thus the MON of autogas rated 87 octane is about 82, which makes it
about the equivalent of 80-octane aviation fuel.. Autogas with a pump
rating of 91 (premium) would be like 86-octane aviation fuel, if there
were such a beast.

(According to the site, aviation rich, the higher value in 80/87 is
only important in supercharged engines.)

This site: http://www.cheresources.com/greengas.shtml

says refineries *can* use catalytic naptha reforming and/or fluidized
catalytic cracking to produce a bunch of stuff, but mustly MTBE and
tertiary amyl methyl ether (TAME). The other refinery products
available for blending have various problems including causing cancer
(benzine), releasing sulphur, and gunking up your tailpipe.

So I haven't found anything on-line (yet) that absolutely persuades me
that high-test isn't just regular with more alcohol in it. (Which is
the part of my screed that actually relates to this thread.

Now for a slight change of direction. If you're writing your
legislators, one thing to remind them of is that we got the TEL out of
gasoline, NOT because it was making us sick (although I was never keen
on eating the blackberries that grow right alongside the highways
everywhere in Oregon), but because it destroyes catalytic converters.
And whatever anybody's opinion about catalytic converters is, nobody
is proposing CCs for the tiny piston-powered general aviation fleet.
Therefore efforts to remove the TEL from aviation fuel for
"environmental" reasons are quixotic and contrary to good sense.

In fact, a good case could be made for a mandate that TEL in avfuel be
REDUCED from the current ridiculous levels to something that wouldn'f
foul sparkplugs without drastic leaning.

THAT would make everybody happy.

Don

On Wed, 09 Aug 2006 18:00:55 GMT, john smith wrote:

Chevy Silverado 1500 AWD 15 11 19 14 $2813 -$10

That's the one that got me. Why does the Silverado do better on E85
than on gasoline? (Since the final figure is "cost", a minus figure is
a savings.)


-- all the best, Dan Ford

email: usenet AT danford DOT net

Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
In Search of Lost Time: www.readingproust.com

Jay Honeck wrote:
\

Few planes have fiberglass tip tanks -- so I think his experience is a
fairly valid test for many aircraft owners. It seems to be "running"
just fine in his low-compression Lycoming O-540, which is exactly what
you might expect from an old 1940's-era tractor engine.

Ethanol based fuels aren't entirely friendly to aluminum either, which
is one of the reasons the STC forbids it.

Cub Driver wrote:
On Wed, 09 Aug 2006 18:00:55 GMT, john smith wrote:

Chevy Silverado 1500 AWD 15 11 19 14 $2813 -$10

That's the one that got me. Why does the Silverado do better on E85
than on gasoline? (Since the final figure is "cost", a minus figure is
a savings.)

There's got to be something else in the figure. The Tahoe,
which essientially is the same chassis and engine gets near
the same milage, the same annual cost but it's on the + side
by $223...

Everyone might drop in on Baylor U's flight research programs. The've
been flying numerous aircraft on everything from straight avgas to 100%
grain alcohol. They even have STC's for the O-235 and IO-540 series
engines to run on any percentage of ethanol.

Absolutely. There were several planes on display at OSH this year that
are STC'd to use alcohol.

It's apparently not that big a deal to make planes work with the stuff
-- but that's not the subject here. I want to know -- is it possible
to REMOVE the stuff, so that our current STCs could be used?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

3. What is *in* that non-alcohol gas in Iowa now that boosts its
octane? TEL? MTBE? Nitroglycerine?

Iowa hasn't used MTBE for many years. Ethanol was its replacement, and
pretty well any automobile engine is allowed to use a mixture of up to 10
percent ethanol.

So how does our "premium" gasoline (no alcohol) achieve its higher
octane?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

One way of removing ethanol would be to mix water with the fuel, and let
it sit for a while. The ethanol would combine with water, then you could
drain both off, (along with any other soluble compounds in the fuel).

This is one of the options being discussed on the 235 group. It
apparently works, but it sure isn't practical, IMHO.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"