Gasohol

On Sat, 2 Jun 2007 22:16:03 -0400, "Morgans"
wrote:

How sure are we that the gasohol in service station tanks contain no water?

It's pretty sure to contain some water, at least some of the time,
especially in summer and especially in the east. As the tank is drawn
down, air is going to replace what's been pumped out. That air is
going to contain some water, which will be absorbed in time by the
alcohol.


Is it possible that all tanks containing gasohol contain at least some water
dissolved?

See above.


Is it a certainty that the alcohol added to gasoline contains no dissolved
water?

Well, the alky presumably was shipped in full tanks / barrels /
whatever, so we can hope it's undiluted.

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
forthcoming from HarperCollins www.flyingtigersbook.com

"Cubdriver" wrote

Well, the alky presumably was shipped in full tanks / barrels /
whatever, so we can hope it's undiluted.

But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger than
around 98% alcohol. Is that all the alky producers go for, or do they use
the expensive tricks to get the last two percentage points of water out of
the alky?
--
Jim in NC

In rec.aviation.owning Morgans wrote:

"Cubdriver" wrote

Well, the alky presumably was shipped in full tanks / barrels /
whatever, so we can hope it's undiluted.

But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger than
around 98% alcohol. Is that all the alky producers go for, or do they use
the expensive tricks to get the last two percentage points of water out of
the alky?

It would be pointless as 100% alcohol would immediately start absorbing
water from the air.

In another post I said alcohol would absorb about 2-3% by volume. A web
search gives numbers in the range of 2-4%.

--
Jim Pennino

Remove .spam.sux to reply.

wrote

It would be pointless as 100% alcohol would immediately start absorbing
water from the air.

In another post I said alcohol would absorb about 2-3% by volume. A web
search gives numbers in the range of 2-4%.

I'm not disagreeing with you. I do wonder what the water content of the
pure alky is, the moment it comes out of production, though.
--
Jim in NC

In rec.aviation.owning Morgans wrote:

wrote

It would be pointless as 100% alcohol would immediately start absorbing
water from the air.

In another post I said alcohol would absorb about 2-3% by volume. A web
search gives numbers in the range of 2-4%.

I'm not disagreeing with you. I do wonder what the water content of the
pure alky is, the moment it comes out of production, though.

Probably around 5-8%.

Back in my college days I did "fermentation and chemistry experiments"
and with half-way decent temperature control that's what you get.


--
Jim Pennino

Remove .spam.sux to reply.

"Morgans" wrote in message
...

"Cubdriver" wrote

Well, the alky presumably was shipped in full tanks / barrels /
whatever, so we can hope it's undiluted.

But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger
than
around 98% alcohol. Is that all the alky producers go for, or do they use
the expensive tricks to get the last two percentage points of water out of
the alky?
--
Jim in NC


I don't know whether they do any initial distillation, to get to
approximately the 60% (or 120 proof) level, but the rest is apparently now
done by filtration through molecular sieves. The process is far less
expensive than distillation and achieves about 99% purity.

Various sources are offering a variety of grades of pure ethanol, up to
99.9%--although that does get expensive. Here is just one of the many links
that I found with Google:
http://www.alibaba.com/catalog/11549..._Grade_Bio_Eth
anol.html

Peter

In article ,
"Morgans" wrote:

"Cubdriver" wrote

Well, the alky presumably was shipped in full tanks / barrels /
whatever, so we can hope it's undiluted.

But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger than
around 98% alcohol. Is that all the alky producers go for, or do they use
the expensive tricks to get the last two percentage points of water out of
the alky?

I doubt that they would go for the expensive tricks, since the alcohol
will absorb moisture out of the air and from the bottom of the fuel
tanks as soon as it contacts either. There is no point in trying for
higher purity.

On Sun, 3 Jun 2007 12:37:37 -0400, "Morgans"
wrote:

But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger than
around 98% alcohol.

I think that's correct. When I was a student in England years ago, we
used to buy a liquor known as Polish White Spirits, which was 180
proof or 90 percent. The local wisdom (university students) held that
anything stronger would promptly dilute itself back to 180 proof from
water in the air (this was England, remember, very humid).

Google tells me that one can buy 190 proof (95 percent) "Everclear"
grain alcochol in British stores today.

Blue skies! -- Dan Ford

(Proof = the concentration of alcohol at which gunpowder soaked with
it will still explode, or rather flash up. It was therefore called
"proof", which later became 100 proof. It just happened to be 50
percent alcohol, so 200 proof is 100 percent.

(More student wisdom.)

(Wiki tells me that 100 proof is actually 49.28 percent alcohol BY
WEIGHT. By volume, it's less, so the student wisdom is a bit shaky.)

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
forthcoming from HarperCollins www.flyingtigersbook.com

On Jun 5, 12:22 pm, Cubdriver usenet AT danford DOT net wrote:
On Sun, 3 Jun 2007 12:37:37 -0400, "Morgans"

wrote:
But, it is _very_ difficult (it takes some expensive chemistry tricks) to
get all of the water distilled out of alcohol, in other words, stronger than
around 98% alcohol.

I think that's correct. When I was a student in England years ago, we
used to buy a liquor known as Polish White Spirits, which was 180
proof or 90 percent. The local wisdom (university students) held that
anything stronger would promptly dilute itself back to 180 proof from
water in the air (this was England, remember, very humid).

Google tells me that one can buy 190 proof (95 percent) "Everclear"
grain alcochol in British stores today.

Blue skies! -- Dan Ford

(Proof = the concentration of alcohol at which gunpowder soaked with
it will still explode, or rather flash up. It was therefore called
"proof", which later became 100 proof. It just happened to be 50
percent alcohol, so 200 proof is 100 percent.

(More student wisdom.)

(Wiki tells me that 100 proof is actually 49.28 percent alcohol BY
WEIGHT. By volume, it's less, so the student wisdom is a bit shaky.)

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
forthcoming from HarperCollinswww.flyingtigersbook.com


The only real difference between the 190 proof Everclear you refer to
and the alcohol that is added to auto gas is that the alcohol to be
added to auto fuel is "denatured". All this means is that it has been
poisioned so that it is unfit for human consumption. This is usually
done with natural gasoline and the regulations allow them to vary the
amount they add to 3-5%.

How can "pure gasoline" coming out of a 'supply depot' have the same 87 octane as the same "pure gasoline" mixed with
10% ethanol? Since all auto gasoline is coming from the same distribution pipes, what is the octane in those pipes?

Folks have said that the various sellers have their own additive packages, and others have said that the ethanol is
added near the point of use, and still others have indicated the ethanol is added to increase the octane rating. If all
this is true, then the gas in hte pipes could be some low octane rating which is then boosted with ethanol to 87 octane
for the pumps. That infers to me that even if you bought gas straight from the pipe it would not be 87 octane. Not good
for STC holders...