Gasohol

"Blueskies" wrote

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...

Not to worry.

The pipeline people send many various grades of gas, all through the same
pipeline. They may send 95 octane straight gas for 4 hours, then switch to
82 octane for 2 hours, and so on, with the right storage facilities along
the way intercepting it, and putting it into separate tanks. I believe how
they know how to switch over, is to first know how long the switch in types
to get to them, then the senders put a dye package into the fuel to alert
the storage and distribution people that it is time to switch some valves,
and send the next fuel into a different tank.

When the tanker comes to deliver the fuel to the gas station, they blend the
correct amounts of each into the tank, and you get what you ordered.

Specialty fuels may not travel the pipeline, but be shipped some distances
by tanker truck, or barge.
--
Jim in NC

"Morgans" writes:


The pipeline people send many various grades of gas, all through the same
pipeline. They may send 95 octane straight gas for 4 hours, then switch to
82 octane for 2 hours, and so on, with the right storage facilities along
the way intercepting it, and putting it into separate tanks. I believe how
they know how to switch over, is to first know how long the switch in types
to get to them, then the senders put a dye package into the fuel to alert
the storage and distribution people that it is time to switch some valves,
and send the next fuel into a different tank.

Pretty close.

We never used dye. The operator has a stainless sink that drains into the
slop tank. In it is a large graduated cylinder. The faucet samples the
incoming line and pours into the cylinder; it oveflows into the sink. He
has an approprite hydrometer bobbing in it.

He "makes the cut" by observing the color change and the specific
gravity. He punches the [explosion-proof, of course!] pushbutton on the
valve panel when it's time.

He may cut early. middle or late; it depends on the two products. The
schedulers try to make adjacent 'tenders' friendly. Say $2 Fuel Oil
followed by Jet-A. That would be an late cut; he waits until he's sure
it's all Jet-A then he swings the valve. A few barrels of Jet-A aka
Kerosene will not hurt 100,000 bbls of #2FO.

If an unfriendly cut, say gas to Jet-A; he'll cut early to the slop
tank, and then ~~5-10 min later to Jet-A.

The slop tank is eventually emptied by being slowly injected into
a Kero/FO incoming stream; the tank is later tested to be sure its
flashpoint remains above 110F.


Specialty fuels may not travel the pipeline, but be shipped some
distances by tanker truck, or barge.

Fuels such as.... AvGas.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"David Lesher" wrote in message ...

We never used dye. The operator has a stainless sink that drains into the
slop tank. In it is a large graduated cylinder. The faucet samples the
incoming line and pours into the cylinder; it oveflows into the sink. He
has an approprite hydrometer bobbing in it.

He "makes the cut" by observing the color change and the specific
gravity. He punches the [explosion-proof, of course!] pushbutton on the
valve panel when it's time.

He may cut early. middle or late; it depends on the two products. The
schedulers try to make adjacent 'tenders' friendly. Say $2 Fuel Oil
followed by Jet-A. That would be an late cut; he waits until he's sure
it's all Jet-A then he swings the valve. A few barrels of Jet-A aka
Kerosene will not hurt 100,000 bbls of #2FO.

If an unfriendly cut, say gas to Jet-A; he'll cut early to the slop
tank, and then ~~5-10 min later to Jet-A.

The slop tank is eventually emptied by being slowly injected into
a Kero/FO incoming stream; the tank is later tested to be sure its
flashpoint remains above 110F.


Specialty fuels may not travel the pipeline, but be shipped some
distances by tanker truck, or barge.

Fuels such as.... AvGas.
--

Thanks Dave! Can 87 octane be mixed with ~93 octane to arrive at 90 octane? Seems like a lot of black magic (no pun
intended) in the oil business...

On Thu, 28 Jun 2007 00:15:25 +0000 (UTC), David Lesher
wrote:

"Morgans" writes:


The pipeline people send many various grades of gas, all through the same
pipeline. They may send 95 octane straight gas for 4 hours, then switch to
82 octane for 2 hours, and so on, with the right storage facilities along
the way intercepting it, and putting it into separate tanks. I believe how
they know how to switch over, is to first know how long the switch in types
to get to them, then the senders put a dye package into the fuel to alert
the storage and distribution people that it is time to switch some valves,
and send the next fuel into a different tank.

Pretty close.

We never used dye. The operator has a stainless sink that drains into the
slop tank. In it is a large graduated cylinder. The faucet samples the
incoming line and pours into the cylinder; it oveflows into the sink. He
has an approprite hydrometer bobbing in it.

Over 20 years ago I had the chance to tour the pumping and fuel
distribution control facility at a refinery. *Everything* was
controlled from that room. They measured flow rates
Vs time and claimed they could control the flow to the remote storage
facilities hundreds of miles away within several gallons. the system
was automated. The operator told it how many gallons of what to go
where. Different mixes and fuels were sent through the same pipeline
with no one on the other end to either make the switch or to monitor
it.

He may cut early. middle or late; it depends on the two products. The
schedulers try to make adjacent 'tenders' friendly.

Interesting post. Thanks Dave

Paul
N1431A
KPLU