E85 vs Gasoline - credible numbers?

Gordon wrote:
> On 8 Sep 2006 07:01:20 -0700, "ghostwriter"
> > wrote:
>
> >
> >Gordon wrote:
> [snip]
> >> Can ethanol be polymerized up to something approximately like
> >> octane? Gordon
> >
> >Yes, but increasing the energy density means a loss in absolute energy
> >output. Thats a waste in the case of ethanol but very useful for
> >something like the Fischer-Tropsch reaction where you are taking
> >something like syngas with very low energy density and transforming it
> >into diesel.
> >
> >Ghostwriter
> >
> I was leading into the school of thought that perhaps in the
> future it might be possible to use a polymerization process
> (Fisher Tropish or something similar) to produce fuels like JP-8
> and diesel, by means of energy inputs from, say, nuclear power
> plants. This might provide means for using nuclear power,
> indirectly, as aircraft fuel.
>
> If the organic sludge from the deep ocean floor could be
> retrieved and processed for ethanol, this would provide a nearly
> endless source of fuel with very little chance of any
> environmental harm.
>
> Gordon

The problem would be the water content in the sludge, the water would
have to be removed before you could process it into anything. Their
might be a process that ignores the water but something like FT or
thermal depolymerization which are the first processes to come to my
mind would not handle the water well.

Thinking further, with wet material syngas generation is about 50%
efficient which sucks but if the feedstock is near free that wouldnt be
a huge problem. Pumping the sludge however might be expensive given the
density difference between it and the water. If the end result was only
20-30% efficient it might not be worth the destruction of a carbon
trap. I will think about the numbers and see if I can come up with
anything else.

Ghostwriter

On Mon, jim > wrote:

>> ......
>> Actually, since you insist on saying irrelevant pedantic things, I thought
>> I'd chime in one of my own.... Oxygen and acetylene _will_ spontaneously
>> ignite without an ignition source, under the right conditions.
>
>So will diesel fuel. Happens all the time
>-jim

Are you sure, in 1957 a White truck trouble shooter
asked to park the big West Coast rig he was delivering in
my Dad's gas station in winter when there was an overheat
heater running.

He said not to worry, but I was surprised the building
was still there the next morning, diesel fuel was all over the
floor because the tanks were filled cold, and expanded.

Joe Fischer

"ghostwriter" > wrote in message oups.com...
>
> wrote:
>> "ghostwriter" > wrote in message
>> oups.com...
>> >
>> >> Can ethanol be polymerized up to something approximately like
>> >> octane?
>> >
>> > Yes, but increasing the energy density means a loss in absolute energy
>> > output. Thats a waste in the case of ethanol
>>
>> Yes, as an example, ethanol can be dehydrated to ethylene, which can be
>> oligomerized to octene (which can be further hydrogenated to octane if
>> necessary).
>>
>> This increases energy density modestly (about 30 % by the deltaH(combustion)
>> numbers). I'm not sure what you mean "a loss in absolute energy output",
>> but the process I just described does consume considerable energy. Perhaps
>> you meant "a loss in total energy when summed across the cycle." However,
>> that is trivially true for any processing step, even for your F-T example,
>> since the syngas must have come from something lower in energy like
>> methanol. In fact, any conversion step involves a loss in total energy,
>> unless there is some mechanism to introduce energy into the system (for
>> example, plant photosynthesis).
>
> 1kg of ethanol burns for 409cals, it can be converted to 0.6kg of
> ethylene and 0.4kg of water. Ethylene burns at 370cals/kg so that gives
> off 225cals. A little more than 50% eifficient assuming you achieve
> 100% yeild (which you cant) and dont have to input heat to drive the
> reacion (which you must). Thats before you add any other steps, I am
> using the 1982 edition of the CRC handbook, but I doubt much has
> changed.
>
> F-T-diesel is actually worse from a total energy efficiency standpoint,
> but works out better since it isnt necessary to ferment and distill
> anything to produce syngas. A syngas generator doesnt care what the
> feedstock is, whereas a dehydration system would only run on straight
> ethanol. Diesel also has much higher energy density than ethanol.
>
> Ethanol is useful because it is well understood and easy to produce on
> a relativly low capital budget. F-T is only efficient as a large scale
> process currently, since cleaning the syngas so that it doesnt poision
> the catayst is a difficult and intensive process.
>
> In the end it comes down to priorities and available resourses not to
> any paticular advantage to either system.
>
I have read about microbes that can convert syngas to ethanol as well
as catalysts that can convert syngas to ethanol under the right conditions.
I wondered why you would not just make SNG or methanol and then I
figured that SNG and methanol might sell for a $1 per unit and ethanol
might sell for twice that.

jim wrote:
>
> wrote:
>
>>"Lloyd Parker" > wrote in message
...
>>
>>
>>>Ever use an oxy-acetylene torch? Or an atomic esmission spectrometer?
>>>Oxygen
>>>and acetylene. Do they ignite spontaneously at the tip of the burner?
>>>No.
>>>Requires a spark or a flame.
>>
>>Actually, since you insist on saying irrelevant pedantic things, I thought
>>I'd chime in one of my own.... Oxygen and acetylene _will_ spontaneously
>>ignite without an ignition source, under the right conditions.
>
>
> So will diesel fuel. Happens all the time
>
> -jim

If we're going to all be pedantic, then you're wrong Jim. There IS an
ignition source, its the heat generated by compression of the intake
air. :-p

Lloyd Parker wrote:

> In article >,
> Steve > wrote:
>
>>Lloyd Parker wrote:
>>
>>
>>>>Just the heat
>>>>generated by turning the knob can set it off and cause a fire/explosion.
>>>>
>>>
>>>
>>>But not O2 at 1 atm. Otherwise nobody could breathe it without combustion.
>>>
>>
>>Nobody DOES breathe PURE 02 at 1 atmosphere. Even wearing an O2 mask,
>>there is dilution with nitrogen (primarily) and all the other gasses
>>that make up the soup we call "air."
>>
>>I agree that technically you are correct- there is an activation energy
>>required to start combustion when pure o2 and a fuel are mixed, but the
>>PRACTICAL result is that its much easier to light a mixture of 02 and
>>fuel than air and fuel. Whoever said that you don't need ANY activator
>>was certainly wrong, but the activator can be much more trivial.
>
>
> Ever use an oxy-acetylene torch? Or an atomic esmission spectrometer? Oxygen
> and acetylene. Do they ignite spontaneously at the tip of the burner? No.
> Requires a spark or a flame.

This is the point that comes in any discussion in which I have been
agreeing with Lloyd where I stop and say "DUH! I was agreeing with you,
you nincompoop." And regret ever posting that I agreed in the first place.

"Steve" > wrote in message
...
> daestrom wrote:
>
>>
>> "Steve" > wrote in message
>> news >>
>>> aarcuda69062 wrote:
>>>
>>>> In article >,
>>>> "daestrom" > wrote:
>>>>
>>>>
>>>>> In many cars, the oil-pressure sensor is used to enable the electric
>>>>> fuel pump, if it fails you get nowhere.
>>>>>
>>>>> daestrom
>>>>
>>>>
>>>>
>>>> Which?
>>>> Not GM, Ford, Chrysler, Toyota, Nissan.
>>>
>>>
>>> I've seen lots of oil-pressure ignition cut-outs, but only on stationary
>>> industrial engines (welders, air-compressors, generators, etc.) because
>>> those are left running unattended. Never one on any car. There's no
>>> REASON because the driver is always there to see the gauge and shut the
>>> engine down if a problem occurs.
>>>
>>>
>>
>> The REASON GM uses an oil-pressure cut-out is *not* to save the engine.
>> It's to prevent fires in an accident.
>
> Oil pressure responds too slowly for that. See previous post- the fuel
> pump is disabled in accidents by the PCM no longer detecting pulses from
> the crankshaft position sensor.

Better write Chilton's and let them know then. Both them and the GM
maintenance manual for my '84 Celebrity say you're wrong.

daestrom

"Bob" > wrote in message
...
>
> "daestrom" > wrote in message
> ...
>>
>> "aarcuda69062" > wrote in message
>> ...
>>> In article >,
>>> "daestrom" > wrote:
>>>
>>>> In many cars, the oil-pressure sensor is used to enable the electric
>>>> fuel pump, if
>>>> it fails you get nowhere.
>>>>
>>>> daestrom
>>>
>>> Which?
>>> Not GM, Ford, Chrysler, Toyota, Nissan.
>>
>> Guess again. I've had several GM cars where the oil-pressure sensor is
>> used in the fuel pump circuit.
>
> This is true
>
>> The 'design' was so the electric fuel pump would shut off if the engine
>> stopped with the ignition still on, such as an accident.
>
> Not true of anything GM has built in at least 20 years.
>
>> Interesting side story: In very cold weather (-17F), the car would start
>> on the gasoline left in the carb. But since the oil was so cold, the oil
>> pressure would not build up and enable the fuel pump before the carb ran
>> dry and the engine died. Happened every morning for a couple of weeks,
>> but would start fine once the day warmed up to abotu 5F. Fix was to go
>> to an even lighter grade of engine oil (5W).
>>
>> daestrom
>>
>
> And what was the year make and model of that car? The only ones I can
> think of off hand that could have worked that way were the old Monzas or
> Vegas

I can't honestly remember the name of all of them, but you're right they
were pretty old. One was an 84 Celebrity (or Citation??)

daestrom

"Steve" > wrote in message
...
> daestrom wrote:
>
>>
>> "aarcuda69062" > wrote in message
>> ...
>>
>>> In article >,
>>> "daestrom" > wrote:
>>>
>>>> In many cars, the oil-pressure sensor is used to enable the electric
>>>> fuel pump, if
>>>> it fails you get nowhere.
>>>>
>>>> daestrom
>>>
>>>
>>> Which?
>>> Not GM, Ford, Chrysler, Toyota, Nissan.
>>
>>
>> Guess again. I've had several GM cars where the oil-pressure sensor is
>> used in the fuel pump circuit.
>>
>> The 'design' was so the electric fuel pump would shut off if the engine
>> stopped with the ignition still on, such as an accident.
>
> That's not done with the oil pressure sensor. Its done by the crank
> position sensor no longer detecting crankshaft rotation, and the PCM
> opening the ASD relay shutting off both fuel and ignition systems.

Ah, well, if you're talking those 'new-fangled' cars :-) I'm thinking of
some old ones that still had distributer ignition. '80 to '84 vintage.
Guess things have changed.....

daestrom

In article >,
"daestrom" > wrote:

> > That's not done with the oil pressure sensor. Its done by the crank
> > position sensor no longer detecting crankshaft rotation, and the PCM
> > opening the ASD relay shutting off both fuel and ignition systems.
>
> Ah, well, if you're talking those 'new-fangled' cars :-) I'm thinking of
> some old ones that still had distributer ignition. '80 to '84 vintage.
> Guess things have changed.....
>
> daestrom

Includes the older vehicles such as your 84 Citation.

The oil pressure switch is connected in parallel with the fuel
pump relay. Having either oil pressure or a distributor signal
to the ECM causes the fuel pump to run.
The exception would be early 70s to early 80s carbureted
Monzavegas which only had an oil pressure switch.

SJC wrote:
> "ghostwriter" > wrote in message oups.com...
> >
> > wrote:
> >> "ghostwriter" > wrote in message
> >> oups.com...
> >> >
> >> >> Can ethanol be polymerized up to something approximately like
> >> >> octane?
> >> >
> >> > Yes, but increasing the energy density means a loss in absolute energy
> >> > output. Thats a waste in the case of ethanol
> >>
> >> Yes, as an example, ethanol can be dehydrated to ethylene, which can be
> >> oligomerized to octene (which can be further hydrogenated to octane if
> >> necessary).
> >>
> >> This increases energy density modestly (about 30 % by the deltaH(combustion)
> >> numbers). I'm not sure what you mean "a loss in absolute energy output",
> >> but the process I just described does consume considerable energy. Perhaps
> >> you meant "a loss in total energy when summed across the cycle." However,
> >> that is trivially true for any processing step, even for your F-T example,
> >> since the syngas must have come from something lower in energy like
> >> methanol. In fact, any conversion step involves a loss in total energy,
> >> unless there is some mechanism to introduce energy into the system (for
> >> example, plant photosynthesis).
> >
> > 1kg of ethanol burns for 409cals, it can be converted to 0.6kg of
> > ethylene and 0.4kg of water. Ethylene burns at 370cals/kg so that gives
> > off 225cals. A little more than 50% eifficient assuming you achieve
> > 100% yeild (which you cant) and dont have to input heat to drive the
> > reacion (which you must). Thats before you add any other steps, I am
> > using the 1982 edition of the CRC handbook, but I doubt much has
> > changed.
> >
> > F-T-diesel is actually worse from a total energy efficiency standpoint,
> > but works out better since it isnt necessary to ferment and distill
> > anything to produce syngas. A syngas generator doesnt care what the
> > feedstock is, whereas a dehydration system would only run on straight
> > ethanol. Diesel also has much higher energy density than ethanol.
> >
> > Ethanol is useful because it is well understood and easy to produce on
> > a relativly low capital budget. F-T is only efficient as a large scale
> > process currently, since cleaning the syngas so that it doesnt poision
> > the catayst is a difficult and intensive process.
> >
> > In the end it comes down to priorities and available resourses not to
> > any paticular advantage to either system.
> >
> I have read about microbes that can convert syngas to ethanol as well
> as catalysts that can convert syngas to ethanol under the right conditions.
> I wondered why you would not just make SNG or methanol and then I
> figured that SNG and methanol might sell for a $1 per unit and ethanol
> might sell for twice that.

The problem is that installing a generator and selling the power is a
lot cheaper and you already have a regular customer in the power
company. Firmgreen is installing a landfill gas to methanol plant just
south of Columbus, Ohio. I assume that a syngas system could be used
to make something like that if you had a near free energy source.

Ghostwriter