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From: jim beam on 21 Jun 2010 20:52
On 06/21/2010 05:47 PM, jim wrote:
>
>
> hls wrote:
>>
>> "jim"<"sjedgingN0Sp"@m(a)mwt,net> wrote in message
>>> That is false.
>>
>> It isnt false. Thermodynamics doesnt lie. Your argument cannot
>> hold water.
>
> Nobody but you and Mr. Bean said anything about thermodynamics.

/you/ didn't say anything about thermodynamics because /you/ just don't
understand enough of the physical fundamentals and what it all means.
trying to present underinformed and ignorant opinions as fact, as you
have done, especially on a hard physical science where the numbers are
easily available, is the mark of a true retard.


> Thermodynamics may predict how much heat is produced from a gallon of
> fuel. But thermodynamics does not predict how far you will travel on a
> gallon of fuel.

????????????????????? get back to your school bus, retard.


> If you think that the amount of heat produced and gas
> mileage are the same thing you know little about IC engines.

as opposed to someone that doesn't understand anything about
thermodynamics!!!!


> If
> thermodynamics could predict real world mileage of vehicles they
> wouldn't do any fuel economy testing. They would just calculate the
> mileage for each vehicle.

wow. just, fuckin' wow.


--
nomina rutrum rutrum
From: jim on 21 Jun 2010 21:18


jim beam wrote:

>
> /you/ didn't say anything about thermodynamics because /you/ just don't
> understand enough of the physical fundamentals and what it all means.

I never said anything about thermodynamics because it is not relevant to
the point. You have never explained how you think it might be relevant
or made any sort of coherent point of any kind.
From: Don Stauffer on 22 Jun 2010 09:45
jim wrote:
>
> Don Stauffer wrote:
>> jim wrote:
>>> No it is not true. E10 has 3% less energy than E0. But with 75% of the
>>> energy content of E0 gasoline being wasted and good reason to believe
>>> that ethanol blended gasoline can be burned more efficiently than
>>> gasoline alone it is not a given that ethanol blends will reduce gas
>>> mileage. In fact several studies have shown some engines get better
>>> mileage with ethanol blends. For instance, MIT has a prototype
>>> ethanol+gasoline engine that is 30% more efficient than a equivalent
>>> gasoline engine alone. That is special engine deigned to take
>>> advantage of certain properties that ethanol has that gasoline doesn't.
>>> Now that the vast majority of spark engines are being fueled with
>>> ethanol blended gasoline in the continental US you can expect to see
>>> engines designed for the US market to be more efficient on ethanol blend
>>> than straight gasoline.
>>>
>>> -jim
>> Losses in a heat engine have little to do with the fuel.
>
> Oh really? Apparently you never heard of the diesel engine. A diesel is
> typically 20% more efficient per calorie that a gasoline engine.
>
>
>> These losses
>> are do to inefficiencies in using the heat produced. About a third of
>> the thermal energy released in the fuel goes into useful work at
>> reasonable throttle openings, a third goes into exhaust entropy and a
>> third into the cooling system. That is true reguardless of the fuel.
>
> No it is not. It is only true when no particular engineering effort is
> made to take advantage of the nature of the fuel. If you use the same
> engine design for diesel fuel as gasoline it wouldn't be more efficient,
> but that would not demonstrate anything useful.
>
>
>> Now, it IS true that both ethanol and methanol have a higher octane than
>> most gasolines.
>
> Ethanol has higher octane than any commercially available gasoline.
>
>> If the CR is increased to take advantage of this higher
>> octane, then indeed we could have increased efficiency.
>
> Yes that is a significant part of the increased efficiency.
>
>
>> To a limited degree, if a certain gasoline is too low in octane so that
>> a knock sensor equipped ignition is retarding the spark, then an alcohol
>> mix could allow the engine to regain proper spark timing.
>
> Almost every car in the US now has ethanol in the tank. Engines are
> being designed around that fact. Go back about 4 years and the majority
> of spark engine cars didn't have ethanol in the gas tank and back then
> engines were being designed around that fact.
>
>
>> But the increase in efficiency in that case would come nowhere near 30%.
>> What alcohol ratio is the MIT engine using?
>
> This particular engine is a high compression (compression is as high as
> the highest diesel) turbo charged engine. The ethanol and gasoline are
> kept in separate fuel tanks. The gasoline is fed to the engine under
> light load conditions from multi-port injection. The ethanol is direct
> injected into the cylinders under heavy load conditions. The ratio of
> ethanol to gasoline increases with engine load. The mix of gasoline to
> ethanol on average is about 30% ethanol and 70% gasoline and yet fuel
> efficiency is much better than a efficient gasoline engine of the same
> weight and torque.
> It isn't just the direct injection that allows for better efficiency
> due to reduce pumping losses (like a diesel) it is also the much higher
> latent heat of evaporation of ethanol that produces pumping efficiencies
> not possible with either gasoline or diesel as the fuel.
>
> -jim

Jim, I certainly have heard of the Diesel engine- and the Diesel cycle.
Its efficiency is not due to the fuel used per se. Kerosene has been
used in a number of spark ignition engines, especially in the US in the
late 19th Century and early 20th.

Further, gasoline can be used in the Diesel cycle.

From: jim on 22 Jun 2010 10:41


Don Stauffer wrote:

>
> Jim, I certainly have heard of the Diesel engine- and the Diesel cycle.
> Its efficiency is not due to the fuel used per se. Kerosene has been
> used in a number of spark ignition engines, especially in the US in the
> late 19th Century and early 20th.

Yes kerosene has been used. What conclusion are you trying to draw from
that fact??


>
> Further, gasoline can be used in the Diesel cycle.

You claimed that: "Losses in a heat engine have little to do with the
fuel"

Yes it is true that gasoline can be used in a diesel but it is horribly
inefficient used in that configuration which is why nobody in their
right mind would burn gasoline in a diesel. This illustrates why your
statement is false. The fuel used is the most important determining
factor of losses in a heat engine. Engine efficiency has always been
built around the properties of the available fuel. And gasoline presents
less opportunity for incorporating thermal efficiency into the engine
design compared to a fuel like diesel or ethanol.

-jim
From: jim on 25 Jun 2010 15:43


"C. E. White" wrote:
>
> "jim beam" <me(a)privacy.net> wrote in message
> news:5PqdnaaS2JY7cYLRnZ2dnUVZ_v-dnZ2d(a)speakeasy.net...
> > On 06/21/2010 12:53 PM, C. E. White wrote:
> >> A few counterpoints:
> >>
> >> 1)Ethanol has value as an oxygenate that helps lower HC emmisions. I'd
> >> rather they use ethanol for this purpose instead of MBTE.
> >
> > it increases the "oxygen content" of exhaust, simply because there is
> > oxygen in an ethanol molecule. but that oxygen doesn't help combustion
> > because it's already chemically combined.
>
> OK. I buy that, but if the choice is MBTE or ethanol, I'd rather have
> ethanol. If the choice also includes neither, I am for that.

Use of ethanol as fuel for the most part has nothing to do with oxygen.
Most of the ethanol is being added as an octane booster. MTBE was the
first choice of the refiners to replace lead in gasoline when the phase
out of lead started in the mid 70's. After most of the states and
finally the EPA banned the use of MTBE because it was showing up in
drinking water all over the country, ethanol took off because it is
really the only viable octane booster available. Everything else has
environmental ot economic disadvantages.
And the main reason an octane booster is used is it saves petroleum at
the foundry. The refiners can meet the octane requirements without
ethanol but it would require about 3% more petroleum input.

The EPA also claims an oxygenate must be added in the winter in some
urban areas in the country where smog is a problem.


>
> >> 2) While the sort of corn used to make ethanol is food, it is mostly food
> >> for livestock. And after you use it to make ethanol, the stuff left over
> >> is
> >> actually still usable as high protein animal feed, so the loss to the
> >> food
> >> chain is much much less than the anti-ethanol people claim.
> >
> > isn't livestock classified as "food"? feeding corn to cattle makes a
> > damned sight more sense than burning it. especially when that corn
> > consumes more energy during cultivation and processing than it yields in
> > energy output.
>
> See references further below regarding the "energy balance." And of course
> there is a whole different discussion rearding the use of corn to feed
> animals, instead of using corn (or other crop grown instead of corn) to feed
> people directly. I raise around 50 head of cattle. I don't feed them any
> corn at all. They eat grass, with limited quantities of oats and stored hay
> as a winter supplement. But most Americans prefer beef with high fat contnet
> and that means "grain fed" beef.

That is right. The more corn that goes into ethanol the less diabetes
and heart disease.

> Think how many Mexicans we could feed if we
> stopped diverting all that corn to cattle, hogs, and chickens.

Mexicans had no problem growing enough corn to feed themselves before US
dump surplus grain on Mexico in the 90's. Destroying rural economies is
not feeding people it is wiping out their livelihood through greedy
predatory marketing.


>
> Actaully I am against the ethanol subsidies paid to oil companies.
>

The stated purpose of the subsidy when passed by congress was to
compensate the oil companies for closing down their MTBE production
facilities. The ethanol producer organizations say they can do without
the subsidy as it won't affect ethanol usage, but eliminating it will
raise the cost of gasoline.
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