OT: Energy=Horsepower-Hours ???

If you add in all the fuel used plant, fertilize, harvest
and process the grain used to make ethanol, it is clearly
more energy wasteful and carbon emissive to use ethanol as
fuel than it is to just use the fossil fuel, directly.

Someday, when the technology is available to make high grade
ethanol from wood waste and grasses that grow without much
assistance, that may change.

 

Anyone have effective energy numbers for gasoline and ethanol in units
of horsepower-hours?

Likewise equivalent pounds of CO2 and H2O output?

Thanks!

...Jim Thompson

 

Maybe this helps:
http://bioenergy.ornl.gov/papers/misc/energy_conv.html

Has conversion factors in there as well. Horses are a bit unusual here
so I guess you'd have to go from BTU to kWh and then horses per hour.

Probably the DOE has that info, somewhere. Probably needs a bit of googling.

 

I just realized that I, myself, have been succumbing to the greenie
bullshit... ethanol IS a hydrocarbon ;-)

My bet is, when normalized to unit energy, they're equivalent
greenhouse gas polluters.

...Jim Thompson

 

How many gallons of fossil fuel does it take to grow and
process that slightly more than 1 gallon of ethanol (that
contains the same energy as a gallon of fossil fuel)?

Right now, it is considerably more than 1. Of course, you
could use ethanol instead, for those steps, but that only
increases the fossil need more.

It is like losing money on each item sold, but making up the
loss with high volume.

 

Everyone kids "W" about his references to prairie grass, but I think
that's where it'll be.

Ever struck a match to tumbleweed ?

You'd think you just threw gasoline on a fire.

...Jim Thompson

 

Yeah, I guess. It's just that oil comes out of the ground and generates
"new" CO2 while planted stuff consumes CO2 during growth and then
releases it again. Of course that doesn't take into account other
nasties such as fertilizer usage.

It's like our wood stove versus other people's gas heaters. Wood burning
is CO2 neutral while gas isn't.

 

(snip)

The octane rating is not meant to measure the energy content
of fuel. It is a measure of the knock (pre-ignition)
resistance of the fuel. If you don't have a pre-ignition
problem to solve, higher octane fuel is all cost (including
higher exhaust pollution and worse engine grime) and no
benefit for you.

 

Yep, sounds like hydrogen which, at the present stage of how to go about
it, is IMHO not the solution to our oil dependence.

 

One of my rants has been with the Bureau of Weights and Measures that
seals all the scales and gas pumps to ensure accurate delivery. There is an
Octane rating but that does not really equate to the energy content in a
gallon of fuel.
I care less about the quantity of the fuel than the BTU per gallon. With
lots of distributors now adding alcohol to gasoline, the miles per gallon is
decreasing and cost keeps increasing.

 

You can find out this information easily enough on the web, or in a
decent technical library

My pocket scientific data books lists enthalpies of combustion for
ethanol - 1371 kilojoule per mole - and for n-octane - 5512 kilojoule
per mole. You need to know the molecular weight of ethanol - 46.07 -
and of n-octane -114.23 - before you can do anything useful with these
numbers, as a mole of ethanol is 46.07 grams of ethanol, and a mole of
n-octane is 114.23 grams.

If you really do want to convert joules in to horse-power hours, you
will also need to know that one horsepower is 745.7 watts (or joules
per second) and that an hour contains 3600 seconds.

The molecular weight of CO2 is 44.01 and of H2O is 18.016, and there
are 454 grams to the pound.

Jim either didn't do high school chemistry or has forgotten all he was
taught.

 

The technology is already available. Most Swedish schnapps is made by
fermenting paper mill waste - which is to say the degraded cellulose -
which is a polmer of glucose - that didn't end up in the paper being
made at the paper mill.

Termites have commensural bacteria in their stomachs which degrades
cellulose to digestible sugars, if you don't want to use a paper mill
to do the job.

 

Ethanol is C2H6O - two carbon, six hydrogen and one oxygen. That
single oxygen molecule means that it isn't a hydrocarbon, but an
alcohol.

As has been pointed out by Joerg, ethanol is produced from green
plants, which absorb their carbon from atmospheric CO2, making ethanol
carbon-neutral.

Furthermore, it contains a lttle more hydrogen than regular
hydrocarbons fuels - octane is C8H18 - so a bit more of the energy you
get from burning ethanol comes from turning hydrogen into water, which
isn't a greenhouse gas.

 

On 10 Apr 2007 14:56:54 -0700, in sci.electronics.design

Nah, he needs to eat more greens and stuff, like Mr Kellogg suggested


martin

 

I wouldn't bet on the "accurate delivery". I've been keeping a
spreadsheet on the new car and discovered that mileage was low about
5% from a certain store... could be junk gas of course, but I suspect
more likely a "tweaked" pump.

...Jim Thompson

 

There is also some good research and development of high
efficiency catalysts that de-polymerized cellulose into
fermentable glucose. But these or the methods you describe
are not yet in significant use in the production of fuel
ethanol in the U.S. They are still using food grade crops,
grown, fertilized and harvested, using lots of fossil fuel
to make a lower grade fuel that is only salable with large
government subsidies. These subsidies are not so much
helping the future methods to be developed as they are
restraining their development, because big money is being
made without them.

 

The internal combustion I am looking forward to operating is
a variable displacement, variable compression ratio design
that has no carburetors or throttle body, but just intake
ports with fuel injectors. It adjusts its displacement and
stroke to compress the fuel air mixture to just below that
which causes pre-ignition while producing only the horse
power required, from idle to full, high speed acceleration.
It can also adjust to run on any vaporizable fuel of any
octane rating, from hydrogen to ethanol to 98 octane jet
fuel, obtaining the maximum practical mechanical energy from it.

Experimental (and impractically heavy) hydraulically
adjusted versions are being tested in dynamometer, and the
test results, so far, indicate that a typical vehicle with a
given peak horsepower capability would use about half the
fuel, on average, compared to a fixed displacement and
compression ratio engine in use, today.

How would you like to have a vehicle that goes something
like 50 miles on a gallon of low grade gasoline with 200 HP
available, or 55 on premium with 220 HP available?

 

Detailed comparisons at http://www.tinaja.com/glib/energfun.pdf

A more reasonable unit of measurement is the watthour per liter.


Ethanol, of course, is utterly worthless in that it is simply diesel
fuel in disguise when grown as corn under US farm conditions.

You have basically a big funnel. You pour lots of diesel fuel in the
top, and a little ethanol dribbles out the bottom.

Ethanol is pretty much an outrgeous twelve billion dollar federal vote
buying scam.

Ethanol from switchgrass or bagasse MAY EVENTUALLY have some net energy
potential.

--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email:

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

I'm always surprised to see the low efficiency wood stoves
(creosote manufacturing machines) in use almost everywhere.
We, as a species have been using fire long enough to do it
better than most wood stoves do it. So many people seem
proud of how primitive their wood burners are.

 

I don't have a study handy, but I have read some. Have you
thought about how many times you have to drive a tractor
(that has not been made to be particularly energy efficient)
up and down the rows to spray herbicide (and manufacture
that) or plow, plant, fertilize (and manufacture and deliver
that), harvest corn, then deliver it to an ethanol plant,
convert the corn to ethanol, deliver that to fuel mixing and
storage stations, deliver the fuel to consumers?

I'm not saying that there are no fuel costs in drilling,
pumping, delivering, fractionating, delivering to storage
facilities and delivering fossil fuel to consumers, but that
farming adds a a very energy intensive branch to the total
process.