Hybrid Car – More Fun with Less Gas

Has anyone seen a steam engine/electric battery hybrid vehicle? - Page 22

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Posted by residualselfimage1999 on June 8, 2009, 3:28 am
 

No. I am not implying anything at all.

It is likely it will take more energy to pressurized gas
to an energy density that equals diesel fuel - however, if
one does not have diesel fuel available (because of an
oil embargo or something like that) but one does have
another more abundent energy source that could be used
like electric power from hydro electric dams - it might still be
a possible energy alternative if we cannot increase the
energy density of electric storage devices in the future.

As the cost of finding, extracting, and refining
fossil fuels  increases - the time may come when
it will cost just as much or more energy to make
a gallon of gas/diesel  than it produces when it is
burned.




Posted by Joesepi on June 9, 2009, 12:36 pm
 
Compressed air is not an energy source.


No. I am not implying anything at all.

It is likely it will take more energy to pressurized gas
to an energy density that equals diesel fuel - however, if
one does not have diesel fuel available (because of an
oil embargo or something like that) but one does have
another more abundent energy source that could be used
like electric power from hydro electric dams - it might still be
a possible energy alternative if we cannot increase the
energy density of electric storage devices in the future.

As the cost of finding, extracting, and refining
fossil fuels  increases - the time may come when
it will cost just as much or more energy to make
a gallon of gas/diesel  than it produces when it is
burned.




Posted by Richard W. on June 9, 2009, 3:22 pm
 

When they make air into a liquid, don't they do it by freezing the air. It's
my understanding that at certain cold temperatures the different gases turn
liquid. So the different types of gas is sorted by measuring temperature and
draining of that particular gas in liquid form. Or have I been told wrong?

Richard W.



Posted by Stormin Mormon on June 9, 2009, 7:15 pm
 As I remember from school, air is about 80% nitrogen, and
19% oxygen, the rest being argon and some other trace
gasses.

The air is compressed and cooled. To separate it, heat is
slowly allowed in, and the gasses boil at different
temperatures.

--
Christopher A. Young
Learn more about Jesus
  www.lds.org
.




When they make air into a liquid, don't they do it by
freezing the air. It's
my understanding that at certain cold temperatures the
different gases turn
liquid. So the different types of gas is sorted by measuring
temperature and
draining of that particular gas in liquid form. Or have I
been told wrong?

Richard W.




Posted by daestrom on June 10, 2009, 12:06 am
 

That's quite right.  The most common way to make liquid N2 for example is to
compress the air to about 3000-4500 psi, then pass it through a regenerative
heat exchanger.  After that it is expanded back down to atmospheric
pressure.  The expansion cools it a lot.  Then the cool gas is passed back
through the regenerative heat exchanger.  After this goes on for a while,
the cool gas leaving will pre-cool the incoming compressed gas more and
more.  Finally it will be cooled enough that when expanded some of it
liquifies.  Keep going and almost all the liquid formed in N2 and all the
'gas' that is left to pass back out the heat exchanger is O2 and other trace
gasses.

This is sort of like a distillation column in reverse.  The first gas to
liquify is the one with the highest boiling point (CO2 I think), then N2.
Keep it up and you can liquify the O2 as well.

Needless to say, compressing all that air to 3000-4500 psi takes a lot of
energy and very little of that is recovered.

daestrom


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