It's a whole new way of thinking about energy!
by Sudden Disruption - Saturday, January 19, 2008
Amazing New Air Car - It's NOT About the Air!

And it's not even about the car!
Every now and then an idea comes along that will change the world - and gets
mostly ignored. Some of you have heard me talking about this new air powered
car from MDI (Moteur Development International) in France which is now to be
manufactured by Tata Motors of India.
MDI did a press release a few weeks back and it was handled like, well,
another press release. The automotive press paraphrased a few paragraphs, but I
wonder if they actually THOUGHT ABOUT what they wrote?
And when Tata Motors introduced their more conventional yet inexpensive Nano at
the Detroit Auto Show last week, it got amazing coverage, but not ONE mention of
this new air car to be manufactured by the very SAME company!
The highly touted Tata Nano is a cute little bug that will get more than 50 MPG
- cool. But the MDI OneCat which is about the same size will go more than 20
TIMES farther on the same gallon of fuel! Did no one actually READ the spec
sheet on the OneCAT?
To be fair, the objective of the Nano is low price, not mileage. And the OneCat
is much lighter, which helps, but surprisingly, that's not the key to it's
mileage advantage. Here's how they do it...
As almost everyone knows, the standard internal combustion engine is only
about 30% efficient under the very best of conditions. This means 70% of the
energy in a gallon of gasoline leaves the car as wasted heat.
The only heat that produces power is that narrow band of highest temperature
that causes rapid expansion of air when the spark plug fires. Once the piston
reaches the bottom of it's cycle, all the lower temperature energy from that
cycle is wasted and must be pumped out the exhaust pipe.
If you add MORE heat at the point of ignition (higher octane), you get more
power. But Newton and his second law of thermodynamics limits us from using any
of the heat BELOW the temperature of ignition. THAT is the primary reason for
the inefficiency of the internal combustion engine. But what if we COULD use ALL
of that heat?
CAT - Compressed Air Technology
Guy Nègre of Formula 1 fame and his company, Moteur Development International
have spent the last 14 years developing a new type of engine for automobiles.
Compressed Air Technology has been described as using air as fuel, but that's
not quite right. The air works more like a battery. It actually uses a
carbon-fiber air tank with up to 300 times normal atmospheric pressure driving a
piston to give the car a range of 100 Km. You can think of this system as a
standard compressor motor and air tank - except it's running backwards. The air
tank drives the compressor, instead of the other way around.
So far, no big deal. Any advantage is a matter of strength, weight and volume
per unit of energy stored in the "battery" - the carbon-fiber tanks helps some.
But if a short range compressed air car is all they had, it wouldn't be very
impressive. The next detail is the key. When you think about it, you'll discover
it's the biggest advancement in thermal energy extraction since the invention of
the Otto-cycle in 1860! It effectively uses "wasted heat".

Bi-Energy Breakthrough
Guy Nègre’s brilliant innovation is to add a small fuel burner between the
air tank and the motor. The heat from this burner extends the range for the
compressed air tank by increasing the pressure of the air even more on it's way
to the motor. Properly insulated, this burner could approach 100% conversion
efficiency of the burned fuel. Here's the reason...
Small amounts of heat are not enough to turn over a reciprocating motor. But
when you add a compressed air tank, it provides a pressure bias great enough to
drive the motor on it's own. Now add the burner. Per the gas laws, the pressure
increase is proportional to the heat added - it doesn't require a critical
temperature of ignition! You could run it tepid or boiling - ANY heat adds
power. It's just a matter of how much.
If you double the burn rate, you'll double the added expansion. Since there's no
point of ignition, there's no critical temperature before this energy is
extracted. ANY heat added by a burner (or other source) will simply add
proportional expansion and energy extraction. Theoretically, most of the energy
from a gallon of gasoline (or stack of firewood) could be used to drive the
motor.

Check the spec sheet above. I assume these are actual
measurements. The OneCAT will go 100 Km on air alone, but another 700 Km on
only 1.5 liters of fuel! That works out to almost 1,100 MPG!
More Than JUST an Amazing New Car
MDI has a good chance of creating an amazingly efficient little car, and
that's cool. But what's REALLY exciting are all the other potential industrial
applications.
Considering generation and line losses when producing electricity, it may even
now be more efficient to run Bi-Energy motors at the site of the application
instead of buying electricity. Or we could boost power from solar heating. Or
hot sewer water for that matter! ANY source of heat could be used. It's just a
matter of degree and effectiveness. Any of a thousand sources of wasted heat can
now be used.
OK. You'll still need electricity to provide the compressed air bias, but the
rest of the energy would be more efficiently extracted - the hotter, the better.
What about recycling the heat from air conditioners to drive their OWN motors?
I'm not talking about perpetual motion here. There's no free ride. It's just
that the heat is no longer has to be totally wasted. This approach provides an
excellent possibility of dramatically increased efficiency in anything that
needs a rotating motor and has wasted heat available. (Note - MDI was WAY ahead
of me - I just found this link on their site...
Further Applications -
WOW!)
These ideas are worth more than just a press release. We need a new college
of engineering at every university!
It's a whole new way of thinking about energy!
Reproduced with kind permission from
http://suddendisruption.blogspot.com/2008/01/amazing-new-air-car-moving-at-heat-of.html