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Old May 10th 15, 06:13 PM posted to rec.aviation.piloting
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Default CAFE Electric Aircraft Symposium Set For May 1

Dave Doe wrote:
In article , ,
says...

Vaughn wrote:
On 5/9/2015 4:32 PM,
wrote:

If you burn hydrogen in an engine, you get lots of NOX byproducts, i.e.
smog, because air is mostly nitrogen and hydrogen has a very high
flame temperature.

Fuel cells do not have that problem as the temperatured involved are
much lower.



Yes, but my point was that you are still left with the problem of the
pollution and greenhouse gas generated by the production of your "clean"
hydrogen fuel.

Besides, for at least the last 30 years, mass consumer fuel cells have
been "just around the corner". Even if they suddenly became practical
and economical, we would still be left with the huge problems involved
in producing and distributing hydrogen.

You can wave your arms and talk about fuel cells all day, but the
problems with hydrogen won't go away. Hydrogen is not an energy source.
To make hydrogen, you make pollution.


And my point was if you BURN hydrogen, you make pollution.



Water is pollution?

I think you either need to get your chemistry right, or define
"hydrogen" - or perhaps, what you are burning. Hydrocarbons?


Air is 78% nitrogen.

Air is used as the oxidizer in an engine.

At high temperatures, i.e. inside an engine, the nitrogen combines
with the excess oxygen to produce NOx; mostly NO and NO2.

It does not matter what is actually "burning", it is the temperature
that causes the reaction and hydrogen has a very high flame temperature.

As hydrocarbons as a rule do not contain nitrogen, where do you think
the NOx emmisions come from?


--
Jim Pennino