The person talking about hydrogen flammability limits was very likely confusing
hydrogen in oxygen limits with hydrogen in AIR limits... two very different
situations. Yes, flammability limits in OXYGEN are from 4.7 to 15 and 90 to 93.9
with detonation limits in between (15 to 90% by volume) BUT this is good! It is
one of the reasons it is a vastly superior fuel to all others in use now..
The flammability limits of hydrogen in AIR are 4.0 to 18.2 and again above
detonation limits at from 58.9 to 75% with the 18.2 to 58.9% by volume zone
between the detonation limits this is a fuel it has to burn to work. Propane
in use everywhere with hardly anyone objecting has DETONATION limits from 2.1
to 9.5 in AIR! (would prefer to use hydrogen)
>Abraham Moses Genen wrote:
>>
>> Abraham Moses Genen
>> **************************************************************
>> Being dedicated to the future progress of humankind
>> should be the prime concern of all civilized beings.
>> **************************************************************
>>
>> Dear fellow Extropians,
>>
>> The was a news item on the web several days ago that indicated that a
>> German company (I believe it was Mercedes, but don't honestly recall.)
>> announced that they had developed a prototype fuel cell for automobiles.
>> They further stated that they believed that it would replace the internal
>> combustion engine within the next decade. They claim that the fuel cell
>> uses hydrogen as is source of energy.
>> Obviously, this is outside my area of expertise. I suspect, however, that
>> there are those among you with substantially more technological knowledge
>> than I have who might understand the broad implications of this particular
>> development.
>> My concern is with its impact on social, economic and international
>> relations initiatives.
>>
>> Your thoughtful responses would be appreciated.
>>
>> AMG
>
>The Hydrogen must itself be generated, generally from a more
>traditional energy source. Since you can use electricity to
>generate the hydrogen, you can make fairly efficient and clean
>use of just about anything, notably including nuclear power.
>However, the result still depends on large centralized
>power generation. You can convert the electricity to hydrogen
>locally or even within the fuel cell itself, in which case the
>fuel cell is essentially acting as a battery. Or, you can
>try to convert to a "hydrogen economy", with distribution
>of hydrogen via pipelines. This is a non-trivial excersize,
>since hydrogen/air mixtures are explosive in any ratio
>from 90%/10% to 10%/90%, and hydrogen molecules are very
>tiny, requireing specialized pipes and joints.
>
>If you use coal or nukes, world energy potitics may change
>dramatically. If you use oil-fired plants to generate
>electricity, there's no big change at this level.
>
>