How much electricity is required to make 1 gallon of liquid hydrogen ?

I am doing some feasability studies for a potential hydrogen generation
plant and one of the questions is how big should the wind turbine be.
Specifically :

Q1: How much electricity is required to make 1 gallon of liquid hydrogen
?
Q2: When liquifying Hydrogen, how much liquid in ml does 1 cubic meter of
Gas become when cooled from standard conditions ?

Can anyone point me in the right direction ?

Thanks

in article MfjPb.4263$[Only registered users see links. ], steve mew at
[Only registered users see links. ] wrote on 1/20/04 3:57 PM:

Hire a registered chemical engineer and pay a fee.

Bill

1. I think you will find that this newsgroups and newsgroups in general are
free services provided as part of any internet access package.

2. This particular newsgroup is prepended with the prefix. sci. to indicate
non profit scientific community. It is used by people trying to learn
something new or trying to overcome a problem they have with what ever
projects they are involved in whether professional / acedemic or hobby. The
common glue here is that we all try to help each other our with the spirit
of community and sharing.

3. My problem is academic, its a homework assignment for a paper I am
writing.

4. Please give others the benefit of the doubt before you send
de-constructive useless comments.

"Repeating Rifle" <[Only registered users see links. ]> wrote in message
news:[Only registered users see links. ]...
hydrogen
meter of

Dear steve mew:

"steve mew" <[Only registered users see links. ]> wrote in message
news:MfjPb.4263$[Only registered users see links. ]...
hydrogen
of

You have my guess on question 1...

As to question 2, density of hydrogen (rho_H2) at STP is _____, density of
liquid hydrogen (rho_LH2) is ____, then rho_H2 * 1m / rho_LH2. Watch the
units...

Most of this stuff is on the internet...

David A. Smith

"steve mew" <[Only registered users see links. ]> wrote:


This is pretty elementary stuff. What are you going to do when faced
with actual challenges?

Steve Turner

Real address contains worldnet instead of spamnet

in article rmkPb.31206$[Only registered users see links. ], steve mew at
[Only registered users see links. ] wrote on 1/20/04 5:12 PM:


If you do expect help, please describe what you have done and what you have
calculated. If this is homework, why should someone else do if for you? Will
you give credit to the person who prepared it? My guess is that you intend
to plagerize whatever is sent to you. I am willing to be convinced
otherwise.

Bill

"steve mew" <[Only registered users see links. ]> wrote in message news:<MfjPb.4263$[Only registered users see links. ]>...

Well, that's not going to help much... do you want one gallon of
liquid hydrogen per hour? per day? per year? Also, don't forget, if
you want liquid hydrogen, you need a BIG cooler (to condense the
hydrogen down) and also likely a compressor (which takes a LOT of
power to run) in order to keep the hydrogen a liquid. So, I'd say you
need a pretty big wind turbine... order of megawatts, if not larger.


Might be easier to answer Q2 and then Q1.

Q2: obtain the density of liquid hydrogen (I'm sure you can look it up
on the internet, or if you really want to impress your professor you
can calculate it). Obtain moles of H2 from the 1 cubic meter of gas,
then convert moles H2 to grams H2, then with your density, convert
grams H2 to mL liquid H2.

Q1: 1 gallon of liquid hydrogen from water? The reaction goes
something like H2O -> H2 + 1/2 O2... look up the enthalpy of formation
of water and negate it (you're putting energy into the water for
electrolysis, not combusting the hydrogen gas)... then figure out how
many moles of H2 are in a gallon of liquid H2, and go from there.

Like I said earlier though, good luck getting liquid H2 without a
cooler and/or compressor...

Have fun!

Mike Darrett (a really bored chemical engineer)

"Mike Darrett" <[Only registered users see links. ]>

[snip]



[snip]


If your really want to impress your professor ... find out how much electricity
would be required to make a gallon of solid hydrogen!!


--
donald j haarmann - independently dubious

Bill,

Your whining is becoming extremely tedious.

1. I am an electrical engineer. The electrical part for the excercise is
done.
The chemical part was assigned purely to see how resourceful we were in
completing the areas that were are not experts in. ie. real world scenario
limited time.
2. Obvioulsy you have never been to university, if you had you wouldn't be
making childish remarks such as "My guess is that you intend to plagerize
whatever is sent to you"
(you also can't spell)
Any engineer worth his salt knows when to look stuff up. we are not expected
to reinvent the wheel. As long as you note your sources in any documentation
it is perfectly above board.
It's all good. Do you rediscover / derive basic physics everytime you use
taken for granted equations like f = ma. no..I don't think so.
3. I do not want help from you, the others have already been encouraging and
forthwith.
4. I am ignoring any more further mail from you. I suspect your out just to
antagonize people I do not have to justify myself to you or any other. [go
f**k yourself.]

Sincerely

Dr. Steve Mew PhD

"Repeating Rifle" <[Only registered users see links. ]> wrote in message
news:[Only registered users see links. ]...
are
indicate
The
spirit
have
Will

in article Q3GPb.12439$[Only registered users see links. ], steve mew at
[Only registered users see links. ] wrote on 1/21/04 5:54 PM:


I love you too1