Hydrogen

J

Jacobl

Well-Known Member
Joined
Oct 18, 2004
Messages
108
Reaction score
0
Location
Vanderbijlpark
To all the physics and thermodynamics guru's out there, I have this question, what formula should I use to calculate the amount of H2 that will flow into a cylinder of 755ml water volume @ 10 bar.

I have experimental results obtained from filling above cylinder with a mass flow controller, however, I am not sure if the results can be trusted, and I would like to confirm it with a calculation/s.

Thanks in advance for all the replies
 
Yes use the Ideal gas law.

pV = nRT

p is the absolute pressure of the gas,
V is the volume of the gas,
n is the number of moles of gas,
R is the universal gas constant,
T is the absolute temperature.

R = 8.314472 kPa·L·mol-1·K-1
 
@werries2, that I did, however the difference between the calculation and the actual measured values are just too large, I am talking here 8.2L calculated and 12.8L measured, something does not add up....?
 
For what gas is your mass flow controller callibrated?
It usually is for dry air or nitrogen. to my knowledge you would have to compensate for the lighter H2 molecules.
 
It was calibrated at the Sasol calibration lab for H2.

BTW if I first calculate the specific gas (Rs) constant which is Real gas constant (R)/molar mass (H2), and I use that (Rs) as the gas constant in PV=nRsT I get a result that resembles the measured value closer.

Measured 12.8L vs 13.8L calculated.
 
I have not done gas calculation in years, but here goes:

p1V1 = nRT
p2V2 = nRT

p1V1 = p2V2
V2 = p1V1 / p2
p1 = (89kpa + 1000kpa)
P2 = 89kpa (~atmospheric pressure in Sasolburg/vdb)
V1 = 0.755L

V2 = 9.23L
 
Sir, are
you building
a
6707-4712Bomb.jpg

?​
 
Thank you for all the replies, it is back to lab to test the above results. To all those concerned, No a bomb is not being built, something far worse, I am busy with my D-Tech, "Storing H2 in carbon nano tubes"
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X