Saturday, 11 February 2017

EQULIBRIUM CONSIDERATIONS

F[CH4 ] F[H2O] 1
Kms =
F[CO ] F[H2]3
Pt2
F[CO ] F[H2]3 Kms Pt2
F[CH4] =
F[H2O]
Equilibrium Considerations
CH4 + H2O CO + 3...Effect of Pressure
• Exit methane proportional to pressure squared
• lower exit methane at lower pressures
• overall plant...Effect of Pressure
• Exit methane proportional to pressure squared
• lower exit methane at lower pressures
• overall plant...• Exit methane proportional to Kms
• Kms approx inversely proportional to temperature
• lower methane requires higher temp...Temperature Pressure Steam/Carbon Ratio
Exit Temperature
Exit Pressure
Steam/Carbon Ratio
Exit Gas Composition
(% dry)
850...Feedstock Refinery Off
Gas
Methane Butane Naphtha
C/H Ratio CH6 CH4 CH2.5 CH2.2
Exit Gas
CH4
CO
CO2
H2
6.67
8.14
4.45
80.7...

70
60
50
40
30
20
10
0
Methane Feedstock
Exit Temperature 850 C (1472 F)
Exit Pressure 30 atas (435 psi)
Steam/Carbon Rati...Approach to equilibrium
 The system is not actually at equilibrium,
but close to it
 A measure of catalyst performance i...Temperature oC (oF)
770 780 790 800 810 820
2
4
6
8
10
12
Methaneslip(%)
(1418) (1454)(1436) (1472) (1490)
Exit CH4
Approa...0 0.2 0.4 0.6 0.8 1
200
(392)
400
(752)
600
(1112)
800
(1472)
Fraction down tube
TemperatureoC(oF)
Gas Temp Eq'm Temp
Appr...















No comments:

Post a Comment

New ISO Standards Transition Workshop (Auditors) ISO 9001:2015 What has Changed?

New ISO Standards Transition Workshop (Auditors) ISO 9001:2015 What has Changed? new concepts are considered - more risk based thi...