Correlations are valid within +/À1
C (1.8
F) between 200 and 1,200
C
(400–2,200
F):
K SMR ¼ expðÀ4:8858E À 14 à T
5
þ 2:1457E À 10 Ã T
4
À 3:8682E À 07 Ã T
3
þ 3:7620E À 04 Ã T
2
À 2:2251E À 01 Ã T þ 5:8282E þ 01Þ
(12)
T,
C ¼ À 1:7663E À 05 Ã ln K SMR
ð
Þ
5 þ 1:1690E À 03 Ã ln K SMR
ð
Þ
4
À 3:5357E À 02 Ã ln K SMR
ð
Þ
3 þ 9:4694E À 01 Ã ln K SMR
ð
Þ
2
À 2:9272E þ 01 Ã ln K SMR
ð
Þþ6:1880E þ 02
(13)
Water-gas shift reaction:
K WGS ¼ P H 2 Â P CO 2
½
= P H 2 O Â P CO
½
(14)
Note that this is the reciprocal of the normal WGS K value.
Partial pressures are in atmospheres absolute and temperature is
C.
K WGS ¼ expðÀ7:1865E À 15 à T
5
þ 3:3071E À 11 Ã T
4
À 6:2984E À 08 Ã T
3
þ 6:4760E À 05 Ã T
2
À 3:9276E À 02 Ã T þ 1:1066E þ 01Þ
(15)
T,
C ¼ À 2:9492E À 01 Ã ln K WGS
ð
Þ
5 þ 4:4116E þ 00 Ã ln K WGS
ð
Þ
4
À 2:6510E þ 01 Ã ln K WGS
ð
Þ
3 þ 9:3947E þ 01 Ã ln K WGS
ð
Þ
2
À 2:9167E þ 02 Ã ln K WGS
ð
Þþ8:0912E þ 02
(16)
It should be noted that inerts entering the furnace will pass through unreacted
and dilute the products. These inerts will affect the equilibrium by reducing the
reactant and product partial pressures.
If the feedstock contains CO, CO 2 , or O 2 (as some natural gas does), you have to
remember to account for this in the equilibrium calculations.
Key operating conditions around the primary reforming furnace are thus:
Process-side conditions
Steam/carbon molar ratio
2.0–5.0+
Temperatures
Feed preheat coil inlet
700–750
F
Preheat coil outlet
800–1,150
F
Reforming furnace outlet
1,350–1,740
F
Pressures
Reforming furnace outlet
250–350 psig
(continued)
580
S.A. Treese
C (1.8
F) between 200 and 1,200
C
(400–2,200
F):
K SMR ¼ expðÀ4:8858E À 14 à T
5
þ 2:1457E À 10 Ã T
4
À 3:8682E À 07 Ã T
3
þ 3:7620E À 04 Ã T
2
À 2:2251E À 01 Ã T þ 5:8282E þ 01Þ
(12)
T,
C ¼ À 1:7663E À 05 Ã ln K SMR
ð
Þ
5 þ 1:1690E À 03 Ã ln K SMR
ð
Þ
4
À 3:5357E À 02 Ã ln K SMR
ð
Þ
3 þ 9:4694E À 01 Ã ln K SMR
ð
Þ
2
À 2:9272E þ 01 Ã ln K SMR
ð
Þþ6:1880E þ 02
(13)
Water-gas shift reaction:
K WGS ¼ P H 2 Â P CO 2
½
= P H 2 O Â P CO
½
(14)
Note that this is the reciprocal of the normal WGS K value.
Partial pressures are in atmospheres absolute and temperature is
C.
K WGS ¼ expðÀ7:1865E À 15 à T
5
þ 3:3071E À 11 Ã T
4
À 6:2984E À 08 Ã T
3
þ 6:4760E À 05 Ã T
2
À 3:9276E À 02 Ã T þ 1:1066E þ 01Þ
(15)
T,
C ¼ À 2:9492E À 01 Ã ln K WGS
ð
Þ
5 þ 4:4116E þ 00 Ã ln K WGS
ð
Þ
4
À 2:6510E þ 01 Ã ln K WGS
ð
Þ
3 þ 9:3947E þ 01 Ã ln K WGS
ð
Þ
2
À 2:9167E þ 02 Ã ln K WGS
ð
Þþ8:0912E þ 02
(16)
It should be noted that inerts entering the furnace will pass through unreacted
and dilute the products. These inerts will affect the equilibrium by reducing the
reactant and product partial pressures.
If the feedstock contains CO, CO 2 , or O 2 (as some natural gas does), you have to
remember to account for this in the equilibrium calculations.
Key operating conditions around the primary reforming furnace are thus:
Process-side conditions
Steam/carbon molar ratio
2.0–5.0+
Temperatures
Feed preheat coil inlet
700–750
F
Preheat coil outlet
800–1,150
F
Reforming furnace outlet
1,350–1,740
F
Pressures
Reforming furnace outlet
250–350 psig
(continued)
580
S.A. Treese