chapter 6 update (1)
DESCRIPTION
MEK productionTRANSCRIPT
CHAPTER 6
ENERGY BALANCE
6.1INTRODUCTION
The energy balance is based on the temperature of the each equipment. Heat capacity of each component is specified base on the heat capacity of each component which is 2-butanol, methyl ethyl ketone and hydrogen. In calculation of energy balance it can be seperated by 2 phase which are liquid and gas phase.
After doing manual calculation for mass balance, energy consumption is calculated and the mole flow rate is used based the manual calculation from mass balance. As our reference state where H = 0, we consider Po = 1 atm, To = 298 K and elemental species. Beside that there is no enthalpy for pressure change of ideal gas.
6.2HEAT OF VAPORIZATION
Heat of vaporization is the the amount of heat require to change the phase from liquid to gas. This heat of vaporization can be calculated from chemical properties hadbook :
1b=
Table 6.1 Heat of vaporization for each component
Component
A
n
2 butanol
75.278
536.01
0.512
MEK
50.652
535.50
0.450
Hydrogen
0.659
33.18
0.380
6.3HEAT CAPACITY
Heat capacity is the amount of heat require to change the temperature by 1C.The heat capacity of liquid and gas can be calculate by using formula:
= (liquid)
= + ET4(gases)
Table 6.2 Heat capacity of gas for each component
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
MEK
61.406
7.532X10-1
- 2.3814X10-3
3.2240X10-6
Hydrogen
50.607
-6.1136
3.0930X10-1
- 4.1480X10-3
Table 6.3 Heat capacity of gas for each component
Compound
A
B
C
D
E
2-Butanol
22.465
3.5134x10-1
- 1.2858x10-4
1.193X10-8
1.294X10-11
MEK
37.369
2.3045X10-1
5.7387x10-6
-8.6168X10-8
2.9637X10-11
Hydrogen
25.399
2.0178X10-2
-3.8549x10-5
3.1880X10-8
-8.7585X10-12
6.4ENTHALPHY OF FORMATION OF GAS
Entalphy of formation of gas is the che nage of entalphy from the formation of 1 mole of the compound from its constituent elemnt
Table 6.4 Entalphy of formation of gas for each component
Components
A
B
C
2- Butanol
-265.140
-1.0695x
5.1693x
Methyl Ethyl Ketone
-216.593
-8.4826x
3.9084x
Hydrogen
-
-
-
6.5ENERGY BALANCE CALCULATION
The total energy for each equipment are calculated manually. Then the energy compared with the total energy from Aspen hysys 8.0.
Assumption
Energy ideal property is used
All equipment in steady state
Temperature of 100kPa is used as atmospheric pressure
6.5.1Heat Exchanger E-101
(Liquid) (Liquid) (T = 110 oC = 383KP = 195 Kpa==+) (T= 25oC = 298 KP = 200 Kpa==+)
(Stream 2) (Stream 3)
=
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
Reference state ; Liquid, 25 oC, 1 atm(100kpa)
Stream 2
Component for 2-butanol
Change in pressure of liquid from 100kPa to 200kPa
1 =
1 = 9.0168
Stream 3
For 2-butanol
Change in temperature of liquid from 298K to 372.55K
1 = 1a+1b
1a =
1a =
1a =
Change in pressure of liquid from 100kPa to 195kPa
1b =
1b =
Change in temperature of liquid from 372.55K to 383K
1c =
1c =2007.6381
Total entalphy
1 =
1 =
Table 6.5 Entalphy inlet and outlet for 2-butanol
Species
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
181.8613
9.0168
1639.8070
181.8613
15472.1671
2813788.423
1639.8070
2813788.423
6.5.2Heat Exchanger E-102
(T= 110oC = 383KP = 195 Kpa==+) (T = 500 oC = 773KP = 190 Kpa==+)Assumption: No entalphy for pressure change of ideal gases
(Liquid) (Gas)
(Stream 5) (Stream 4)
=
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
MEK
61.406
7.532X10-1
- 2.3814X10-3
3.2240X10-6
Reference state ; Liquid, 25 oC, 1 atm(100kpa)
Stream 4
For 2-butanol
Change in temperature of liquid from 298K to 372.55K
1a =
1a =
1a =
Change in pressure from 100kPa to 195kPa
1b=100)kPa
1b=8.6514
Change in temperature of liquid from 372.55K to 383K
1c =
1c = 2007.6381
Total Entalphy
1 =13455.8776 + 8.6514 +2007.6381
1 =15472.1671
For MEK
Change in temperature of liquid from 298K to 352.55K
2a =
2a =
Change in pressure from 1 atm to 1.95 atam
2b =
2b =
Change in temperature from 352.55K to 383K
2c =
2c =
Total entalphy
2 = 9032.7474 + 8.4678 + 5382.869
2 =14424.0842
Stream 5
For 2-butanol
Change in temperature of liquid from 298K to 372.55K
1a =
1a =
1a =
Change in phase from liquid to gas at 372.55K
1b=
A
T
n
75.278
536.01
372.55
0.512
1b=
1b=
1b=40982.4801
Change in temprature of gas from 372.55K to773K
1c =
1c = 71690.0315
Total Entalphy
1 =13455.8776 + 40982.4801 +71690.0315
1 =
For MEK
Change in temperature of of liquid from 298K to 352.55K
2a =
2a =
Change in phase from liquid to gas at 352.55K
1b=
A
T
n
50.652
535.50
352.55
0.450
1b=
1b=
1b=31239.5249
Change in temperature of gas from 352.55K to 773K
1b=
1b=65286.0477
Total entalphy
1=65286.0477 + 31239.5249 +
1 =
41
Component
(Table 6.6 Enthalpy component of the heat exchanger E-102)Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
124.7176
15472.1671
1929651.548
124.7176
126128.3892
16422408.04
MEK
1.2122
14424.0842
17484.8749
1.21220
127957.7955
1947136.423
16550365.84
-1882285.055
6.5.3 Heat Exchanger E-103
Assumption: No entalphy for pressure change of ideal gases
(Gas) (Gas) (T= 400oC = 673 KP = 185 Kpa==+) (T = 200 oC = 473KP = 180 Kpa==+)
(Stream 6) (Stream 7)
= + ET4
Compound
A
B
C
D
E
2-Butanol
22.465
3.5134x10-1
- 1.2858x10-4
1.193X10-8
1.294X10-11
MEK
37.369
2.3045X10-1
5.7387x10-6
-8.6168X10-8
2.9637X10-11
Hydrogen
25.399
2.0178X10-2
-3.8549x10-5
3.1880X10-8
-8.7585X10-12
Reference state ; gas, 673K, 1.85 atm(185kpa)
Stream 6
For 2-butanol
Change in temperature from 663K to 473K
1a=
1a=-36061.0118
For MEK
Change in temperature from 663K to 473K
1b=
1b=-31601.4079
For Hydrogen
1c=
1c=-5870.8451
Table 6.7 Enthalpy of component in heat exchanger E-103
Component
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
2.9068
0
0
6.2359
-36061.0118
-224872.9071
MEK
80.3947
0
0
119.6939
-31601.4079
-3782495.757
Hydrogen
0.0002
0
0
118.4871
-5870.8451
-695619.4104
0
-4702988.075
6.5.4Heat Exchanger E-106
(Liquid) (Liquid) (T = 70 oC = 343 KP = 155 Kpa==+) (T= 0 oC = 273 KP = 160 Kpa==+)
(Stream 12) (Stream 19)
=
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
MEK
61.406
7.532X10-1
- 2.3814X10-3
3.2240X10-6
Hydrogen
50.607
-6.1136
3.0930X10-1
- 4.1480X10-3
Reference state ; Liquid, 25 oC, 1 atm(100kpa)
Stream 12
Component 2-butanol
1 = 1a+1b
Change in temperature from 25 oC to 0 oC
1a =
1a =
1a =
Change in pressure from 100kPa to 160kPa
1b =
1b =
Total entalphy
1 =
1 =
Component Methyl Ethyl Ketone (MEK)
2 = 2a+2b
Change in temperature from 25 oC to 0 oC
2a =
2a =
2a =
Change in pressure from 100kPa to 160kPa
2b =
2b =
Total entalphy
2 =
2 =
Component Hydrogen
3 = 3a+3b
Change in temperature from 25 oC to 0 oC
3a =
3a =
3a =
Change in presusre from 100kPa to 160kPa
3b =
3b =
Total entalphy
3 =
3=
Stream 19
For 2-butanol
1 = 1a+1b
Change in temperature from 298K to 343K
1a =
1a =
1a =
Change in presurre from100kPa to 155kPA
1b =
1b =
Total entalphy
1 =
1 =
Component Methyl Ethyl Ketone (MEK)
2 = 2a+2b
Change in temperature from 298K to 343K
2a =
2a =
2a =
Change in presurre from100kPa to 155kPA
2b =
2b =
Total entalphy
2 =
2 =
FOr Hydrogen
3 = 3a+3b
Change in temperature from 298K to 343K
3a =
3a =
3a =
Change in presurre from100kPa to 155kPA
3b =
3b =
Total entalphy
3 =
3=
Table 6.8 Enthalpy of component in heat exchanger E-106
Component
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
2.8676
-3934.55
-11282.7156
2.9068
7962.5938
23146.4412
MEK
78.2898
-3930.2019
-307694.7207
80.3947
7405.1457
598901.66
-318977.4363
622048.1012
6.5.5 Reactor R-101
(T=400 oC = 673KP = 185 kPa==+) (T=500 oC = 773KP = 190 kPa==+)
(Stream 6) (Stream 5)
Components
A
B
C
2- Butanol
-265.140
-1.0695x
5.1693x
Methyl Ethyl Ketone
-216.593
-8.4826x
3.9084x
Hydrogen
-
-
-
Reference 1atm, 25C, gas
Stream 5
2-butanol
Heat of formation
Change in temperature of gas from 298K to 773K
1a=
1a=81043.0563
Total entalphy
1=-292420.5548 + 81043.0563
1=-211377.4985
Methyl Ethyl Ketone
Heat of formation
Change in temperature of gas from 298K to 773K
1b=
1b=71302.2356
Total entalphy
1=-273645.5945 + 71302.2356
1=-202352.3589
Stream 6
2-Butanol
Heat of formation
Change in temperature of gas from 298K to 673K
1a=
1a=60222.7058
Total Entalphy
1=-292420.5548 + 60222.7058
1=-232197.849
MEK
Heat of formation
Change in temperature of gas from 298K to 673K
1b=
1b=53057.6208
Total entalphy
Hydrogen
1c=
1c=10955.9027
Table 6.9 Enthalpy of component in reactor E-101
Component
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
124.7176
-211377.4985
-26362494.31
6.2359
-232197.849
-1447962.567
MEK
1.2122
-202352.3589
-245291.5295
119.6939
-179140.2282
-21441992.56
Hydrogen
-
-
-
118.4817
10955.9027
1298073.977
-26607785.84
-21591881.15
6.5.6 Heat exchanger E-101 and Separator V-101
Assumption
(Stream 9)No heat of vaporization of hydrogen since temperature since hydrogen already in gas state
(T = 70 oC =343 KGas phase)
(T = 200oC =343 KGas phase) (T = 70 oC =343 KLiquid phase)
(Stream 7)
(Stream 10)
Reference: 343 K, 1 atm, Liquid phase
Changing in temperature ;
=
=
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
MEK
61.406
7.532X10-1
- 2.3814X10-3
3.2240X10-6
Hydrogen
50.607
-6.1136
3.0930X10-1
- 4.1480X10-3
Changing in phase
Compound
A
T(K)
Tc
n
2-Butanol
75.278
343
536.01
0.512
MEK
50.562
343
535.50
0.450
Hydrogen
0.659
343
33.18
0.380
Stream 7
Component 2-butanol
Total entalphy
Component Methyl Ethyl Ketone (MEK)
Heat of vaporization at 343K
Change in temperature from 343K to 473K
Stream 9
Heat of formation
Component 2-butanol
Component Methyl Ethyl Ketone (MEK)
Component of hydrogen
Assumption
Since the reference temperature is 70 C, there is no heat of vaporization of hydrogen
2720635.765-7274971.454
Species
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
6.2359
71298.1366
444608.05
2.8770
44621.9366
128377.3116
MEK
119.6939
57065.259
6830363.404
81.2460
31906.2902
2592258.454
Hydrogen
118.4817
0
0
118.4854
0
0
7274971.454
2720635.765
Table 6.10 Entalphy of component in heat exchanger E-101
6.5.7 Separator 2 (V-102)
Assumption
No heat of vaporization of hydrogen since temperature since hydrogen already in gas state
(T = 0oC = 273 KLiquid phase) (T = 0oC = 273 KGas phase) (T = 70oC = 343 KGas phase)
Reference: 273 K, 1 atm, Liquid phase
Changing in temperature ;
=
=
Compound
A
B
C
D
2-Butanol
95.037
5.6593X10-1
- 1.8256X10-3
2.6675X10-6
MEK
61.406
7.532X10-1
- 2.3814X10-3
3.2240X10-6
Hydrogen
50.607
-6.1136
3.0930X10-1
- 4.1480X10-3
Changing in phase ;
Compound
A
T(K)
Tc
n
2-Butanol
75.278
273
536.01
0.512
MEK
50.562
273
535.50
0.450
Hydrogen
0.659
273
33.18
0.380
For inlet of Separator
Heat of vaporization
Component 2-butanol
Therefore;
Component Methyl Ethyl Ketone (MEK)
Heat of formation at 273K
Change in temperature of liquid from 343K - 273K
Total entalphy
For outlet (top) of Separator
Component 2-butanol
Heat of formation at 273K
Component Methyl Ethyl Ketone (MEK)
(Table 6.11 Entalphy of component in separator 2 (V-102))Heat of formation at 273K
36685.1812
Component
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
2.8770
12204.166
644886.7868
0.0121
52282.6208
632.6197
MEK
81.2460
48019.9784
3901431.165
2.4182
36685.1812
88712.1052
Hydrogen
118.4854
-
-
118.4807
-
-
4546317.952
89344.7249
36685.1812
89344.7249-4546317.952
6.5.8 Heat Exchanger E-107
Assumption
Assume the top product in liquid form
From the manual calculation the mass flow of hydrogen is 0 so the flow rate is negligible
There is no entalphy at stream because it same with the reference condition which is at 1 atm, 25C , liquid
(Liquid) (Liquid) (T = 25 oC = 298KP = 145 Kpa==+) (T= 93oC = 366 KP = 150Kpa==+)
(Stream 3) (Stream 2)
Reference 1 atm , 25C, liquid
2 butanol
Change in temperature of liquid from 298K to 366K
1a =
1a =
1a =
MEK
Change in temperature from 298K to 352.55K
2a =
2a =
Heat of vaporization at 352.55
Change in phase from liquid to gas at 352.55K
1b=
A
T
n
50.652
535.50
352.55
0.450
1b=
1b=
1b=31239.5249
Change in temperature of liquid from 352.55K to 366
2a =
2a =
Total entalphy
Table 6.12 Enthalpy component in Heat exchanger E-107
Component
Inlet
Outlet
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
0.0690
12419.2890
1639.8070
0.0690
0
0
MEK
115.9732
42614.6243
4942154.3470
115.9372
0
0
4943794.154
0
4943794.154
6.5.9 Distillation column T-101
Assumption
Liquid phase at the top outlet of distillation column
Liquid phase at the inlet of distillation column
No entalphy of hydrogen since the flowrate is very small
(93C=366K)
(150kPa) (Gas)
(Liquid)
(155kPa)
(70C=343K)
(105C=378K) (150kPa)
(Liquid)
Reference at 25C, 1 atm, liquid
Stream 16
Component For 2-butanol
Change in temperature of liquid from 298 to 343
1 = 1a+1b
1a =
1a =
1a =
Change in pressure of liquid from 1 atm to 1.55atm
1b =
1b =
Total entalphy
For MEK
Change in temperature of liquid from 298K to 343K
2a =
2a =
Change in pressure from 1 atm to 155 atam
2b =
2b =
Total entalphy
Stream 17
For 2-butanol
Heat of vaporization at 366K
For MEK
Heat of vaporization at 366K
Stream 18
2 butanol
Change int temperature from 298K to 378K
1a =
1a =
1a =
Change in pressure from 150kPa to 100kPa
1b =
1b =
Total entalphy
For Mek
Change int temperature from 298K to 378K
2a =
2a =
Change in pressure from 150kPa to 100kPa
2b =
2b =
Total entalphy
2 =13511.4764 +
2b =
(Table 6.13 Enthalpy of component in Distillation column T-101)
Component
Inlet
Outlet
Stream 16
Stream 17
Stream 18
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
,
kmol/hr
,
kJ/kmol
kJ/hr
2-butanol
6.2662
7962.5938
49895.2053
0.0690
41815.l289
2885.2439
6.1972
140502.9957
870725.165
MEK
117.2301
7540.1467
883932.1517
115.9732
3013.674
349505.4175
1.2929
13515.9331
17474.7499
933508.8532
352390.6614
888199.9149
933508.8532
LIST OF REFERENCES
Yaws, C. L., (1999). Chemical properties handbook. McGraw-Hill,United State of
America, p.106,132,156,