Upload
durt-daim
View
225
Download
0
Embed Size (px)
Citation preview
8/2/2019 Chapter 7 - Energy Balance New
1/28
CHAPTER 7
ENERGY BALANCE
7.1 METHOD OF CALCULATION
7.1.1 Assumptions in Calculations
The assumption used for the calculations of the energy balance for all the streams
are:
i. The system is an open system at steady state.
ii. There are no moving parts in the system.
iii. The linear velocities of all streams are the same
iv All streams enter and leave the process at a single height
8/2/2019 Chapter 7 - Energy Balance New
2/28
iv All streams enter and leave the process at a single height
107
Therefore, the equation can be reduced to:
Q = H
7.1.2.2 Equation for Reactive Process
(
) (
)
() ()
(7.2)
(7.3)
(7.4)
8/2/2019 Chapter 7 - Energy Balance New
3/28
108
Or
[ ]
7.1.2.5 Equation for Heat Capacity, Cp
Hence for sensible heat,
7.1.2.6 Total Heat for the Energy Balance (for Non-reactive Process):
(7.9)
(7.10)
(7.11)
8/2/2019 Chapter 7 - Energy Balance New
4/28
109
P-41 P-42
7.2 ENERGY BALANCE CALCULATION
The calculation is done by using Microsoft Excel to make changes and calculationif
in case the temperature or pressure in any equipment change during the design
process to meet with the equipment needs.
This sectionshows the deatil calculation of energy balance at the hydrolysis reactor
only, for detail calculation of all the equipment please refer to Appendix K-2.
7.2.1 Balance at Reactor
Stream 1
Temperature : 28.4 C
Pressure :170 kPa
Stream 9
Temperature : 85 C
Pressure :150 kPa
8/2/2019 Chapter 7 - Energy Balance New
5/28
110
Table 7.1: Total Amount of Enthalphy at Reactor
Hr(kJ/hr)
H inlet(kJ/hr)
Houtlet(kJ/hr)
H(kJ/hr)
2.18E+7 8.95E+06 1.48E+07 2.77E+7
8/2/2019 Chapter 7 - Energy Balance New
6/28
111
Table 7.2: Inlet Stream Component Enthalphy for Reactor
Component
Inlet Stream
Stream 1 Stream 2 Stream 3
ninlet
(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr) ninlet(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr) ninlet(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr)CA
5.36E+01 6.25E+02 3.35E+04 - - - - - -
MA- - - - - - - - -
HCl- - - 7.15E+01 1.24E+05 8.90E+06 - - -
H2O - - - - - - 1.45E+02 1.51E+02 2.19E+04
NH4Cl - - - - - - - - -
AA- - - - - - - - -
MIBK- - - - - - - - -
CO2 - - - - - - - - -
H3.35E+04 8.90E+06 2.19E+04
8/2/2019 Chapter 7 - Energy Balance New
7/28
112
Table 7.3: Outlet Stream Component Enthalphy for Reactor
Component
Outlet Stream
Stream 10 Stream 9
noutlet
(kmol/hr)
outlet(kJ/kmol)
HComponent
(kJ/hr)
noutlet
(kmol/hr)
outlet(kJ/kmol)
HComponent
(kJ/hr)
CA1.75E+01 1.10E+04 1.93E+05 - - -
MA3.47E+01 7.66E+03 2.66E+05 - - -
HCl3.49E+01 4.05E+05 1.41E+07 - - -
H2O 7.22E+01 4.52E+03 3.27E+05 - - -
NH4Cl 3.55E+01 5.42E+03 1.93E+05 - - -
AA8.16E-01 7.98E+03 6.52E+03 - - -
MIBK- - - - - -
CO2 - - - 8.16E-01 -4.43E+05 -3.62E+05
H
1.51E+07 -3.62E+05
8/2/2019 Chapter 7 - Energy Balance New
8/28
113
7.2.1.1 Balance for Stream 1
Cyanoacetic acid;
Where,
And;
7.2.1.2 Balance for Stream 2
Hydrochloric Acid;
8/2/2019 Chapter 7 - Energy Balance New
9/28
114
And;
7.2.1.4 Balance for Stream 10
Cyanoacetic Acid;
Where,
And;
8/2/2019 Chapter 7 - Energy Balance New
10/28
115
Hydrochloric Acid;
Where,
And; For Water:
Where,
8/2/2019 Chapter 7 - Energy Balance New
11/28
116
Acetic Acid:
Where,
And;
7.2.1.5 Balance for Stream 9
8/2/2019 Chapter 7 - Energy Balance New
12/28
117
7.2.1.6 Heat of Reaction
The heat of reaction can be calculated by modifying Equation 7.5:
[ ]
and r can be calculated by refering to thestoichiometric equation of the reaction,
for this process the stochiometric equation is as follows:
From equation 7.5:
8/2/2019 Chapter 7 - Energy Balance New
13/28
118
Henceforth, Hr is:
[ ]
7.2.1.7 Total Balance
The total overall energy balance from the reactor can be calculated by using
Equation 7.4:
() ()
8/2/2019 Chapter 7 - Energy Balance New
14/28
119
(
)
(
)
8/2/2019 Chapter 7 - Energy Balance New
15/28
120
E-22
P-60
7.2.2 Evaporator 1
Stream 10
Temperature : 85 CPressure :150 kPa
Stream 11
Temperature : 110 C
Pressure :130 kPa
8/2/2019 Chapter 7 - Energy Balance New
16/28
121
Table 7.5: Component Enthalphy for Evaporator 1
Component
Inlet Stream Outlet Stream
Stream 10 Stream 11 Stream 12
ninlet(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr) noutlet(kmol/hr) outlet(kJ/kmol) HComponent(kJ/hr) noutlet(kmol/hr) outlet(kJ/kmol) HComponent(kJ/hr)
CA1.75.E+01 1.10.E+04 1.93.E+05 - - - 1.75.E+01 1.56.E+04 2.74.E+05
MA3.47.E+01 7.66.E+03 2.66.E+05 - - - 3.47.E+01 1.08.E+04 3.76.E+05
HCl3.32.E+01 4.05.E+05 1.34.E+07 3.17.E+01 5.84.E+05 1.85.E+07 1.41.E+00 5.74.E+05 8.12.E+05
H2O7.22.E+01 4.52.E+03 3.27.E+05 2.14.E+01 4.67.E+04 9.99.E+05 4.70.E+01 6.41.E+03 3.01.E+05
NH4Cl3.55.E+01 5.42.E+03 1.93.E+05 - - - 3.64.E+01 7.68.E+03 2.80.E+05
AA8.16.E-01 7.98.E+03 6.52.E+03 3.62.E-01 3.59.E+04 1.30.E+04 1.41.E+00 1.15.E+04 1.61.E+04
MIBK- - - - - - - - -
CO2- - - - - - - - -
H1.44.E+07 1.95.E+07 2.06.E+06
8/2/2019 Chapter 7 - Energy Balance New
17/28
122
E 22
P-60
7.2.3 Evaporator 2
Stream 14
Temperature : 110 C
Pressure :150 kPa
Stream 15
Temperature : 140 C
Pressure :130 kPa
8/2/2019 Chapter 7 - Energy Balance New
18/28
123
Table 7.7: Component Enthalphy for Evaporator 2
Component
Inlet Stream Outlet Stream
Stream 14 Stream 15 Stream 16
ninlet(kmol/hr)
inlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
CA1.75.E+01 1.56.E+04 2.74.E+05 - - - 1.75.E+01 2.11.E+04 3.70.E+05
MA3.47.E+01 1.08.E+04 3.76.E+05 - - - 3.47.E+01 1.47.E+04 5.09.E+05
HCl1.41.E+00 5.74.E+05 8.12.E+05 1.23.E+00 5.85.E+05 7.20.E+05 1.82.E-01 7.78.E+05 1.42.E+05
H2O 4.70.E+01 6.41.E+03 3.01.E+05 9.09.E+00 4.77.E+04 4.33.E+05 3.79.E+01 8.67.E+03 3.29.E+05
NH4Cl3.64.E+01 7.68.E+03 2.80.E+05 - - - 3.64.E+01 1.04.E+04 3.79.E+05
AA1.41.E+00 1.15.E+04 1.61.E+04 1.60.E-01 3.87.E+04 6.20.E+03 1.25.E+00 1.58.E+04 1.97.E+04
MIBK- - - - - - - - -
CO2- - - - - - - - -
H 2.06.E+06 1.16.E+06 1.75.E+06
8/2/2019 Chapter 7 - Energy Balance New
19/28
124
7.2.4 Balance on Heat Exchanger 1 (Condensor)
Figure 7.4: Inlet and Outlet Stream for Heat Exchanger 1
Table 7.8: Total Amount of Enthalphy at Heat Exchanger 1
H inlet
(kJ/h )
Houtlet
(kJ/h )
H
(kJ/h )
Stream 11
Temperature : 110 C
Pressure : 130 kPa
Stream 13
Temperature : 60 C
Pressure :152 kPa
8/2/2019 Chapter 7 - Energy Balance New
20/28
125
Table 7.9: Component Enthalphy for Heat Exchanger 1
Component
Inlet Stream Outlet Stream
Stream 11 Stream 13
ninlet(kmol/hr)
inlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
CA- - - - - -
MA- - - - - -
HCl3.17.E+01 2.47.E+03 7.85.E+04 3.17.E+01 -3.13.E+05 -9.94.E+06
H2O2.14.E+01 2.89.E+03 6.18.E+04 2.14.E+01 4.02.E+04 8.60.E+05
NH4Cl- - - - - -
AA3.62.E-01 6.04.E+03 2.19.E+03 3.62.E-01 2.36.E+04 8.53.E+03
MIBK- - - - - -
CO2- - - - - -
8/2/2019 Chapter 7 - Energy Balance New
21/28
126
P-60
P-6
7.2.5 Balance on Distillation Column
Stream 22
Temperature : 97 C
Pressure : 263.45 kPa
S
Stream 23
Temperature : 117 C
Pressure :253.31 kPa
8/2/2019 Chapter 7 - Energy Balance New
22/28
127
Table 7.11: Component Enthalphy for Distillation Column
Component
Inlet Stream Outlet Stream
Stream 22 Stream 23 Stream 24
ninlet(kmol/hr)
inlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
CA1.75E+01 1.32E+04 2.32E+05 - - - 1.75E+01 2.51E+04 4.40E+05
MA3.47E+01 9.19E+03 3.19E+05 - - - 3.47E+01 1.74E+04 6.05E+05
HCl1.82E-01 4.86E+05 8.85E+04 1.82E-01 6.22E+05 1.13E+05 - - -
H2O 3.79E+01 5.43E+03 2.06E+05 3.79E+01 6.94E+03 2.63E+05 3.00E-03 1.03E+04 3.09E+01
NH4Cl- - - - - - - - -
AA1.25E+00 9.64E+03 1.20E+04 1.04E+00 1.25E+04 1.30E+04 2.05E-01 1.90E+04 3.90E+03
MIBK6.94E+01 1.53E+04 1.06E+06 6.20E+01 1.95E+04 1.21E+06 7.35E+00 2.89E+04 2.13E+05
CO2- - - - - - - - -
H 1.91E+06 1.60E+06 1.26E+06
8/2/2019 Chapter 7 - Energy Balance New
23/28
128
7.2.6 Balance on Heat Exchanger
Figure 7.6: Inlet and Outlet Stream for Heat Exchanger 2
Stream 27
Temperature : 80 C
Pressure : 131.72 kPa
Stream 26
Temperature : 259.31 C
Pressure : 101.3 kPa
8/2/2019 Chapter 7 - Energy Balance New
24/28
129
Table 7.12: Component Enthalphy for Heat Exchanger 2
Component
Inlet Stream Outlet Stream
Stream 26 Stream 27
ninlet(kmol/hr)
inlet(kJ/kmol)
HComponent(kJ/hr)
noutlet(kmol/hr)
outlet(kJ/kmol)
HComponent(kJ/hr)
CA1.75E+01 2.51E+04 4.40E+05 1.75E+01 1.38E+04 2.41E+05
MA3.47E+01 1.74E+04 6.05E+05 3.47E+01 9.56E+03 3.32E+05
HCl- - - - - -
H2O3.00E-03 1.03E+04 3.09E+01 3.00E-03 5.65E+03 1.70E+01
NH4Cl - - - - - -
AA5.00E-03 1.90E+04 9.51E+01 5.00E-03 1.01E+04 5.03E+01
MIBK7.35E+00 2.89E+04 2.13E+05 7.35E+00 1.59E+04 1.17E+05
CO2- - - - - -
8/2/2019 Chapter 7 - Energy Balance New
25/28
130
7.2.7 Crystalyzer
Stream 27
Temperature : 100 C
Pressure : 131.72 kPa
Stream 28
Temperature : -17 C
Pressure : 30.40 kPa
8/2/2019 Chapter 7 - Energy Balance New
26/28
131
Table 7.15: Component Enthalphy for Crystalyzer
Component
Inlet Stream Outlet Stream
Stream 27 Stream 28
ninlet(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr) noutlet(kmol/hr) outlet(kJ/kmol) HComponent(kJ/hr)
CA1.75E+01 1.38E+04 2.41E+05 1.75E+01 -7.72E+03 -1.35E+05
MA3.47E+01 9.57E+03 3.32E+05 3.47E+01 -5.37E+03 -1.86E+05
HCl- - - - - -
H2O3.00E-03 5.66E+03 1.70E+01 3.00E-03 -3.17E+03 -9.51E+00
NH4Cl- - - - - -
AA5.00E-03 1.01E+04 5.03E+01 5.00E-03 -5.26E+03 -2.63E+01
8/2/2019 Chapter 7 - Energy Balance New
27/28
132
P-41
7.2.8 Dryer
Steam 28
Temperature : -17 C
Pressure :30.40 kPa
Stream 30
Temperature : 12.57 C
Pressure :101.3 kPa
Stream 29
Temperature : 17 C
Pressure :101.3 kPa
P-60
P-60
8/2/2019 Chapter 7 - Energy Balance New
28/28
133
Table 7.16: Component Enthalphy for Dryer
Component
Inlet Stream Outlet Stream
Stream 28 Stream 29 Stream 30
ninlet(kmol/hr) inlet(kJ/kmol) HComponent(kJ/hr) noutlet(kmol/hr) outlet(kJ/kmol) HComponent(kJ/hr) noutlet(kmol/hr) outlet(kJ/kmol) HComponent(kJ/hr)
CA1.75E+01 -7.72E+03 -1.35E+05 - - - 1.75E+01 -6.06E+03 -1.06E+05
MA3.47E+01 -5.36E+03 -1.86E+05 3.47E+01 -4.21E+03 -1.46E+05 - - -
HCl- - - - - - - - -
H2O3.00E-03 -3.17E+03 -9.50E+00 - - - 3.00E-03 -2.49E+03 -7.46E+00
NH4Cl- - - - - - - - -
AA5.00E-03 -5.26E+03 -2.63E+01 - - - 5.00E-03 -4.15E+03 -2.08E+01
MIBK7.35E+00 -8.90E+03 -6.54E+04 - - - 7.35E+00 -6.98E+03 -5.13E+04
CO2- - - - - - - - -
H-3.86E+05 -1.46E+05 -1.57E+05
E-22
P-5
P-6