chapter 7 - energy balance new

8/2/2019 Chapter 7 - Energy Balance New

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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


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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)


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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)


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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


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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


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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


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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


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113

7.2.1.1 Balance for Stream 1

Cyanoacetic acid;

Where,

And;


Hydrochloric Acid;


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114

And;


Cyanoacetic Acid;

Where,

And;


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115

Hydrochloric Acid;

Where,

And; For Water:

Where,


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116

Acetic Acid:

Where,

And;



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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:


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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:

() ()


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119

(

)

(

)


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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


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Table 7.5: Component Enthalphy for Evaporator 1

Component

Inlet Stream Outlet Stream


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


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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


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Table 7.7: Component Enthalphy for Evaporator 2

Component



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


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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


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Table 7.9: Component Enthalphy for Heat Exchanger 1

Component


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- - - - - -


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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


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Table 7.11: Component Enthalphy for Distillation Column

Component



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


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7.2.6 Balance on Heat Exchanger

Figure 7.6: Inlet and Outlet Stream for Heat Exchanger 2

Stream 27

Temperature : 80 C


Stream 26




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Table 7.12: Component Enthalphy for Heat Exchanger 2

Component


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- - - - - -


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7.2.7 Crystalyzer

Stream 27

Temperature : 100 C


Stream 28

Temperature : -17 C



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Table 7.15: Component Enthalphy for Crystalyzer

Component


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


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P-41

7.2.8 Dryer

Steam 28

Temperature : -17 C

Pressure :30.40 kPa

Stream 30


Pressure :101.3 kPa

Stream 29

Temperature : 17 C

Pressure :101.3 kPa

P-60

P-60


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Table 7.16: Component Enthalphy for Dryer

Component



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

chapter 7 - energy balance new

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