Energy Balance

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ENERGY BALANCE

Compressor K-100:

Inlet Conditions: Temperature 303 K Outlet conditions: Pressure 202 Kpa

mass flow rate of air ### kg/hr 1.07 kgmol/sec Inlet volumetric flow rate:

26.74 m3/sec poly tropic efficiency 76%

Outlet temperature for poly-tropic flow:

then m 0.38

T2 393.2 K 120.05 C

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n 1.6

Work 68.9 KJ/kgmol Power Requirement

actual work 90.66 KJ/kgmol power requirment 97.45 KW

Air Pre-heater E-101:

Inlet conditions temperature 120.05 C Outlet conditions temperature 380 C reference temperature 120 C

moisture in air 107.5 kgmol

heat taken by air ### KJ/hr

Benzene Pre-heater E-100:

Inlet conditions temperature 30 C Pressure Outlet conditions temperature 110 C Pressure boiling point of benzene 104.7 C

reference temperature 30 C

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heat taken by benzene ### KJ/hr

Feed Mixer MIX-100:

reference temperature 110 C

Assuming Tmix 350 C average temperature 230 C

component m (kgmole/hr) Cp (KJ/kgmole oC)

Air ### 30.57 Benzene 59.02 59.02 ### (Tmix-110) = ### Tmix 363.36 C

Reactor PFR-100:

Chemical Reactions:

C6H6 + 4.5 O2 C4H2O3 + 2CO2 +2H2O (Maleic Anhydride)

C6H6 + 7.5O2 6CO2 +3H2O C6H6 + 4.5 O2 6C0 + 3H2O

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C6H6 + 1.5 O2 C6H4O2 + H2O (quinon)

At steady state

Heat input to reactor = Heat output from reactor

component m Cpℓ ΔTℓ

Air 3816

Moisture 107.5 72.94 75

Benzene 59 133 53

entahlpy of reactants ### KJ/hr Enthalpy of products leaving at 400C:

component m Cpℓ ΔTℓ Nitrogen 3014 Oxygen 512 Water 225 72.94 75 CO2 122 MAN 43 158 177 CO 26 Benzene 5 133 53 Quinone 0.94 182 155

Enthalpy of products leaving at 400C ### Heat produced by reactions assuming reaction takes place at 25C

By reaction (R1) ### By reaction (R2) ### By reaction (R3) ### By reaction (R4) ### Total Heat of reaction at 25C ΔHR ### Heat taken by cooling salt ###

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Product steam (8) from the reactor is cooled from 400C to 76.5C at 152Kpa. For energy balance around Waste Heat Boiler assume 76.5C as reference temperature.

average temperature 238.25 C enthalpy of stream (8) component m Cpℓ ΔTℓ Nitrogen 3014 Oxygen 512 Water 225 73.56 24 CO2 122 MAN 43 163 126 CO 26 Benzene 5 Quinone 0.94 189.2 104

Heat removed in waste heat boiler

Pre-scrubber cooler E-103:

Stream(11) is cooled from 76.5C to 50C before it enters Gas Scrubber. For energy balance assuming 50C as reference temperature.

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component m Cpℓ ΔTℓ Nitrogen 3014 Oxygen 512 Water 225 72.94 26.5 CO2 122 MAN 25.35 148 26.5 CO 26 Benzene 4.71 137 26.5 Quinone 0.71 171.2 26.5

heat removed in Pre-Scrubber cooler

Mixer MIX-101:

Pure water stream (16) is added to scrubbed liquid (13) to keep the concentration of MAC solution up to 40%. Assuming water enters at 30C and 101Kpa while scrubbed liquid is entering at 45C.

stream (15) and (17) are leaving at same temperature. So T15 = T17 = T Energy balance around mixer MIX-101 is

assuming 30oC as reference temperature Enthalpy of stream (13)

Water 4426.43 72.8 15

MAC 495.81 206.5 15

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Total Enthalpy ### KJ/hr Enthalpy of stream (15) component m Cpℓ ΔTℓ Water 4551.1 72.8 (T-30) MAC 470.9 206.5 (T-30) Total Enthalpy ### (T-30) KJ/hr Enthalpy of stream (17) component m Cpℓ ΔTℓ Water 236.3 72.8 (T-30) MAC 24.89 206.5 (T-30) Quinone 0.71 164.3 (T-30) Total Enthalpy ### (T-30) KJ/hr temperature of stream(15) and (17)T ###

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Scrubber T-100:

MAN is absorbed in 40% solution of MAC entering at 44.2C while the gases leaves from the top of scubber in vent stream (14).

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Reaction involved in scrubber Reaction taking place:

C4H2O2 + H20 C4H4O4 (maleic acid) ∆H ### KJ/kgmol Enthalpy of stream (12) component m Cpℓ ΔTℓ Nitrogen 3014.4 29.33 6.8 Oxygen 512 29.51 6.8 Water 234 72.78 6.8 CO2 122 39.25 6.8 MAN 25.35 144.4 6.8 CO 26.22 29.91 6.8 Benzene 4.71 133.3 6.8 Quinone 0.71 167 6.8 Total Enthalpy ### Enthalpy of stream (13) component m Cpℓ ΔTℓ Water 4426.43 72.8 0.8 MAC 495.81 206.5 0.8 Quinone 0.71 164.3 0.8 Total Enthalpy ### Enthalpy of stream (14) component m Cpg ΔTg Nitrogen 3014 29.26 (T-44.2) Oxygen 512 29.48 (T-44.2) Water 333.6 72.79 (T-44.2) CO2 122 39.16 (T-44.2) MAN 0.43 144.4 (T-44.2)

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CO 26 29.22 (T-44.2)

Benzene 4.71 131.2 (T-44.2)

Total Enthalpy ### energy balance provides T14 48.03 C

Dehydrator feed pre-heater E-104:

Feed is heated from 44.2C to 95C in vapor phase befor it enters the dehydrator

Water 236.3 73.1 51

MAC 24.89 215.8 51

Quinone 0.71 173.6 51

heat duty of Dehydrator feed preheater

Dehydrator T-101:

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Top plate temperature = 55C Re-boiler temperature = 120 C Operating pressure = 15.2 kpa Assuming 100C as reference temperature

Reactions involved

(maleic acid) (fumaric acid)

Overhead condenser:

Overhead product is condensed from 55C to 45C at 15.2Kpa.

Boiling point of water at 15.2Kpa = 53.6C Boiling point of O-xylene at 15.2Kpa = 85.05C Taking 25oC as reference temperature

Enthalpy of stream (19) component m Cpℓ Water 248 72.77 O-xylene 72 194.3 Total Enthalpy Enthalpy of stream (20) component m Cpℓ Water 248 72.77 O-xylene 72 192.3 Total Enthalpy

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heat duty of overhead condenser

heat duty of overhead condenser ### Enthalpy of stream (18) entering at 95C and 101Kpa

component m Cpℓ

Water 236.3 72.9

MAC 24.89 212.4

Quinone 0.71 170.4

Total Enthalpy Enthalpy of stream (26) leaving at 120oC and 15.2KPa

component m Cpℓ Water 13.07 72.77 MAN 24.77 149.7 O-xylene 3.79 200.4 Fumaric acid 0.12 251 Quinone 0.71 173.8 Total Enthalpy Enthalpy of reflux stream (21) ### Heat required by reaction (R1) ### Heat required by reaction (R2) ### Total heat required for reactions ### heat duty of Re-boiler

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Mixer MIX-102

Stream (27) entering at 120oC and 101Kpa is mixed with crude MAN stream (10).

Assuming 25oC as reference temperature so Enthalpy of stream (27)

component m Water 13.07 MAN 24.77 O-Xylene 3.79 Fumaric Acid 0.12 Quinone 0.71 Enthalpy of stream (28) component m Water 14.75 MAN 42.51 O-Xylene 3.79 Fumaric Acid 0.12 Quinone 0.94 Total Enthalpy Enthalpy of stream (10) component m water 17.74

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MAN 1.68 quinon 0.23

enthalpy balance around mixer is ### = ###

Distillation Coulmn T-102

Operating conditions:

Operating pressure = 101Kpa

Assuming 25C as reference temperature Enthalpy of feed stream (29) entering at 108C

component m

Water 14.75

MAN 42.51

Top plate temperature = 160

o

C

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O-Xylene 3.79 Fumaric Acid 0.12 Quinone 0.94 Enthalpy of stream (30) component m Water 54.15 MAN 1.03 O-Xylene 13.27 Quinone 3.06 Enthalpy of stream (31) component m Water 36.9 MAN 0.73 O-Xylene 9.5 Quinone 2.2 Enthalpy of stream (32) component m Water 14.75 MAN 0.29 O-Xylene 3.79 Quinone 0.87 Enthalpy of stream (36) component m MAN 42.21 Fumaric Acid 0.12 Quinone 0.17

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Heat duty of condenser

Heat duty of re-boiler

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ENERGY BALANCE

Pressure 101 Kpa

4

2 1.3

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0.38 1.3 0.3 231.47 R 0.08 m3atm/kgmolK 8.31 KJ/kgmolK Zi 1 Pressure 202 Kpa Pressure 202 Kpa 202 Kpa 202 Kpa

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m Cp ### ### (R1) ∆H ### KJ/kgmol (R2) ∆H ### KJ/kgmol (R3) ∆H ### KJ/kgmol

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(R4) ∆H ### KJ/kgmol

Heat input to reactor = Heat output from reactor

CpℓΔTℓ Cpg ΔTg λ 32.21 338 ### 5470.5 35.65 263 ### ### 7049 136.4 285 38874 ### CpℓΔTℓ Cpg ΔTg λ 30.16 375 11310 30.94 375 ### 5470.5 35.83 300 10749 ### 43.87 375 ### 27966 162.5 198 32175 ### 29.81 375 ### 7049 140.4 322 ### ### 28210 172.6 220 37972 ### KJ/hr KJ/hr KJ/hr KJ/hr KJ/hr KJ/hr KJ/hr Cpg∆Tg Cpg∆Tg

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Product steam (8) from the reactor is cooled from 400C to 76.5C at 152Kpa. For energy balance around Waste Heat Boiler assume 76.5C as reference temperature.

CpℓΔTℓ Cpg ΔTg λ 30.27 324 ### 31.18 324 ### ### 35.77 300 10731 ### 44.47 324 ### 20538 162.2 198 ### ### 29.93 324 ### 140.2 322 ### ### ### 172.3 220 37906 ### ### KJ/hr

Stream(11) is cooled from 76.5C to 50C before it enters Gas Scrubber. For energy balance

heat removed in pre-scrubber = {ehtahlpy of stream (12)}-{enthalpy of stream (11)}

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CpℓΔTℓ Cpg ΔTg λ 29.4 26.5 779.1 29.6 26.5 784.4 ### 39.72 26.5 ### 3922 29.22 26.5 774.33 3630.5 4536.8 ### KJ/hr

Pure water stream (16) is added to scrubbed liquid (13) to keep the concentration of MAC solution up to 40%. Assuming water enters at 30C and 101Kpa while scrubbed liquid is

stream (15) and (17) are leaving at same temperature. So T15 = T17 = T

CpℓΔTℓ ∆H

1092 ###

3097.5 ### 2464.5 1749.8

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∆H ### (T-30) ### (T-30) ∆H ### (T-30) ### (T-30) 116.65 (T-30) C C

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C4H4O4 (maleic acid) CpℓΔTℓ ∆H 199.44 ### 200.67 ### 494.9 ### 266.9 ### 981.92 ### 203.39 ### 906.44 ### 1135.6 806.28 KJ/hr CpℓΔTℓ ∆H 58.24 ### 165.2 ### 131.44 93.32 KJ/hr ∆H ### (T-44.2) ### (T-44.2) ### (T-44.2) ### (T-44.2) 62.09 (T-44.2)

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759.72 (T-44.2) 617.95 (T-44.2) (T-44.2) KJ/hr

Feed is heated from 44.2C to 95C in vapor phase befor it enters the dehydrator

CpℓΔTℓ ∆H

3728.1 ###

### ###

8853.6 ###

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Re-boiler temperature = 120 C Operating pressure = 15.2 kpa

∆H ### KJ/kgmol

Overhead product is condensed from 55C to 45C at 15.2Kpa.

Boiling point of water at 15.2Kpa = 53.6C Boiling point of O-xylene at 15.2Kpa = 85.05C

ΔTℓ CpℓΔTℓ Cpg ΔTg 28.6 2081.22 33.8 1.4 47.32 30 5829 ### KJ/hr ΔTℓ CpℓΔTℓ ∆H 20 1455.4 ### 20 3846 276912 ### KJ/hr Cpg∆Tg

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KJ/hr ΔTℓ CpℓΔTℓ ∆H 70 5103 ### 70 14868 ### 70 11928 ### ### KJ/hr ΔTℓ CpℓΔTℓ Cpg ΔTg 28.6 2081.22 34.03 66.4 ### 95 14221.5 60 12024 163.1 35 5708.5 95 23845 95 16511 ### KJ/hr

heat duty of Re-boiler ### KJ/hr

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Stream (27) entering at 120oC and 101Kpa is mixed with crude MAN stream (10).

Assuming 25oC as reference temperature so Enthalpy of stream (27)

Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 72.77 75 ### 34.42 20 149.7 95 ### 207 95 19665 251 95 23845 173.8 95 16511 Total Enthalpy ### KJ/hr Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 73.12 75 5484 34.4 (T-100) 149.7 (T-25) 207 (T-25) 251 (T-25) 173.8 (T-25) Total Enthalpy 670889 + 507.4 (T-100) + ### (T-25) Cpℓ ΔTℓ CpℓΔTℓ ∆H 145.3 51.5 ### ###

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72.8 51.5 3749.2 ### 168.5 51.5 ### ### Total Enthalpy ### KJ/hr 670889 + 507.4 (T-100) + ### (T-25) = ### + ### T T = 95.42 C

Top plate temperature = 160C

Re-boiler temperature = 200 C

Reflux temperature = 112C Operating pressure = 101 kpa Assuming 25C as reference temperature

Enthalpy of feed stream (29) entering at 108C

Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg

73.12 75 5484 34.38 8

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204.9 83 ### 250.2 83 ### 172 83 14276 Total enthalpy ### KJ/hr Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 73.12 75 5484 34.57 60 153.6 135 20736 212.3 119 ### 181.8 16 179.1 135 Total enthalpy ### KJ/hr Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 73.12 75 5484 34.38 12 148.4 87 ### 204.9 87 ### 172 87 Total enthalpy ### KJ/hr Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 73.12 75 5484 34.38 12 148.4 87 ### 204.9 87 ### 172 87 14964 Total enthalpy ### KJ/hr Cpℓ ΔTℓ CpℓΔTℓ Cpg ΔTg 157.8 175 27615 256.6 175 44905 181.9 155 ### 152.2 20

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Total enthalpy ### KJ/hr

Heat duty of condenser

### KJ/hr

Heat duty of re-boiler

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∆H ### ### ### ∆H ### ### ### ### ### ### 406289 ###

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∆H ### ### ### ### ### ### 375722 ###

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∆H ### ### ### ### ### ### ### ###

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λ ∆H

### ###

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λ ∆H ### ### ### ### ### 2861.4 ###

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λ ∆H 688.4 ### ### ### ### 2861.4 ### λ ∆H 34.4 (T-100) ### 670889 + 507.4 (T-100) ### (T-25) 784.53 (T-25) 30.12 (T-25) 163.37 (T-25) Cpg∆Tg Cpg∆Tg

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λ ∆H

275.04 40000 ### ###

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### ### ### λ ∆H 2074.2 40000 ### ### 2908.8 37000 ### λ ∆H 412.56 40000 ### ### ### λ ∆H 412.56 40000 ### ### ### ### λ ∆H ### 5388.6 3044 46000 ### Cpg∆Tg Cpg∆Tg Cpg∆Tg Cpg∆Tg

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