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• Shahid Ismail

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N2 (g) 300C, 3 bar

DECANTER

P-C8H10 (l)

N2 (g)

M- C8H10 (l) O- C8H10 (l) C7H8 (l)

H2O (l) C7H8 (l) P-C8H10 (l) M-C8H10 (l) O-C8H10 (l) 400C, 3.5 bar

Assumption: Nitrogen is ideal gas

H2O (l) 400C, 3 bar

300C, 3 bar

Specific heat table Substances N2 (g) H2O (l) C7H8 (l) P-C8H10 (l) M-C8H10 (l) O-C8H10 (l)

A 29x10-3 75.4x10-3 148.8x10-3 -11.035x10-3 70.916x10-3 56.460x10-3

B 0.2199x10-5 32.4x10-5 1.5158 x10-3 8.045 x10-4 9.4926 x10-4

C 0.5723x10-8 -3.9039 x10-6 -2.1885 x10-6 -2.4902 x10-6

D -2.871 x10-12 2.9193 x10-9 2.5061x10-9 2.6838 x10-9

References: N2 (g), H2O (l), C7H8 (l), P-C8H10 (l), M-C8H10 (l), O-C8H10 (l) at 400C, 3.5 bar. Substances N2 (g) H2O (l) C7H8 (l) P-C8H10 (l) M-C8H10 (l) O-C8H10 (l)

ṅin (mol/h) 238.4 x 103 119.2 x 103 834.4 x103 119.07 x103 95.7 23.6

Ĥ1: N2 (g, 400C, 3.5 bar)

Ĥin (kJ/mol) 0 0 0 0 0 0

N2 (g, 300C, 3 bar)

ΔH1a 0

N2 (g, 40 C, 3.5 bar)

Ĥ1= ΔHpath= ΔH1a+ ΔH1b 30

=

∫ cpdT 40

ṅout (mol/h) 238.4 x 103 119.2 x 103 834.4 x103 119.07 x103 95.7 23.6

ΔH1b 0

N2 (g, 40 C, 3 bar)

N2 (g, 300C, 3 bar)

Ĥout (kJ/mol) Ĥ1 Ĥ2 Ĥ3 Ĥ4 Ĥ5 Ĥ6

−5

0.2199 x 10 −3 ( 29 x 10 ) +(¿)T + ( 0.5723 x 10−8 ) T 2+ (−2.871 x 10−12 ) T 3 dT =

30

∫¿ 40

=

−¿ 0.2908 kJ/mol

Ĥ2: H2O (l, 400C, 3.5 bar)

H2O (l, 400C, 3 bar)

ΔH2a 0

H2O (l, 400C, 3 bar)

H2O (l, 40 C, 3.5 bar) Ĥ2= ΔHpath= ΔH2a

–

= v ΔP = 0.018m3/kmol(3

= 0.009 m3 bar/kmol x (

3.5)bar

1 ¯¿ 1 x 102 N /m2 ¿

)x

(

1 kmol ) 1000 mol

since, 1J = 1N.m

= 0.0009 kJ/mol

Ĥ3: C7H8 (l, 400C, 3.5 bar)

C7H8 (l, 300C, 3 bar)

ΔH3a C7H8 (l, 400C, 3.5 bar)

ΔH3b C7H8 (l, 400C, 3 bar)

C7H8 (l, 300C, 3 bar)

Ĥ3= ΔHpath= ΔH3a+ ΔH3b 30

= v ΔP +

=

=

∫ (148.8 x 10−3+32.4 x 10−5 T ) dT 40

¯ 0.1064 m3/kmol (3 −3.5 ¿ ¿

0.0532 m3bar/kmol x (

+ ( −1 . 6014 ) kJ/mol

1 ¯¿ 1 x 102 N /m2 ¿

)x

(

1 kmol ) −1 . 6014 ) kJ/mol 1000 mol + (

= 0.00532 kJ/mol + ( −1 . 6014 ) kJ/mol = - 1.5961 kJ/mol

Ĥ4: P-C8H10 (l, 400C, 3.5 bar)

P-C8H10 (l, 300C, 3 bar)

ΔH4a

ΔH4b

0

0

P-C8H10 (l, 40 C, 3.5 bar)

P-C8H10 (l, 300C, 3 bar)

P-C8H10 (l, 40 C, 3 bar)

Ĥ4= ΔHpath= ΔH4a+ ΔH4b 30

= v ΔP +

∫ ( 70.916 x 10−3 )+(1.5158 x 10−3 )T +(−3.9039 x 10−6 )T 2 +(2.9193 x 10−9 T 3) dt 40

¯ = 0.1234 m3/kmol (3 −3.5 ¿ ¿ + ( −¿ 1.1928) kJ/mol

=

0.0617 m3bar/kmol x (

1 ¯¿ 1 x 10 kN /m2 ¿ 2

)x

(

1 kmol ) −¿ 1.1928) kJ/mol 1000 mol + (

= 0.00617 kJ/mol + ( −¿ 1.1928) kJ/mol = - 1.1866 kJ/mol

Ĥ5: M-C8H10 (l, 400C, 3.5 bar)

M-C8H10 (l, 300C, 3 bar)

ΔH5a 0

M-C8H10 (l, 40 C, 3.5 bar)

ΔH5b 0

M-C8H10 (l, 40 C, 3 bar)

M-C8H10 (l, 300C, 3 bar)

Ĥ5= ΔHpath= ΔH5a+ ΔH5b −9

3

2.5061 x 10 ¿T dt −3 (−11.035 x 10 ) +(8.045 x 10−4 ) T +(−2.1885 x 10−6)T 2+¿ = v ΔP +

30

∫¿ 40

¯ = 0.1229 m3/kmol (3 −3.5 ¿ ¿ +

= 0.0615 m3bar/kmol x (

(−0.1453 ) kJ/mol

1 ¯¿ 1 x 10 kN /m2 ¿ 2

(

)x

1 kmol ) (−0.1453 ) kJ/mol 1000 mol +

= 0.00615 kJ/mol+ (−0.1453 ) kJ/mol =

−0.1392kJ /mol

Ĥ6: O-C8H10 (l, 400C, 3.5 bar)

O-C8H10 (l, 300C, 3 bar)

ΔH6a

ΔH6b

O-C8H10 (l, 400C, 3.5 bar)

O-C8H10 (l, 400C, 3 bar)

O-C8H10 (l, 300C, 3 bar)

Ĥ6= ΔHpath= ΔH6a+ ΔH6b 3

−9

2.6838 x 10 ¿ T dt −3 ( 56.460 x 10 ) +(9.4926 x 10−4) T +(−2.4902 x 10−6) T 2 +¿ = v ΔP +

30

∫¿ 40

¯ = 0.1206 m3/kmol (3 −3 . 5 ¿ ¿

=0.0603 m3bar/kmol x (

+ ( −0. 8673 ¿ kJ/mol

1 ¯¿ 1 x 10 kN /m2 ¿ 2

)x

(

1 kmol ) + ( −0. 8673 ¿ kJ/mol 1000 mol

= 0.00603 kJ/mol+ ( −0. 8673 ¿ kJ/mol = -0.8613 kJ/mol

Substances N2 (g)

ṅin (mol/h) 238.4 x 103

Ĥin (kJ/mol) 0

ṅout (mol/h) 238.4 x 103

Ĥout (kJ/mol) −¿ 0.2908

H2O (l) C7H8 (l)

119.2 x 103 834.4 x103

0 0

119.2 x 103 834.4 x103

−1.5961

P-C8H10 (l)

119.07 x103

0

119.07 x103

−1.1866

0.0009

M-C8H10 (l)

95.7

0

95.7

−0.1392

O-C8H10 (l)

23.6

0

23.6

-0.8613

ΔH = Σout ṅi Ĥi – Σin ṅi Ĥi = [(238.4 x 103 x

−¿ 0.2908) + (119.2 x 103 x 0.0009) + (834.4 x103 x –1.5961) +

(119.07 x103 x –1.1866) + (95.7 x –0.1392) + (23.6 x -0.8613)] – [0] = – 1542.33 x 103 kJ/h

QQ= ΔH= – 1542.33 x 103 kJ/h