Hoja19.28El etilbenceno se transforma en estireno en la reaccion
de deshidrogenacion catalitica
C8H10 (g)C8H8(g)+H2:Hr(600C)=124.5KJ/mol
A continuacion se muestra el diagrama de flujo de una version
simplificada del proceso comercial:
DATOS Y PROPIEDADES
FISICAS:35%etilenbenceno:(Cp)liquido=182J/(molC)(Hv)=36kJ/mol a
136c(Cp)vapor[J/(molC)]=118+0.30T(c)
estireno:(Cp)liqudio=209J/(molC)(Hv)=37.1kJ/mol a
145c(Cp)vapor[J/(molC)]=115+0.27T(c)
BASE:100KG C8H81000g1mol=960.15mol/hestireno
producidoh1kg104.15g
a.C8H10(g)C8H8(g)+H2(g)OVERALL SYSTEM
n2(mol H2/h)Alimento frescon1 (molc8H10/h)960.15mol C8H8/h
FRESH FEED RATE:n1=960.15molC8H101molC8H10=960.15molC8H10/h
Alimento frescoC8H10balanceh1molC8H8
H2 balance:n2=960.15molC8H101molH2=960.15mol H2/hh1molC8H10n3
(molC8H10 /h)n5 (molC8H10 /h)n4 (mol H2O(v)/h)n4 (mol H2O(v)
/h)600C960.15(mol C8H8 /s)960.15(mol H2 /s)560c
35% 1 - pass conversion0.35n3[molC8H10 react]1molC8H8=960.15mol
C8H8 /hh1molC8H10
n3=2743.30mol C8H10 /hfeed to reactor
recycle rate=2743.30-960.15=1783.14mol C810 /h recycled
reactor feed mixing point
2743.30molC8H10(v) /h2743.30molC8H10(v) /h500c n4 [mol
H2O(v)/h]600c
n4 [mol H2O(v)/h]700c
ENERGY BALANCE:H =2743.30H C8H10+n4 H H2O=0kJ/h
600H C8H10 =..118+0.30TdTJx1kJ=28.3kJ500mol C1000Jmol
TABLA H.8P=1BARH H2O =-3.9Kjmol
2743.30+28.3n4-3.9=0
n4=1.99E+04mol H2O/h
etilenbenceno preheater
960.15mol fresh feed+1783.14mol recycled=2743.30mol
EB(l)a25chhh
2743.30mol EB (v)a500ch
136500H =..CpdT+H136C+..CpvdT25136
H =20.2+36+77.7=133.9KJmol
QA=H=2743.30mol C8H10x133.9kj=3.67E+05KJpreheaterhmol C8H10h
steam generatorF
19400mol/hH2O (l)25c19400mol/hH2O (V)
TABLE B.5H (l)25C=104.8kj/kgTABLE B.7H
(v)700C1atm1bar=3928kj/kg
QF=H=19400mol H2O18g1kg3928-104.8h1mol1000gkg
QF=H=1.34E+06kJ/hsteam generator
REACTOR C
reference:C8H8 (v),C8H10(v),H2(g)H2O(v)a600C
560Hi560C=..Cp dTPARAC8H10C8H8600
H(T)PARAH2H2O
interpolacion de TABLE B.8
SUBSTANCIAn inH inn outH
out(mol/h)(KJ/mol)(mol/h)(KJ/mol)C8H10274001780-11.68H2O19900019900-1.56C8H8--960-10.86H2--960-1.19
BALANCE DE ENERGIA
Qc=H=960.15mol C8H8 produced124.5kJh1mol C8H8
Qc=H=5.61E+0.4KJ/HREACTOR
REACTORREACTORQc(kJ/h)REACTOR
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