Input data file for simplified EB plant model

The following is the input data file for a complete process model. Of course, the model does not represent actual technology currently offered by any licensor. However, it does show how easy such a model can be assembled and how calculator blocks can be used to advantage. The data file would be prepared and changed using any text editor, such as EDIT or NOTEPAD.

View output file.


 

*REMARK
Simplified process for manufacture of ethylbenzene from ethylene
and benzene. Benzene and ethylene are reacted in a multi-bed,
vapor-phase alkylation reactor at high temperature. Part of the
ethylene and benzene are fed between reactor beds to absorb heat
of reaction and prevent overheating. Reactor effluent is used to
vaporize fresh and recycle benzene to the reactor.
In the first distillation, unreacted benzene is recovered and
recycled to the reactor. Bottoms from the column is fed to the
second column, where ethylbenzene product is recovered as
distillate. The ethylbenezene column bottoms is fed to the third
column, where diethylbenzene is recovered and recycled to the
reactor for conversion to more ethylbenzene. The bottoms of third
column is heavy residue.
*END
*COMPONENTS,
 LIBRARY   1, NAME= 'Hydrogen',
 LIBRARY  22, NAME= 'Ethylene',
 LIBRARY   3, NAME= 'Ethane',
 LIBRARY  40, NAME= 'Benzene',
 LIBRARY  41, NAME= 'Toluene',
 LIBRARY  45, NAME= 'Ethylbenzene',
 LIBRARY  43, NAME= 'm/p-Xylene',
 LIBRARY 574, NAME= 'Cumene',
 LIBRARY 611, NAME= 'Diethylbenzenes'
 LIBRARY 666, NAME= 'Heavies'
 LIBRARY  51, NAME= 'Water',
*KVALUES, SRK
*ENTHALPY, SRK
*PROPS
*UNITS PSIG BTU LB F
*PRINT ONLY STREAM NAMES
 1  'Fresh benzene to process'
 2  'Cold ethylene feed'
 2A 'Hot ethylene to reactor'
 3  'Fresh & recycle benzene from benzene column'
 3A 'Benzene from feed pump'
 3B 'Benzene from feed preheater'
 3C 'Benzene vapor from vaporizer'
 3D 'Benzene for reactor bed 1 to fired heater'
 3E 'Quench benzene for remaining reactor beds'
 3F 'Benzene for reactor bed 1 from fired heater'
 4  'Hot reactor effluent'
 4A 'Reactor effluent from feed vaporizer'
 4B 'Reactor effluent from column reboiler'
 5  'Benzene recovery column bottoms'
 5A 'Benzene column bottoms fed to EB column'
 6  'Hot EB product from EB column'
 6A 'Cool EB product to tankage'
 7  'EB recovery column bottoms'
 8  'PEB column distillate'
 8A 'Recycle PEB from pump'
 8B 'Recycle PEB from heater'
 9  'Process residue'
 10 'Vent from benzene column'
*RECYCLE DEFAULTS, TOLER= 0.0001, TOLER=0.1 LB, TEMP TOLER 0.1 F,
 BOUNDS -50 0,
*STREAM 1 TEMP 250 F, PRES 250 PSIG, FLOW 10000 LB/HR,
 COMPOS= 0.0 0.0 0.0 99.5 0.5
;Benzene feed composition, flow calc by process
*STREAM 2 TEMP 80 F, PRES 350 PSIG, FLOW 3500 LB/HR,
 COMPOS= 0.0 0.998 0.002; ethylene feed composition
*STREAM CWS TEMP 85 F, PRES 60 PSIG, FLOW 1000 LB/HR,
 COMPOS 10*0 1.0; cooling water supply
*STREAM HPS L/F=0, PRES 600 PSIG, FLOW 1000 LB/HR,
 COMPOS 10*0 1.0; high pressure steam supply
*REMARK
-------------------------------------------------
Recycle stream estimates
*END
*STREAM 3C TEMP 500 F, PRES 315 PSIG, FLOW 200000 LB/HR,
 COMPOS= 0.0 0.0 0.0 0.999 0.001
*STREAM 8A TEMP 100 F, PRES 300 PSIG, FLOW 1000 LB/HR,
 COMPOS= 7*0.0 0.01 0.989 0.001

*HEATEXCH E104C 'Ethylene feed heater, E-104, cold side'
 COLD STREAM 2, OUTLET STREAM 2A, TEMP 250 F, PRES DROP 5 PSI,
*CALCULATOR CALCBZ 'Calculate flow of benzene needed for reactor'
; Set benzene mass flow at 20 times that of feed ethylene
BZFLOW = STREAM 2A COMP 2 WT FLOW *20
STREAM 3C WT FLOW = BZFLOW ;poke flow into recycle benzene estimate.
NONOUTPUT 3C; setting flow does not close the recycle - tell PD-PLUS!
BLOCK C101 BZDIST = BZFLOW; also poke needed flow into column spec.
*HEATEXCH H101A 'Heat recycled PEB in heater',
 COLD STREAM 8A, OUTLET STREAM 8B, TEMP 400 F, PRES DROP 20 PSIG,
*SPLIT BED1BZ 'Split off benzene for first reactor bed',
 FEED IS STREAM 3C,
 STREAM 3D FLOW = 0.75 OF FEED,
 STREAM 3E FLOW IS BALANCE,
*HEATEXCH H101B 'Heat bed 1 benzene in heater',
 COLD STREAM 3D, OUTLET STREAM 3F, TEMP 810 F, PRES DROP 35 PSIG,
*REACTOR R101 'Alkylation reactor, R-101',
 FEED IS STREAMS 2A 3E 3F 8B, PRODUCT IS STREAM 4,
 PRES DROP 50 PSI, CALCULATE HEAT,
 EQUATION 8 -1.0 6 +1.0 2 +0.5, CONVERT 0.050, COMP 8,
 EQUATION 9 -1.0 4 -1.0 6 +2.0, CONVERT 0.500, COMP 9,
 NEXT LEVEL,
 EQUATION 2 -1.0 4 -1.0 6 +1.0, CONVERT 0.883, COMP 2,
 EQUATION 2 -1.0 4 -1.0 7 +1.0, CONVERT 0.001, COMP 2,
 EQUATION 2 -1.5 4 -1.0 8 +1.0, CONVERT 0.004, COMP 2,
 EQUATION 2 -2.0 4 -1.0 9 +1.0, CONVERT 0.100, COMP 2,
 EQUATION 2 -1.0 4 -2.0 10 +1.0 1 +1.0, CONVERT 0.010, COMP 2,
*HEATEXCH E101E102 'Cool effluent in E-101 & E-102'
 HOT STREAM 4, OUT STREAM 4B, TEMP 500 F, PRES DROP 10 PSI,
*FLASH EFFLDP 'Check effluent dew point at column inlet pressure',
 FEED IS STREAM 4B, L/F=0, PRES DROP 0 PSI,
*COLUMN C101 'Benzene recovery column, C-101', STAGES= 45,
 FEED 4B STAGE 20,
 FEED 1 STAGE 44 VARIES,
 CIRCULATING REBOILER, FRAC VAPOR 0.20, STREAM C101RBFD, BAFFLE,
 CONDENSER, LABEL QC,
 VAPOR DISTILLATE STREAM 10, FLOW 10 LBMOL/HR,
 LIQUID DIST STREAM 3, FLOW= 70000 LB/HR, EST MW 78, LABEL BZDIST,
 BOTTOMS STREAM 5,
 WT FRACTION= 0.01, COMP 6, STREAM 3  ; EB overhead
 WT FRACTION= 0.001, COMP 4, STREAM 5 ; Benzene bottoms
 PRES 110 PSIG, STAGE 45,
 PRES 113 PSIG, STAGE 44,
 PRES 117 PSIG, STAGE 1,
 EST TEMP 320 F, STAGE 45,
 EST TEMP 470 F, STAGE 1,
 VAPOR EST FLOW 3500 LBMOL/HR, STAGE 44,
 VAPOR EST FLOW 3500 LBMOL/HR, STAGE 20,
 VAPOR EST FLOW 500 LBMOL/HR, STAGE 19,
 TRACE LEVEL 0
*PUMP P101 'Reactor feed pump, P-101',
 FEED IS STREAM 3, PROD IS STREAM 3A, PRES 335 PSIG, EFF=68 %,
*HEATEXCH E103 'Reactor feed preheater, E-103',
 HOT STREAM HPS, L/F=1, PRES 585 PSIG, CALC FLOW,
 COLD STREAM 3A, OUT STREAM 3B, TEMP=430 F, PRES DROP 5 PSI,
*CALCULATOR E101DUTY 'Set vaporizer duty by difference'
;Hot reactor effluent vaporizes benzene in E-101 and reboils the
;benzene column (E-102); combined duty was calculated before to fixed
;column feed temperature; get the heat available for vaporization and
;superheating the benzene here, and replace the dummy duty value below
;in block E101.
 BLOCK E101 'Q-SPEC' = BLOCK E101E102 'Q-CALC' -BLOCK C101 Q1
*HEATEXCH E101 'Reactor feed vaporizer, E-101',
 HOT STREAM 4, OUT STREAM 4A, PRES DROP 5 PSI,
 COLD STREAM 3B, OUT STREAM 3C, PRES DROP 10 PSI,
 DUTY= 999 BTU/HR; (duty replaced)
 WEIGHTED MTD, SECTIONS=10,
*HEATEXCH E102 'Benzene column reboiler, E-102',
 HOT STREAM 4A, OUT STREAM 4B, TEMP 500 F, PRES DROP 5 PSI,
 COLD STREAM C101RBFD,
 WEIGHTED MTD, SECTIONS=10,
*HEATEXCH E104 'Ethylene feed heater, E-104',
 HOT STREAM 5, OUT STREAM 5A, PRES DROP 2 PSI,
 COLD STREAM 2, OUTLET STREAM 2A, TEMP 250 F, PRES DROP 5 PSI,
*COLUMN C102 'EB recovery column, C-102', STAGES= 50,
 FEED 5A STAGE 15,
 REBOILER, CONDENSER,
 VAPOR DISTILLATE FLOW=0 LBMOL/HR,
 LIQUID DISTILLATE STREAM 6, EST FLOW= 110 LBMOL/HR,
 BOTTOMS STREAM 7,
 WT FRACTION= 0.000100, COMP 8, STREAM 6 ; cumene overhead
 WT FRACTION= 0.05, COMP 6, STREAM 7     ; EB bottoms
 PRES 5 PSIG, STAGE 50,
 PRES 7 PSIG, STAGE 49,
 PRES 12 PSIG, STAGE 1,
 EST TEMP 300 F, STAGE 50,
 EST TEMP 320 F, STAGE 15,
 EST TEMP 400 F, STAGE 1,
 VAPOR EST FLOW 400 LBMOL/HR, STAGE 49,
 TRACE LEVEL 0
*HEATEXCH E105 'EB product cooler, E-105',
 HOT STREAM 6, OUT STREAM 6A, TEMP 105 F, PRES DROP 2 PSI,
 COLD STREAM CWS, TEMP 105 F, CALCULATE FLOW
*COLUMN C103 'PEB recovery column, C-103', STAGES= 10,
 FEED 7 STAGE 6,
 REBOILER, CONDENSER,
 VAPOR DISTILLATE FLOW=0 LBMOL/HR,
 LIQUID DISTILLATE STREAM 8, EST FLOW= 5 LBMOL/HR,
 BOTTOMS STREAM 9,
 REFLUX RATIO= 5,
 WT FRACTION= 0.05, COMP 9, STREAM 9; DEB bottoms
 PRES 5.0 PSIA, STAGE 10,
 PRES 6.0 PSIA, STAGE 9,
 PRES 7.0 PSIA, STAGE 1,
 EST TEMP 275 F, STAGE 10,
 EST TEMP 315 F, STAGE 3,
 EST TEMP 450 F, STAGE 1,
 TRACE LEVEL 0
*PUMP P102 'PEB recycle pump, P-102',
 FEED IS STREAM 8, PRODUCT IS STREAM 8A, PRES 300 PSIG, EFFIC 50 %,
*CALCULATOR SUMMARY 'Summary of process results'
   REPORT 1,(BLOCK E103 'Q-CALC'/1E6)
 1 FORMAT(' Reactor benzene preheating (via HPS):',F7.2,' MMBTU/hr')
   REPORT 2,(BLOCK H101B 'Q-CALC'/1E6)
 2 FORMAT(' Fired heater: Benzene superheating: ',F7.2,' MMBTU/hr')
   REPORT 3,(BLOCK H101A 'Q-CALC'/1E6)
 3 FORMAT(' Recycle DEB vaporizing:',F7.2,' MMBTU/hr')
   QR_C101= BLOCK C101 Q1/1.E6
   QR_C102= BLOCK C102 Q1/1.E6
   QR_C103= BLOCK C103 Q1/1.E6
   REPORT 4,QR_C101
 4 FORMAT(' Reboiler duties: Benzene column: ',F7.2,' MMBTU/hr')
   REPORT 5,QR_C102
 5 FORMAT(' EB column: ',F7.2,' MMBTU/hr')
   REPORT 6,QR_C103
 6 FORMAT(' PEB column: ',F7.2,' MMBTU/hr')
   REPORT 7,(QR_C101 +QR_C102 +QR_C103)
 7 FORMAT(' Total: ',F7.2,' MMBTU/hr')
   REPORT 8,(ABS(BLOCK C101 QC/1.0E6))
 8 FORMAT(' Benzene column steam generation: ',F7.2,' MMBTU/hr')
   REPORT 9,(STREAM 6A COMP 6 WT FRACTION*100)
 9 FORMAT(' EB product purity:',F6.2,' %')
   REPORT 10,(STREAM 6A COMP 4 WT FRACTION*1E6)
10 FORMAT(' Benzene:',I6,' ppm(wt)')
   REPORT 11,(STREAM 6A COMP 5 WT FRACTION*1E6)
11 FORMAT(' Toluene:',I6,' ppm(wt)')
   REPORT 12,(STREAM 6A COMP 7 WT FRACTION*1E6)
12 FORMAT(' Xylenes:',I6,' ppm(wt)')
   REPORT 13,(STREAM 6A COMP 8 WT FRACTION*1E6)
13 FORMAT(' Cumene: ',I6,' ppm(wt)')

*HCURVE, STREAM 4, PRES 220 PSIG, FROM STREAM CONDITIONS TO DP,
 VARY TEMP, SIZE=10 F,