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Simulation Of Industrial Catalytic-Distillation Process

Simulation Of Industrial Catalytic-Distillation Process
Simulation Of Industrial Catalytic-Distillation Process

Chemical Engineering Journal90(2002)

253–266

Simulation of industrial catalytic-distillation process for production of methyl tert-butyl ether by developing user’s model

on Aspen plus platform

Jie Bao a,*,Buliang Gao b,Xiaoqun Wu c,Makoto Yoshimoto a,Katsumi Nakao a

a Department of Applied Chemistry and Chemical Engineering,Faculty of Engineering,Yamaguchi University,

Tokiwadai2-16-1,Ube,Yamaguchi755-8611,Japan

b Qilu Petrochemical Research Institute of Sinopec,Zibo,Shandong255400,China

c Department of Chemical Engineering,Zhejiang University,Hangzhou,Zhejiang310071,China

Received30October2001;accepted26March2002

Abstract

The industrial catalytic-distillation process for the production of methyl tert-butyl ether(MTBE)from methanol and isobutylene was simulated by developing the process model as a user modular on Aspen plus platform.The model utilizes the Aspen plus system and retains the characteristics of the self-designed model,which has been veri?ed in various scale-up processes.The experimentally determined reaction kinetics was applied in the model.NRTL and Redlick–Kwong–Soave equations were selected for the vapor–liquid equilibrium calculation. The NRTL binary interaction parameters were estimated from the experimental data of the two-component vapor–liquid equilibrium.Two typical industrial plants for the MTBE production,one using the loose-stack-type package technology and the other using the bale-type package technology in the catalytic-distillation column,were chosen as the sample processes to demonstrate the validity of the model.The ?owsheet simulations of the two industrial plants were done on Aspen plus platform,in which the simulation of the catalytic-distillation column used the developed user modular.The results show that fair agreements between the calculated and operating data were obtained.?2002Elsevier Science B.V.All rights reserved.

Keywords:Industrial simulation;Catalytic-distillation process;Methyl tert-butyl ether;Aspen plus;User modular

1.Introduction

Catalytic-distillation technology for the production of methyl tert-butyl ether(MTBE)has been commercialized to the scale of annual productivity more than100,000t in many countries[1–4].To meet the needs of the de-sign for the new plants and optimization of the existing ones,an accurate mathematical model for simulating the industrial-scale catalytic-distillation process is needed.On the other hand,very few industrial cases were reported, although many studies were devoted to the modeling of catalytic-distillation process[5].A practical model should have at least the following capacities:(1)it describes the structural characteristics of catalyst packages used in in-dustrial processes,(2)the fundamental parameters such ?Corresponding author.Present address:Department of Bioscience and Biotechnology,Faculty of Engineering,Okayama University,Tsushi-manaka3-1-1,Okayama700-8530,Japan.Tel.:+81-86-251-8202;fax: +81-86-231-0257.

E-mail address:baojie@biotech.okayama-u.ac.jp(J.Bao).as reaction kinetics and vapor–liquid equilibrium data are supported by either experimental data or reliable database, (3)it is veri?ed by industrial operation data,and(4)the industrial?owsheet can be simulated,not merely in a single catalytic-distillation unit.

In our previous reports,the model for the catalytic-distillation process in the MTBE production was success-fully applied in various scales from bench tests,pilot tests, and in a semi-industrial plant with the annual productivity of2000t MTBE[3,6].With the rapid industrialization rate of the process,some shortages in the model appeared.First, the model was a self-designed Fortran program used to simulate a single catalytic-distillation unit.Thus,the whole ?owsheet composed of different unit operations could not be simulated.Second,only?ve components were used in the model instead of the12main components in the real case.The eight main hydrocarbon components were repre-sented by only three key components,isobutylene,1-butane and1-butylene.This certainly created the inaccuracy in the real industrial operation with massive productivity.Third, the database and calculation functions in the previous model

1385-8947/02/$–see front matter?2002Elsevier Science B.V.All rights reserved. PII:S1385-8947(02)00041-4

254J.Bao et al./Chemical Engineering Journal90(2002)253–266

Nomenclature

A,B,C,D coef?cients of tridiagonal matrix

A1Arrhenius frequency factor of rate

constant k1

A2Arrhenius frequency factor of rate

constant k2

b NRTL binary interaction parameter

c component number

C molar concentration(mol/m3)

E1activation energy of rate

constant k1(J/mol)

E2activation energy of rate constant

k2(J/mol)

FI1molar?owrate of the mixed

C4/methanol feedstock(mol/s)

FI2molar?owrate of the methanol

feedstock(mol/s)

h enthalpy of liquid stream(J/mol)

H enthalpy of vapor stream(J/mol)

H heat of reaction(J/mol)

HI enthalpy of feedstock(J/mol)

k1?rst-order rate constant of the

forward reaction of reaction(1)(s?1) k2?rst-order rate constant of the reverse

reaction for reaction(1)(s?1)

L liquid molar?owrate(mol/s)

N number of equilibrium stages

NC1start stage of catalyst packing

NC2end stage of catalyst packing

NF1stage of the mixed C4/methanol

feedstock

NF2stage of the methanol feedstock

P pressure of the system(MPa)

P0vapor Antoine pressure(MPa)

Q total heat of reaction(J)

r reaction rate(mol/m3s)

R gas constant(J/mol K)

R reacted moles of components(mol) t time(s)

T temperature(K)

v molar volume(m3)

V vapor molar?owrate(mol/s)

V C catalyst volume(m3)

V L liquid volumetric?owrate(m3/s)

V T catalyst space velocity(s?1)

x molar fraction of liquid

X B conversion of isobutylene

y molar fraction of vapor

ZI molar fraction of feedstock

Greek letters

αNRTL binary interaction parameters α,δempirical coef?cients of catalyst

package

γliquid activity coef?cient

ρliquid molar density(mol/m3)

φvapor fugacity

Subscripts

B isobutylene

i component(1≤i≤c)

j equilibrium stage(1≤j≤N)

M methyl tert-butyl ether

Superscripts

k reaction section in the small reactor at

each stage(1≤k≤KS)

KS number of package layers at each stage

were limited and it was dif?cult to carry out the detailed optimization calculations.

Aspen plus system is one of the standard software for ?owsheet simulation in the processing industries.It is supported by strong databases,complete sets of modules, and?exible simulation tools.The system provides many built-in modules for simulating various processes,and the modular for simulating the reactive-distillation process is also one of them.An important assumption is given in this reactive-distillation modular,that is,both reaction and separation are assumed to take place in the liquid phase in the column trays or packings.Therefore,the liquid residue time or liquid holdup is required[7,8].In the heterogeneous catalytic-distillation process,however,the solid catalyst particles are packed into many catalyst envelopes,instead of the homogeneous dispersion in the liquid phase in the trays or packings.The reactions occur inside the catalyst packages when the liquid contacts the catalyst particles. Then,the products?ow out of the packages,and the sep-aration takes place on the trays or packings through the count-current vapor–liquid contact.This fact indicates a major difference between homogeneous and heterogeneous processes:the reaction and separation actually take place in the different locations of the column in the heterogeneous process,i.e.reaction in the catalyst packages and separation in the trays or packings.Therefore,the parameters of liquid residue time or the liquid holdup on the trays or packings in the heterogeneous process can only be used in the separa-tion calculation,whereas the reaction calculation needs the parameters of contacting time of liquid with catalyst in the catalyst packages.Hence,we may conclude that the built-in reactive-distillation modular in Aspen system is not suit-able for simulating the heterogeneous catalytic-distillation process for the above reason.

To overcome the above problems,an effort was made in this study to develop a self-de?ned model for simulating heterogeneous catalytic-distillation,and then to connect the model with Aspen plus as a user modular.In the new model,

J.Bao et al./Chemical Engineering Journal90(2002)253–266255 the contacting time of liquid with catalyst is represented by

the catalyst space velocity V T appearing in the reaction equa-

tions.In this way,not only the user modular takes advan-

tages of strong database,?exible simulation functions and

optimization tools of Aspen plus system,but it also keeps

the characteristics of the model that had been veri?ed in the

previous scale-up experiments.

The purpose of this study is(1)to establish a mathemati-

cal model oriented to the heterogeneous catalytic-distillation

structure,(2)to build the mathematical model in the user

modular provided by Aspen plus and compile it into an avail-

able modular on Aspen plus platform,(3)to connect the

database and calculation functions of Aspen plus with the

user model,and(4)to apply the model into the industrial

applications.

2.Reaction kinetics and thermodynamics

2.1.Reaction kinetics

The synthesis of MTBE from methanol and isobuty-

lene catalyzed by Amberlyst-15or similar sulphonic

ion-exchange resin catalysts[3]is a reversible etheri?cation

as shown in Eq.(1):

CH3C(CH3)=CH2(B)+CH3OH k1

k2

CH3C(CH3)2OCH3(M)

(1)

According to Yang et al.[9],the forward reaction of reaction

(1)is?rst-order with respect to the isobutylene concentra-

tion and zero-order with respect to the methanol concentra-

tion,respectively,and the reverse reaction is?rst-order with

respect to the MTBE concentration as shown in Eq.(2):?r B=k1C B?k2C M(2) where k1=A1exp(?E1/RT)and k2=A2exp(?E2/RT) are the?rst-order rate constants for the forward and reverse

reactions,respectively.The values of Arrhenius frequency

factors A1,A2and activation energy E1,E2for the sul-

phonic ion-exchange resin catalyzed reaction are listed in

Table1[9].The reaction kinetic data had been veri?ed in

several industrial applications of the MTBE production,

in which the?xed-bed reactor packing of the same catalyst

was used.

The main side reactions are the dimerization of isobuty-

lene to diisobutylene(2,4,4-trimethyl-1-pentene),and the

hydration of isobutylene to tert-butyl-alcohol(TBA)as

Table1

Arrhenius parameters of rate constant k1and k2for MTBE synthesis catalyzed by sulphonic ion-exchange acidic resin catalysts

A1A2E1(J/mol)E2(J/mol) 6.50×105 1.36×108 4.74×1047.04×104shown in Eqs.(3)and(4),respectively:

2CH3C(CH3)=CH2→CH2=C(CH3)CH2C(CH3)2CH3

(3) CH3C(CH3)=CH2+H2O→CH3C(CH3)2OH(4) The kinetic study shows that reaction(3)can only take place when the addition of methanol is insuf?cient(the molar ra-tio of methanol to isobutylene is lower than0.8)[9].Since the methanol addition is carefully arranged to allow the mo-lar ratio of methanol to isobutylene to be higher than0.8 at each stage of the catalytic-distillation column,reaction (3)can be reasonably neglected in the catalytic-distillation unit.For reaction(4),the minor water in hydrocarbon and methanol feedstocks is consumed in the pre-reactor before it is fed into the catalytic-distillation column.Therefore,re-action(4)can also be neglected in the catalytic-distillation unit.The products of the two side reactions are considered in the vapor–liquid equilibrium calculation,whereas the re-action kinetics are not included in the calculation.

2.2.Vapor–liquid equilibrium

A typical industrial process for the MTBE produc-tion involves at least12components:propylene,isobu-tane,1-butane,1-butylene,isobutylene,cis-2-butylene, trans-2-butylene,methanol,MTBE,diisobutylene,TBA, and water.Since methanol associates almost all hydrocar-bon components into azeotropic pairs,the system shows the strong non-ideal properties.The vapor–liquid equilibrium constant K i for component i is expressed in Eq.(5):

K i=γi

φ0i

φi

P0i

P exp

v i(P?P0i)

RT

(5)

whereγi is the liquid activity coef?cient,φ0i andφi the vapor fugacity in pure and mixture state,respectively,P0i the vapor Antoine pressure,v i the molar volume and P is the total pressure of the system.The NRTL equation and Redlick–Kwong–Soave equation are selected to calculate liquid activity coef?cientγi and the vapor fugacityφi(and φ0i),respectively.The NRTL activity coef?cient equation is expressed in Eq.(6):

lnγi=

j

x jτji G ji

k

x k G ki

+

j

x j G ij

k

x k G kj

τij?

m

x mτmj G mj

k

x k G kj

(6) where G ij=exp(?αijτij),τij=b ij/T andαij=αji.The NRTL binary interaction parameters b ij,b ji andαij were estimated from the experimental data of two-component vapor–liquid equilibrium using data regression system (DRS)in the Aspen plus system,followed by the thermo-dynamics consistence check.The estimated NRTL binary

256J.Bao et al./Chemical Engineering Journal90(2002)253–266

Table2

Values of NRTL binary interaction parameters for components involved

in MTBE synthesis

Components i–j b ij b jiαij Propylene–methanol b617.96258.780.30

Propylene–MTBE b204.97?114.110.30

Propylene–tert-butyl alcohol b617.96258.780.30

Isobutane–methanol a663.40505.940.47

Isobutane–MTBE a204.96?114.110.30

Isobutane–tert-butyl alcohol a663.40505.940.47

1-Butane–methanol a672.37516.540.47

1-Butane–MTBE a230.71?117.970.47

1-Butane–tert-butyl alcohol a672.37516.540.47

1-Butylene–methanol a695.79440.170.47

1-Butylene–MTBE a?288.49440.510.30 1-Butylene–tert-butyl alcohol a695.79440.170.47

Isobutylene–methanol a790.53435.530.47

Isobutylene–MTBE a?141.72225.700.30 Isobutylene–tert-butyl alcohol a790.53435.530.47 Trans-2-butylene–methanol a695.79440.170.47 Trans-2-butylene–MTBE a?288.49440.510.30 Trans-2-butylene–tert-butyl alcohol a695.79440.170.47 Cis-2-butylene–methanol a190.02237.430.30 Cis-2-butylene–MTBE a440.17695.790.47 Cis-2-butylene–tert-butyl alcohol a?162.1746.980.30 Methanol–MTBE a663.40505.940.47 Methanol–diisobutylene b204.96?114.110.30 Methanol–tert-butyl alcohol b663.40505.940.47 Methanol–water b828.39?1329.540.30 MTBE–diisobutylene b440.51?288.490.30 MTBE–tert-butyl alcohol b489.67?240.510.30 MTBE–water b682.051108.820.30 Diisobutylene–tert-butyl alcohol b695.79440.170.47 Tert-butyl alcohol–water b217.51?1395.020.30

a Parameters estimated from experimental VLE data.

b Parameters from Aspen database DIPPR[8].

interaction parameters b ij,b ji andαij are shown in Table2. The other fundamental properties such as molar volume, heat capacity,vapor capacity and density,etc.were called from DIPPR database in the Aspen plus system.

3.Model development on Aspen plus platform

3.1.Model con?guration of catalytic-distillation column

For developing a practical catalytic-distillation process, the design of an ef?cient catalyst package poses considerable challenges[5].For the MTBE production process,the?ne sulphonic ion-exchange resin particles with its size less than 1.0mm have to be enveloped in various conceivable shapes [5,10–12].Among them,two typical structures had been applied to an industrial scale of more than100,000t annually, one being the bale-type package[13–16]and the other the loose-stack package[6,3,17].

Two considerations are taken as the most important factors for the catalyst packages:one being the contact ef?ciency of liquid with catalyst,and the other being the reaction ef?ciency of catalyst.Correspondingly,the model development should re?ect the characteristics of the cat-

alyst packages.Two empirical coef?cientsαandδwere

introduced in the model:αrepresents the ratio of the liquid

?owrate entering the catalyst package to the total liquid

?owrate,re?ecting the contact ef?ciency of liquid to cat-

alyst(liquid?ows into the passby ways in many kinds of

packages).δrepresents the ratio of the real reaction rate to

the kinetic reaction rate under the same conditions(liquid

?oods through catalyst in non-plug?ow in many packages).

The value ofαwas determined by measuring the cross-area

occupied by catalyst to the total cross-area in the reactive

section.The value ofδwas determined separately in a spe-

cially designed small reactor.The detailed procedure:put a

single catalyst package in the small reactor under the same

reaction and hydrodynamic conditions(same count-current

vapor–liquid?owrates),then determine its reaction rate and

compare with the kinetic rate.The two coef?cients were

used to model various types of catalyst packages during the

process development from bench tests,and different scales

of pilot tests[3,6].The value ofαwas between0.5and1.0,

the value ofδwas between0.6and1.0.

On the other hand,the catalyst package had shown contin-

uous improvement in both the aspects.In the?nal type used

in the commercial plant,the design of the loose-stack pack-

age let all the liquid enter the catalyst envelope,and then

?ood smoothly through the catalyst container.As the result,αwas1.0by its de?nition.The experimental determination ofδwas also close to the unity value of1.0,because of the

perfect contacting of liquid with catalyst in the packages,

and because the?ow is close to the plug-?ow pattern inside

the packages.The trial-and-error method was used to search

the most suitable value ofαandδfor the bale-type package

[3,6,17].We found that the calculation results gave the best

?tness to the operating ones using the unity value of1.0to

both of the parameters.This fact indicates that the industrial

packages of the bale-type package are also under the condi-

tions of perfect contacting of liquid with catalyst and stable

plug?ow inside the packages.In other words,the two co-

ef?cients in the current model for the industrial simulations

can be ignored.This is why we keep the coef?cients in the

model for consistency with the previous model[3,6],and to

give them the value of1.0in the current industrial cases.

The equilibrium stage model based on the bale-type and

loose-stack-type packages in the reactive section is shown

in Fig.1.Fig.1(a)indicates the whole catalytic-distillation

column,and Fig.1(b)indicates the detailed structure of a

typical equilibrium stage in the reactive section.There are

N equilibrium stages in the column.The catalyst packages

are installed from stages NC1to NC2,forming the reactive

section.The catalyst packages at each stage of the reactive

section are represented by a corresponding small reactor.

This small reactor is divided into several layers from1to

KS corresponding to the real arrangement of the catalyst

packages.The mixed C4stream FI1and pure methanol

stream FI2are fed into the column at stages NF1and NF2,

respectively.The radial gradients of composition and heat

J.Bao et al./Chemical Engineering Journal90(2002)253–266

257

Fig.1.Schematic diagram and con?guration of catalytic-distillation column:(a)whole column model;(b)equilibrium stage model. transfer are neglected at the equilibrium stage.The reaction

is considered taking place in the liquid phase.

3.2.Model equations

The model equations based on the typical equilibrium

stage j are shown as follows:

(1)Mass balance equation:

d(E j x j,i)

d t =L j?1x j?1,i+V j+1,i y j+1,i?L j x j,i

?V j y j,i+FI j ZI j,i+ R j,i(7)

where FI j and ZI j are the feedstock?owrate and compo-sition at stage j(NF1or NF2),respectively. R j,i is the consumption rate for component i at stage j.The terms of R j,i>0, R j,i<0and R j,i=0correspond

to the reactants,the products,and the unreacted compo-nents,respectively.

(2)Reaction equations:

The reaction kinetics equation(2)is rearranged regarding to isobutylene conversion X B for the merit of application convenience as shown in Eq.(8):

X B=

k1

k1+k2

1?exp

?(k1+k2)

V C

V L

=

k1

12

1?exp

?

k1+k2

T

(8)

where V C is the catalyst volume,V L the liquid vol-umetric?owrate?owing through the catalyst and V T (=V L/V C)is the catalyst space velocity,meaning the liquid volumetric rate?owing through per volume unit of solid catalyst.The swelling of the catalyst is taken into

258J.Bao et al./Chemical Engineering Journal90(2002)253–266 account in the volume calculation(20%increase in

volume after the dry resin catalyst particles are bathed

in liquid).V T is decided by the catalyst amount and

the liquid?owrate of the column.The reciprocal of

V T,1/V T,indicates the contacting time of liquid with

catalyst,corresponding to the liquid residue time in

the homogeneous reactive-distillation process.The dif-

ference between the two parameters is that the liquid

residue time in the homogeneous process is a parameter

used for both reaction and separation,while the space

velocity V T is only used to describe the reaction behav-

iors in the heterogeneous process.The liquid residue

time in the heterogeneous process is also calculated at

each equilibrium stage but it has no direct relations to

the reaction behaviors,since the reaction and separation

occurs at different locations of the catalytic-distillation

column(reaction in the catalyst package,and separation

in the trays or packings).

The consumption rate R j,i on stage j is calculated

in Eq.(9).The catalyst space velocity on each catalyst

package is calculated to give the conversion yield of

isobutylene at each package:

R j,i=

KS

k=1

αL k j?1

k1

k1+k2

×

1?exp

?

δ(k1+k2)V C

(NC2?NC1+1)·KS·αL k j?1ρj

(9)

whereρj is the liquid molar density,k the layer of cat-alyst package at stage j(1≤k≤KS),αthe contacting ef?ciency of liquid to catalyst,andδis the reaction ef?-ciency in the catalyst package.The value forαandδin the two industrial cases was taken to be unity,because of the reasons described in Section3.1.

(3)Vapor–liquid equilibrium equation:

y j,i=K j,i x j,i(10) where K j,i is the vapor–liquid equilibrium coef?cient for component i at stage j,calculated from Eqs.(5)and

(6).

(4)Component summation equations:

c

i=1

x j,i=1(11) c

i=1

y j,i=1(12) (5)Enthalpy balance equations:

L j?1h j?1+V j+1H j+1?L j h j?V j H j

+FI j HI j+ Q j=0(13) Q j= H j R j,i(14) where HI j is the molar enthalpy of feedstock,and H j and Q j are the molar heat of reaction and total heat of reaction at stage j,respectively.

The model equations(Eqs.(7)–(14))are rearranged into the form of tridiagonal matrix as shown in Eq.(15):

A j x t+1

j?1,i

+B j x t+1

j,i

+C j x t+1

j+1,i

=D j(15) where the matrix coef?cients A j,B j,C j,D j take different values at the different section of the column from N=1,2 to NC1?1;NC1,NC1+1to NC2?1;NC2,NC2+1to N?1 and N.The independent variables in the catalytic-distillation column include the number of equilibrium stages N,the number of package layers at each stage KS,the locations of the methanol and mixed C4feedstock streams NF1and NF2,the start and end stages of catalyst packing NC1and NC2,the pressure on the top stage,the pressure drop of the column(or the pressure on the bottom),the catalyst volume packed in the column V C,the re?ux ratio,the re?ux tem-perature,distillate?owrate,and the feedstock?owrate and composition variables.The model equations(Eqs.(7)–(14)) are simultaneously solved using the relaxation algorithm af-ter the independent variables,and the relaxation coef?cient and the initial values of the parameters are given.The dia-gram of the detailed calculation?owsheet is shown in Fig.2.

3.3.Design of catalytic-distillation user modular on Aspen plus platform

(1)The program is written into the user modular using the

built-in Fortran language following the grammar and communication rules issued by Aspen plus system,and then compiled it into an executive?le using NDP Fortran compiler.

(2)The reaction kinetic model is developed as a subroutine

of the user modular.

(3)The vapor–liquid equilibrium model is developed by

calling NRTL equation for liquid activity coef?cient calculations and Redlick–Kwong–Soave equation for vapor fugacity calculations.The NRTL binary inter-action parameters b ij,b ji andαij estimated from the experimental data are applied to replace the data from UNIFAC model in Aspen plus.

(4)Other general thermodynamic properties are calculated

by calling DIPPR database through the subroutines such as VTHRM for vapor pure substance proper-ties,LTHRM for liquid pure substance properties, VMTHMY for vapor mixture properties,LMTHMY for liquid mixture properties,ENTHV for vapor mixture enthalpy,ENTHL for liquid mixture enthalpy,VOLV for vapor mixture molar volume,VOLL for liquid mix-ture molar volume,FUGV for vapor mixture fugacity, FUGLY for liquid mixture fugacity,etc.

J.Bao et al./Chemical Engineering Journal90(2002)253–266

259

Fig.2.Calculation?owsheet of user model USROPT developed for simulating catalytic-distillation column.

(5)The communication between the user modular and

other system modules,database,function tools and monitor systems are realized through the connection of material streams,enthalpy and entropy streams as well as information streams according to the rules and formats of Aspen plus system.

(6)Writing the input parameters,calculation results and

calculation information into the report?les by calling common subroutines.

The detailed communication and calling processes are also shown in Fig.2.The user program USROPT includes one main program and13self-de?ned subroutines.4.Results and discussion

4.1.Simulation of Plant A using loose-stack package technology

Fig.3(a)shows the industrial?owsheet of Plant A using the loose-stack package technology in the catalytic-distillation column with the annual MTBE pro-duction of20,000t.The mixed C4hydrocarbons containing about32%(wt.)isobutylene is mixed with methanol in the static mixer V-2and then pumped into the pre-reactor R-1, in which about90%isobutylene is converted.The products

260J.Bao et al./Chemical Engineering Journal 90(2002)

253–266

Fig.3.Diagrams of (a)industrial and (b)Aspen plus ?owsheets of Plant A.

from R-1are fed into the catalytic-distillation column CD-1after the heat exchanger E-1.The methanol feedstock is split into two streams by the splitter V-1;one is mixed with the mixed C4in the static mixer V-2as described above,the other is fed into CD-1directly at the upper location of the column.The sulphonic ion-exchange resin catalysts packing in the loose-stack envelopes are installed in the reactive section of CD-1.The MTBE product is obtained as the bottom products of CD-1.The distillate containing the unreacted C4hydrocarbons and methanol are fed into the water stripper column D-1.The hydrocarbons are recovered from the top of D-1,and the methanol/water mixture from the bottom of D-1is fed into the methanol distillation col-umn D-2after another heat exchanger E-2.The methanol is recovered as the distillate of D-2(the recycling of methanol is not included in the ?owsheet).Water from the bottom of D-2is also fed back to D-1for recycling.Fresh water is added to D-2to compensate the loss in D-1and D-2.

J.Bao et al./Chemical Engineering Journal 90(2002)253–266261

The Aspen plus ?owsheet of Plant A is shown in Fig.3(b).The splitter V-1and static mixer V-2are represented by MIXER modules,the pre-reactor R-1by RSTOIC modu-lar,the heat exchangers E-1and E-2by HEATER modules,the catalytic-distillation column CD-1by USER modular USROPT,the water stripper D-1by SEP modular,and the methanol distillation column D-2by RADFRAC modular.The NRTL equation and Redlick–Kwong–Soave equation are applied for the whole ?owsheet except the water stripper D-1.In D-1,the UNIF-LL equation is applied because of the existence of the liquid–liquid equilibrium inside D-1.There are 14streams,8unit operation blocks,1tear stream and 1design-spec block included in the Aspen plus ?owsheet.The catalytic-distillation column CD-1is the key equip-ment of the Plant A.The recti?cation section is packed with structured packings,with 4m in height and 1m in diameter.The reactive section is packed with 10layers of the catalyst packages and 10layers of the valve trays,with 23m in height and 1.4m in diameter.The stripping section is packed with 30layers of the valve trays,with 14.5m in height and 1.4m in diameter.Before the catalytic-distillation technology was put into application,MTBE was commercially produced in the ?xed-bed reactor using the same catalysts [3].The sepa-ration of the MTBE products was carried out in a distillation column using the same kind of the valve trays and structured packings.The ef?ciency of the valve trays and the HETP height of the structured packings were determined in the

Table 3

Comparison between calculated and operating results in Plant A Operating conditions

Case 1Case 2Case 3Number of equilibrium stage

(excluding condenser and reboiler)323232Recti?cation section 777Reactive section 101010Stripping section

151515Mixed C4/methanol feedstock (kg/h)809098608170Methanol feedstock (kg/h)130150130Feedstock temperature (?C)66.768.677.2Isobutylene in feedstock (wt.%) 2.45 2.45 2.32Methanol in feedstock (wt.%)0.61 2.03 1.54Catalyst weight (kg)350035003500Re?ux ?owrate (kg/h)468059205021Re?ux temperature (?C)46.076.456.9Pressure at top (MPa)0.800.800.80Pressure at bottom (MPa)0.850.850.85Results

Case 1

Case 2

Case 3

Operating data

Calculated data Operating data Calculated data Operating data Calculated data Composition (wt.%)

Isobutylene in distillate 0.060.0480.070.0540.080.037MTBE in bottom 99.5499.6899.3699.6299.3399.45TBA in bottom 0.790.0480.410.0820.420.06Methanol in bottom 0.050.250.060.240.050.36C4in bottom

0.110.070.170.060.090.13Conversion yield of isobutylene (%)CD-1

98.1798.8698.0499.7097.6699.08Total process

99.85

99.90

99.83

99.88

99.83

99.92

rating experiments of the industrial distillation column.The ef?ciency or HETP data obtained were used to calculate the number of the equilibrium stages in the current industrial catalytic-distillation column.The data are shown in Table 3.Three operating cases with different ?owrates of the mixed C4and methanol were simulated as shown in Table 3.The conversion yields of isobutylene in R-1were 91.81,92.52and 92.76%in Cases 1–3,respectively.Table 3shows that the calculated compositions in both distillate and bottom streams of CD-1agree well with the operating data.The calculated isobutylene conversion in each case is also close to the operating data.The axial distributions of isobutylene,methanol,MTBE,and temperature pro?les are shown in Fig.4.The ?gure indicates that the calculated temperature pro?les are in good agreements with the oper-ating data.It can be concluded that the user modular can be used in the ?owsheet simulation of the catalytic-distillation process with the loose-stack-type catalyst package.

The kinetic study shows that the molar ratio of methanol to isobutylene should be no less than 0.8to prevent the dimerization of isobutylene.The molar ratios of methanol to isobutylene in the feedstock to CD-1are 1.58,2.54and 2.36for Cases 1–3,respectively.Fig.4(a)shows an axial distri-bution of low methanol concentration,particularly in the re-active section.This fact indicates that Case 1might be under the risk of isobutylene dimerization due to the de?ciency of methanol in the feedstock.On the other hand,Case 2gives

262J.Bao et al./Chemical Engineering Journal 90(2002)

253–266

Fig.4.Axial distributions of component concentrations and temperature along column height for Plant A ((a)Case 1;(b)Case 2;(c)Case 3):(?, ,?)calculated molar fractions of MTBE,isobutylene and methanol,respectively;(?,?)calculated and observed stage temperatures,respectively.

an opposite tendency of the axial methanol distribution as shown in Fig.4(b),in which the axial ratio of methanol to isobutylene is too high due to the higher methanol feed-stock.This leads to a high methanol concentration in the distillate,and consequently,the high methanol concentra-tion in the distillate increases the operating cost of the water stripper D-1and methanol distillation column D-2.Case 3gives a reasonable axial methanol distribution as shown in Fig.4(c),indicating that the optimal molar ratio of methanol to isobutylene in the feedstock might be around 2.36.

It is also found from Fig.4that the peak value of the isobutylene and methanol concentrations appears in the

stripping section.This might indicate that the present feed-stock location at stage 17is too low to take advantage of higher reactant concentrations as the driving forces of reaction.

4.2.Simulation of Plant B using bale-type package technology

Another industrial application is for Plant B using the bale-type package technology in the catalytic-distillation column with the MTBE production of 40,000t annually as shown in Fig.5(a).The catalytic-distillation column DA-301

J.Bao et al./Chemical Engineering Journal90(2002)253–266

263

Fig.5.Diagrams of(a)industrial and(b)Aspen plus?owsheets of Plant B.

is composed of two columns,the combination of the recti?-cation and reactive sections as the upper column,with36m in height and0.95m in diameter,and the stripping section as the down column.The upper column is56m in height and 2.2m in diameter.The down column is15m in height and 1.05m in diameter.The recti?cation section is packed with 10layers of the valve trays.The reactive section is packed with9layers of the catalyst packages.The stripping section is packed with25layers of the valve trays.The numbers of the equilibrium stages in each section of the column DA-301 were obtained in the industrial rating tests,carried out soon after Plant B was operated to its optimal conditions.The data obtained are shown in Table4.

Plant B is more complicated than Plant A because the methanol recycling is taken into account.The mixed C4 hydrocarbons containing about40wt.%isobutylene is mixed

264J.Bao et al./Chemical Engineering Journal90(2002)253–266

Table4

Comparison between calculated and operating results in Plant B

Operation conditions Value

Number of equilibrium stage(excluding condenser and reboiler)29

Recti?cation section7

Reactive section9

Stripping section13

Mixed C4/methanol feedstock to DA-301(kg/h)10596

Methanol feedstock to DA-301(kg/h)280

Feedstock temperature to DA-301(?C)60.0

Isobutylene concentration to DA-301(wt.%) 3.23

Methanol concentration to DA-301(wt.%) 2.29

Catalyst weight in DA-301(kg)1473

Re?ux?owrate in DA-301(kg/h)2759.4

Re?ux temperature in DA-301(?C)40.0

Pressure at top of DA-301(MPa)0.784

Pressure at bottom of DA-301(MPa)0.945

Results Distillate Bottom stream

Operating data Calculated data Operating data Calculated data Compositions(wt.%)

Propylene 1.14 1.130.000.00 Isobutene 1.03 1.030.000.00

1-Butane 3.11 3.090.020.00

1-Butylene57.1356.720.090.00 Isobutylene0.240.440.000.00 Trans-2-butylene20.3420.370.170.00

Cis-2-butylene12.3812.500.190.00 Methanol 4.61 4.710.020.80 Methyl tert-butyl ether0.000.0098.6498.66 Diisobutylene0.000.000.680.43

Tert-butyl alcohol0.000.000.190.10 Water0.000.000.000.01 Operating parameters Operating data Calculated data Distillate?owrate(kg/h)5494.005494.00

Bottom?owrate(kg/h)5428.435428.43

Distillate temperature(?C)63.0062.00

Bottom temperature(?C)144142.39 Isobutylene conversion(%)96.3092.96

Total isobutylene conversion(%)99.6299.30

with methanol in static mixer V-202B and then pumped into the protective reactor R-201to remove the harmful heavy metal ions.The stream enters the pre-reactor R-202conse-quently after a heat exchanger E-201in which about90% isobutylene is converted.The product stream from R-202is fed into the main catalytic-distillation column DA-301after another heat exchanger V-203.The methanol feedstock is split into two streams by the splitter V-202A;one is mixed with the mixed C4in the static mixer V-202B as described above,and the other is fed into DA-301directly.The cat-alyst particles packed into the bale-type envelopes are in-stalled in the middle section of DA-301.MTBE is obtained as the bottom products of DA-301.The unreacted C4hydro-carbons and methanol from the distillate of DA-301are fed into the water stripper column T-201.The hydrocarbons are recovered from the top stream of T-201.The methanol/water mixture from the bottom of T-201after a heat exchanger E-205is fed into the methanol distillation column T-202for the recovery of methanol.The unreacted methanol is recov-ered as the distillate and recycled back to V-202A as the methanol feedstock again.Part of the recovered methanol is removed to tank reservoir in the splitter V-205.Water is recovered as the bottom stream of T-202,and then fed back to T-201.Fresh water is added to T-202to compensate the loss in T-201and T-202.

The Aspen plus?owsheet for Plant B is shown in Fig.5(b).The splitter V-202A is represented by MIXER modular,the static mixer V-202B,the splitter V-205and water stripper T-201by SEP modules,the protective reac-tor R-201and main reactor R-202by RSTOIC modules, the heat exchangers E-201and E-205by HEATER mod-ules,the heat exchanger V-203by MIXER modular,the catalytic-distillation column DA-301by USER modular USROPT,and the methanol distillation column T-202by RADFRAC modular.Similar to the simulation of Plant A, the modi?ed NRTL equation and Redlick–Kwong–Soave

J.Bao et al./Chemical Engineering Journal90(2002)253–266

265

Fig.6.Axial distribution of component concentrations and temperature along column height for Plant B:(?, ,?)calculated molar fractions of MTBE, isobutylene and methanol,respectively;(?,?)calculated and observed stage temperatures,respectively.

equation of state are applied in the whole?owsheet except D-1in which the UNIF-LL equation is applied.There are 11unit operation blocks,19streams,2tear streams,1 design-spec block,2convergence blocks and1on-line For-tran block in the Aspen plus?owsheet as shown in Fig.5(b). Table4shows that the calculated component concen-trations in both distillate and bottom stream of DA-301 agree well with the operating data.The axial distributions of isobutylene,methanol,MTBE,and temperature pro?les are shown in Fig.6.The calculated temperature pro?les are in good agreement with the operating data.It indicates that the user modular can be used in the?owsheet simulation of catalytic-distillation process with the bale-type catalyst package.

The calculated conversion of isobutylene is3.34%lower than the observed one although the total conversion of isobutylene is very close.A possible explanation is given. In the real operation,a small portion of catalyst particles was gradually ground into powder in the strikes with the upward vapor streams and downward liquid streams in the long-term operation.The powders slowly moved out of the catalyst bales and settled down in the bottom reboiler. The accumulation of the catalyst powders in the reboiler caused MTBE to decompose,and let the MTBE concen-tration below the product standard98wt.%with higher methanol concentration in the product.Therefore,the cat-alyst powders had to be removed from the reboiler during the periodic maintenance of the equipment.However,the catalyst amount used in the calculation was measured af-ter2years’operation in the maintenance.Obviously,the real catalyst amount should be larger than the measured data,because the catalyst loss could not be included. This loss of catalyst might be responsible for the isobuty-lene conversion decrease.Different from Plant B,Plant A was a new equipment.The catalyst weight was measured before the operation started.The operating data were also obtained several days after the start-up of the plant.So there is no signi?cant difference in the conversion yield of isobutylene between the calculated and operating data for Plant A.

The molar ratio of methanol to isobutylene in the feed-stock to DA-301is2.67.This ratio is even much higher than that of Plant A in Case2.So it is not surprising to?nd that the axial methanol concentration shows an unreason-able distribution.A big peak of the methanol concentration is found near the bottom besides the one in the reactive section.To improve the present situation,the following measures should be taken:(1)to increase the feeding location of mixed C4stream;(2)to decrease methanol in the feedstock to the ratio of methanol to isobutylene of2.36.

5.Conclusion

(1)The industrial catalytic-distillation process for the

MTBE production was simulated by developing the catalytic-distillation model as a user modular on the Aspen plus platform,taking advantage of the strong database,?exible simulation functions and optimiza-tion tools of the Aspen plus system,while retaining the characteristics of the previous veri?ed model.

(2)The experimentally determined reaction kinetics was

applied in the model.NRTL and Redlick–Kwong–Soave equations were selected for the vapor–liquid equilib-rium calculation.The NRTL binary interaction param-eters were estimated from the experimental data of the two-component vapor–liquid equilibrium.

(3)The?owsheet simulations of the two industrial plants,

using the loose-stack-type package and the bale-type

266J.Bao et al./Chemical Engineering Journal90(2002)253–266

package technologies in the catalytic-distillation column,were simulated on the Aspen plus platform.

The results show that fair agreements between the calculated and operating data were obtained. References

[1]M.M.Sharma,Separation through reaction,J.Sep.Process Technol.

6(1985)9–16.

[2]M.F.Doherty,G.Buzad,Reactive distillation by design,Chem.Eng.

Res.Design,Trans.Inst.Chem.Eng.(Part A)70(1992)448–458.

[3]X.Hao,J.Wang,Z.Yang,J.Bao,Novel catafractionation technology

for the production of methyl tert-butyl ether,Chem.Eng.J.56(1995) 11–18.

[4]J.G.Stichlmair,T.Frey,Reactive distillation processes,Chem.Eng.

Technol.22(1999)95–103.

[5]R.Taylor,R.Krishna,Modeling reactive distillation,Chem.Eng.

Sci.55(2000)5183–5229.

[6]J.Bao,G.Yan,X.Wu,Mathematical simulation of the non-

homogeneous catalytic-distillation process for MTBE production, Chem.Eng.(China)22(5)(1994)6–12.

[7]S.Venkataraman,W.K.Chen,J.F.Boston,Reactive distillation using

Aspen plus,Chem.Eng.Prog.86(1990)45–54.

[8]AspenTech User Guide Reference for Aspen Plus System,V ols.1–6,

1994.

[9]Z.Yang,M.Liu,X.Luan,Macroscopic kinetics for MTBE synthesis

using macroporous ion-exchange resin catalyst,Qilu Petrochem.

Technol.(China)12(1)(1984)27–31.

[10]M.J.Lockett,Distillation Tray Fundamentals,Cambridge University

Press,Cambridge,UK,1986.

[11]J.G.Stichlmair,J.R.Fair,Distillation Principal and Practice,Wiley,

New York,1999.

[12]G.P.Towler,S.J.Frey,Reactive distillation,in:S.Kulprathipanja

(Ed.),Reactive Separation Process,Taylor&Francis,Philadelphia, 2000.

[13]K.H.Johnson,A.B.Dallas,Catalytic distillation structure,US Patent

5336373(1993).

[14]L.A.Smith Jr.,Catalytic distillation structure,US Patent4443599

(1984).

[15]L.A.Smith Jr.,Catalytic distillation process and catalyst,European

Patent008860B1(1985).

[16]C.S.Crossland,G.R.Gildert, D.Hearn,Catalytic distillation

structure,US Patent5431890(1995).

[17]Chinese Patent ZL901095265.5;ZL88109705.5.

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8.已知x,y满足约束条件,则z=2x+y的最大值为() A.2 B. C.4 D. 9.在△ABC中,内角A、B、C的对边分别是a、b、c,若c2=(a﹣b)2+6,△ABC的面积为,则C=() A.B.C.D. 10.设f′(x)为函数f(x)的导函数,已知x2f′(x)+xf(x)=lnx,f(1)=,则 下列结论正确的是() A.xf(x)在(0,+∞)单调递增B.xf(x)在(1,+∞)单调递减 C.xf(x)在(0,+∞)上有极大值 D.xf(x)在(0,+∞)上有极小值 二、填空题:本大题共5小题,每小题5分,共25分. 11.右面的程序框图输出的S的值为. 12.在区间[﹣2,4]上随机取一个点x,若x满足x2≤m的概率为,则m= .13.若点(a,9)在函数的图象上,则a= . 14.已知x>0,y>0且2x+y=2,则的最小值为.

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