Chemical Reaction EngineeringâBoston - American Chemical Society

21 Modeling Zeolite Catalyst Deactivation by Coking and Nitrogen Compound Poisoning Downloaded by KTH ROYAL INST OF TECHNOLOGY on October 29, 2015 | http://pubs.acs.org Publication Date: September 16, 1982 | doi: 10.1021/bk-1982-0196.ch021

CHEN-CHIH LIN and WILLIAM J. HATCHER, JR. University of Alabama, Department of Chemical and Metallurgical Engineering, University, AL 35486

The d e a c t i v a t i o n o f a lanthanum exchanged z e o l i t e Y c a t a l y s t f o r i s o p r o p y l benzene (cumene) c r a c k i n g was studied u s i n g a thermobalance. The k i n e t i c s o f the main r e a c t i o n and the coking r e a c t i o n were determined. The e f f e c t s of c a t a l y s t coke content and poisoning by n i t r o g e n compounds, q u i n o l i n e , p y r i d i n e , and a n i l i n e , were evaluated. The Froment-Bischoff approach to modeling c a t a l y s t d e a c t i v a t i o n was used.

C a t a l y s t d e a c t i v a t i o n by f o u l i n g has been i n v e s t i g a t e d f o r a number o f hydrocarbon r e a c t i o n s . In most instances of coke format i o n , h i g h l y unsaturated species of high molecular weight are s t r o n g l y adsorbed on the c a t a l y s t s u r f a c e . D e a c t i v a t i o n can occur by the blockage of access to the a c t i v e surface o r by the d e p o s i t s covering the a c t i v e s u r f a c e . G e n e r a l l y , polynuclear aromatics have been associated w i t h coke formation, and most o f the proposed mechanisms i n v o l v e aromatic condensation r e a c t i o n s . The s t a r t i n g p o i n t of the f o u l i n g of c r a c k i n g c a t a l y s t s by coke d e p o s i t i o n i s the study by Voorhies (1_). Voorhies reported that the coke formation on c r a c k i n g c a t a l y s t s could be r e l a t e d to the processing p e r i o d involved f o r a f i x e d bed o p e r a t i o n . Wojciechowski (2) used a "time-on-stream" aging f u n c t i o n which r e l a t e s c a t a l y s t a c t i v i t y s o l e l y to the length o f time the c a t a l y s t i s i n use. Froment and co-workers (3, 4^ 5) proposed s e v e r a l forms o f a d e a c t i v a t i o n f u n c t i o n r e l a t e d t o the coke content r a t h e r than time-on-stream. T h e i r approach accounts f o r d e a c t i v a t i o n e f f e c t s i n a separable r a t e equation. A c i d c a t a l y s t s such as z e o l i t e s can be r e a d i l y poisoned by b a s i c organic compounds. One o f the e a r l i e r s t u d i e s o f the deact i v a t i o n of s i l i c a - a l u m i n a c r a c k i n g c a t a l y s t s by organic n i t r o g e n compounds such as q u i n o l i n e , q u i n a l d i n e , p y r r o l e , p i p e r i d i n e , decylamine and a n i l i n e was done by M i l l s e t a l (6). The r e s u l t s of t h e i r p a r t i a l poisoning s t u d i e s showed an exponential dependence of the c a t a l y s t a c t i v i t y f o r cumene c r a c k i n g r e a c t i o n o r 0097-6156/82/0196-0249$06.00/0 © 1982 American Chemical Society In Chemical Reaction Engineering—Boston; Wei, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1982.

CHEMICAL REACTION ENGINEERING

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250

poison c o n c e n t r a t i o n o f the c a t a l y s t . A poisoning study by t i t r a t i o n o f q u i n o l i n e on z e o l i t e c a t a l y s t was i n v e s t i g a t e d by Golds t e i n and Morgan ( 7 ) . They concluded that the c o n c e n t r a t i o n o f q u i n o l i n e r e q u i r e d to completely poison a s i e v e was equal to the d e n s i t y o f supercages i n the s t r u c t u r e of z e o l i t e . The a c t i v e s i t e s o f z e o l i t e f o r the c r a c k i n g r e a c t i o n are a l s o a c t i v e f o r the chemisorption o f poisons such as organic n i t r o g e n compounds. The e f f e c t s o f poison compounds on the cracki n g r e a c t i o n need to be considered. T h i s study concerns the deact i v a t i o n e f f e c t s o f organic n i t r o g e n compounds on the cumene c r a c k i n g r e a c t i o n on z e o l i t e s . The a c t i v i t y o f z e o l i t e s used f o r c r a c k i n g d e c l i n e s r a p i d l y because of coke d e p o s i t i o n on the zeol i t e s u r f a c e ; t h e r e f o r e , the i n f l u e n c e o f coke must be a l s o taken i n t o c o n s i d e r a t i o n along w i t h the d e a c t i v a t i o n e f f e c t s o f n i t r o g e n compounds on the c r a c k i n g r e a c t i o n . Experimental The lanthanum exchanged Y z e o l i t e (LaY) was made by c o n t a c t i n g an ammonium Y (Linde type 31-200 powder) w i t h an aqueous s o l u t i o n of lanthanum c h l o r i d e . Approximately 60-70 percent o f the ammonium ions were exchanged i n the procedure. The r e s u l t i n g LaY powder was pressed i n t o t a b l e t s , crushed and sieved to -60+80 mesh. A F i s h e r thermogravimetric analyzer equipped with a 2 cm d i ameter quartz r e a c t o r was used f o r t h i s study. The r e a c t o r was surrounded by an e l e c t r i c t u b u l a r furnace, a c a t a l y s t sample was placed i n a platinum sample basket i n s i d e the quartz r e a c t o r . The c a t a l y s t was heated to 500°C a t a r a t e o f 10°C/min i n helium. The c a t a l y s t sample was then held a t 500°C f o r 4 hours. The temperature was adjusted to the d e s i r e d l e v e l . For the coking study cumene was continuously introduced to the r e a c t o r by passing helium through a f r i t t e d g l a s s d i s k i n t o a sparger c o n t a i n i n g cumene. For the study o f poisoning by n i t r o g e n compounds, p y r i dine was introduced i n the same way as cumene, q u i n o l i n e and a n i l i n e were introduced by i n j e c t i o n o f a c e r t a i n amount of these compounds i n t o a stream o f heated helium gas. A f t e r a d s o r p t i o n o f the n i t r o g e n compound, helium gas was used to purge the remaining n i t r o g e n compound from the system and to desorb p h y s i c a l l y adsorbed n i t r o g e n compound from the c a t a l y s t . T h i s purge was f o r 30 minu t e s . Then cumene was introduced to t e s t the c r a c k i n g a c t i v i t y o f p a r t i a l l y poisoned c a t a l y s t . Changes o f c a t a l y s t weight and r e a c t o r temperature were recorded continuously by a s t r i p chart r e c o r d e r . Product gases were analyzed by a gas chromatograph w i t h a t e n f e e t long column o f 10% SE-30 on -60+80 mesh Chromosorb W. Results and D i s c u s s i o n I t i s most accepted that the c r a c k i n g o f cumene over amorphous s i l i c a - a l u m i n a or z e o l i t e c a t a l y s t s takes p l a c e by a s u r f a c e r e a c t i o n c o n t r o l l i n g mechanism. C o r r i g a n et a l (8) and P r a t e r (9)

In Chemical Reaction Engineering—Boston; Wei, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1982.

21.

LIN AND HATCHER

251

Zeolite Catalyst Deactivation

have s u c c e s s f u l l y f i t t e d the r e s u l t s to the s i n g l e s i t e mechanism w i t h amorphous s i l i c a - a l u m i n a c a t a l y s t s . More r e c e n t l y , Hatcher et a l (10) found that the s i n g l e s i t e surface r e a c t i o n c o n t r o l l i n g mechanism was c o n s i s t e n t w i t h cumene c r a c k i n g over z e o l i t e c a t a l y s t i n both d i f f e r e n t i a l and i n t e g r a l r e a c t o r s t u d i e s . The r a t e expression f o r t h i s mechanism i s : k

K

L


r - l A c 1 4

( P

A - Vs

P

+

*A A

K

/ K )

(1)

P

R R

At c o n d i t i o n s o f t h i s study P

Ά *

P

R S

/ K

(

2

)

and ( K

' »

P

A A

+

K

P

Thus the r a t e expression r

P

- W c

(

R R>

3

)

can be s i m p l i f i e d and becomes (

A

4

)

The i n f l u e n c e o f the coke on the k i n e t i c s o f the main r e a c t i o n can be accounted e m p i r i c a l l y by m u l t i p l y i n g the k i n e t i c c o e f f i c i e n t of eq. (4) by a d e a c t i v a t i o n f u n c t i o n φ , r e l a t e d t o the coke content o f the c a t a l y s t , C^: r

m

k

K

L

l A c

(5)

Φ J P

Dumez and Froment (5) proposed s e v e r a l p o s s i b l e forms o f the t i o n s h i p between φ and C^.

rela

The coke might be formed by a p a r a l l e l step, a consecutive step o r combined steps from reactant and products. These can be shown as f o l l o w s : Parallel reaction:

A^«P=^ R + S coke

Consecutive r e a c t i o n :

A

^r-

5

R + S

\ coke Combined r e a c t i o n :

A

^5

R + S

\ / coke For a p a r a l l e l coking mechanism, the conversion coke i s given by

of A into



252

r

. = i ~ = k cl dt

-K L φ cl A c A

P

Y

(6)

A

A

where k - i s the i n i t i a l r a t e constant of coke r e a c t i o n f o r the cl p a r a l l e l step.


be

The r a t e of formation of coke f o r a consecutive written

r

c2

• Î T

where k ^

P

W c *

represents

mechanism can

( 7 )

R

the i n i t i a l r a t e constant of coke r e a c t i o n

for the consecutive step. For the combined step, the r a t e of coke r e a c t i o n can be shown as f o l l o w s : r

c3

( k

»

where k ^

K

L

P

represents

( 8 )

W . V *

+

c3 A c A

the i n i t i a l r a t e constant of coke formation

from the reactant and k ^

from the products.

For each run i n a d i f f e r e n t i a l r e a c t o r the plug flow p e r f o r mance equation was used to o b t a i n the r e a c t i o n r a t e of cumene c r a c k i n g as f o l l o w s : Γ

F

X

( 9 )

- Ao A w

where

i n moles/sec i s the gas

weight i n grams and

flow of cumene, W i s the

catalyst

i s the f r a c t i o n cumene converted i n the

r e a c t o r . The r e a c t i o n r a t e data were f i t t e d to the k i n e t i c s models with l i n e a r or n o n - l i n e a r l e a s t squares e s t i m a t i o n s . The exponential form of the d e a c t i v a t i o n f u n c t i o n , φ

= exp

v

(

- oiC ) c

(10)

gave the best f i t of the data f o r both the main r e a c t i o n and the coking r e a c t i o n . The parameter Ot was found to be the same f o r both r e a c t i o n s . The exponential form of the d e a c t i v a t i o n f u n c t i o n has been r e l a t e d to a pore b l o c k i n g mechanism (11). The r e s u l t i n g r a t e equation f o r the main r e a c t i o n i s : τ_ P

. k K L x

A

c

exp

(- 0C C )

(11)

c

A

k K L L

A

c

- 2.82

OC = 20.8

exp

(

- 6.36

3

χ 10 /RT)

(12) (13)


21.

LIN AND HATCHER


253

The n o n - l i n e a r l e a s t square r e l a t i o n s h i p s o f equation (11) a r e shown i n F i g u r e 1. Equations f o r the k i n e t i c mechanisms o f coke formation w i t h the exponential form o f the d e a c t i v a t i o n f u n c t i o n are obtained by i n t e g r a t i n g eqs. ( 6 ) - ( 8 ) : For the p a r a l l e l mechanism,


C

c

- i l n

( l «k +

c l

K L P t) A

c

(14)

A

For the consecutive mechanism, (15) For the combined mechanism,

C

c

- I i n [1 + 0 C ( k K L P c 3

A

c

+ k

A

c 4 K R

L P )t] c

R

(16)

The r e s u l t s showed that the p a r a l l e l mechanism had a b e t t e r c o r r e l a t i o n c o e f f i c i e n t than the consecutive mechanism. The coke compound would be more l i k e l y formed from the cumene by p a r a l l e l mechanism a t low conversions o f cumene c r a c k i n g because the p a r t i a l pressure o f cumene would be much greater than that o f the products. The values o f the c o r r e l a t i o n c o e f f i c i e n t f o r a combined mechanism o f coke formation were l a r g e r than those f o r a p a r a l l e l or a consecutive mechanism of coke formation. However, the v a l u e s of k ^ K ^ L have a negative s i g n . Studies (12) a t higher tempera t u r e s than i n the present study r e s u l t e d i n the combined mechanism g i v i n g the best f i t with a l l c o e f f i c i e n t s being p o s i t i v e . I n the 200-300°C temperature range o f the present i n v e s t i g a t i o n , the p a r a l l e l mechanism gave the best r e p r e s e n t a t i o n o f the data. C o r r e l a t i o n p l o t s o f the p a r a l l e l mechanism and the combined mechanism are shown i n F i g u r e 2. The p a r a l l e l mechanism can be considered as a reasonable d e a c t i v a t i o n mechanism. T h i s ^ ^ ^ parameter can be expressed as c

c

K

C

k

K

L

cl A c

=

2

1

2

,

1e

x

p

1

ί" ·

0 3 4

x

4

10 /RT)

L

C

(17)

The cumene c r a c k i n g a c t i v i t i e s over z e o l i t e s w i t h d i f f e r e n t amounts o f p y r i d i n e , q u i n o l i n e and a n i l i n e a d s o r p t i o n were s t u d i e d . The r e a c t i o n r a t e data o f cumene c r a c k i n g were t r e a t e d by l i n e a r i z a t i o n o f eq. (11) as f o l l o w s : In | - « l n P A A

k.K.L. - * i C 1A c c

The l i n e a r r e l a t i o n s h i p o f In r / P

(18)

w i t h C h e l d a t low coking A c l e v e l s . The c o r r e l a t i o n c o e f f i c i e n t s f o r eq. (18) are above 0.95, and these values i n d i c a t e an adequate f i t o f the data. A


254



Γ

CO Ο

Figure 1.

r/P

A

vs. C for cumene cracking at reaction temperature. Key: 300°C; Δ, 250°C; and • , 200°C. e

80

100 t ,min

Figure 2.

C vs. t for coking reaction. Key: , parallel mechanism; combined mechanism; 0 , 3 0 0 ° C ; A, 250°C; and • , 200°C. e


180

O,

21.

L I N AND HATCHER

255


The p l o t o f et versus poison compounds l o a d i n g i s shown i n Figure 3. I t shows that oC i s l i n e a r l y dependent on the p y r i d i n e l o a d i n g and independent o f the c r a c k i n g temperature. The param e t e r , oc , can be expressed f o r p y r i d i n e p o i s o n i n g as f o l l o w s : 5


OC

= 20.8 + 3.39 χ 1 0 Cps

(19)

where Cps i n e q u i v a l e n t s / g i s the c o n c e n t r a t i o n o f p y r i d i n e adsorbed on the c a t a l y s t . For the n i t r o g e n compound s t u d i e d , the b a s i c i t y can be l i s t e d i n the f o l l o w i n g order: P y r i d i n e > q u i n o l i n e > a n i l i n e . The oc values f o r a given dosage o f poison followed the same trend as the order o f b a s i c i t y , so the degree of p o l y m e r i z a t i o n o f coke decreas ed with the i n c r e a s e o f b a s i c i t y o f n i t r o g e n compounds. The ot values increase more r a p i d l y a t higher loadings than a t low l o a d ings o f q u i n o l i n e and a n i l i n e . The r a t e c o e f f i c i e n t o f c r a c k i n g r e a c t i o n , k ^ K ^ L ^ was found to be p r o p o r t i o n a l t o the number o f a v a i l a b l e a c t i v e s i t e s . can be expressed as f o l l o w s : k K L x

A

c

= (k K L ) 1

where (k^K^L^o

A

c

(1 - o-Cps)

c

It

(20)

i s the r a t e constant o f c r a c k i n g r e a c t i o n i n

absence o f poison compound, β" i s a s o r p t i o n d i s t r i b u t i o n c o e f f i c i e n t . P l o t s o f k^K L^ versus the l o a d i n g o f poison a r e shown i n A

F i g u r e 4. The l i n e a r r e l a t i o n s h i p o f p o i s o n i n g might be due t o uniform poisoning, i . e . , s i t e s o f equal a c t i v i t y were d e a c t i v a t e d at zero coke content. Figure 4 shows that p y r i d i n e and q u i n o l i n e are more poisonous than a n i l i n e . I t shows that the higher b a s i c i t y compounds have greater e f f e c t i v e n e s s as poisons. Quinoline which has a higher molecular weight and lower b a s i c i t y than p y r i dine showed a s l i g h t l y lower e f f e c t i v e n e s s than p y r i d i n e . On the b a s i s o f the p o i s o n i n g s t u d i e s , the number of a c t i v e s i t e s o f the c a t a l y s t were 1.63 χ 1 0 ^ r gram obtained from p y r i d i n e poisoning and cumene c r a c k i n g r e a c t i o n a t 300°C. T h i s number i s c l o s e to the number reported by Jacobs and Heylen (13) i n the study o f poisoning with 2,6-methylpyridine o f cumene crack i n g a c t i v i t y o f the HY z e o l i t e s . p

e

Comparison With Other Models I f equation

φ =

(14) i s s u b s t i t u t e d i n t o equation

-

l

(10), then (21)

1 + «ck ,K L P t cl A c A A

A

T h i s form o f the d e a c t i v a t i o n f u n c t i o n i s very s i m i l a r t o forms used i n the time-on-stream approach t o c r a c k i n g c a t a l y s t a c t i v i t y



256


Figure 3. Poison compound loading vs. a. Key: O, 300°C; Δ, 250°C; and • , 200°C in pyridine; V , 300°C in quinoline; and 0,300°C in aniline.

P o i s o n , Eq/g χ 10* Figure 4. Poison compound loading vs. ktK L . Key: O, 300°C; Δ, 250°C; and • , 200°C in pyridine; - V - , 300°C in quinoline; and 0, 300°C in aniline. A

c


21.

257


LIN AND HATCHER

decay. F o r example, i n bench s c a l e s t u d i e s o f c r a c k i n g commercial feedstocks, Jacob e t a l (14) reported that the f o l l o w i n g e m p i r i c a l d e a c t i v a t i o n f u n c t i o n represented t h e i r data.

ψ =

a


P

m

(22) C

(1 + b t )

In equation (22) ρ i s the i n l e t p a r t i a l pressure o f o i l and a,b,c, and m are constants that depend on the feedstock. The e f f e c t o f n i t r o g e n compound p o i s o n i n g found i n the p r e s ent study i s two-fold as shown by equations (19) and (20). These e f f e c t s are p o s s i b l y due to the c o n t r i b u t i o n to pore blockage and to chemisorption on a c t i v e s i t e s r e s p e c t i v e l y . P u t t i n g the two n i t r o g e n p o i s o n i n g e f f e c t s together r e s u l t s i n the f o l l o w i n g expression. φ

1

-

Ν

(1 + oi k

- q~cps c l

K L P A

c

A

t) Ρ

C

p

s

/

*

(23)

N i t r o g e n d e a c t i v a t i o n e f f e c t s o f commercial feedstocks as reported by Jacob e t a l (14) was represented by an equation o f the f o l lowing form.

Φ

Ν

-

I 1 + K

1

(2*> Cps t

By u s i n g the parameter v a l u e s obtained i n the present study and assuming values o f i n equation (24), d e a c t i v a t i o n e f f e c t s o f n i t r o g e n as p r e d i c t e d by equations (23) and (24) can be q u i t e s i m i l a r . A b a s i c d i f f e r e n c e i n the method o f n i t r o g e n p o i s o n i n g i n the two s t u d i e s i s that i n the present study the c a t a l y s t was poisoned with the n i t r o g e n compound and then the c r a c k i n g a c t i v i t y was determined w h i l e i n the study by Jacobs e t a l (14), n i t r o g e n p o i s o n i n g and c r a c k i n g occurred simultaneously. Conclusions The e f f e c t s o f coking and n i t r o g e n compound p o i s o n i n g on a z e o l i t e c a t a l y s t a c t i v i t y can be modeled w i t h a separable r a t e expression. The e f f e c t o f coking on c a t a l y s t a c t i v i t y was accounted f o r by a d e a c t i v a t i o n f u n c t i o n i n an e x p o n e n t i a l form. The c r a c k i n g r e a c t i o n and the coking r e a c t i o n were s i m i l a r l y dependent on the c a t a l y s t coke content. The mechanism o f d e a c t i v a t i o n by n i t r o g e n compound p o i s o n i n g appeared t o be uniform p o i s o n i n g i n the absence o f coke e f f e c t . The value o f the deac t i v a t i o n c o e f f i c i e n t increased w i t h i n c r e a s i n g poison l o a d i n g on the z e o l i t e .


258

CHEMICAL REACTION

ENGINEERING

Legend of Symbols a,b,c Cc Cps


*Ao Κ Kl K k i A

c

k 2 c

k 3 c

k 4 c

KR kl L m ρ PA PR Pg R r r c

c

r r i c

c

r 2 c

r 3 c

t Τ W oc Q v

$

^

m

decay constants i n equation (22) coke content on the c a t a l y s t , g/g poison c o n c e n t r a t i o n i n the gas phase i n s i d e the c a t a l y s t , mole/g ° l - r a t e of cumene vapor i n the feed, mole/s e

e q u i l i b r i u m constant f o r cumene c r a c k i n g , atm constant i n equation (24) a d s o r p t i o n c o e f f i c i e n t f o r cumene, atm~l i n i t i a l r a t e constant o f coke formation f o r p a r a l l e l step, 8-1 i n i t i a l r a t e constant o f coke formation f o r consecutive step, s""* i n i t i a l r a t e constant o f coke formation f o r combined step for reactant, s " l i n i t i a l r a t e constant of coke formation f o r combined step from product, s ~ l a d s o r p t i o n c o e f f i c i e n t f o r propylene, atm~l s u r f a c e r e a c t i o n r a t e constant, s*"l c o n c e n t r a t i o n o f t o t a l a c t i v e s i t e s , mole/g constant i n equation (22) i n l e t p a r t i a l pressure of o i l , atm p a r t i a l pressure o f cumene, atm p a r t i a l pressure o f propylene, atm p a r t i a l pressure o f benzene, atm gas law constant r a t e o f cumene c r a c k i n g , mole/g - s r a t e o f coke formation, g/g - s i n i t i a l r a t e o f coke formation, g/g - s r a t e of conversion of r e a c t a n t i n t o coke, p a r a l l e l model, g/g - s r a t e o f conversion o f product i n t o coke, consecutive model, g/g - s r a t e of conversion o f reactant and product i n t o coke, com bined model, g/g - s time, s r e a c t i o n temperature, Κ i n i t i a l weight o f c a t a l y s t , g f r a c t i o n a l conversion o f cumene c o e f f i c i e n t of d e a c t i v a t i o n f u n c t i o n , g/g constant i n equation (23) s o r p t i o n d i s t r i b u t i o n c o e f f i c i e n t of the poison compound, g/mole d e a c t i v a t i o n f u n c t i o n by coking d e a c t i v a t i o n by n i t r o g e n p o i s o n i n g


21.

L I N AND HATCHER


259

Literature Cited 1. 2. 3. 4.


5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

V o o r h i e s , A. Ind. & Eng. Chem., 1945, 37, 318 Wojciechowski, Β. W. Can. J. Chem. Eng., 1968, 46, 48 Froment, G. F. and B i s c h o f f , Κ. Β. Chem. Eng.Sci.,1961, 16, 189 DePauw, R. P. and Froment, G. F. Chem. Eng. Sci., 1975, 30, 789 Dumez, F. J. and Froment, G. F. Ind. Eng. Chem. Process Design Develop., 1976, 15, 291 M i l l s , G. Α.; Boedeker, E. R. and Oblad, A. G. J . Amer. Chem. Soc., 1950, 72, 1554 G o l d s t e i n , M.S. and Morgan, T. R. J . C a t a l . , 1970, 16, 232 C o r r i g a n , T. E.; Graver, J. C.; Rase, H. F. and K i r k , R. S. Chem. Eng. Progress, 1953, 49, 603 P r a t e r , C. D. and Lago, R. M. Advances i n C a t a l y s i s , 1956, 8, 293 Hatcher, W. J . ; Park, S. W. and Lin, C. C., April 1979, 86th N a t i o n a l Meeting o f AIChE, Houston, Paper 72a Beeckman, J. W. and Froment, G. F. Ind. Eng. Chem. Fund., 1979, 18, 245 L i n , C. C.; Park, S. W. and Hatcher, W. J . , June 1982, N a t i o n a l Meeting o f AIChE, Anaheim, C a l i f o r n i a Jacobs, P. A. and Heylen, C. F. J . C a t a l . , 1974, 34, 267 Jacob, S. M.; Gross, B,; V o l t z , S. E. and Weekman, V. W. AIChE J . , 1976, 22, 701

RECEIVED April 27, 1982.


Chemical Reaction EngineeringâBoston - American Chemical Society

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