Adsorption Studies at Reaction ConditionsâReactor Development

5

Chemical Reaction Engineering—Houston Downloaded from pubs.acs.org by UNIV OF MASSACHUSETTS AMHERST on 09/25/18. For personal use only.

Adsorption Studies at Reaction Conditions—Reactor Development and Evaluation for Transient Studies at Millisecond Rates R I C H A R D D. S T O L K *

and A L D R I C H

SYVERSON

Department of Chemical Engineering, Ohio State University, Columbus, OH

43210 The role of adsorption in heterogeneous catalysis is not easily evaluated because of the simultaneous occurrence of adsorption and reaction and the difficulty of measuring surface concentrations of reacting species on the catalyst at these conditions. Exploratory research directed toward devising a method for studying adsorption in gas-solid systems by means of a batch adsorber-reactor has been underway in this laboratory for several years. This technique provides an opportunity to examine the "adsorption" and "reaction" steps sequentially at reaction temperatures and pressures. How sharply the individual steps can be separated depends largely upon the magnitude of the differences in rates and upon the data resolution capability of the experimental apparatus. Interpretation of the transient rapid response measurements in terms of steady state operation is needed if these results are to be most useful. Recent studies in this laboratory indicate that this approach holds some promise and it is the purpose of this paper to describe the adsorber-reactor system and its performance capabilities. The most recent design provides rapid gas-solid contact in a constant volume cell with transient rates for temperature and pressure measurements in the millisecond region. Few adsorber-re actors have been devised to measure adsorption at reaction conditions. Winfield (1) described a high speed apparatus for adsorption studies at low pressure. Macarus (2) reported results on a high speed adsorption-reaction apparatus; his data were correlated with fixed bed catalyst studies of Sashihara (3) with encouraging results. The second generation high speed adsorption apparatus was built by Edwards (4) and Keller (5) and improved by Haering (6) in the early 1960's. They overcame many of the previous limitations by first treating and sealing the catalyst sample in a glass capsule which was then placed in the adsorber-reactor containing gaseous reactants at the desired temperature and *Present Address: Monsanto Enviro-Chem Systems, Inc. 800 N. Lindbergh Blvd., St. Louis, Missouri 63166 ©

0-8412-0401-2/78/47-065-050$05.00/0

5.

STOLK A N D SYVERSON

Adsorption Studies at Reaction Conditions

51

p r e s s u r e . The r e a c t i o n w a s i n i t i a t e d by c r u s h i n g the c a p s u l e b y remote c o n t r o l u s i n g a feedthrough d e v i c e . T h i s procedure a l l o w e d a pretreatment o f the c a t a l y s t w i t h r e a c t a n t s or products before s e a l i n g the c a p s u l e . For a binary s y s t e m either of the g a s e o u s r e a c t a n t s may be a d s o r b e d by the c a t a l y s t prior to the r e a c t i o n . Pretreating the c a t a l y s t p r o v i d e s some i n s i g h t i n t o the e f f e c t s of m u l t i - c o m p o n e n t a d s o r p t i o n at r e a c t i o n c o n d i t i o n s . The reactor d e s c r i b e d h e r e i n may be c o n s i d e r e d third g e n e r a t i o n . D a t a c o l l e c t i o n w a s f i r s t a c c o m p l i s h e d by r e c o r d i n g the a n a l o g s i g n a l s o n a tape r e c o r d e r . Later a m o d i f i e d P D P - 1 5 d u a l p r o c e s s o r d i g i t a l computer w a s d i r e c t l y c o u p l e d to the reactor i t s e l f . The equipment w a s c o m p l e t e d i n 1971 (7). S i n c e that time others i n c l u d i n g Becher (8), W o l f e (9), and N a s h (10) have u s e d the system for h i g h speed t r a n s i e n t a d s o r p t i o n / r e a c t i o n s t u d i e s .

Reactor D e s i g n Features The primary d e s i g n c o n s i d e r a t i o n w a s the arrangement of r e actor components to i n s u r e r a p i d g a s - s o l i d c o n t a c t . T h e m e a s u r ing d e v i c e s had to be c a p a b l e of operating at high temperature and have m i l l i s e c o n d time c o n s t a n t s . The parameters of i n t e r n a l and c a t a l y s t volume and their ratio are k e y elements i n a constant volume s y s t e m . The i n t e r n a l reactor volume must be m i n i m i z e d . C a t a l y s t volume w a s c h o s e n to c a u s e a d e t e c t a b l e p r e s s u r e change i n the s y s t e m d u r i n g the e x p e r i m e n t . After e v a l u a t i n g s e v e r a l d e s i g n c o n c e p t s to a c h i e v e r a p i d g a s - s o l i d c o n t a c t f o l l o w e d by e f f e c t i v e m i x i n g , a c o m b i n a t i o n " f l y w h e e l / f a n " w a s d e s i g n e d to c r u s h the g l a s s c a p s u l e and to provide gas c i r c u l a t i o n . A n i n c l i n e d grid and s c r e e n were added to separate the c a t a l y s t p a r t i c l e s from the c a p s u l e before c o n t a c t with the f l y w h e e l to reduce a t t r i t i o n . C l e a r p l a s t i c prototypes were b u i l t for e v a l u a t i o n at ambient c o n d i t i o n s . H i g h s p e e d (4000 fps) motion p i c t u r e s permitted o b s e r v a t i o n of a c a p s u l e b e i n g broken i n s i d e the r e a c t o r . E x a m i n a t i o n of the p i c t u r e s showed that g a s - s o l i d m i x i n g was e f f e c t i v e i n the m i l l i s e c o n d range and that v e r y l i t t l e d i s i n t e g r a t i o n of the c a t a l y s t o c c u r r e d . The reactor components and the a s s e m b l e d reactor are shown i n Figure 1 . Components of the reactor i n c l u d e : (1) c a p s u l e h o l d e r , (2) f l y w h e e l , (3) rotary f e e d t h r o u g h , (4) grid and s c r e e n , (5) p r e s s u r e t r a n s d u c e r , and (6) t h e r m o c o u p l e . The i n t e r n a l volume was 415 c c and h e l d a 24 c c c a p s u l e . The reactor w a s made of 304 s t a i n l e s s s t e e l and w e i g h e d about 35 p o u n d s . S p e c i f i c a t i o n s are p r e s e n t e d i n T a b l e 1 d e s c r i b i n g the upper l i m i t s of temperature and pressure for the major c o m p o n e n t s .

52

CHEMICAL REACTION ENGINEERING—HOUSTON

Figure 1. Adsorber-reactor

5.

A.

B.



53

T a b l e 1 . S p e c i f i c a t i o n s for the A d s o r b e r - R e a c t o r (1) Rotary Feedthrough 450 C 6Ô"psia (2) Pressure T r a n s d u c e r 485°C 68 p s i a (3) Thermocouple 485 C (4) M a n u a l Feedthrough B e l l o w s 30 p s i a Response Time to a Step C h a n g e (Time Constant) (1) Pressure T r a n s d u c e r 2-3 m i l l i s e c o n d s (2) Thermocouple 2-10 m i l l i s e c o n d s U

The capsule h o l d e r c o n t a i n e d the a c t i v a t e d catalyst i n a s e a l e d g l a s s c a p s u l e at the start of the t e s t . The r e a c t i o n w a s i n i t i a t e d b y m a n u a l l y rotating the holder 180 d e g r e e s r e l e a s i n g the c a p s u l e into the f l y w h e e l . H i g h Speed Pressure T r a n s d u c e r . The c h a r a c t e r i s t i c s of the D a t a m e t r i c s T y p e 531 B a r o c e l p r e s s u r e transducer are shown i n T a b l e g[. It c a n be operated a s a d i f f e r e n t i a l or a b s o l u t e type up to 450 C without c o o l i n g .

A. B. C. D. E.

T a b l e II. C h a r a c t e r i s t i c s of P r e s s u r e Transducer S e n s i n g Element: c a p a c i t i v e potentiometer R i s e T i m e : 2-3 m i l l i s e c o n d s H y s t e r e s i s : L e s s than 0.2% Temperature C o e f f i c i e n t of S e n s i t i v i t y : 0.01% C A c c u r a c y at 7 5 ° C : 0.2% of Reading p l u s 0 . 0 1 % F . S .

H i g h Speed T h e r m o c o u p l e , M i c r o - m i n i a t u r e c h r o m e l - a l u m e l t h e r m o c o u p l e s h a v i n g 0 . 0 0 2 - 0 . 0 1 0 s e c o n d time c o n s t a n t s were p u r c h a s e d from B L H E l e c t r o n i c s / I n c . The thermocouple w i r e i s 0 . 0 0 1 i n c h i n d i a m e t e r . A n a m p l i f i e r w i t h a g a i n up to 1000 w a s u s e d to produce a 10 v o l t s i g n a l . D a t a C o l l e c t i o n and Reduction In the b e g i n n i n g a tape recorder w a s u s e d to record the h i g h s p e e d t r a n s d u c e r d a t a . H o w e v e r , b e c a u s e of h i g h n o i s e l e v e l i n the s y s t e m , the data c o l l e c t i o n w a s i n t e r f a c e d w i t h a m o d i f i e d P D P - 1 5 d u a l p r o c e s s o r d i g i t a l computer. C o m p a r i n g the s i g n a l - t o n o i s e r a t i o for both s c h e m e s , the former h a d a 14:1 ratio w h i l e the latter h a d a 250:1 r a t i o . The p r e c i s i o n h a s been improved from about 10 torr for the tape recorder scheme to 0 . 3 torr for the c o m puter scheme without time a v e r a g i n g the d a t a . The e l e c t r i c a l s i g n a l s from the m e a s u r i n g d e v i c e s were t r a n s mitted v i a s h i e l d e d c a b l e d i r e c t l y into the computer. Internal to

54


the computer, the a n a l o g data were d i g i t i z e d to binary d e c i m a l and f i n a l l y recorded on D E C t a p e . The quantity of gas adsorbed w a s determined from the p r e s s u r e and temperature changes i n the constant volume c e l l . A f a s t r e s p o n s e pressure transducer and thermocouple monitored c o n t i n u o u s l y at a m i l l i s e c o n d f r e q u e n c y p r o v i d e d the b a s i c t r a n s i e n t d a t a . M e a s u r e m e n t of gas c o m p o s i t i o n i n s u c h a r a p i d l y changing s y s t e m i s d i f f i c u l t b e c a u s e of the n e e d to sample at high rates for a n a l y s i s . H o w e v e r , both i n i t i a l and f i n a l c o m p o s i t i o n s may be s a m p l e d when the s y s t e m i s at e q u i l i b r i u m . A p r o v i s i o n w a s made to i n s t a l l a p a i r of f i l a m e n t s for c o n t i n u o u s measurement of the gas thermal c o n d u c t i v i t y but they were not u s e d i n this s t u d y . Computer Program D e s c r i p t i o n . Computer programs were w r i t ten i n both Fortran IV and M a c r o - 1 5 a s s e m b l e r l a n g u a g e . The p r o gram u s e d to c o l l e c t and store the data was written i n M a c r o - 1 5 language to a l l o w a 1000 c y c l e per s e c o n d s a m p l i n g r a t e . The program c a n sample three data c h a n n e l s , perform time a v e r a g e s , and make other c a l c u l a t i o n s a l l w i t h i n one m i l l i s e c o n d . It "waits" u n t i l the next m i l l i s e c o n d before r e p e a t i n g the c a l c u l a t i o n s and storage of d a t a . F i v e data sets were c o l l e c t e d during the e x p e r i m e n t . Two were at steady state prior to b r e a k i n g the c a p s u l e to evaluate the reactor c o n d i t i o n s . Thirty s e c o n d s of steady state data were c o l l e c t e d at a one s e c o n d f r e q u e n c y . One hundred data p o i n t s w i t h a one m i l l i s e c o n d s e p a r a t i o n were recorded to evaluate the n o i s e l e v e l o n the n o n - t i m e averaged d a t a . The three r e m a i n i n g data sets were a v e r a g e s b a s e d on 16 m i l l i s e c o n d v a l u e s . After the f i r s t s e c o n d of time had b e e n r e c o r d e d with m i l l i s e c o n d data p o i n t s , the s a m p l i n g rate was r e d u c e d to ten p o i n t s per s e c o n d for a ten s e c o n d p e r i o d . It w a s further r e d u c e d to one point per s e c o n d for the r e m a i n i n g p e r i o d . A t o t a l of 6390 data p o i n t s were c o l l e c t e d during the experiment l a s t i n g 15 m i n u t e s . Other computer programs were u s e d to reduce the data to p r e s sure and temperature v a l u e s . The data i n the two steady state data sets were reordered w i t h r e s p e c t to time s i n c e e a c h w a s c o l l e c t e d i n a l o o p w h i c h w a s c o n t i n u o u s l y b e i n g rewritten before the c a p s u l e b r o k e . A time b a s e w a s added to the data before b e i n g transferred to t a p e . Experimental Results In order to i l l u s t r a t e the c a p a b i l i t y of t h i s d e v i c e and p o s s i b l e areas of a p p l i c a t i o n to r e s e a r c h i n c a t a l y s i s , examples of

5.


Adsorption Studies at Reaction Conditions 55

r e s u l t s are reported i n the f o l l o w i n g c a t e g o r i e s : (a) d y n a m i c r e s p o n s e of the s y s t e m to a step p r e s s u r e c h a n g e , (b) a d s o r p t i o n rate s t u d i e s of water o n an a l u m i n a c a t a l y s t , and (c) t y p i c a l a d s o r p t i o n - r e a c t i o n r e s u l t s for c a t a l y t i c dehydration of tertiary butanol on alumina. Pressure R e s p o n s e C h a r a c t e r i s t i c s . A m e c h a n i c a l d e v i c e w a s not u s e d to i n i t i a t e the data c o l l e c t i o n b e c a u s e a f i n i t e time e l a p s e d after the c a p s u l e w a s r e l e a s e d from the holder u n t i l i t c o n t a c t e d the f l y w h e e l ; i n s t e a d a v o l t a g e change o n the t r a n s ducer s i g n a l e q u i v a l e n t to 15 torr w i t h i n 10 m i l l i s e c o n d s w a s found to be the b e s t w a y to start data c o l l e c t i o n . The s y s t e m r e s p o n s e to a step change c a u s e d by b r e a k i n g an empty c a p s u l e under v a c u u m surrounded by air i s shown i n Figure 2 . Time c o n stants were c a l c u l a t e d for 63.2% r e s p o n s e to the pressure change. T h e v a l u e s of 0 . 9 and 0 . 8 m i l l i s e c o n d s were r e c o r d e d at 13 and 196 C r e s p e c t i v e l y . The r e s p o n s e time of the pressure t r a n s d u c e r w a s adequate for t h i s m e c h a n i c a l s y s t e m and for the water and t - b u t a n o l s t u d i e s o n a l u m i n a . (Prior work showed that a 100 torr p r e s s u r e change o c c u r r e d i n 20-30 m i l l i s e c o n d s after the alumina w a s e x p o s e d to the a d s o r b a t e ) . 0

Transient Adsorption Studies: Water on Alumina. One e i g h t h i n c h a l u m i n a p e l l e t s (Type 100S) s u p p l i e d b y A i r Products C o r p . , Houdry D i v i s i o n were c r u s h e d i n t o s m a l l e r p a r t i c l e s and separated i n t o v a r i o u s f r a c t i o n s from - 1 0 to +200 m e s h . The alumina w a s a c t i v a t e d at 300 C at l e s s than 100 microns pressure for three h o u r s . A l l c a l c u l a t i o n s were b a s e d o n sample weight after activation. A s e r i e s of samples w a s t e s t e d u s i n g the s i z e f r a c t i o n s p r e sented i n Table III. Ad s o r p t i o n - t i m e c u r v e s of t h e s e samples are shown i n Figure 3 .

- M e s h Size 12/20 C a t . W e i g h t (g) 5 . 7 7 5 Initial Conditions Pressure (torr) 787 Temperature ( C)193

20/35 7.421

770 111

20/35 7.936

35/65 7.476

65/100 6.382

784 203

782 196

783 195

F i n a l C o n d i t i o n s After 15 minutes Pressure (torr)

579

357

525

523

545

Temperature ( C) 191 Max-temp. Ob s.( C.)223

114 136

199 227

194 215

193 220

$$ϊ£λ%

( g /g)*0-52 . 1.06 . 0.47 0.51 , 0.54 * m g m / g - m i l l i g r a m m o l e s adsorbed per gram o f c a t a l y s t m

T

m

u


56

Figure 2.

System response to pressure change

Figure 3.

Adsorption of water on 100S alumina

5.



57

The c u r v e s i n Figure 3 i n t e r s e c t the time corrdinate at 1 to 2 m i l l i s e c o n d s . T h i s time l a g a r i s e s b e c a u s e of the w a y the c o m puter c o r r e c t s for the c a p s u l e v o l u m e and sets time zero w h i l e the c a p s u l e i s b r e a k i n g i n the f i r s t two m i l l i s e c o n d s . S i n c e p a r t i c l e s i z e and shape are s i g n i f i c a n t factors i n m a s s transfer c o n s i d e r a t i o n s and the s i z e and shape d i s t r i b u t i o n s w i t h i n a g i v e n mesh s i z e for t h e s e experiments are not known , q u a n t i t a t i v e e v a l u a t i o n o f transport properties may not be m e a n i n g f u l . C e r t a i n l y the p o t e n t i a l for s u c h quantitative measurements seems p o s s i b l e . In a q u a l i t a t i v e s e n s e , the c u r v e s of Figure 3 are i n the order e x p e c t e d i f m a s s transfer were a dominant f a c t o r . A d s o r p t i o n R e a c t i o n S t u d i e s : D e h y d r a t i o n of t - b u t a n o l on A l u m i n a . Previous work i n t h i s laboratory has g i v e n e n c o u r a g i n g r e s u l t s i n a r r i v i n g at L a n g m u i r - H i n s c h e l w o o d or H o u g e n and W a t s o n type k i n e t i c models ( 2 , 6 , 8 , 1 0 ) w h e n the amount of a d s o r p t i o n at r e a c t i o n c o n d i t i o n s has b e e n d e t e r m i n e d . The t y p i c a l r e s u l t s p r e s e n t e d here repeat some e a r l i e r experiments w i t h , h o w e v e r , a much superior a p p a r a t u s . The b a s i s for t h i s procedure for e v a l u a t i n g the c o n c e n t r a t i o n o f a b s o r b e d s p e c i e s at r e a c t i o n c o n d i t i o n s r e s t s upon b e i n g able to measure a d s o r p t i o n w h i l e a much s l o w e r r e a c t i o n step t a k e s p l a c e . If the study i s to go b e y o n d the a d s o r p t i o n s t e p , the r e a c t i o n must be of the type that p r o d u c e s a change i n p r e s s u r e at c o n s t a n t v o l u m e and temperature. Figure 4 shows portions of a t y p i c a l a d s o r p t i o n r e a c t i o n h i s t o r y for the c a t a l y t i c d e h y d r a t i o n o f t - b u t a n o l on A l u m i n a 100S w h i c h has been treated or " c o n d i t i o n e d " w i t h water (6). The r e a c t i o n w h i c h i s endothermic p r o d u c e s one mole of i s o b u t y l e n e and a mole of water for e a c h mole of t - b u t a n o L The steep d e c r e a s e i n p r e s s u r e during the f i r s t s e c o n d (approximately) w a s c a u s e d by a d s o r p t i o n , then the s l o w r i s e r e s u l t e d from the r e a c t i o n . The ratio of a d s o r p t i o n rate to r e a c t i o n rate for t h i s c a s e w a s about 1700. The temperature r o s e during the f i r s t three s e c o n d s as a r e s u l t of the heat of adsorption then f e l l b e c a u s e of the endothermic r e a c t i o n and heat l o s s to the r e a c t o r . The temperature l a g may be due i n part to the s l o w e r r e s p o n s e of the t h e r m o c o u p l e . The amount of t - b u t a n o l w h i c h w a s measured b y the drop i n p r e s s u r e from the i n i t i a l v a l u e to the minimum i s c o n s i d e r e d to be the a d s o r p t i o n at r e a c t i o n c o n d i t i o n s . The t e c h n i q u e of c o n f i n i n g the c a t a l y s t i n a c a p s u l e permits v a r i o u s treatment or a c t i v a t i o n procedures as w e l l as e x a m i n a t i o n of m u l t i - c o m p o n e n t a d s o r p t i o n e f f e c t s . For a s i n g l e reactant s y s t e m r e a c t i o n products c a n be p r e a d s o r b e d at a known quantity to a s c e r t a i n the e f f e c t t h e s e might have on reactant a d s o r p t i o n and

58


700 h

Figure 4. Adsorption-reaction pressure transient for catalytic dehydration of tert-butanol

ί 0

I

I

I

I

L

0.2

0.4

0.6

0.8

1.0

Time-seconds

Figure 5.

Effect of water on tert-butanol adsorption

5.



59

r e a c t i o n r a t e . To a v o i d transport or d e s o r p t i o n the i n i t i a l p a r t i a l p r e s s u r e of the products i n s i d e and o u t s i d e the c a p s u l e c a n be made e q u a l . For r e a c t i o n s w i t h more than one r e a c t a n t , the b i n a r y a d s o r p t i o n e f f e c t s c a n a l s o be m e a s u r e d . Figure 5 shows the e f f e c t o f water o n the adsorption of t - b u t a n o l on 100S a l u m i n a . A i l r u n s i n v o l v i n g t - b u t a n o l (TBA) had about the same i n i t i a l p a r t i a l p r e s s u r e . M o s t adsorption-reaction experiments r e a c h the minimum pressure i n one s e c o n d , hence the time s c a l e for Figure 5 . The top curve r e p r e s e n t s the a d s o r p t i o n of 2:1 mixture of TBA and w a t e r . T h i s curve i s o n l y s l i g h t l y above the TBA c u r v e , w h e r e a s , were the a d s o r p t i o n of the two c o m p o n ents i n d e p e n d e n t , the total a d s o r p t i o n w o u l d be 60-100% higher as c a n be s e e n by adding the two s i n g l e component c u r v e s . The lower curve r e p r e s e n t s the a d s o r p t i o n of TBA o n a surface h a v i n g a b s o r b e d water e q u i v a l e n t to a pressure of 208 t o r r . The s u p p r e s s i o n of the a d s o r p t i o n of TBA by preadsorbed water i s i n d e e d substantial. A d s o r p t i o n measurements at r e a c t i o n c o n d i t i o n s have b e e n c o u p l e d w i t h f i x e d b e d k i n e t i c data to arrive at s i m p l e k i n e t i c models w i t h one or two a d j u s t a b l e parameters (2 and 6). In r e c e n t work (10) the a d s o r b e r - r e actor has b e e n u s e d as a b a t c h reactor far o b t a i n i n g k i n e t i c data up to h i g h c o n v e r s i o n s i n a d d i t i o n to i t s u s e as an a d s o r b e r . Conclusions The d e s i g n and experimental r e s u l t s for some t y p i c a l a p p l i c a t i o n s of a h i g h temperature, h i g h speed constant volume a d s o r b e r reactor have b e e n p r e s e n t e d . Preliminary experiments i n d i c a t e that a d s o r p t i o n s t u d i e s c a n p r o v i d e a better i n s i g h t i n t o transport m e c h a n i s m s and the role of a d s o r p t i o n i n heterogeneous c a t a l y s i s thereby a s s i s t i n g the development of i m p r o v e d k i n e t i c models for these complex reactions. Acknowledgement The authors thank P r o f e s s o r E . R . H a e r i n g for h i s h e l p f u l a d v i c e on the t - b u t a n o l k i n e t i c s , Professor J . T . H e i b e l for h i s a s s i s t a n c e o n the computer data a c q u i s i t i o n f a c i l i t i e s and programming and M i c h a e l Kukla for h i s h e l p o n e l e c t r o n i c s . Financial support for f e l l o w s h i p s and g r a n t s - i n - a i d from The A m e r i c a n O i l C o m p a n y , Exxon C o m p a n y , E . I . duPont C o m p a n y , M o n s a n t o C o m p a n y , H e n r y D r e y f u s T e a c h i n g F e l l o w s h i p Program and the C h e m i c a l E n g i n e e r i n g D e v e l o p m e n t Fund are gratefully acknowledged.

60

CHEMICAL REACTION

ENGINEERING—HOUSTON

Literature Cited 1. W i n f i e l d , M.E., Aust. J. of C h e m . , (1953),6, 221. 2. Macarus, D.P., Syverson,A. I&EC Proc. Design Dev, (1966), 5, 397. 3. Sashihara, T.F., Syverson, Α . , I&EC Proc. Design D e v . , (1966),5, 392. 4. Edwards, D.C., M.Sc. Thesis (1961), The Ohio State University, Department of Chemical Engineering. 5. Keller, R.M., M.Sc. Thesis (1962), The Ohio State University, Department of Chemical Engineering. 6. Haering, E.R., Syverson, Α . , (1974). J . of C a t a l y s i s , 3 2 , (3), 396-414. 7. Stolk, R.D., PhD. Dissertation, (1971), The Ohio State University, Department of Chemical Engineering. 8. Becher, J.H., PhD. Dissertation, (1972), The Ohio State University, Department of Chemical Engineering. 9. Wolfe, D.B., PhD. Dissertation, (1974), The Ohio State University, Department of Chemical Engineering. 10. Nash, G.L., M.S. Thesis, (1976), The Ohio State University, Department of Chemical Engineering.

Adsorption Studies at Reaction ConditionsâReactor Development

Recommend Documents

Adsorption Studies at Reaction ConditionsâReactor Development