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Scientia Iranica C (2011) 18 (3), 458–464

Sharif University of Technology

Scientia IranicaTransactions C: Chemistry and Chemical Engineering

www.sciencedirect.com

Kinetic modeling of side reactions in propane dehydrogenation overPt-Sn/γ -Al2O3 catalyst

A. Farjoo a, F. Khorasheh a,∗, S. Niknaddaf a, M. Soltani b

a Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iranb National Iranian Petrochemical Company, Research and Technology Division, Tehran, Iran

Received 2 January 2010; revised 17 June 2010; accepted 18 September 2010

KEYWORDS

Propane dehydrogenation;

Side reactions;

Platinum catalyst;

Kinetics.

Abstract The kinetics of side reactions in the dehydrogenation of propane over a supported platinum

catalyst modified by tin, were investigated. Catalytic dehydrogenation over a commercial Pt-Sn/γ -Al2O3wascarried out in a laboratory-scale plug-flowreactor at 580–620 °C under atmospheric pressure. Several

kinetic models derived from different reaction mechanisms were testedusing experimental data obtained

under a range of reaction conditions. It was found that the kinetics of the main dehydrogenation reaction

was best described in terms of a Langmuir–Hinshelwood mechanism, where the adsorption of propane

was the ratecontrolling step. Simple power low rate expressions were used to express the kinetics of side

reactions.

© 2011 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.

1. Introduction

The current chemical scenario shows an increased interest

in the production of light olefins as starting materials for someof the most important chemical products including polymers,

synthetic rubbers and oxygenated compounds for reformulatedfuels [1,2]. Propylene is a major co-product from steam crackers

and the economics of the process are highly dependent on thesupply/demand situation for both propylene and ethylene. In

some geographic areas, propylene demand is increasing fasterthan ethylene demand. The dehydrogenation of propane with

high selectivity to propylene gives the chance to de-couple theproductions of ethylene and propylene, and will be of great

interest in the coming years if the trend in the market for

polymers persists [1].

∗ Corresponding author.E-mail address: [email protected] (F. Khorasheh).

The dehydrogenation of light alkanes is an important

reaction from an industrial point of view, since it is a selective

process to produce the corresponding short-chain alkenes

via direct catalytic dehydrogenation. Two types of catalyst

have been developed and patented for this reaction, including

chromia-based catalysts [3–5], and, more recently, supported

platinum catalysts [6–9]; both suffer from deactivation due

to coke deposition, and often a feed of hydrogen is used to

improve the catalyst stability. The addition of tin to platinum

catalysts has proved to be an effective way to reduce undesired

reactions and prevent rapid deactivation due to coke formation.

The platinum–tin catalyst has therefore received considerable

attention [6–9].Propane dehydrogenation is an endothermic process that

requires relatively high temperatures to obtain a high yield of propylene, and is commercially carried out in a temperature

range of 450–650 °C under atmospheric pressure. The following

reactions occur during propane dehydrogenation [10–13]:

C3H8 ↔ C3H6 + H2, (R1)

C3H8 → CH4 + C2H4, (R2)

C2H4 + H2 → C2H6, (R3)

C3H8 + H2 → CH4 + C2H6. (R4)Reaction (R1) is the main reaction and reactions (R2)–(R4)are the possible side reactions. Reaction (R2) can take place

1026-3098 © 2011 Sharif University of Technology. Production and hosting by

Elsevier B.V. All rights reserved. Peer review under responsibility of Sharif

University of Technology.

doi:10.1016/j.scient.2011.05.009

http://dx.doi.org/10.1016/j.scient.2011.05.009http://www.sciencedirect.com/mailto:[email protected]://dx.doi.org/10.1016/j.scient.2011.05.009http://dx.doi.org/10.1016/j.scient.2011.05.009mailto:[email protected]://www.sciencedirect.com/http://dx.doi.org/10.1016/j.scient.2011.05.009

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A. Farjoo et al. / Scientia Iranica, Transactions C: Chemistry and Chemical Engineering 18 (2011) 458–464 459

Table 1: Specifications of the commercial catalyst for propane dehydro-

genation.

Diameter 1.8 mm

Bulk Density (ρb) 0.65 g

cm3

Catalyst Density (ρc ) 1.12 g

cm3

Catalyst Surface Area (Sa) 200 m2

g

both in the gas phase (thermal conversion) and on the

surface of the catalyst (catalytic conversion). Thermal cracking

and catalytic cracking are both side reactions in propane

dehydrogenation, resulting in formation of methane and

ethylene as major side products. These reactions, however,

occur via different mechanisms. Thermal cracking involves a

free radical chain mechanism, while catalytic cracking proceeds

via surface species. Reaction (R4) is the hydrogenolysis

reaction which occurs on the surface of the catalyst. The side

reactions can be divided into two distinct categories; thermal

side reactions including thermal cracking, and catalytic side

reactions including propane hydrogenolysis, catalytic cracking

and ethylene hydrogenation. The objective of this study is to

investigate the kinetics of side reactions during the catalyticdehydrogenation of propane over a commercial Pt-Sn/γ -Al2O3catalyst.

The major side products were CH4, C2H4 and C2H6. The mainside product under the reaction conditions employed in this

study was CH4, as it was produced via hydrogenolysis, thermal

cracking and catalytic cracking reactions.

2. Methods and materials

The extent of side reactions in propane dehydrogenation

were examined over a commercial Pt-Sn/γ -Al2O3 catalyst. A

simplified schematic of the laboratory scale setup used for the

propane dehydrogenation experiments is shown in Figure 1.

Using a three-lined setup, propane, hydrogen and nitrogen gasmixtures could be introduced, whose composition and total

flow was set using Brooks mass flow controllers. The inside

diameter of the reactor was 12 mm, the length of the reactor

was 90 cm, and the catalyst was loaded in the middle section of

thereactor, in betweentwo layersof quartsparticles. Theheight

of the catalyst zone was approximately 2 cm. The specifications

of the catalyst are given in Table 1.

In each experiment, the catalyst sample was heated under

nitrogen flow from ambient temperature to 150 °C in 25 min.

The temperature was then held constant for 3 h. The catalyst

was then heated from 150 °C to the desired reduction

temperature of 450 °C in 3 h under hydrogen flow. During this

period, nitrogen flow was decreased gradually, such that when

the catalyst temperature reached 450 °C, the nitrogen flow waszero. The temperature wasthen increased from 450 °Cto530 °C

in 16 min under hydrogen flow only.The temperature was then

held constant for 1 h at 530 °C, and then reduced to 350 °C in

3 h under hydrogen flow at which point the flow of propane

was started. The feed to the reactor consisted of propane and

hydrogen with H2/propane molar ratio of 0.8. The temperaturewas then increased to the desired reaction temperatures of

580 °C, 600 °C or 620 °C at a rate of 5 °C per minute. Productgases were analyzed after a 90 min stabilization period. The

outlet stream from the reactor was analyzed by an online

Gas Chromatograph (model PERICHROM 2100 Packed column,

SS316,6 m,1/8 in, 28%DC200 on Chromsorb PAW 60/80,ENRO3015).

Figure 1: The simplified sketch of propane dehydrogenation setup.

Table 2: Propane conversion for catalyst at different feed flow rates.

Run Catalyst

weight (g)

Q C3(cc/min)

Q H2(cc/min)

WHSV

(1/h)

Conversion

(%)

1 1 39.96 31.968 4 20.45

2 1.2 44.36 35.488 4 23.07

3 1.5 55.45 44.36 4 23.32

4 1.6 59.3 47.44 4 23.35

3. Results and discussions

To obtain proper kinetic data for determination of intrin-

sic reaction rates, it was necessary to perform experiments in

the absence of external and internal mass transfer limitations.Experiments were conducted using catalyst particles of differ-

ent sizes to investigate internal mass transfer limitations. Feed

flow rates were also varied over a wide range, keeping WHSV

(Weight Hourly Space Velocity) constant to investigate exter-

nal mass transfer limitations under reaction conditions.

3.1. External mass transfer limitations

In order to eliminate the external mass transfer limitations,

several experiments were conducted in which the size of the

catalyst pellet was kept constant and the feed flow rate was

varied over a wide range, while keeping WHSV constant at

4 h−1. If conversion wasunaffected by varying the propane flow

rate at constant WHSV, it could be concluded that the reactionwas independent of the external mass transfer of the fluid

outside the catalyst pellet. The results of these experiments are

shown in Table 2, indicating that when propane flow rate, Qc3,

was greater than 44.36 cc/min, there were no external mass

transfer limitations.

3.2. Internal mass transfer limitations

In order to eliminate internal mass transfer limitations,

several experiments were performed using different sizes of

catalyst pellet at a feed flow rate where external mass transfer

limitations were absent. (Qc3 > 55.45 cc/min) The resultsare presented in Table 3. If the conversion did not change by

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460 A. Farjoo et al. / Scientia Iranica, Transactions C: Chemistry and Chemical Engineering 18 (2011) 458–464

Table 3: Propane conversion for catalyst pellets of different sizes.

Run Catalyst

weight

(g)

Q C3(cc/min)

Catalyst

diameter

(mm)

Q H2(cc/min)

WHSV

(1/h)

Conversion

(%)

1 0.75 55 1.8 44 9 13.72

2 0.75 55 1 44 9 23.1

3 0.75 55 0.71 44 9 23.9

4 0.75 55 0.50 44 9 24.15 0.75 55 0.35 44 9 24.3

Figure 2: Effect of temperature on propane conversion.

further reduction in the size of the catalyst pellet, there would

be no internal mass transfer limitations. Kinetic studies were

performed using catalyst pellets of 0.35 mm in diameter.

3.3. Effect of temperature on conversion and selectivities

Propane dehydrogenation is an endothermic reaction,

and increasing the temperature increases the equilibrium

conversion. Propane conversion increased with increasingreaction temperature (Figure2), but increasing the temperature

also caused the side reactions to become more significant,

thus decreasing propylene selectivity (Figure 3). Propylene

selectivity is defined by Eq. (1):

Selectivity to C3H6 =C3H6 Produced

Input(C3H8)− Output(C3H8). (1)

Figure 4 shows the effect of temperature on the formation

of side products. Temperature increase beyond 650 °C is not

recommended, as it would result in a significant decrease in

propylene yield. To investigate the extent of thermal cracking

reactions, dehydrogenation was carried out in the absence of

the catalyst at 580 °C, 600 °C and 620 °C, and results were

compared with those in the presence of the catalyst. Theamounts of side product formed via thermal side reactions and

catalytic side reactions are shown in Figure 5, indicating that

the catalytic reactions are more dominant and, with increasing

reaction temperature, the extent of both catalytic and thermal

reactions would increase.

3.4. Effect of residence time on conversion and selectivities

Temperature and WHSV are two parameters that affect

propane conversion. WHSV is the inverse of residence time

and as indicated by Figures 6 and 7, respectively, both propane

conversion and the formation of side products increase with

decreasing WHSV. For a given reaction temperature, the molar

Figure 3: Effect of temperature on propylene selectivity.

Figure 4: Effect of temperature on the formation of side products (WHSV =8 (1/h)).

Figure 5: Comparison of formation of thermal catalytic side products.

ratio of side products to all products at the reactor exit

was found to increase with decreasing WHSV (Figure 8),

resulting in a decrease in propylene selectivity with decreasing

WHSV (Figure 9). Propylene selectivities presented in Figures 3

and 9 indicated that the reaction temperature had a more

pronounced effect on propylene selectivity in comparison with

WHSV.

3.5. Kinetic modeling

Intrinsic kinetics of the main reaction in catalytic dehy-

drogenation of propane over the Pt-Sn/γ -Al2O3 catalyst canbe well represented in terms of Langmuir–Hinshelwood rate

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Figure 6: Effect of residence time on propane conversion.

Figure 7: Effect of residence time on formation of side products (T = 600 °C).

Figure 8: Molar ratio of side products to all products at different WHSV and

reaction temperatures.

expressions [13], where either an adsorption, surface reac-tion, or desorption step is considered as the rate controllingstep. Based on experimental data, Airaksinen et al. (2002) indi-cated that desorption of propylene from the surface sites wasnot likely to be the rate controlling step and suggested sev-eral mechanisms for propane dehydrogenation, where eitheradsorption or surface reaction was rate controlling [14]. A re-cent study, where the same commercial catalyst as that used inthe current investigation was employed, suggested that mech-anisms involving propane adsorption either on single or dualsites as the Rate Controlling Step (RCS) were most consistentwith experimental data [15].

The Langmuir–Hinshelwood mechanisms that were studiedin the current investigation to describe the kinetics of the

Figure 9: Effect of residence time on propylene selectivity.

main reaction in catalytic dehydrogenation of propane are

given in Table 4. The corresponding rate expressions given in

Table 5 are referred to in the form ‘‘model I-a’’ or ‘‘model IV-

b’’, where the Roman numeral indicates the mechanism and

the letter (a or b) indicates the RCS, with ‘‘a’’ referring to the

adsorption of propane on active sites and ‘‘b’’ referring to thesurface reaction. It should be noted that competitive adsorption

of side products, including CH4, C2H4 and C2H6, were also

considered in the above mechanisms. Simple power law rate

expressions, Table 6, were used to describe the kinetics of the

side.

3.6. Estimation of kinetic parameters

The estimation of the kineticparameters involved a two step

optimization procedure. The first step involved the estimation

of parameters appearing in the rate expression for the main

propane dehydrogenation reaction (as specified in Table 5).

Having evaluated the parameters for the main reaction, the

second step involved the estimation of kinetic constants forthe side reactions (as specified in Table 6). This two-step

procedure was necessary, since the side products were present

in very small amounts compared with propane and propylene

as major species. The governing differential equations for the

isothermal plug flow reactor employed in the experiments

are:

dF i

dW =−

j

−r i,

i = C3H8, C3H6, C2H4, C2H6, CH4, (2)where F i is the molar flow rate of component i, W is the massof catalyst,

−r i is the reaction rate for component i, and the

summation coversall reactions j leading to theformation and/ordisappearance of component i. Experimental data for each run

included the inlet molar flow rate of propane and the exit

molar flow rates of propane, propylene, methane, ethylene

and ethane. Hydrogen flow rates were obtained by difference

from an overall material balance. Numerical integration of

the system of Eqs. (2) was carried out by the ode15s, and

the optimization procedure was performed with the aid of

the Genetic Algorithm function of MATLAB. For each reaction

temperature, the optimized kinetic parameters were obtained

by minimizing the following objective function:

OF =4−

k

=1

5−i

=1

(F exp

iE − F pre

iE )2W i, (3)

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Table 4: Mechanisms for propane dehydrogenation.

Mechanism I Mechanism II

C3H8(g)+ 2S ←→ C3H7 · · · S+ H · · · S (RCS) C3H8(g)+ S ←→ C3H7 · · · S · · ·H (RCS)C3H7 · · · S + S ←→ C3H6 · · · S+ H · · · S C3H7 · · · S · · ·H+ S ←→ C3H6 · · · S · · ·H+ H · · · SC3H6 · · · S ←→ C3H6(g)+ S C3H6 · · · S · · ·H ←→ C3H6(g)+ H · · · S2H · · · S ←→ H2(g)+ S 2H · · · S ←→ H2(g)+ 2SCH4 + S ←→CH4 · · · S CH4 + S ←→ CH4 · · · S

C2H4 + S ←→ C2H4 · · · S C2H6 + S ←→ C2H6 · · · SC2H6 + S ←→ C2H6 · · · S C2H4 + S ←→ C2H4 · · · SS: Active sites on the catalyst S: Active site on the catalyst

Mechanism III Mechanism IV

C3H8(g)+ S ←→ C3H7 · · · S · · ·H (RCS) C3H8(g)+ S ←→ C3H8 · · · SC3H7 · · · S · · ·H ←→ C3H6(g)+ H · · · S · · ·H C3H8 · · · S+ S ←→ C3H7 · · · S+ H · · · S (RCS)H · · · S · · ·H ←→ H2(g)+ S C3H7 · · · S+ S ←→ C3H6 · · · S+ H · · · SCH4 + S ←→ CH4 · · · S C3H6 · · · S ←→ C3H6(g)+ SC2H4 + S ←→ C2H4 · · · S 2H · · · S ←→ H2(g)+ 2SC2H6 + S ←→ C2H6 · · · S CH4 + S ←→ CH4 · · · SS: Active sites on the catalyst C2H4 + S ←→ C2H4 · · · S

C2H6 + S ←→ C2H6 · · · SS: Active site on the catalyst

Table 5: Langmuir–Hinshelwood rate expressions for the main propane dehydrogenation reaction.

Model Equation rate

1 (I-a) −r ′ A =k′

P P −P Pr P H2

K eq

(1+K ′P PrP 1/2H2 +K PrP Pr+(K ′′′P H2 )

1/2+K H2 P H2+K CH4 P CH4+K C2H4 P C2H4+K C2H6 P C2H6 )2

2 (II-a) −r ′ A =k′

P p−P Pr P H2

K eq

1+K PrH 2 P PrP H2+(K H2 P H2 )1/2+K ′P PrP 1/2H2

+K CH4 P CH4+K C2H4 P C2 H4+K C2H6 P C2 H6

3 (III-a) −r ′ A =k′

P A−P B P C K eq

1+K PrH 2 P C3 H6 P H2+K H2 P H2+K CH4 P CH4+K C2H4 P C2H4+K C2H6 P C2H6

4 (IV-b) −r ′ A =k′

P p−P Pr P H2

K eq

(1+K pP p+K PrP Pr+(K H2 P H2 )1/2+K ′P Pr√

P H2+K CH4 P CH4+K C2 H4 P C2H4+K C2 H6 P C2H6 )2

P: Propane (A) k′: Rate constantPr: Propylene (B) K eq: Equilibrium constant

H2 = Hydrogen (C) K : Adsorption constant

where F exp

iE and F pre

iE are the experimental and predicted molarflow rates of component i at the reactor exit, W i are weight-ing factors, and summation k extends over experimental dataatdifferent WHSV. The optimized parameter values were highlyinfluenced by the choice of weighting factors, as propane andpropylene were major species, while methane, ethane andethylene were present in minor quantities. In the optimizationprocedure for parameter estimation, first a preliminary esti-mate for the kinetic parameter was obtained using a weigh-ing factor of one for each component. Subsequently, the revisedweighting factors were evaluated as follows:

W i = Errori/Total error, (4)

Errori =4−

k=1(F expiE − F preiE )2, (5)

Total error =5−

i=1Errori. (6)

The normalized weighting factors were then used to optimizethe kinetic parameters of the main reaction for each reactiontemperature. The temperature dependence of the rate con-stants and equilibrium adsorption constants were determinedby the Arrhenius and van’t Hoff equations, respectively, asfollows:

ln(ki) = ln(ki0)+ (−E i/RT ), (7)ln(K i)

=ln(K i0)

+(

−H i/RT ). (8)

Table 6: Proposed reaction rate equations for side reactions.

Side reaction Kinetic equation

Catalytic cracking (I) r = k1P C3 H8Ethylene hydrogenation (II) r = k2P C2 H4 P H2Hydrogenolysis (III) r = k2P C3 H8 P H2Thermal cracking (IV) r = k4P C3 H8

Theconstantsare reported in Table 7 forthe main reaction using

different reactions [10–12]. Proposed Langmuir–Hinshelwood

rate expressions. Having evaluated the parameters for the main

reaction, the second step involved the estimation of the rate

expressions of the optimized kinetic parameters for the main

reaction, and the rate constants for the side reactions using thefollowing objective function:

OF =4−

k=1

3−i=1

(F exp

iE − F pre

iE )2, (9)

where summation i extends for side products only. The

optimized rate constants for each of the side reactions were

obtained for different temperatures and the corresponding

Arrhenius parameters are reported in Table 8. It shouldbe noted

that the Arrhenius parameters for the rate constants of the

thermal cracking side reaction were obtained from separate

experimental data at different temperatures, under similar

conditions, but in the absence of the catalyst.

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Table 7: Kinetic constants for the proposed Langmuir–Hinshelwood rate expressions, E (kJ/mol), H (kJ/mol).

Model 1 Model 2 Model 3 Model 4

k′ = 3.17× 103 exp −61.79

RT

k′ = 1.21× 103 exp

−53.71RT

k′ = 3.71× 103 exp

−59.39RT

k′ = 4.25× 101 exp

−70.66RT

K Pr = 7.44× 10−7 exp

89.07

RT

K H2 = 1.61× 10−3 exp

36.03

RT

K H2 = 9.71× 105 exp

52.22

RT

K p = 6.70× 10−3 exp

18.92

RT

K H2 = 2.18× 10−1 exp

9.36RT

K CH4 = 1.37× 10−5 exp

52.63

RT

K CH4 = 1.70× 103 exp

21.28

RT

K Pr = 1.42× 10−5 exp

69.31

RT

K CH4 = 9.07 × 10−3 exp

16.06RT

K C2H6 = 1.34× 10−6 exp 64.39

RT K C2 H6 = 1.85× 104 exp

38.23RT

K H2 = 2.01× 10−4 exp 51.24

RT K C2H6 = 3.60× 10−2 exp 5.75RT K C2H4 = 5.15× 10−5 exp 42.84RT K C2 H4 = 7.22× 105 exp 4.17RT K CH4 = 1.98× 10−2 exp 6.83RT K C2H4 = 6.97× 10−3 exp

16.44

RT

K Pr H2 = 3.70× 10−2 exp

7.41RT

K Pr H2 = 1.67× 10−2 exp

18.35

RT

K C2H6 = 2.99×10−2 exp

5.48

RT

K ′ = 3.44× 10−2 exp

12.63

RT

K ′ = 3.47× 10−1 exp

−9.16RT

K C2H4 = 3.39×10−2 exp

5.61

RT

K ′′′ = 1.02× 10+4 exp−49.97

RT

K ′ = 7.73× 104 exp

68.46

RT

Table 8: Rate constants for proposed rate expressions for side reactions.

Model 1 Model 2 Model 3 Model 4

k1 = 1.14 exp −6488

T

K 1 = 7.53× 108 exp

−273938T

k1 = 3.36× 1017 exp

−40451T

k1 = 3.09× 104 exp

−16661T

k2 = 1.34× 107 exp

−27393T

k2 = 9.62× 107 exp

−28187T

k2 = 3.94× 1011 exp

−30754T

k2 = 1.25× 109 exp

−25692T

k3 = 3.36× 104 exp

−14723T

k3 = 5.57× 105 exp

−17926T

k3 = 1.47× 101 exp

−8498T

k3 = 2.85× 109 exp

−5757.6T

k4

=1.53E

+09 exp

−1598.23T k4 =

1.53E

+09 exp

−1598.23T k4 =

1.53E

+09 exp

−1598.23T k4 =

1.53E

+09 exp

−1598.23T

Table 9: Average % error between predictedand experimentalflow rates at

reactor exit.

Model Absolute error %

Model 1 Main species 4.02

Side products 14.68


Side products 21.74


Side products 17.74


Side products 25.98

The kinetic constants reported in Table 7 for the main reac-

tion and in Table 8 for the side reactions were used to predict

the exit molar flow rates of various spices under different reac-

tion conditions. Comparison between the experimental values

andpredictedvalues from each model would serve as a measure

to differentiate between the predictive ability of different mod-

els. Table 9 presents the average percent absolute error for each

model for both major species (propane and propylene) and side

products, indicating that model 1, where dual site adsorption

of propane is considered as the rate controlling step, provides

the best agreement with experimental data. A typical compari-

sonof experimental exit molar flow rates,with predicted values

from model 1 as a function of residence time at 580 °C, is pre-

sented in Figures 10 and 11 for the major species and the sideproducts, respectively.

4. Conclusions

The kinetics of propane dehydrogenation over a commercial

Pt-Sn/γ -Al2O3 catalyst was best described in terms of a Lang-

muir–Hinshelwood mechanism, where dual site adsorption of

propane was considered as the rate controlling step. The ki-

netics of side reactions leading to the formation of methane,

ethylene and ethane as minor products could reasonably be de-

scribed by simplepower-law rate expressions. The proposed ki-

netic model resulted in an average relative error of 4.0% and

14.7% between predicted and experimental molar flow rates

Figure 10: Comparison between experimental exit molar flow rates and

predicted values from model 1 for major products at reaction temperature of

580 °C.

Figure 11: Comparison between experimental exit molar flow rates and

predicted values from model 1 for side products at reaction temperature of

580 °C.

of major species and side products, respectively, at the reactor

exit, over therange of experimental conditionsemployedin this

study.

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Acknowledgments

The authors acknowledge financial support from the Iranian

National Petrochemical Research and Technology Company for

the experimental work involved in this study.

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Afrooz Farjoo was born in 1985. She obtained her B.S. degree from IsfahanUniversity of Technology in 2007 and her M.S. degree in 2009 from theDepartment of Petroleum and Chemical Engineering at Sharif University of Technology in the area of Thermo Kinetics and Catalysis.

Farhad Khorasheh was born in 1961. He took his B.S. degree in ChemicalEngineering in 1983 from Queen’s University, Ontario, Canada and his M.S.and Ph.D. degrees in Chemical Engineering, in 1986 and 1992, respectively,from the University of Alberta, Edmonton, Canada. He is now a Professor inthe Department of Petroleum and Chemical Engineering at Sharif University of Technology. His research interests include Modeling and Reactor Design.

Saeed Niknaddaf was born in 1985. He obtained his B.S. and M.S. degrees fromthe Department of Petroleum and Chemical Engineering at Sharif University of Technology in 2007 and 2009, respectively, in the area of Thermo Kinetics andCatalysis.

Mahnaz Soltani was born in 1974. She obtained her B.S. and M.S. degrees fromtheDepartmentof ChemicalEngineeringat Tehran Universityin 1996and 1998,respectively. Sheis nowworkingas a ChemicalEngineerin theNational IranianPetrochemical Company.

far joo 2011

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