Mathematical Modeling of Propylene Polymerization with Ziegler-Natta Catalyst and Hydrogen Response Validation

Document Type: Research Article


1 Department of Petroleum and Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, I.R. IRAN

2 Department of Chemical and Bimolecular Engineering, Research Associates of Rice University, USA



< p>Hydrogen in spite of having a chain transfer agent role is one of the most important factors which directly affecting on kinetic of propylene polymerization. Hydrogen causes to dramatically increase the percentage of activated sites in proportion to being total potential sites on the catalyst surface. On the other hand, the chain transfer agent role of hydrogen gives rise to changing some vital indices of final product properties. This study has attempted to present a validated mathematical model that able to predicting profile polymerization rate and also calculating some of the vital indices of the final product, properties to be derived from kinetic equations. Furthermore, in this paper, we present a developed model that calculates fraction activated sites catalyst via hydrogen concentration based on dormant site theory and determining the best process condition. The modeling approach is based on the polymer moment balance method, i.e. population balance technique, and validated by experimental works. The main aim of this study is assigned to investigate the behavior change of polymerization rate to hydrogen. The experimental data and model outputs were compared and concluded that the global errors were in the acceptable range.


Main Subjects

[1] Busico V., Cipullo R., Mingione A., Rongo L. Accelerating the Research Approach to Ziegler–Natta Catalysts,  Industrial & Engineering Chemistry Research, 55(10): 2686-2695(2016).
[2] Shaffer W.K.A. and Ray W.H., Polymerization of Olefins through Heterogeneous Catalysis. XVIII.
a Kinetic Explanation for Unusual Effects
, Appl. Polym. Sci., 65, 1053-1080 (1997). 
[4] Neto A.G.M., Pinto J.C., Steady-State Modeling of Slurry and Bulk Propylene Polymerizations, Chem. Eng. Sci., 56: 4043 (2001).
[6] Sarkar P and Gupta S.K., Steady State Simulation of Continuous -Flow Stirred - Tank Slurry Propylene Polymerization Reactors; Polym. Eng. Sci., 32: 732- (1992).
[8] Luo Zh.H., Zheng Y., Cao Z.K., Wen S.H, Mathematical Modeling of the Molecular Weight Distribution of Polypropylene Produced in a Loop Reactor, Polymer Engineering and Science, Volume 47: 1643–1649 (2007).
[9] Reginato A.S., Zacca J.J.,  Secchi A.R., Modeling and Simulation of Propylene Polymerization in Nonideal Loop Reactors, AIChE Journal, 49(10): 2642-2654 (2003).
[10] Samson J.J.C., Bosman J.B, Weickert G., Westerterp K.R., Liquid-Phase Polymerization of Propylene with a Highly Active Ziegler-Natta Catalyst.Influence of Hydrogen, Cocatalyst, and Electron Donor on Reaction Kinetics. Journal of Polymer Science: Part A: Polymer Chemistry, 37: 219–232 (1999).
[11] Al-haj A.M., Betlem B., Roffel B. and Weickert G., Hydrogen Response in Liquid Propylene Polymerization: Towards a Generalized Model, AIChE Journal, 52( 5): 1866-1876 (2006).
[12] Guastalla G. and Gianinni U., The Influence of Hydrogen on the Polymerization of Propylene and Ethylene with an MgCl2 Supported Catalyst, Makromol. Chem., Rapid Commun., 4: 519-527 (1983).
[13] Soga K., Siano T. Effect of Hydrogen on the Molecular Weight of Polypropylene with Ziegler-Natta Catalysts. Polymer Bulletin, 8: 261-268 (1982).
[14] Kahrman R., Erdogan M., Bilgic T., Polymerization of Propylene Using a Prepolymerized High-Active Ziegler-Natta Catalyst, I Kinetic Studies. Journal of Applied Polymer Science, 60: 333-342(1996).
[15] Varshouee, G.H., Heydarinasab, A., Shaheen, U., Aborehab, M.A.S., Vaziri, A., El Ouadi, Y., Roozbahani, B., Bouyanzer, A., Hammouti, B. and Hadda, T.B., Hydrogen Effect Modeling on Ziegler-Natta Catalyst and Final Product Properties in Propylene Polymerization, Bulletin of the Chemical Society of Ethiopia, 32(2): 371-386(2018).
[16] Varshouee G.H., Heydarinasab A., Vaziri A., Roozbahani B. Determining Final Product Properties and Kinetics Studies of Polypropylene Polymerization by a Validated Mathematical Model, Bulletin of the Chemical Society of Ethiopia, 32(3): 79-94(2018).
[17] Varshouee G.H., Heydarinasab A., Vaziri A., Zarand S.M.G.,Determining the Best Reaction Temperature and Hydrogen Amount for Propylene Polymerization by a Mathematical Model, Kem. Ind., 68(7-8): 119–127 (2019).
[18] Varshouee G.H., Heydarinasab A., Vaziri A., Roozbahani B., A Mathematical Model for Determining the Best Process Conditions for Average Molecular Weight and Melt Flow Index of Polypropylene, Bulletin of the Chemical Society of Ethiopia, 33: 169-  (2019).
[19] Varshouee G.H., Heydarinasab A., Vaziri A., Zarand S.M.G., A Mathematical Model for Investigating the Effect of Reaction Temperature and Hydrogen Amount on the Catalyst Yield during Propylene PolymerizationKem. Ind.,68(7-8): 269–280 (2019).
[20] Varshouee G.H., Heydarinasab A., Vaziri A., Roozbahani B., Predicting Molecular Weight Distribution, Melt Flow Index and Bulk Density in Polypropylene Reactor via a Validated Mathematical Model, Theoretical Foundations of Chemical Engineering. (2019) (in press).
[21] Spitz R., Masson P., Bobichon C. and Guyot A.. "Activation of Propene Polymerization by Hydrogen for Improved MgCl2-Supported Ziegler-Natta Catalysts, Makromol. Chem.,  190, 717- 723 (1989)
[22] Busico, V., R. Cipullo and P. Corradini; Ziegler-Natta Oligomerization of 1- alkenes: A Catalyst''s "Fingerprint", 1." Macromolecular Chemistry and Physics, 194: 1079-l093 (1993).
[23] Chadwick J.C., Miedema A., Sudmeijer O., Hydrogen Activation in Propene Polymerization with MgClrSupported Ziegler-Natta Catalysts: The Effect of the External Donor, Macromolecular Chemistry and Physics, 195: 167-172,(1994).
[26] Costa G. M. N., Kislansky S., Oliveira L. C., Pessoa F. L. P., Vieira de Melo S. A. B., Embiruc M., Modeling of Solid-Liquid Equilibrium for Polyethylene and Polypropylene Solutions with Equations of State, Journal of Applied Polymer Science, 121: 1832–1849 (2010).
[27] Yuan H. G., Taylor T.W., Choi K.Y. and Ray W.H., Polymerization of Olefins through Heterogeneous Catalysis. 1. Low-Pressure Propylene Polymerization in Slurry with Ziegler-Hatta Catalyst, Journal of Applied Polymer Science, 27: 1691-1706 (1982).
[29] Keii, T., Suzuki, E., Tamura, M., Murata, M.. Propene Polymerization with a Magnesium Chloride‚ÄźSupported Ziegler Catalyst, 1. Principal kinetics, Macromolecular Chemistry and Physics, 183(10): 2285-2304 (1982).