Determination of kinetic parameters for ethylene polymerization (with and without hydrogen) by Ziegler-Natta catalyst

Ghafelebashi Zaranda, Seyed Mehdi; Safinejad, Ali

doi:10.22063/poj.2020.2703.1157

Determination of kinetic parameters for ethylene polymerization (with and without hydrogen) by Ziegler-Natta catalyst

Document Type : Original research

Authors

Polymer Research Group, National Petrochemical Research and Technology Company, Tehran, 1497713115, Iran

10.22063/poj.2020.2703.1157

Abstract

In this study, slurry polymerization kinetics of ethylene with TiCl₄/Mg(OEt)₂/AlR₃ Ziegler-Natta catalysts in various conditions using the model of sum square error (SSE) (method I) and model of least square error (LSE) (Method II) was investigated. For this purpose the molecular weight distributions of the samples were deconvoluted to the minimum number of Flory type distributions where each represents a different active center type of Ziegler-Natta catalyst. The first method used to determine the leading apparent polymerization kinetic constants for each site in absence of hydrogen by simultaneously fitting the instantaneous polymerization rate, cumulative polymer yield, and molecular weight distribution measured for various samples with various conditions. Second method was used to determine all kinetics parameters such as initiation, propagation, termination and transfer to monomer reaction in absence and also in the presence of hydrogen. For the later, transfer to hydrogen also determined. The results showed that this simulation package is a powerful tool for design and scale up this kind of processes.

Keywords

References

Andrady AL (2003) Plastics and the Environment. John Wiley & Sons
Peacock A (2000) Handbook of polyethylene: structures: properties, and applications. CRC Press
Jozaghkar MR, Jahani Y, Arabi H, Ziaee F (2018), Preparation and assessment of phase morphology, rheological properties and thermal behavior of low density polyethylene / polyhexene-1 blends. Polym Plast Technol Eng 57: 757- 765
Ghafelebashi Z. SM , Mortazavi SMM, Najafi M, Haddadi-Asl V (2012) Effects of Temperature and Cocatalyst Concentration on the Number of Active Sites in a TiCl4/Mg(OEt)2 Catalyst for Ethylene Polymerization. J Pet Sci Technol 2: 12–16
Skomorokhov VB, Zakharov VA, Kirillov VA (1996) Investigation of the kinetics of ethylene polymerization with supported titanium-magnesium catalysts of various composition. Macromol Chem Phys 197: 1615–1631
Barabanov AA, Zakharov VA, Sukulova VV (2015) Kinetic evidences for reversible transformations of active centers in ethylene polymerization by titanium–magnesium catalyst: Effect of the polymerization temperature. J Organomet Chem 79: 292–298
Zacca JJ (1995) Distributed parameter modelling of the polymerization of olefins in chemical reactors. PhD Thesis, Wisconsin University, Madison
Casalini T, Visscher F, Janssen E, Bertola F, Storti G, Morbidelli M (2017) Modeling of Polyolefin Polymerization in Semibatch Slurry Reactors: Experiments and Simulations. Macromol React Eng 11: 1600036
Salami-Kalajahi M, Haddadi-Asl V, Najafi M, Ghafelebashi Zarand SM (2008) Investigation of ethylene polymerization kinetics over Ziegler- Natta catalysts: Employing moment equation modeling to study the effect of different active centers on homopolymerization kinetics. E-Polymers 8: DOI: 10.1515/epoly.2008.8.1.29
Kim JH, Kim I, Woo SI (1991) Computer simulation study of ethylene polymerization rate profile catalyzed over highly active Ziegler-Natta catalysts. Ind Eng Chem Res 30: 2074–2079
Hutchinson RA, Chen CM, Ray WH (1992) Polymerization of olefins through heterogeneous catalysis X: Modeling of particle growth and morphology J Appl Polym Sci 44: 1389–1414
Gemoets F, Zhang M, Karjala TW, Kolthammer BWS (2010) Kinetic study of ethylene homopolymerization in slurry using a Ziegler-Natta catalyst. Macromol React Eng 4: 109–122
Alshaiban A, Soares JBP (2012) Effect of hydrogen and external donor on propylene polymerization kinetics with a 4th-generation Ziegler- Natta catalyst, Macromol React Eng 6: 265–274
Matsko MA, Echevskaya LG, Zakharov VA, Nikolaeva MI, Mikenas TB, Vanina MP (2009) Study of multi-site nature of supported Ziegler- Natta catalysts in ethylene-hexene-1 copolymerization. Macromol Symp 282: 157–166
Zheng ZW, Shi DP, Su PL, Luo ZH, Li XJ (2010) Steady-state and dynamic modeling of the basell multireactor olefin polymerization process. Ind Eng Chem Res 50: 322–331
Kissin YV, Mink RI, Nowlin TE (1999) Ethylene polymerization reactions with Ziegler–Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism. J Polym Sci Pol Chem 37: 4255–4272
Kissin YV (1995) Molecular weight distributions of linear polymers: detailed analysis from GPC data. J Polym Sci Pol Chem 33: 227–237
Soares JBP (1994) Dynamic mathematical modelling of polymerization of olefins using heterogeneous and homogeneous Ziegler-Natta catalysts. PhD Thesis, McMaster University, Ontario
Chen K, Mehdiabadi S, Liu B, Soares JBP (2016) Estimation of apparent kinetic constants of individual site types for the polymerization of ethylene and α-olefins with Ziegler–Natta catalysts. Macromol React Eng 10: 551-556
Flory PJ (1937) The mechanism of vinyl polymerizations1. J Am Chem Soc 59: 241–253
Kissin YV, Mink RI, Nowlin TE, Brandolini AJ (1999) Kinetics and mechanism of ethylene homopolymerization and copolymerization reactions with heterogeneous Ti-based Ziegler–Natta catalysts. Top Catal 7: 69–88
Kissin YV (1995) Kinetics of olefin copolymerization with heterogeneous Ziegler-Natta catalysts. Macromol Symp 89: 113–123
Orbey H, Bokis CP, Chen C (1998) Equation of state modeling of phase equilibrium in the low-density polyethylene process: The Sanchez−LaCombe, statistical associating fluid theory, and polymer-Soave−Redlich−Kwong Equations of State. Ind Eng Chem Res 37: 4481–4491
Kissin YV (2001) Main kinetic features of ethylene polymerization reactions with heterogeneous Ziegler–Natta catalysts in the light of a multicenter reaction mechanism. J Polym Sci Pol Chem 39: 1681–1695