Determination of optimal reaction temperature and hydrogen amount for propylene polymerization by a mathematical model

Abstract

Regarding the complexity of Ziegler-Natta catalyst kinetics in polypropylene polymerization, so far, there is no adequate model to determine the best process conditions for predicting average molecular weight and dispersity as the most crucial final product properties index. Consequently, a validated model has been developed which describes the relationship between the kinetic model and the existing gap using the polymer moment balance approach. It was concluded that increasing reaction temperature and hydrogen amount are useful and improve the final product indices to a certain limit, but afterwards they have harmful effects on the indices.

Investigating the effect of co-catalyst on the final product properties and the yield of ziegler–natta catalyst in propylene polymerization in optimum temperature reaction in absence of hydrogen via mathematical model

“…The used materials and Experimental polymerization procedure are exactly in a similar way that described in detail in the previous works and not repeated here for the sake of brevity [3,12]. In this study, a commercial catalyst was used.…”

“…In this study, the assumptions for modeling are: (1) It was supposed that propylene polymerization was carried out in the amorphous phase (2) the amorphous phase concentrations during polypropylene polymerization were at the thermodynamic equilibrium condition that obeys the one from Sanchez and Lacombe equation (SLE) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. 2It was assumed that γ1 = γ2 = ••• = γNC, where γ is equilibrium constant and NC are several solvents in slurry phase components [2].…”

“…1. The proposed model of this study is the developed model of the previous work [3,12]. In this model, the co-catalyst reaction equations from Table 1 were added to the model and the program is run based on the co-catalyst performance in the polymerization.…”

“…In this research, we attempted to investigate these issues to cover the existing gap by using a mathematical model and comparing its outputs with an experimental result at the optimal temperature reaction, i.e. 70 °C, in absence of hydrogen [3].…”

“…Varshouee et al performed a computational study by proposing a new validated model based on kinetics study and found that hydrogen has directly impact on final properties so that increasing hydrogen amount in the recipe of the polymerization causes to decreasing of Average Molecular Weights; and also leads to higher activated sites percent on the surface catalyst [3,10]. They conducted a comprehensive study on Final Product Properties and Kinetics Studies of the polymerization [11][12][13][14] and compared the outputs coming from their model with the experimental results to prove their model and explained the reasons that justify their model was validated [12], then they found that 70 °C is the optimum temperature in their study [3].…”