A Mathematical Model for Investigating the Effect of Reaction Temperature and Hydrogen Amount on the Catalyst Yield during Propylene Polymerization

Abstract

In this study, the effect of reaction temperature and hydrogen amount, as the most effective process variables on the Ziegler-Natta catalysts yield during propylene polymerization, was investigated with the aid of a validated mathematical model. The approach applied in this modelling was the <i>polymer moment balance technique</i> (<i>population balance approach</i>) derived from the statistics expected value. The model was coded in MATLAB<sup>®</sup> & Simulink<sup>®</sup>, and then validated by experimental data coming from a laboratory-scale reactor. The main target of this study was to gain considerable insight into Ziegler-Natta catalyst performance against variables change. The model might be applicable for catalyst makers to evaluate and improve their catalysts, and could also be useful for process chemical engineers to easily operate the plant, replace new catalyst, optimise process conditions, generate new formulation for a new grade, and use maximum catalytic potential. Accordingly, the model could be applied in basic and applied research in this field.

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].…”

“…RT Equations (2) and (3) could be used for obtaining Ea and Kd and ultimately for checking validation of the model [12].…”

“…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.…”

“…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].…”