In this paper n-hexane is chosen as typical volatile in condensed mode polymerization process, and the adsorption equilibrium of volatile in polyethylene particles is studied through experiments at different temperatu...In this paper n-hexane is chosen as typical volatile in condensed mode polymerization process, and the adsorption equilibrium of volatile in polyethylene particles is studied through experiments at different temperatures, pressures and particle diameters. It is found that more adsorbed quantity of volatile at equilibrium can be obtained with lower temperature, higher pressure and smaller particle diameter. Under polymerization conditions, the adsorbed quantity at equilibrium is more strongly affected by temperature than by pressure, and if the diameter distribution of particles is very wide the effect of diameter on the adsorbed quantity must be taken into consideration. With theoretical analyses a model is proposed for calculating the adsorbed quantity of volatile at equilibrium.展开更多
In this paper the desorption kinetics of volatile in condensed mode polyethylene process is studied through experiments. It is found that though the residual volatile in particles at the later stage of desorption acco...In this paper the desorption kinetics of volatile in condensed mode polyethylene process is studied through experiments. It is found that though the residual volatile in particles at the later stage of desorption accounts for a relatively small portion of the total quantity, the desorption of this part of volatile requires much longer time than at the earlier stage. For high requirement of devolatilization, the total time needed will be predominately determined by the residual amount of volatile in particles. Temperature has greater effect on the desorption rate than other influence factors, especially in the later period of desorption. A model is proposed to calculate the volatile desorption rate for condensed mode polyethylene process.展开更多
文摘In this paper n-hexane is chosen as typical volatile in condensed mode polymerization process, and the adsorption equilibrium of volatile in polyethylene particles is studied through experiments at different temperatures, pressures and particle diameters. It is found that more adsorbed quantity of volatile at equilibrium can be obtained with lower temperature, higher pressure and smaller particle diameter. Under polymerization conditions, the adsorbed quantity at equilibrium is more strongly affected by temperature than by pressure, and if the diameter distribution of particles is very wide the effect of diameter on the adsorbed quantity must be taken into consideration. With theoretical analyses a model is proposed for calculating the adsorbed quantity of volatile at equilibrium.
文摘In this paper the desorption kinetics of volatile in condensed mode polyethylene process is studied through experiments. It is found that though the residual volatile in particles at the later stage of desorption accounts for a relatively small portion of the total quantity, the desorption of this part of volatile requires much longer time than at the earlier stage. For high requirement of devolatilization, the total time needed will be predominately determined by the residual amount of volatile in particles. Temperature has greater effect on the desorption rate than other influence factors, especially in the later period of desorption. A model is proposed to calculate the volatile desorption rate for condensed mode polyethylene process.
