Two-phase modeling of a gas phase polyethylene fluidized bed reactor

Fluidized Bed Polyethylene Reactor Modeling in Condensed Mode Operation

“…In the proposed models in the literature for the fluidized bed reactors in the dry mode operation, the most attention has been on the kinetics [13,14] and particularly on the hydrodynamic and flow regimes of the gas and powder phases in the reactor. [7][8][9][10][11][12] However, the fluid phase equilibrium has not been studied extensively. Almost in all of these proposed models, Henry's law has been assumed to consider solubility of low molecular weight components such as ethylene and hydrogen in the polyethylene powders.…”

“…[7][8][9][10][11][12] Some of them [7][8][9][10] have employed the simple two-phase model, which assumes all of the excess gas required for the minimum fluidization passes through the bed as solid free bubbles, whereas the emulsion stays at the minimum fluidization conditions. Others [11,12] were employed the dynamic two-phase model, which takes into account that the emulsion phase does not remain at minimum fluidization condition beyond the minimum fluidization velocity of the gas stream and the bubbles may contain the polymer particles.…”

“…It has been shown that the heat-removal rate can be further increased by adding nonpolymerizing condensable materials to raise the dew point of the recycle gas stream. [5,6] Although several models have been proposed to describe the performance of the fluidized bed reactor for olefin polymerization in the literature, [7][8][9][10][11][12] however, in all of these cases only the dry mode operation has been considered.…”

Modeling of Carbochlorination of Zircon in Fluidized Bed Reactor

“…The exchange of gaseous species was simplified accordingly to be between the bubble and emulsion phases like earlier. [15][16][17][18][19] (c) The gas compositions in the bubble and emulsion phases changed with bed height, but the solids were mixed uniformly throughout the bed. (d) Horizontal variations of gas concentrations in each phase could be neglected.…”

“…Detail descriptions of the reactor are available elsewhere. [10] Manieh et al [10] used an electrothermal reactor (reactor is composed of the following items: (1) gas preheating section, (2) fluidizing section, (3) disengaging section, (4) reactor cover, (5) distributor plate, (6) gas exit tube, (7) supporting plate, (8) central electrode, (9) level sensing electrode, (10) bed thermocouple well, (11) solids feed line, (12) fused alumina tube, (13) fiberfrax alumina fiber, (14) carbon black, (15) refractory bricks, (16) fireclay bricks, (17) transited sheet, (18) refractory cement, and (19) steel angles) to carry out the chlorination of zircon. The experimental conditions used by Manieh et al [10] are shown in Table II.…”