Different hydrodynamic model for gas-phase propylene polymerization in a catalytic fluidized bed reactor

The flow state of both the solid and gas phase in the fluidized-bed photo-oxidation reactor for Shenfu coal was studied by cold-model tests. The results showed that the appropriate pipe diameter, particle size of coal, and the coal addition for the gas-solid fluidized-bed reactor were 22 mm, 60-80 mesh, and 10g, respectively.

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The Phase Transformations during Fluidized-Bed Combustion of Biomass

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.419.366 ◽

2013 ◽

Vol 419 ◽

pp. 366-369 ◽

Cited By ~ 2

Author(s):

Hai Peng Teng ◽

Bin Yang ◽

Bin Liang

Keyword(s):

Gas Phase ◽

Fluidized Bed ◽

Solid Phase ◽

Fluidized Bed Reactor ◽

Biomass Combustion ◽

Material Surface ◽

Fluidized Bed Combustion ◽

Biomass Ash ◽

Equilibrium Modeling ◽

Bed Material

FactSage6.1 was used to study the phase transformation at high temperature when biomass combustion in a fluidized bed reactor. The results show that eutectic was formed during the reaction process, the eutectics are formed mainly by the reaction between the silica in bed particles and the alkali species in biomass ash. The solid phase transformed to melt layer on the surface of sands particle mainly contains potassium, some calcium and magnesium, and also a few phosphorus and chlorine are found in the melt layer. The result utilizing FactSage equilibrium modeling shown that the distribution ratio of potassium in the gas phase increased with the increase of temperature, moreover, the melt of bed material surface increased when defluidized occurred.

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Comparative simulation study of gas-phase propylene polymerization in fluidized bed reactors using aspen polymers and two phase models

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111214038s ◽

2013 ◽

Vol 19 (1) ◽

pp. 13-24 ◽

Cited By ~ 6

Author(s):

Ahmad Shamiria ◽

M.A. Hussaina ◽

Farouq Mjallic ◽

Navid Mostoufid

Keyword(s):

Molecular Weight ◽

Gas Phase ◽

Production Rate ◽

Fluidized Bed ◽

Average Molecular Weight ◽

Phase Model ◽

Propylene Polymerization ◽

Flow Index ◽

Fluidized Bed Reactors ◽

Two Phase

A comparative study describing gas-phase propylene polymerization in fluidized-bed reactors using Ziegler-Natta catalyst is presented. The reactor behavior was explained using a two-phase model (which is based on principles of fluidization) as well as simulation using the Aspen Polymers process simulator. The two-phase reactor model accounts for the emulsion and bubble phases which contain different portions of catalysts with the polymerization occurring in both phases. Both models predict production rate, molecular weight, polydispersity index (PDI) and melt flow index (MFI) of the polymer. We used both models to investigate the effect of important polymerization parameters, namely catalyst feed rate and hydrogen concentration, on the product polypropylene properties, such as production rate, molecular weight, PDI and MFI. Both the two-phase model and Aspen Polymers simulator showed good agreement in terms of production rate. However, the models differed in their predictions for weight-average molecular weight, PDI and MFI. Based on these results, we propose incorporating the missing hydrodynamic effects into Aspen Polymers to provide a more realistic understanding of the phenomena encountered in fluidized bed reactors for polyolefin production.

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