High performance gas-phase ethylene polymerization metallocene catalyst investigation in a pilot-plant fluidized bed reactor (1) experimental analysis

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.

Download Full-text

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.

Download Full-text

Modeling of Ethylene Polymerization with Ziegler-Natta Catalyst in a Bubbling Fluidized Bed Reactor

10.32920/ryerson.14660778.v1 ◽

2021 ◽

Author(s):

Neda Felorzabihi

Keyword(s):

Molecular Weight ◽

Kinetic Model ◽

Fluidized Bed ◽

Ethylene Polymerization ◽

Fluidized Bed Reactor ◽

Polymerization Reaction ◽

Solid Catalyst ◽

Gas Temperature ◽

Natta Catalyst ◽

Ziegler Natta Catalyst

In the present study, a new dynamic fluidized bed reactor (FBR) model is developed to account for the effect of bubble growth in the bed height on the dynamic behaviour of the reactor and the molecular properties of the polymer product. The model takes into account the existence of solid catalyst in both phases and consequently, the occurrence of polymerization reaction in both bubble and emulsion phases. A dynamic two-phase model is employed for predicting the key hydrodynamic parameters of the bed. A comprehensive kinetic model for ethylene polymerization in the presence of multiple-site Ziegler-Natta catalyst is considered to describe the number and molecular weight averages and molecular weight distribution of polymer in the FBR. The hydrodynamic model and the kinetic model have been coupled and solved simultaneously to simulate the performance of the fluidized bed reactor. The study incorporates the effects of the most important reactor parameters such as superficial gas velocity, mean particle size, inlet gas temperature, bubble size, recycle stream and chain transfer agent on the steady-state behaviour of the FBR. The proposed dynamic model is capable of predicting both the performance of the reactor and the polymer physiochemical properties.

Download Full-text