Two-phase modeling of a gas phase fluidized bed reactor for the fluorination of uranium tetrafluoride

2008 ◽  
Vol 35 (12) ◽  
pp. 2321-2326 ◽  
Author(s):  
M.H. Khani ◽  
H. Pahlavanzadeh ◽  
M. Ghannadi
2006 ◽  
Vol 61 (12) ◽  
pp. 3997-4006 ◽  
Author(s):  
Ali Kiashemshaki ◽  
Navid Mostoufi ◽  
Rahmat Sotudeh-Gharebagh

2018 ◽  
Vol 156 ◽  
pp. 07002
Author(s):  
Nazratul Fareha Salahuddin ◽  
Ahmad Shamiri ◽  
Mohd Azlan Hussain ◽  
Navid Mostoufi

A modified two-phase model for gas phase propylene and ethylene copolymerization was chosen to represent the process in a fluidized bed reactor. This model considered the entrainment of solid particles in the reactor, as a modification to the original two-phase model assumptions. The non-linearity of this process makes it difficult to control just by using conventional controller such as PID. A hybrid control strategy (a simple designed fuzzy logic controller (FLC) integrated with generic model control (GMC)) is designed to control the temperature of the reactor. This advanced control system was compared with the GMC and conventional PID controller. The simulation results showed that the hybrid controller (Fuzzy-GMC) performed better than both GMC and PID in terms of both servo and regulatory control.


2011 ◽  
Vol 312-315 ◽  
pp. 1079-1084 ◽  
Author(s):  
Ahmad Shamiri ◽  
Mohd Azlan Hussain ◽  
Farouq S. Mjalli

A two-phase model is proposed for describing the dynamics of a fluidized bed reactor used for polypropylene production. In the proposed model, the fluidized bed is divided into an emulsion phase and bubble phase where the bubble phase flow pattern is assumed to be plug flow and the emulsion phase is considered to be perfectly mixed. Similar previous models consider the reaction in the emulsion phase only. In this work the contribution of reaction in the bubble phase is considered and its effect on the overall polypropylene production is investigated. The kinetic model combined with hydrodynamic model in order to develop a comprehensive model for gas-phase propylene copolymerization reactor. Simulation profiles of the proposed model were compared with those of well mixed model for the emulsion phase temperature. The simulated temperature profile showed a lower rate of change compared to the previously reported models due to lower polymerization rate. Model simulation showed that about 13% of the produced polymer comes from the bubble phase and this considerable amount of polymerization in the bubbles should not be neglected in any modeling attempt.


1996 ◽  
Vol 51 (5) ◽  
pp. 713-723 ◽  
Author(s):  
M. Foka ◽  
J. Chaouki ◽  
C. Guy ◽  
D. Klvana

2011 ◽  
Vol 201-203 ◽  
pp. 2741-2744
Author(s):  
Ya Ting Zhang ◽  
Guang Heng Wang ◽  
Wei Zhao ◽  
An Ning Zhou

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.


2013 ◽  
Vol 419 ◽  
pp. 366-369 ◽  
Author(s):  
Hai Peng Teng ◽  
Bin Yang ◽  
Bin Liang

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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