Hydrodynamic Study of an Ebullated-bed Reactor in the H-oil Process

Study on an Ebullated-bed Reactor in the H-oil Process
  • Mohammad Fadhil AbidEmail author
  • Shakir Mahmood Ahmed
  • Halah Hussein Hasan
  • Dawood Al-Mously
  • Shahzad Barghi
Research Note


The effectiveness and performance of industrial hydro-processing ebullated bed reactors (EBRs) are highly dependent on the bed hydrodynamics and operating conditions. Hydrodynamics of ebullated bed reactors was studied in a cold model experimental setup. The results of a dynamic similarity test showed that the experimental data could be applied in the study of a large scale unit (Refinery of Lukoil, Burgas, Bulgaria) within a reasonable accuracy. Air and magnesium sulfate 20 wt% (MgSO4 + H2O) solution and solid catalyst particles were used as the gas, liquid and solid phases, respectively. For the design of experiments in the lab-scale cold-flow column, factorial method was introduced to study the influence of operating variables on the individual holdups and bubble characteristics. Pressure gradient method was used to estimate the individual holdups and bed porosity along the column, while photographic method was utilized to obtain images of the moving gas bubble. The images were analyzed using Ai Adobe illustrator CC (64 Bit) software to determine the bubbles geometric characteristics. Large gas bubbles were broken to smaller ones due to the increased turbulent intensity and shear forces at higher liquid velocities, reducing mass transfer resistances. Empirical correlations were developed for prediction of phase holdups and bed porosity with high accuracy. The results showed that liquid internal reflux ratio, which characterized the ebullated bed reactors has a predominant effect on the individual holdups and bubble size. A good agreement was observed between the results and available data in the literature.


Fluidization Ebullated bed reactor Phase holdups Bubble characteristics 

List of Symbols


The diameter of the equivalent sphere (mm)


Gravity force (m/s2)


High of solid in the column (cm)


Mass of sold (kg)


Superficial gas velocity (m/s or cm/s)


Superficial liquid velocity (ms or cm/s)


Minimum liquid fluidizing velocity (m/s or cm/s)


Volume of the bed (cm3)


Volume of the particles (cm3)


Bed porosity


Gas holdup in the dispersed bed (–)


Liquid holdup in the dispersed bed (–)


Solid holdup in the dispersed bed (−)


Density of gas (kg/m3)


Density of liquid (kg/m3)


Density of solid (kg/m3)


Liquid viscosity (mPa s)


Gas viscosity (mPa s)


Gas–Liquid surface tension (kg/s2)


Pressure drop (kPa)



Authors are thankful to the Department of Chemical Engineering-University of Technology for providing facilities and space where the present work was carried out. The authors gratefully acknowledge the Petroleum Research and Development Center-Ministry of Oil-Iraq for believing in this project and for their generosity in sponsoring the work (Grant Number {3721/15-8-2013}).


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Copyright information

© Shiraz University 2019

Authors and Affiliations

  • Mohammad Fadhil Abid
    • 1
    Email author
  • Shakir Mahmood Ahmed
    • 2
  • Halah Hussein Hasan
    • 1
  • Dawood Al-Mously
    • 3
  • Shahzad Barghi
    • 3
  1. 1.Chemical Engineering DepartmentUniversity of TechnologyBaghdadIraq
  2. 2.Ministry of Oil, SCOPBaghdadIraq
  3. 3.Faculty of Chemical and Biochemical EngineeringWestern UniversityLondonCanada

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