Abstract
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.
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Abbreviations
- d p :
-
The diameter of the equivalent sphere (mm)
- g :
-
Gravity force (m/s2)
- Hs:
-
High of solid in the column (cm)
- Ms:
-
Mass of sold (kg)
- U g :
-
Superficial gas velocity (m/s or cm/s)
- U l :
-
Superficial liquid velocity (ms or cm/s)
- U mf :
-
Minimum liquid fluidizing velocity (m/s or cm/s)
- V b :
-
Volume of the bed (cm3)
- V p :
-
Volume of the particles (cm3)
- ɛ b :
-
Bed porosity
- ɛ g :
-
Gas holdup in the dispersed bed (–)
- ɛ l :
-
Liquid holdup in the dispersed bed (–)
- ɛ b :
-
Solid holdup in the dispersed bed (−)
- ρ g :
-
Density of gas (kg/m3)
- ρ l :
-
Density of liquid (kg/m3)
- ρ s :
-
Density of solid (kg/m3)
- μ l :
-
Liquid viscosity (mPa s)
- μ g :
-
Gas viscosity (mPa s)
- σ :
-
Gas–Liquid surface tension (kg/s2)
- ΔP :
-
Pressure drop (kPa)
References
Begovich JM, Watson JS (1978) Hydrodynamic characteristics of three-phase fluidized beds. In: Keairns DL, Davidson JF (eds) Fluidization. Cambridge University Press, Cambridge, pp 190–195
Brekken RA (1968) Gas fluidization of wheat flour in a stirred bed. Ph. D dissertation, Iowa State University
Burck GM, Kodama K, Markeloff RG, Wilson SR (1975) Co-current three-phase fluidized bed: part 2, report number. ORNL-MIT-213, Oak Ridge Station School of Chemical Engineering Practice, Massachusetts Institute of Technology, USA
Darton RC, Harrison D (1974) The rise of single gas bubbles in liquid fluidized beds. Trans Instn Chem Engrs 52:301
Fan LS (1989) Gas–liquid–solid fluidization engineering. Butterworth series in chemical engineering, Butterworth Publishers, Boston, MA. https://doi.org/10.1016/0017-9310(90)90132-E
Fan LS, Bavarian F, Gorowara RI, Kreischer BE (1987) Hydrodynamics of gas–liquid–solid fluidization under high gas holdup conditions. Powder Technol 53(3):285–293. https://doi.org/10.1016/0032-5910(87)80101-8
Fan LS, Lee DJ, Luo X, Tsuchiya K, Yang GQ (1999) Some aspects of high-pressure phenomena of bubbles in liquid and liquid-solid suspensions. Chem Eng Sci 54:4681–4709
Han JH, Kim SD (1990) Radial dispersion and bubble characteristic in three-phase fluidize beds. Chem Eng Comm 94:9–26
Jiang P, Arters D, Fan LS (1992) Pressure effects on the hydrodynamic behavior of gas–liquid–solid fluidized beds. Ind Eng Chem Res 31(10):2322–2327
Kressmann S, Boyer C, Colyar JJ, Schweitzer JM, Viguie JC (2000) Improvements of ebullated-bed technology for upgrading heavy oils. Oil Gas Sci Technol Rev IFP 55(4):397–406. https://doi.org/10.2516/ogst:2000028
Lin TJ, Tzu CH (2003) Effects of macroscopic hydrodynamics on heat transfer in a three-pase fluidized bed. Catal Today 79–80:159–167. https://doi.org/10.1016/S0920-5861(03)00021-X
Massimilla L, Solimando A, Squillance E (1961) Gas dispersion in solid-liquid fluidized beds. Brit Chem Eng 232
Page RE, Harrison D (1972) The size distribution of gas bubbles leaving a three-phase fluidized bed. Powder Technol 6:245
Paweł M (2011) Scaling flow phenomena in circulating fluidized bed boilers. Chem Process Eng 32(2):91–100. https://doi.org/10.2478/v10176-011-0008-4
Pjontek D (2014) Fluid dynamic studies in support of an industrial ebullated bed hydroprocessor. Ph D. thesis, University of Ottawa, Canada
Ramos G, García M, Prieto JJ, Guardiola J (2002) Minimum fluidization velocities for gas–solid 2d beds. Chem Eng Process 41(9):761–764. https://doi.org/10.1016/S0255-2701(02)00005-3
Rana MS, Samano V, Ancheyta J, Dıaz JAI (2007) A review of recent advances on process technologies for upgrading heavy oils and residua. Fuel 86:1216–1231. https://doi.org/10.1016/j.fuel.2006.08.004
Ruiz RS, Alonso F, Ancheyta J (2005) Pressure and temperature effects on the hydrodynamic characteristics of ebullated-bed systems. Catal Today 109:205–213. https://doi.org/10.1016/j.cattod.2005.08.019
Safoniuk M (1999) Dimensional similitude and the hydrodynamics of three-phase fluidized beds. PhD thesis, Department of Chemical and Bio-Resource Engineering, the University of British Columbia Vancouver, BC, Canada
Safoniuk M, Grace JR, Hackman L, Mcknight CA (2002) Gas hold-up in a three-phase fluidized bed. AIChE J 48(7):1581–1587. https://doi.org/10.1002/aic.690480720
Scheweitzer JM, Kressman S (2004) Ebullated bed reactor modeling for residue conversion. Chem Eng Sci 59:5637–5645. https://doi.org/10.1016/j.ces.2004.08.018
Shin I, Sung-Mo S, Yong K, Suk-Hwan K, Sang-Done KS (2007) Phase holdup characteristics of viscous three-phase inverse fluidized beds. J Ind Eng Chem 13(6):971–978
Silva EL (1999) Hydrodynamic characteristics and gas–liquid mass transfer in a three phase fluidize bed reactor. Proceedings of 15th Brazilian Congress of Mechanical Engineering, November 22–26, São Paulo
Sivalingam A, Kannadasan T (2009) Effect of fluid flow rates on hydrodynamic characteristics of co-current three-phase fluidized beds with spherical glass bead particles. Int J Chem Tech Res 1(4):851–855 (ISSN: 0974–4290)
Song GH, Farshad B, Fan HS, Buttke RD, Peck LB (1989) Hydrodynamics of three-phase fluidized bed containing cylindrical hydrotreating catalysts. Can J Chem Eng 67(2):265–275. https://doi.org/10.1002/cjce.5450670213
Speight JG (2000) The desulfurization of heavy oils and residua. Marcel Dekker, New York. ISBN 0-8247-8921-0
Yang Tao (2011) Research and development of strong ebullated bed residue hydrotreating technology. Proceedings of the 4th Japan-China-Korea Petroleum Technology Congress on February 22–24, Tokyo
Yuandong L, Gao L, Wen L, Zong B (2009) Recent advances in heavy oil hydroprocessing technologies. Recent Patents Chem Eng 2(1):22–36 (ISSN 2211–3347)
Zhang XH, Shaw JM (2006) Impact of multiphase behavior on coke deposition in heavy oils hydroprocessing catalysts. Energy Fuels 20:473–480
Zhang JP, Grace JR, Epstein N, Lim KS (1997) Flow regime identification in gas-liquid flow and three-phase fluidized beds. Chem Eng Sci 52:3979–3992. https://doi.org/10.1016/S0009-2509(97)00241-8
Acknowledgements
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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Abid, M.F., Ahmed, S.M., Hasan, H.H. et al. Hydrodynamic Study of an Ebullated-bed Reactor in the H-oil Process. Iran J Sci Technol Trans Sci 43, 829–838 (2019). https://doi.org/10.1007/s40995-018-0669-7
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DOI: https://doi.org/10.1007/s40995-018-0669-7