TITLE Experimental characterization of mass transfer mechanisms by ert634


									D i r e c t i o n d e l a R e c h e r c h e Te c h n o l o g i q u e
L a b o r a t o i r e d ’ I n n o va t i o n p o u r l e s Te c h n o l o g i e s
d e s E n e r g i e s n o u ve l l e s e t l e s N a n o m a t é r i a u x
D é p a r t e m e n t d e s Te c h n o l o g i e s S o l a i r e s
L a b o r a t o i r e d e s S ys t è m e s Th e r m i q u e s

 Date :             17/12/2010                   Subject :          Post-doctoral proposition

 Place :            CEA Grenoble                 Duration : 12 months from March 2011 to February 2012

                    Zoé Anxionnaz
                    Commissariat à l’Energie Atomique et aux Energies Alternatives - LETH
  Contact : 17 rue des Martyrs, 38054 Grenoble cedex 9, France
                    Tel. : +33 (0)4 38 78 35 67
                    Mail : zoe.anxionnaz@cea.fr

TITLE: Experimental characterization of mass transfer mechanisms into three-phase
bubble columns.

The global energy demand in industry and transport fields is a major challenge for refining
industry for the next decades. For the energy systems of the future (BTL, CTL and GTL
processes) and to optimize the use of present energy resources, the development of
innovative refining conversion processes is necessary. Among those processes, the
hydroprocessing of heavy oil and residue aims at upgrading heavier fractions into lighter
Three-phase reactors (gas/liquid and solid catalyst) can be considered. They undergo very
complicated interactions between each phase. Therefore, the study and understanding of
mass transfer phenomena is a determining step to bring the technology at industrial scale.
TOTAL/RM and CEA/LETH intend to perform a post-doctoral study in this field.
It aims at developing an experimental method to measure and characterize the mass
transfer mechanisms in a three-phase reactor. The main objective is then to increase the
understanding of mass transfer phenomenon to assure the best performances of the

Task 1: Literature review on mass transfer phenomena in three-phase bubble columns (T0 –
 T0+3 mois)
A literature review on available data about mass transfer mechanisms in three-phase bubble
columns will be done. The main objectives are to select the measurement method that will be
implemented in the experimental column and to define the experimental program according
to the measurements uncertainties identified in the literature.

Task 2: Experimental characterization of the mass transfers (T0+1 – T0+10 mois)
The tests will be done in an existing Plexiglas bubble column (15 cm diameter) which will be
adapted to the selected measurement method in task 1. Preliminary and parametric tests will
be done in order to check the measure sensitivity to operating parameters (gas and liquid

Commissariat à l’énergie atomique
Centre de Grenoble - 17, rue des Martyrs - 38054 - Grenoble cedex 9
Tél : 33 - Fax : 33 - - mail : zoe.anxionnaz@cea.fr
superficial velocities, bed expanding, properties of the gas and liquid phases, percentage of
solid,…). The main objectives of this task are first to remove the uncertainties on mass
transfer mechnisms in three-phase bubble columns and then to start the study about the
influence of the scale-up process on mass transfer performances.

Task 3: Theoretical study and modelling of the mass transfers (T0+6 – T0+12 mois)
A physical modelling, of the mass transfer aspects of the reactor will be done, based on
Matlab or Excel. The experimental results will be correlated to the fluid properties and to the
geometrical parameters of the column. The correlations will be compared to experimental
and simulation data available in the literature.

Task 4: Study and implementation of mass transfer determination in large scale columns
(T0+6 – T0+12 mois)
This task will be done from the literature data and the experimental and modelling results. It
concerns the study of the implementation of the measurement method in a scaled-up column
and/or the scale-up of the experimental results obtained in the 15 cm diameter column.

Required skills:
PhD thesis in chemical and process engineering or fluid mechanics (simple and multiphase
flows) with chemical engineering background.

Key words:
Experimental approach, mass transfer, gas/liquid/solid interactions, scale-up, bubble column

Commissariat à l’énergie atomique
Centre de Grenoble - 17, rue des Martyrs - 38054 - Grenoble cedex 9
Tél : 33 - Fax : 33 - - mail : zoe.anxionnaz@cea.fr

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