TITLE: Experimental characterization of mass transfer mechanisms
Transcription
TITLE: Experimental characterization of mass transfer mechanisms
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 : [email protected] 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 products. 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 process. 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 - 04.38.78.35.67 Fax : 33 - 04.38.78.51.61 - mail : [email protected] 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 - 04.38.78.35.67 Fax : 33 - 04.38.78.51.61 - mail : [email protected] 2/2