Influence of particles and electrolyte on gas hold-up and mass transfer in a slurry bubble column

Ruthiya, KC; van der Schaaf, J; Kuster, BFM; Schouten, JC

HERO ID

4947149

Reference Type

Journal Article

Year

2006

HERO ID 4947149
In Press No
Year 2006
Title Influence of particles and electrolyte on gas hold-up and mass transfer in a slurry bubble column
Authors Ruthiya, KC; van der Schaaf, J; Kuster, BFM; Schouten, JC
Journal International Journal of Chemical Reactor Engineering
Volume 4
Abstract In this paper, the influence of carbon and silica particle slurry concentration up to 20 g/l (4 vol%) on regime transition, gas hold-up, and volumetric mass transfer coefficient is studied in a 2-dimensional slurry bubble column. From high speed video image analysis, the average large bubble diameter, the frequency of occurrence of large bubbles, the gas-liquid interfacial area, and the large bubble hold-up are obtained. The liquid side mass transfer coefficient is calculated from the volumetric mass transfer coefficient and the gas-liquid interfacial area. The lyophilic silica particles are rendered lyophobic by a methylation process to study the influence of particle wettability. The influence of organic electrolyte (sodium gluconate) and the combination of electrolyte and particles is also studied. It is found that lyophilic silica, lyophobic silica, and lyophobic carbon particles at concentrations larger than 2 g/l (0.4 vol%) decrease the gas hold-up and shift the regime transition point (where the first large bubbles appear) to a lower gas velocity. The volumetric mass transfer coefficient increases with gas velocity, increases with electrolyte concentration, decreases with slurry concentration, and is higher for lyophobic particles. The liquid side mass transfer coefficient increases with gas velocity, bubble diameter, and is higher for lyophobic particles. A correlation for the mass transfer coefficient based on dimensionless numbers is proposed for the heterogeneous regime.
Wosid WOS:000236517000004
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Dupe Override No
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Keyword slurry bubble column; regime transition; mass transfer; gas hold-up; catalyst support; lyophobicity; high speed video imaging