Experimental Study of the Effect of Catalyst Properties on Hydrodynamics and Mass Transfer in a Slurry Reactor

Abstract

This work was devoted to study the influence of well-known catalyst carriers (activated utilized in catalytic reactions carbon and silica) on the hydrodynamic parameters and mass transfer rate in a slurry reactor. The influence of silica and activated carbon particles concentration up to 20% v/v on regime transition, average gas holdup, mass transfer coefficient, and CO₂ removal was studied in a semi- batch slurry bubble column reactor (SBC) with a porous gas sparger. The effects of hydrophobicity and surfactant were also investigated. It was concluded the gas holdup is reduced and the point of transition from laminar to turbulent regime is shifted to less gas velocity when the hydrophobic and hydrophilic particles concentration was larger than 3% (v/v). The Particle hydrophobicity, gas velocity, and electrolyte concentration have positive impacts on gas holdup while slurry concentration gave a different trend. Experimental results show that the optical fiber probe is valid to use in a slurry bubble column and can also generate useful data such as bubble rise velocity and bubble distribution. The optical fiber probe was proved to be good technique for estimation of volumetric mass transfer coefficient within an error of ±18%.  Mass transfer experiments with gaseous CO₂ showed a behavior of removal in the same trend of increasing gas holdup with gas velocity. A noticeable removal of gaseous pollutants was observed for non-wettable particles at solid loading of 3%v/v. Mathematical correlations were formulated for CO₂ removal as function of studied operating variables with correlation factors of 0.95-0.98. The present study depicts the effect of catalyst carrier on the hydrodynamic characteristics and mass transfer in a slurry reactor.