(575ap) Hydrodynamic and Mass Transfer Parameters of Gases in Organic Liquids Under Fischer-Tropsch Conditions

The Fischer-Tropsch (F-T) synthesis appears to be a promising technology to help reduce the dependence of our society on oil and diversify our energy sources towards more environmentally friendly and sustainable forms of energy. Converting Coal or Biomass into clean Liquid fuels is one of the many attracting aspects of the F-T process. However the scaleup of F-T reactors, such as Slurry Bubble Column Reactors (SBCRs) or Ebulating Bed Reactors (EBRs) still remains a difficult task due to their complex hydrodynamics and lack of knowledge of the heat and mass transfer parameters.

The present study focuses on the determination of the volumetric mass transfer coefficients (k_La), gas holdup (ε_G), Sauter mean bubble diameter (d_S), bubble size distribution, and axial/radial catalyst distributions for H₂, CO, or surrogate components (N₂ and He) in a highly branched isoparaffinic Polyalphaolefin of 8 cSt kinematic viscosity (ExxonMobil SpectraSyn 8) and Sasol wax in the presence and absence of solid catalytic particles. The data are determined under high pressures and temperatures as well as different superficial gas and liquid velocities, and catalyst concentrations typical to those employed in industrial F-T synthesis. The experiments are performed in a small scale Zipper-Clave stirred tank reactor of 4 Liters operating in a gas inducing mode and in a large-scale hot SBCR/EBR of 1-ft diameter and 10-ft height. The effect of operating variables, including pressure, temperature, gas and liquid velocities, solid loading on these hydrodynamic and mass transfer parameters are investigated.