Prediction of Gas Holdup in a Three-Phase Internal Loop Airlift Fluidized Bed Reactor Using Newtonian and non-Newtonian Liquids

The effect of superficial gas and liquid velocities, particle diameter and sphericity, physical and rheological properties of liquids on gas holdup were studied in a three phase internal loop airlift fluidized bed reactor. Air was used as a gas phase. Water, n-butanol, various concentrations of glycerol (60 % and 80 %) were used as Newtonian liquids and different concentrations (0.25 %, 0.6 % and 1.0 %) of carboxy methyl cellulose (CMC) solutions were used as non-Newtonian liquids. Spheres, Bearl saddle and Raschig ring with different diameters were used as solid phases. Superficial gas velocity varied from 0.000142 m/s to 0.005662 m/s and superficial liquid velocity varied from 0.001 to 0.12 m/s. The experimental result shows that increase in particle size and superficial gas velocity increases gas holdup and decreases with increase in concentration of Newtonian and non-Newtonian systems. Based on the experimental results a separate correlation was developed to predict gas holdup for both Newtonian and non-Newtonian liquids for wide range of operating conditions