Prediction of gas holdup in a combined loop air lift fluidized bed reactor using Newtonian and non-Newtonian liquids

Abstract

Many experiments have been conducted to study the hydrodynamic characteristics of column reactors and loop reactors. In this present work, a novel combined loop airlift fluidized bed reactor was developed to study the effect of superficial gas and liquid velocities, particle diameter, fluid properties on gas holdup by using Newtonian and non-Newtonian liquids. Compressed air was used as gas phase. Water, 5% n-butanol, various concentrations of glycerol (60 and 80%) were used as Newtonian liquids, and different concentrations of carboxy methyl cellulose aqueous solutions (0.25, 0.6 and 1.0%) were used as non-Newtonian liquids. Different sizes of spheres, Bearl saddles and Raschig rings were used as solid phases. From the experimental results, it was found that the increase in superficial gas velocity increases the gas holdup, but it decreases with increase in superficial liquid velocity and viscosity of liquids. Based on the experimental results a correlation was developed to predict the gas hold-up for Newtonian and non-Newtonian liquids for a wide range of operating conditions at a homogeneous flow regime where the superficial gas velocity is approximately less than 5 cm/s.

Bacillus based microbial formulations: Optimization of the production process

“…Capacity of oxygen transfer through a vessel is determined on the basis of the oxygen mass transfer coefficient (kLа). In addition to directly applying experimental methods such as sulfite oxidation method, adsorption or a dynamic method, kLа can be predicted by using some of the empirical correlations available, that have shown a satisfactory accuracy [105,106]. For a standard Erlenmeyer flask, existing correlations usually take into account the specific interphase area and the stirring rate [107].…”

Comparative study of advanced oxidation treatment of tannery effluent in Multi-orifice Oscillatory Baffled Column with sono-catalytic treatment using Titanium Dioxide

“…Many contactors like bubble columns, packed columns, sparged agitated vessels have been used for operating gas liquid and liquid-liquid systems and mass transfer has been evaluated (Preethi et al 2008;Sivakumar Venkatachalam et al 2011). New techniques like baffling and pulsating have been studied for effective contacting, the Oscillatory Baffled Column is one which (OBC) combines the effects of baffling and oscillation thereby reducing the bubble size and increasing the contact area and the multi-orifice will increases the rate of mass transfer between multiple streams (Raf Dewilet al 2017).…”