Mass transfer phenomena in an airlift reactor: effects of solids loading and temperature
1Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
Abstract:
Gas holdups and volumetric mass transfer coefficients were measured in a concentric tube airlift reactor designed for the microbial desulfurization of coal. The solutions studied were comprised of an acidified basal salts solution containing thirteen different weight percentages (0 to 40) of coal (74 microm Ohio #1) at three different temperatures (30, 50, and 72 degrees C). Gas holdup epsilon(G) decreased with solids loading for the entire range studied. An enhancement in the volumetric mass transfer coefficient K(L)a with respect to that in pure solution was observed from zero to approximately 5 wt % (solids volume fraction epsilon(s) = 0.035), the maximum enhancement occurring at approximately 2 wt % (epsilon(s) = 0.014). At higher solids fractions, the mass transfer coefficient decreased with further solids additions. Gas holdups and the mass transfer coefficients increased with temperature over the studied range. The K(L)a and epsilon(G) were correlated to three process variables separately and the separate correlations combined to yield generalized correlations for the mass transfer coefficient and gas holdup for this system. The correlations may be used for design, operation, and ost estimation of such systems.
Related Concept Videos
Bioreactor Controls-II
Lift
Bioreactor Design and Operational System
Accelerating Fluids
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
Atomic Spectroscopy: Effects of Temperature
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
Steady, Laminar Flow in Circular Tubes


