Gas absorption in a fluidized-bed column

Abstract

Fluidized-bed column is an interesting technique in gas absorption process. It can be operated at high gas and liquid velocities with low pressure drop. In this work, the fluidized-bed composed of light weight spheres of uniform size, special types of gas distributor and liquid distributor were used to perform uniform fluidization at both high and low velocities of liquid and gas. The first part of the experiment concerned with the study of hydrodynamic characteristics of column in which air and water flowed counter-currently. Hydraulic resistance of bed, minimum fluidization velocity, gas hold-up and liquid hold-up were determined. The variable parameters studied were liquid velocity, gas velocity, and bed height. Correlation of various variables in fluidized-bed column was compared with those in the literature. In the second part, mass transfer coefficients of ammonia were studied. Liquid velocity, gas velocity, bed height, and concentration of ammonia gas were used as variable parameters. The results were summarized and also compared with fixed bed absorbers. The values of mass transfer coefficient expressed in term of Sherwood number can be represented as follows: Sh = 7.17 x 10⁹. Fr[superscript 0.495]. ReL[superscript 0.442]. (Dc/Hs)[superscript 0.621]