Experimental study of mass transfer and H 2S removal efficiency in a spray tower

Abstract

The aim of this study was to characterise the mass transfer parameters and H 2S removal efficiency in a laboratory-made spray tower designed for deodorisation. In order to study mass transfer, the volumic interfacial area ( a) and the volumic mass transfer coefficient ( k L a) were estimated. The influences of both superficial liquid and gas velocities were quantified ( U L from 4.1 × 10 −5 to 4.6 × 10 −4 m s −1, U G from 9.4 × 10 −3 to 2.8 × 10 −2 m s −1). It could be shown that the superficial liquid velocity has a slight influence on the mass transfer parameters whereas the variation of the superficial gas velocity influences them much more. Then H 2S removal efficiency was studied at pH 10 in the presence or not of an oxidant, sodium hypochlorite. The results demonstrated that as soon as the chlorination rate reached 0.5 g Cl 2 L −1, more than 99% of the hydrogen sulphide is removed.