Modeling of mass transfer and hydrodynamic investigation of H2S removal from molten sulfur using porous Sparger

Empirical and theoretical aspects of non-catalytic molten sulfur degassing as one of the vital actions in Claus Unit have been investigated in this article. A laboratory bubble column has been set up to study the hydrodynamic behavior of gas-liquid system. Values of gas holdup were also compared with predictions of some correlations in the case of application of porous spargers. The mathematical model of degassing was also developed considering reaction of H 2 S with sulfur molecules in the molten sulfur and generation of H 2 S x species. The experimentally-measured parameters of gas holdup and bubble size were used in the mathematical model. Other parameters including Henry’s law constant of H 2 S-liquid sulfur system and reaction rate constants were obtained from published formulas presented by Marriott and Ji, respectively. The obtained results were compared to the empirical data of non-catalytic degassing performed in the laboratory setup. Reasonable compatibility was observed between the model-derived and experimental results. The results showed a fast removal of dissolved H 2 S within few minutes, followed by very slow removal of H 2 S x through its chemical conversion to H 2 S and its purging by sweep gas. The novel gas holdup profile and images presented in this article show interesting features of hydrodynamic behavior of molten sulfur.