A modelling study of H2S absorption in pure water and in rainwater

Abstract

Hydrogen sulphide (H2S) in the flue gas is a major air pollutant of concern, and is usually treated through absorption in a scrubber in many industries such as petroleum and chemical industries. However, this gas treating process requires enormous amount of pure water which is not a desirable process for water scarce countries like Singapore. Since Singapore receives a copious amount of rainfall, rainwater is attractive for many industrial applications including the removal of H2S through absorption. However, no data are currently available in the literature on H2S solubility in rainwater. In this study, the model which best fits the phase behaviour of H2S in various aqueous solution was developed using Gamma/Phi formulation for vapour-liquid equilibrium (VLE), with means of equation of state (EOS) and activity function. By applying the model, the solubility of H2S in rainwater was studied as a function of temperature, pressure, presence of electrolyte and pH.