Measurements of H2S solubility in aqueous diisopropanolamine solutions and vapour pressure of diisopropanolamine

Phase equilibrium measurements were conducted for H2S + water + diisopropanolamine (DIPA) systems with a static total pressure method. The measured systems had DIPA mass fractions from 0.10 to 0.35. Each DIPA solution was measured at several temperatures ranging from 322 K to 353 K. The measurements were successfully described with an electrolyte NRTL-model that was earlier presented in the literature even at the lowest DIPA mass fractions. The vapour pressure of pure DIPA was measured with a distillation method within a temperature range from 420 K to 465 K. An Antoine equation for the vapour pressure of pure DIPA is proposed based on measurements from this work and from the literature. Also an expression for the density of water + DIPA solutions was developed using measurements found in the literature.

► H2S into DIPA solubility data was measured at T (from 322 K to 353 K) and DIPA mass fractions from 0.10 to 0.35.
► Vapor pressure of pure DIPA was measured (420–465 K).
► A new density model for the aqueous DIPA system as a function of temperature and composition was developed.