Enthalpies of absorption of hydrogen sulfide in aqueous diethanolamine solutions

Abstract

An isothermal flow calorimeter was used to measure the enthalpies of absorption of hydrogen sulfide in aqueous 2.0, 3.5 and 5.0 M diethanolamine (DEA) solutions. The experimental temperature and pressure ranges were 299.9–399.9 K and 0.087–1.121 MPa respectively. The calorimetric data were found to be useful in determining the equilibrium concentrations of H 2S in the DEA solutions. Enthalpy of absorption and equilibrium concentration data for H 2S-aqueous DEA systems are reported. The enthalpy of absorption of H 2S in aqueous DEA solutions was found to be independent of pressure, and linearly dependent on temperature and concentration. An equation is given for predicting the enthalpy of absorption over the ranges of temperature, pressure and concentration investigated.