The need for fundamental data describing the dissolution of hydrogen sulfide, H2S, in Claus recovered liquid sulfur prompted an examination of equilibrium H2S solubility at typical industrial condensation temperatures and partial pressures. An FT/IR absorption technique has been described and new H2S solubility measurements have been reported for partial H2S pressures from 0.4 to 56kPa and temperatures from 120 to 155 degrees C. The measurements were combined with previously reported values for atmospheric pressures of H2S and used to calibrate a semi-empirical equation for the Henry's law solubility in liquid sulfur as a function of temperature. Estimations were compared to Claus plant field data and appear to underestimate the H2S solubility for the first and second catalyst condenser stages. This underestimation was attributed to rapid condensation resulting in super-saturation of the recovered sulfur liquid, or an inaccurate measurement of the condensation temperatures. (c) 2008 Elsevier B.V. All rights reserved.