Modifying effects of hydrogen sulfide on the rheometric properties of liquid elemental sulfur

Handling molten sulfur is inherently difficult due to liquid sulfur's extreme rheological behavior. Upon melting at 115°C, sulfur's viscosity remains low until reaching 160°C, the λ‐transition region, where the viscosity increases to a maximum of 93,000 × 10−3 Pa s at 187°C. Within this study, our previous viscosity measurements for pure liquid elemental sulfur have been discussed along with new measurements on sulfur containing physically and chemically dissolved hydrogen sulfide (H2S). H2S is always incorporated into industrial sulfur which has been recovered through the modified Claus process in gas plants and oil refineries. Using the experimental data from this study, a semi‐empirical correlation model was reported based on the reptation model of Cates to estimate the impact of H2S on liquid sulfur's viscosity as a function of temperature. The equation can be applied to commercial sources of sulfur with 0–500 ppm of total dissolved H2S.