Reference correlation for the viscosity surface of hydrogen sulfide

Until recently, there was a substantial lack of reliable viscosity data for H ₂S, making the regression of an accurate H ₂S viscosity model significantly difficult. To derive a model for engineering applications (2008 H ₂S model), a corresponding states approach that related molecules of similar shape to H ₂S was applied to cover regions where no experimental data was available. Recently, new primary low-density experimental data and derived theoretical information have been published. Additionally, new high-pressure H ₂S viscosity measurements [at (373.15 and 423.15) K and up to 100 MPa] have also been reported. Based on this, a new revised correlation for the viscosity of H ₂S is presented in this work. The current correlation reproduces the primary H ₂S viscosity data to within experimental uncertainty. The precision of the new correlation varies from reference quality (better than ± 0.20 %) at low-densities to an estimated ± 5 % at 100 MPa and temperatures between (373 and 423) K. Outside this range of temperature there are no data to validate the accuracy of the model at elevated pressures; therefore we have conservatively estimated an uncertainty of roughly 10 % in the low-temperature and high-density region (T < 323 K up to 100 MPa) and 5 % for the high-temperature region (T > 450 K up to 100 MPa).