Elemental mercury partitioning in high pressure fluids part 2: Model validations and measurements in multicomponent systems

A good understanding of the solubility of elemental mercury over wide ranges of temperature, pressure and composition is an important issue to assess the possibility of mercury dropping out in gas processing streams. In this work, new mercury solubility in three multicomponent systems with methane content varying between 89 - 26 mol% have been measured over a wide range of temperature (243.15 to 323.15 K) and pressure and up to 20 MPa. A group contribution method for the Peng-Robinson equation of state has been used to allow calculation of binary interactions between mercury and saturated hydrocarbons, aromatic hydrocarbons, nitrogen and carbon dioxide. The parameters of the group contribution have been adjusted using mercury solubility previously measured in single components. Predictions of the developed model are validated against independent experimental data and the data generated in this work. A good agreement between predictions and experimental data is observed, supporting the reliability of the developed model. (C) 2020 Elsevier B.V. All rights reserved.