Modelling of elemental mercury solubility in natural gas components

Elemental mercury is a natural occurring trace component of fossil fuels, which poses significant health and safety risks during oil and gas processing due to its highly toxic and corrosive nature. In order to anticipate and control the distribution of mercury during industrial processes, there is a necessity for thermodynamic models, which can accurately predict its partitioning in the various phases. In this work, the UMR-PRU model is extended to systems that contain elemental mercury and is employed for predicting its solubility in hydrocarbons, compressed gases, water and methanol. A comparison is also made between UMR-PRU and the two most widely used equations of state, Soave-Redlich-Kwong and Peng-Robinson, with modified attractive terms. The results reveal that all three models can accurately describe the solubility of mercury in the aforementioned compounds, with UMR-PRU being the most accurate.