An empirical correlation-based model to predict solid-fluid phase equilibria and phase separation of the ternary system CH4-CO2-H2S

To cover the expected increased demand for natural gas, energy industry has to exploit sour gas reserves located around world. However, acid gases have be removed before produced from these fields could used. One of novel concepts in this field is utilization solid phase formation carbon dioxide and/or hydrogen sulfide. The main aim study develop an empirical correlation model based on Peng-Robinson equation state (PR EoS), with fugacity expressions, that able first time describe solid-fluid equilibria ternary system CH4-CO2-H2S at pressures 5 30 bar and over a wide range temperature (130–200 K). was tested binary systems CH4-CO2, CO2-H2S CH4-H2S optimized interaction parameters. When proven successful, it then expanded predictive manner CH4-CO2-H2S. predictions solidification points different mixtures were within acceptable error when compared experimental data available literature. A equilibrium stage separation unit used three feed compositions system. Overall, found CO2 improves increasing operating pressure up 20 bar, decreases higher temperatures. Similarly, H2S either liquid or lower recovery CH4 high entire ranges conditions, expect (30 Bar) temperatures below 190 K. This work provides scientists engineers accurate tool may confidence predicting equilibria. Consequently, eliminates difficulties associated need experiments