Structural effects of alcohols on H₂S solubility and thermodynamic modeling of binary mixtures with benzyl alcohol, phenol, and ethanol

The solubility of hydrogen sulfide in benzyl alcohol, phenol, and ethanol was experimentally investigated at low to medium pressures over temperature ranges of 313.15–353.15 K, 318.15–353.15 K, and 303.15–333.15 K, respectively. The results were compared with literature data for methanol, propanol, butanol, ethylene glycol, diethylene glycol, triethylene glycol, and thiodiglycol to study the effect of molecular structure on H₂S absorption. The experimental data were obtained using a static method and were correlated using two modeling approaches: (1) a thermodynamic approach using the Peng–Robinson–Stryjek–Vera (PRSV) equation of state with the Panagiotopoulos–Reid (PR) mixing rule, and (2) a genetic programming (GP) approach. The average and maximum relative deviations ( ARD / MRD %) for the PRSV/PR EoS are 0.96/3.04% for benzyl alcohol, 1.72/8.07% for phenol, and 1.03/4.79% for ethanol, respectively. For the genetic programming approach, these values are 3.24/20.38%, 6.38/30.19%, and 4.43/21.30%, respectively, indicating that the PRSV/PR model produces superior results compared to the GP model. The solubility trend of H₂S in the studied alcohols, diols, and triols follows the order: TEG > phenol > DEG ≈ benzyl alcohol > butanol ≈ thiodiglycol > propanol > methanol > ethanol > propanediol > ethanediol.