Acidic gas absorption by methanol: System modeling and simulation

Acidic gas abatement plays a key role both in energy production systems and chemical plants due to the need of emission containment and catalyst activity preservation. H2S and CO2 capture is usually accomplished by chemical or physical absorption. In this paper, the attention is focused on H2S and CO2 removal from H2‐rich streams using methanol as physical absorbent. A thermodynamic model (with proper interaction parameters regressed from binary vapor-liquid equilibrium data) that ensures a reliable description of the equilibrium conditions for the mixtures of interest over a wide range of temperature and pressure, is proposed. This model has been used within the Aspen Plus® software frame, along with a carefully chosen set of equations for heat and mass transfer, for simulating a pilot scale absorption plant whose experimental data are available. Simulation results are in good agreement with experimental evidence.