Modeling the Effect of Concentration H2S and CO2 on the Formation of a Hydrate of a Mixture Close in Composition to Natural Gas

The application of energy-efficient and environmentally friendly gas hydrate crystallization technology for the purpose of purifying natural gas from hydrogen sulfide (H2S) and carbon dioxide (CO2). The work presents thermodynamic modeling of the influence of concentrations H2S and CO2 from 1.00 to 20.00 mol % on the dissociation pressure of gas hydrates and filling of gas hydrate cavities with a gas mixture of CH4–C2H6–C3H8–n-C4H10–CO2–H2S–N2 in the temperature range of 273.15–283.15 K. It was found that increasing the concentration of H2S leads to a significant decrease in the dissociation pressures of gas hydrates. Filling of small gas hydrate cavities with H2S molecules reaches 0.91. Increase in CO2 concentration leads to a slight increase in the dissociation pressures of gas hydrates. It was found that CO2 poorly concentrated in the gas hydrate phase of the gas mixture under consideration. To extract CO2 it is necessary to use multiple gas hydrate crystallization or the use of natural gas deposits with low concentrations C3H8.