Sensitivity analysis of the H2S breakthrough curve in a column packed with type 13X zeolite: Parametric study of pressure swing adsorption process for CO2 separation and biomethane production

Biomethane is a renewable energy source obtained by purifying biogas, removing impurities such as H 2 S and CO 2 . The removal of H 2 S is essential due to its toxicity and corrosiveness, protecting equipment and improving process efficiency. Pressure Swing Adsorption (PSA) is used to separate CO 2 , which produces a methane-rich gas. This process is efficient, clean, and key to utilizing biogas as a substitute for natural gas. This study aims to perform a sensitivity analysis on the H 2 S removal stage using a packed column with 13X zeolite, and to conduct a parametric study of the PSA process to identify input variables that significantly affect CO 2 adsorption and achieve high-purity biomethane (above 99%). Comparative results showed that a pressure of 10 b a r at a temperature of 298 K achieved the lowest H 2 S removal (1100 p p m ), in a period of 4000 s ; however, the highest H 2 S removal was achieved at 2 b a r and 440 K , reaching 1500 p p m removal in 900 s . In the case of CO 2 retention, the input variables that have the least effect on biomethane purity and that present the least adsorption of CO 2 were the feed pressure and purge pressure variables, achieving a biomethane purity between the ranges of 97.53 % and 98.86 % and adsorbing between 0.35 to 0.38 molar fraction using only 0.6 m of the total bed length. On the other hand, the input variables that achieved the highest adsorption capacity (0.5 molar fraction) were temperature and composition, achieving to use the longest length of the packed bed (0.8 m ) and reaching a biomethane purity of 99.05%, which meets established international criteria to be used as biofuel. • A detailed sensitivity analysis of H 2 S adsorption on 13X zeolite was performed. • A full PSA model was developed using rigorous PDEs and Aspen Adsorption™. • PSA simulations identified key variables affecting CO 2 adsorption and biomethane purity. • Feed and purge pressures had the least impact on CO 2 adsorption and purity. • Temperature and composition strongly increased CO 2 uptake and bed utilization.