Identifying Optimal Zeolitic Sorbents for Sweetening of Highly Sour Natural Gas.

Raw natural gas is a complex mixture comprising methane, ethane, other hydrocarbons, hydrogen sulfide, carbon dioxide, nitrogen, and water. For sour gas fields, selective and energy-efficient removal of H2 S is one of the crucial challenges facing the natural-gas industry. Separation using nanoporous materials, such as zeolites, can be an alternative to energy-intensive amine-based absorption processes. Herein, the adsorption of binary H2 S/CH4 and H2 S/C2 H6 mixtures in the all-silica forms of 386 zeolitic frameworks is investigated using Monte Carlo simulations. Adsorption of a five-component mixture is utilized to evaluate the performance of the 16 most promising materials under close-to-real conditions. It is found that depending on the fractions of CH4 , C2 H6 , and CO2 , different sorbents allow for optimal H2 S removal and hydrocarbon recovery.