Layered Pressure Swing Adsorption for Methane Recovery from CH4/CO2/N2 Streams

In this paper we discuss the performance of Layered PSA (Layered Pressure Swing Adsorption) for methane/carbon dioxide/nitrogen separation for methane upgrading from contaminated natural gas. A four-step PSA cycle was defined using extrudates of zeolite 13X (selective for carbon dioxide) and CMS 3 K (nitrogen selective) in a layered packed bed. Ternary breakthrough curves are reported as well as PSA experiments using a stream composition of 70% CH4–20% CO2–10% N2. Purity of methane of 92% with no carbon dioxide contamination and 43.5% recovery was obtained.