(615g) Separation of Methane/Nitrogen Using Ionic Liquidic Zeolites (ILZ) By Pressure Swing Adsorption: Modelling and Pilot Demonstration

Methane (CH₄) is an important clean energy among fossil fuels. For the same power output, the combustion of methane produces less than half CO₂ compared with coal, and nearly no sulphur oxides or particulate matters. However, the separation of methane and nitrogen poses significant challenge to the enrichment and utilization of low concentration methane due to the similarity in the physical and chemical properties of both molecules. In this work, we investigated the separation of methane from nitrogen using a new ionic Liquidic zeolite (ILZ) material and a pressure swing adsorption process. The effects of operational conditions including desorption pressure and feed gas flowrates were analysed using a numerical model built on the Aspen Adsorption platform. Results demonstrated that determining the optimum desorption pressure is crucial to achieve high product purity, avoid methane loss and minimize energy consumption. Low feed gas flowrate led to inefficient separation while high feed gas flowrate resulted in column breakthrough and energy efficiency drop. Pilot plant tests further demonstrated that the prediction using this model is reliable and the capture of low concentration methane from nitrogen showed energy benefits.