Biogas is a renewable and low-carbon alternative to fossil fuels that can be upgraded to biomethane, which is suitable for injection in natural gas grids, transportation and industrial applications. Since it mainly consists of methane (CH4) and carbon dioxide (CO2), an upgrading step is required to achieve methane content of 95-99%. Membrane separation has become widely used for biogas upgrading due to its low energy demand, modularity and absence of chemical solvents. In particular, polyimide (PI) systems such as UBE membranes, currently represent the most established industrial solution for this application, owing to their mature technology and reliable performance. In parallel, zeolite-based membranes, such as CHA-type SSZ-13, have emerged as high-performance materials of growing interest, due to their well-defined pore structure and potentially superior separation properties.