Large (100 cm² membrane area) tubular chabazite (CHA) zeolite membranes (450 nm thick) were experimentally evaluated for the separation of CO₂/CH₄ in an industrial laboratory. An industrially relevant feed flow rate of 250 Ndm³/min was used. The feed pressure and temperature were varied in the ranges of 5–18 bar and 292–318 K, respectively. For a CO₂/CH₄ feed with a molar ratio of 1:1, the experimental CO₂/CH₄ selectivity was high at 205, and the CO₂ permeance arrived at 52 × 10^–7 mol/(m²·s·Pa) at 5 bar and 292 K. As far as we know, there is no report in the literature on large CHA membranes with such high permeability and selectivity. A high CO₂/CH₄ selectivity was also observed for a 1:4 CO₂/CH₄ feed. However, as indicated by mathematical modeling, concentration polarization was still an issue for membrane performance, especially at high operating pressures, even though the flow rate of the feed was relatively high. Without concentration polarization, the theoretical CO₂/CH₄ selectivity was 41% higher than the experimental value for a 1:1 CO₂/CH₄ feed at 18 bar. The corresponding CO₂ permeance without concentration polarization was 23% higher than the experimentally observed value, reaching 34 × 10^–7 mol/(m²·s·Pa). CHA membrane processes for the removal of CO₂ from CH₄ were designed, and the electricity consumption and module cost of the process were also estimated. All of the results in this study indicate a great potential of the large CHA membranes for biogas and natural gas upgrading; however, concentration polarization should be minimized in industrial processes.