The pure-component adsorption properties of DD3R zeolite were evaluated for various light gases such as H-2, CH4, CO2, CO, and N-2 in a wide temperature range of (195-473) K. These properties, representing the macroscopic results of the microscopic zeolite species interactions, are expressed in terms of parameters of both Langmuir and Sips adsorption models. Furthermore, the CH4/CO2 adsorption selectivity in binary mixture calculated based on the ideal adsorption solution theory (IAST) is also reported as a function of temperature and pressure, showing the actual separation performance of DD3R as adsorbent mean. A number of experimental literature data were considered in order to cover these wide temperature and pressure ranges, wider than available in previous works. A comparative analysis of the two models and the literature data is also provided, showing also the increase of the calculation uncertainty with increasing number of model parameters using the dual-Langmuir model as an instance. The calculated adsorption parameters will be useful to different end-users and purposes, e.g., from zeolites used as adsorbents to zeolites used as membranes in a number of applications ranging from the laboratory to the industrial scale.