Adsorption is one of the key technologies for the removal of sulfur compounds in trace levels from natural gas prior to a technical. utilization. To improve the design of these coupled adsorption- desorption processes a profound insight into the thermodynamics of adsorption is necessary. Therefore, this article provides adsorption isotherms of ethyl mercaptan, methyl mercaptan, hydrogen sulfide, water, and carbon dioxide on a commercial silica-alumina gel used in natural gas purification. The experimental data spans a temperature range between 25 and 300 degrees C at concentrations between 0 and 2000 mol-ppm at total pressure of 1.3 bar. Equilibrium capacities and isosteric heats of adsorption are compared and discussed based on an analysis of specific interactions between the adsorptives and the adsorbent's chemical surface functionality.