Currently in Cuba, working on a new way for the purification of biogas by using natural zeolite membranes. In the study 10 synthesis membranes made from different mass values zinc oxide. System operation with removal percentages between 53 and 100% are achieved, with the higher values when the membranes have greater mass of ZnO (s). The Knudsen number calculation allows knowing the diffusion mechanism that occurs in the membranes, being the Fick, which allows the calculation of the specific flow of H2S (g) is transferred to membranes.