Biogas upgrading in Africa remains a huge challenge for producers of small installations due to the high cost of acquisition of all-in-one installations designed and used in developed countries. This study brings a clear idea on some purification methods accessible to these small producers while proposing those optimal for decarbonation and desulphurization of biogas. Starting from the analysis over time of the biogas resulting from the anaerobic digestion of cow dung, the system of NaOH filters and steel wool mounted in series is the one proposed for optimality (with purification capacities respective CO2 of the order of 95.9063 ± 0.0864 % and H2S of 100 %). Better still, the use of a steel wool filter in series with activated carbon (based on coconut shells or bamboo) makes it possible to increase the desulfurization capacity of the latter up to 100 %.