This article presents the results of a study of the process of cleaning biogas obtained from biomass (dung substrate) from carbon dioxide and other harmful impurities, using a group of crystalline aluminosilicates called zeolites. The cleaning process was carried out directly in an experimental complex device. The nomogram constructed based on the results of experimental studies, the effect of the level of biogas purification with zeolite on its composition and quality, showed that reducing the intensity of the change of the adsorbent (zeolite) in the treatment plant from 7 to 1 day, increases the degree of purification from 25 to 75 %, reducing the amount of harmful components in the composition of biogas from 33 to 12 %, and also increases the share of the useful component of biogas (methane gas) from 65 to 86 %, while increasing the calorific value of combustion from 23 to 31 mJ.