The article covers the results of a theoretical investigation for dung and livestock manure anaerobic fermentation process, substantiated the structural technological scheme and operating modes of the biomethane installation. An investigation complex was carried out on the basis of substantiating the parameters of the technological process, equipment of a biomethane installation, where the goal is to increase the efficiency of substrate processing. Based on the analysis, it was found that the biomethane discharge is one of the main characteristics of processing the substrate, and this moment was taken as the main criterion for optimization work. The rational modes and parameters of the biomethane installation were determined using the mathematical method of planning a multifactorial experiment. The influence of the temperature for the fermentation process of the substrate, the time of mixing the substrate and the number of revolutions of the heat-exchanging mixer on the biogas discharge was established. The influence of design factors, including various factors, was carried out using mathematical statistics and mathematical modeling, where the dependence of the biogas discharge on the temperature of the substrate fermentation process, the time of mixing the substrate and the number of revolutions of the heat exchanging mixer were obtained. The proposed biomethane installation has passed production and laboratory tests in order to optimize the parameters of various capacities for their operation in various regions of the country, the creation of an experimental installation operating in the thermophilic mode, including the stage of preliminary preparation of livestock manure biomass in the technological chain, obtaining liquid and solid fertilizers and other waste-free technology products.