The Use of Straw Pellets with the Addition of Crude Glycerin for the Intensification of Biogas Production during the Anaerobic Fermentation of Cow Manure

Cow manure is a good substrate for producing biogas, since it already contains methanogens. Almost its only drawback is the low productivity of biogas output. The disadvantage of cattle manure is its low biogas yield, to increase which it is proposed to add granulated straw with the addition of crude glycerin. The aim of the work is to increase the biogas yield by adding straw granules containing crude glycerin to the main substrate based on cattle manure. To achieve this goal, the following tasks need to be solved: to determine the biogas and methane yield during methane mono-fermentation of cattle manure and combined methane fermentation of cattle manure with straw granules containing crude glycerin; using a mathematical model, to predict the cumulative biogas and methane yield during methane mono-fermentation of cattle manure and combined methane fermentation of cattle manure with straw granules containing crude glycerin. The novelty of the chosen topic is that for the combined methane fermentation of cattle manure and straw pellets with crude glycerin, the cumulative yield of biogas and methane was determined, which for 30 days is 293.7 l/kg of dry organic matter (DOM) and 143.5 l/kg of DOM, respectively. The significance of the results is that the results of the research can be used in industrial biogas plants in a quasi-continuous loading mode. In this case, the predicted methane yield will be 0.449 l/h⋅kg of DOM, which is higher than with mono-fermentation of cow manure, which is 0.365 l/h⋅kg of DOM.