Abstract
Post-alcohol distillery waste is an environmental pollutant, which determined the relevance of its disposal. One of the ways to utilise post-alcohol distillery waste is through its anaerobic methane destruction in biogas plants. The research aims to determine the optimal amount of post-alcohol distillery wastes to be added to the substrate to achieve maximum biomethane yield. The research was conducted on a laboratory biogas plant consisting of a 30-litre digester and a gas holder in a mesophilic mode at a substrate temperature of 40°C with a periodic substrate loading mode. It was found that the highest biogas yield of 5.369 l/(h×kg DOM) was obtained by anaerobic methane mono-degradation of post-alcohol distillery waste. However, the methane content in the biogas is in the range of 48-52%. During the anaerobic methane destruction of a mixture of post-alcohol distillery waste with cow manure, the methane content in biogas increases to 70-76%, but the biogas yield is lower and is 4.577 l/(h×kg DOM) at 36% post-alcohol distillery waste content in the substrate, 3.294 l/(h×kg DOM) at 27%, 2.960 l/(h×kg DOM) at 18%, 1.538 l/(h×kg DOM) at 9%. The optimum content of post-alcohol distillery waste in the substrate, at which the biomethane yield will be maximum (3.821 l/(h×kg DOM)), is 46.7% of the substrate content and 100% of the organic part of the substrate. The results of this study can be used in planning the composition of the substrate of biogas plants and designing and building new biogas plants near distilleries