Study of Technological Process of Fermentation of Molasses Vinasse in Biogas Plants

The volume of ethanol production waste-molasses waste in Ukraine-reaches up to 4 million m(3) per year. It is not easy to dispose of and is polluting the environment. Currently, the development of an effective technology for using molasses in biogas plants to obtain energy gas-biogas-is an urgent problem. The purpose of our work is to determine the rational volume of loading molasses bard into the methane tank in a quasi-continuous mode to obtain the maximum volume of biogas. To achieve this goal, the following experimental studies were carried out: mono-fermentation of molasses and combined fermentation of cattle manure and molasses on a laboratory biogas plant in a periodic mode; on the basis of the obtained laboratory studies, a special simulation model of biogas output during the quasi-continuous fermentation of substrates was established and the amount of molasses added to obtain the maximum biogas output was determined. The maximum output of biogas under the periodic system of loading the methane tank when adding 10.5% molasses to cattle manure is 1.462 l/(h kg DOM); when adding 26.1% molasses to cattle manure, it is 3.594 l/(h kg DOM). In order to increase the yield of biogas, it is advisable to add molasses in the amount of 30% of the volume of the substrate to the substrate based on cattle manure, which allows the discounted payback period of the biogas plant to be reduced to 1.2 years.

Automated summary

The volume of ethanol production waste-molasses waste in Ukraine reaches up to 4 million m(3) per year and is causing environmental pollution. The development of an effective technology for using molasses in biogas plants to obtain energy gas-biogas is urgently needed. The goal of this study was to determine the optimal volume of molasses bard loaded into the methane tank in a quasi-continuous mode to maximize biogas production. Experimental studies were conducted on a laboratory biogas plant to determine the maximum biogas output based on different molasses compositions. The results showed that adding 10.5% and 26.1% molasses to cattle manure resulted in the highest biogas output under the periodic loading system. Adding molasses in the amount of 30% of the substrate volume based on cattle manure is recommended to increase biogas production.