БІОГАЗОВА УСТАНОВКА СІЛЬСЬКОГОСПОДАРСЬКОГО МАШИНОБУДУВАННЯ МЕТАНОВОГО БРОДІННЯ БУРЯКОВОГО ЖОМУ

Abstract

The relevance of the study is due to the need to increase the productivity of biogas plants due to the expansion of the raw material base. In Ukraine in 2022, 23 sugar factories were operating, the waste from which is beet pulp. It would be possible to build a biogas plant near each of these factories, the raw material for which would be sugar beet processing waste. The purpose of the work is to determine the optimal volume of loading beet pulp into the methane tank to obtain the maximum yield of biogas. The research was carried out at a laboratory biogas installation consisting of a methane tank with a useful volume of 30 liters and a “wet” type gas holder. The methane tank operated with a periodic system of raw material loading. The temperature of the substrate was 38 °С. 2.1 kg, 1.5 kg, 1 kg, 0.5 kg and 0.25 kg of beet pulp with pH=3.69 was added to 20 liters of digestate. The content of beet pulp in the substrate was 10.5; 7.5; 5.0 and 2.5%, 1.25%. With all variants of pulp content in the substrate, the maximum biogas output was obtained the next day after loading the substrate into the methane tank. At the same time, the pH of the substrate decreased sharply. Subsequently, methane fermentation of the pulp occurs in accordance with the way it is carried out for other types of substrates: after reaching the stationary phase on the first day of methane fermentation, a die-off phase is observed, during which the population of methanogens decreases due to depletion of substrate nutrients. At this time, the pH of the substrate gradually increased and reached its initial value at the end of methane fermentation. As a result of the study, it was established that beet pulp is successfully subjected to methane fermentation without the addition of cattle manure when loading up to 10% of the volume of the substrate. However, the increase in the loading volume of beet pulp leads to a decrease in the yield of biogas.The maximum yield of biogas during the fermentation of beet pulp with a periodic system of loading the methane tank is observed already on the next day, and after two days the yield of biogas decreases sharply. The optimal content of beet pulp when loading it into a methane tank, at which the biogas output will be maximum (1.762 l/(h. kg of CO)) is 2.3%.