Study on the Effect of Dedicated Microelement Mixture (DMM) on the Kick-Off Phase of the Digester and Stabilization of the Methane Fermentation Process

The kick-off process is an important aspect of the proper operation of an agricultural biogas plant. At this stage, various operational problems may arise, mainly related to the stabilization of the fermentation process and reaching the full biogas production capacity. This paper presents the results of research on the kick-off of the fermentation process carried out on three selected biogas plants located in Poland. For the experiments, titration, potentiometric, and spectroscopic methods (ICP-MS) were used. The biogas plants during the kick-off period operated on the following substrates: a mixture of cattle and pig manure, corn silage, and whey liquor. Special attention was paid to the dosing process of the formulation developed by the authors (CMP-S1) containing Mo, Co, Ni, Se, and Mn for the fermentation chambers, to which the mixture of the selected microelements was not dosed. The study was carried out under real conditions on an engineering scale. The study showed that supplementing a dedicated mixture of microelements (DMM) in the first days of fermentation chamber kick-off has a positive effect on stabilizing the methane fermentation process and allows a faster and higher loading of fermenters with dry organic matter. The above translates into shortening the time (by more than half) of the kick-off process in the fermentation chamber, as well as brining about a significant reduction in costs.