Potapova M. Biogas production technology at grain distillery spent wash fermentation

The thesis is devoted to the scientific and technical fundamentals of technology for grain distillery spent wash processing with biogas production. The dependence of the biogas output on the ratio of the substrate components, namely DSW and poultry manure, has been determined, which allows to increase the yield of the target product - biogas and the methane content in it. The main parameters of the methanogenesis process are considered in this paper. The optimum temperature and inoculum content in the mixture, in which the maximum biogas output from this raw material is observed, is experimentally determined. As the technology involves a semi-continuous process of distillery spent wash processing, which is ensured by the constant replacement of the part of the fermented mixture with a fresh distillery spent wash, the frequency of substitution data and the amount of substrate replaced is determined. The effect of the granular anaerobic active sludge on the treatment process the liquid fraction of the digested substrate mix: DSW, poultry manure and wastewater for biogas output on this stage was demonstrated. The mathematical model of the biogas output dependence on the pH value and the substitution volume of a substrate part on the raw DSW is proposed, which makes it possible to create a system for controlling the process of distillery spent wash fermentation in the given conditions without changing the process parameters. The technological regimes of the two-stage anaerobic processing of highly concentrated distillery wastewater in full are determined.