TY - JOUR AU - Golub, Nataliia AU - Potapova, Mariana AU - Karpenko, Yuriy PY - 2019/06/20 Y2 - 2024/03/29 TI - Mathematical Modeling of the Biogas Production Process from the Distillery Spent Wash on the First Stage JF - Innovative Biosystems and Bioengineering JA - Innov Biosyst Bioeng VL - 3 IS - 2 SE - Articles DO - 10.20535/ibb.2019.3.2.166429 UR - http://ibb.kpi.ua/article/view/166429 SP - 96-104 AB - <p><strong>Background.</strong> The development of a mathematical model for methane production by the distillery spent wash anaerobic fermentation method in the process of its co-fermentation under conditions of variable pH value is an urgent task. since existing models mainly don’t consider the effect the replacement of a fermented substrate part with a fresh low pH on the methane yield. Such models don’t consider the methane production mechanism under variable environmental conditions, which is the result of the non-constant correlation of the cosubstrates.</p><p><strong>Objective.</strong> The purpose of the paper is to create a model of biogas formation process in the conditions of a constant supply of one of the cosubstrates, which leads to a decrease in the pH value of the medium.</p><p><strong>Methods.</strong> Distillery spent wash (DSW) processing was performed by its co-fermentation with poultry manure at cosubstrates manure/DSW ratio 1.7:1 for dry organic matter (DOM). In order to ensure the DSW utilization, the sixth part of the reactor volume was replaced daily with raw distillery spent wash (pH 3.7), without adding new batches of manure. To create a mathematical model, the initial ratio of components was taken into account and it was considered that the manure concentration doesn’t lead to methanogenesis process inhibition. To create a mathematical description of the process of obtaining methane from DSW the Bernard model was used as the base model.</p><p><strong>Results.</strong> The initial DOM manure/DSW ratio less than 1:1 leads to a change in the pH of the environment, reducing the biogas yield and methane content in it. Periodic daily replacement of fermented substrate part with fresh DSW without disturbing the stabilization of the process is possible when the pH value is not below 6.5. Manure disposal leads to the establishment of a steady state after the 20th day, which is maintained for at least 10 days. A mathematical model is proposed for the biogas formation process from acidic solutions of grain distillery spent wash depending on the daily replacement of 1/6 of the fermented substrate.</p><strong>Conclusions.</strong> It has been established that in the process of distillery spent wash disposing in the anaerobic process, co-fermenting with the rational manure is a daily replacement of 1/6 of the volume of fermented raw materials with fresh distillery spent wash. A mathematical model of biogas formation process was proposed by replacing part of one of the low pH co-substrates. This mathematical model will allow managing the biogas production process at a variable pH value and a part of a substituted substrate in the process of periodical replacement of the part of the reactor working volume into one of the co-substrates, which has a low pH value, without changing the process parameters. ER -