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Introduction. The processing of livestock waste and agricultural production enables not only improving environmental safety, but also obtaining energy resources. Problem Statement. Cow manure is used to produce biogas, but its yield is relatively low. One way to increase biogas yield is the joint fermentation of cow manure with substandard flour, which cannot be used as human food and as feed for farm animals. However, the flour content in the substrate, at which the biogas yield is maximum and there is no inhibition of the methane fermentation process, is not a solved issue. Purpose. Increase biogas yield by adding substandard flour to a cow manure-based substrate. Materials and Methods. Research of biogas yield during methane fermentation of substrate based on cow manure with the addition of substandard flour was carried out on a biogas plant consisting of a methane tank with a working volume of 30 l and wet gasholder at periodic substrate loading and fermentation temperature 35 °C. The portion of the substrate included 1.7 kg of manure, 2.5 kg of water and 50, 100, 250 or 500 g of flour. The composition of flour in the substrate was 1.2%, 2.3%, 5.6% and 10.6%. The dichotomy method was used to determine the optimal flour content in the substrate, provided the maximum biogas yield. Results. The maximum biomethane release is 14.3 l/kg dry organic matter (DOM), at 1.2% of the flour content in the substrate; 20.9 l/kg DOM, at 2.3%; 19.2 l/kg DOM, at 5.6%. At a content of 10.6% flour in the substrate, the biogas did not burn, fermentation quickly stopped. The optimum flour content in the substrate based on cow manure, in which the biogas yield increases 1.5 times, is 3.7%. Conclusions. Based on the conducted experimental studies, a model of biogas yield with gradual loading of the substrate was built and the optimal flour content in the substrate was determined, at which the maximum biogas yield is provided. Вступ. Важливим господарським питанням є переробка відходів тваринництва і сільськогосподарського виробництва не тільки для покращення екологічної безпеки, а й для отримання енергетичних ресурсів. Проблематика. Коров’ячий гній застосовується для отримання біогазу, однак його вихід при цьому відносно низький. Одним із шляхів підвищення виходу є спільне зброджування коров’ячого гною з некондиційним борошном, яке не можна використовувати як продукт харчування для людини та як корм для сільськогосподарських тварин. Проте вміст його в субстраті, при якому вихід біогазу є максимальним і не відбувається інгібування процесу метанового бродіння, не визначено. Мета. Підвищення виходу біогазу шляхом раціонального додавання некондиційного борошна до субстрату на основі коров’ячого гною. Матеріали й методи. Дослідження виходу біогазу при метановому зброджуванні субстрату на основі коров’ячого гною з додаванням некондиційного борошна здійснювали на біогазовій установці у складі метантенка робочим об’ємом 30 л і мокрого газгольдера при періодичному режимі завантаження субстрату і температурі бродіння 35 °С. Порція субстрату: 1,7 кг гною, 2,5 кг води та 50, 100, 250 або 500 г борошна. При цьому склад борошна в субстраті становив 1,2 , 2,3%, 5,6% та 10,6 %. Для визначення оптимального вмісту борошна в субстраті, за умови максимального виходу біогазу, було застосовано метод дихотомії. Результати. Максимальний вихід біометану при вмісті 1,2 % борошна в субстраті становить 14,3 л/кг сухої органічної речовини (СОР), при 2,3 % — 20,9 л/кг СОР, при 5,6 % — 19,2 л/кг СОР. При вмісті 10,6 % борошна в субстраті біогаз не горів, бродіння швидко припинялося. Оптимальний вміст борошна в субстраті на основі коров’ячого гною, при якому вихід біогазу збільшується в 1,5 рази, становить 3,7 %. Висновки. На основі проведених експериментальних досліджень побудовано модель виходу біогазу при поступовому завантаженні субстрату та визначено оптимальний вміст борошна в субстраті, при якому забезпечується максимальний вихід біогазу.

The aim of the work is to increase biogas output and generation of electricity in biogas plants due to the joint fermentation of cattle manure with winemaking waste. To achieve this goal, the following tasks have been solved: the biogas yield from cattle manure with winemaking waste was determined during periodic loading of the digester; based on the obtained experimental data, a mathematical model was calibrated to estimate the biogas yield during fermentation of cattle manure with the addition of winemaking waste. Because of the studies, it had been found that when manure was fermented with part of the water replaced in the substrate 2% of the winemaking waste, the fermentation dynamics in the substrate are similar to the fermentation of pure cattle manure. Biogas obtained by fermentation of manure with the addition of 2%, 6.5% and 13% of wastewater from wine production instead of water in the first day of fermentation either did not burn at all or burned poorly. The addition of winemaking waste to a substrate based on manure in an amount of 13% allows increasing the maximum biogas yield by a third to 1,372 l/(hrkg dry organic matter). The significance of the research results lies in the fact that the use of winemaking waste as a substrate will allow a third increase in biogas output and power generation, and a reduction in the payback period of a 4,4 MW biogas plant using the green tariff to 6,5 years.

The aim of this work is to increase the output of biogas and electricity power generation in biogas plants through the use of stimulating supplements in the form of vegetable oil sediment in the transition from periodic to quasi-continuous loading of the methane tank. To achieve this goal, the following tasks were solved: the biogas yield from cattle manure was defined at various temperature conditions with periodic loading of the methane tank; biogas yield was estimated during the cattle manure fermentation with the added vegetable oil sediment, using a mathematical, biogas yield was predicted for permanent loading of the methane tank. The research was carried out at the laboratory plant consisting of a methane tank useful volume of 30 liters and the gasholder of the wet type. The biogas yield was recorded for lifting of the cylinder-gauge is a wet gasholder with attached to it a scale, calibrated in centimeters. The biogas is burned on a gas stove. Calorific value of biogas was determined by its elemental composition, which was recorded by the gas analyzer. The most important results are according to the experimental researches of biogas in periodic mode, boot using this model provided prediction of biogas yield for quasi-continuous loading of the methane tank. As a result of experimental studies, it was established that during manure milling, the maximum yield of biogas was observed at 3-8 days of fermentation, and then it gradually decreased. When adding to the substrate 1.3% vegetable oil sediment the biogas yield increases and reaches a maximum value for 20 days and then it gradually decreased. The significance of the research results is that the use of vegetable oil sediment as co-substrate will allow almost three times increasing the yield of biogas and electricity generation, to reduce the payback period of a biogas plant with a capacity of 4 MW when using a green tariff to 5.1 years.