Energetic Assessment of Biogas Plant Projects Based on Biowaste and Maize Silage Usage

Maize silage, in spite of its rising prize and technological problems of monoculture in Eastern Germany, is still the most popular substrate for biogas plants. However waste materials often generate income, because of the potential technological or ecological problems they cause. Such an approach seems to be more profitable even considering lower biogas yield of dose waste substrates. To compare these different scenarios energetic and economical assessment of waste fermentation processes such be conducted. In this paper, three different substrates will be evaluated to determine their suitability for agricultural biogas plant feedstock.The research was based on the modified German standards DIN and VDI, while chemical and physical analytical methods were based on the Polish Standard System. Economic analysis was performed using standard prices in the polish biogas market. The calculation was conducted for 500 kW installation. Based on the obtained results, it was proven that refood was characterized by the highest methane and biogas yield from the analyzed substrate group. Maize silage fermentation in the Polish condition is least profitable due to the approximately 50 % income reduction by the costs of obtaining silage. However due to the price received for treating waste materials, refood fermentation is the most economically feasible option.