Efficiency of digestat of biogas plants

Abstract

It has been established that the digestate of biogas plants is a valuable organic fertilizer that is quickly absorbed by plants, contains a complex of macro- and microelements necessary for plant growth, has a high content of readily available nitrogen for plants, has a pH level close to neutral and does not contain viable weed seeds and pathogens. microflora. It is technically difficult to make untreated digestate into the soil, so it is predivided into solid and liquid fractions on separators. A major problem with the commercial use of digestate in Ukraine is the lack of its standardization. When applying digestate to the company's own fields, which owns the biogas plant, the standardization of its quality is not critical. However, the lack of a standard for digestate as a high-quality organic fertilizer significantly limits its use. The needs for digestate were determined to restore soil fertility and fertilize crops in and with a herd of 1,000 cattle (500 heads of dairy cows and 500 heads of young cattle and heifers) and with an arable land area of 1,800 hectares. It is established that only one ton of digestate remains for commercial use after application to the fields, the profit from the sale of which does not significantly affect the profitability of biogas production. The payback period of the biogas plant is 6.4 years and depends on the cost of biogas production. With the commercial use of all digestate produced during the year, the payback period of the biogas plant is reduced to one year and below and does not depend on the cost of biogas production, and the impact of the "green" tariff on the payback period of the biogas plant is leveled.