Hydrothermal Carbonization of Digestate Produced in the Biogas Production Process

In agricultural biogas plants, besides biogas, the by-product digestate is also produced. Due to its high moisture content and organic origin, it can successfully be applied in the hydrothermal carbonization process to avoid the fate of landfilling. This paper reviews the properties of agricultural digestate and its hydrothermal conversion (HTC) into hydrochar and process water. The type of feedstock and the parameters of the HTC process, such as temperature, pressure and residence time, affects the physical and chemical characteristics of hydrochar. Therefore, its possible application might be as a biofuel, fertilizer, soil improver, adsorber, or catalyst. In this paper, the properties of hydrochar derived from agricultural digestate are widely discussed.

Automated summary

In agricultural biogas plants, the by-product digestate is produced along with biogas. This paper examines the properties of agricultural digestate and its hydrothermal conversion into hydrochar and process water. The parameters of the hydrothermal carbonization process affect the characteristics of hydrochar, making it suitable for various applications such as biofuel, fertilizer, soil improver, adsorber, or catalyst. The properties of hydrochar derived from agricultural digestate are extensively discussed in this paper.