Combination of Hydrothermal Carbonization (HTC) and Biogas Production
Biogas production by anaerobic digestion (AD) has attracted growing interest all over the world. However,
how to store and make use of the resulting digestates is still problematic. Digestates from livestock manure
usually contain animal pathogens, which can increase the health risks when these digestates are applied for
fertilizer without sterilization. In addition, transportation cost and seasonal demand of digestates add to
the disposal difficulty.
Since the incomplete conversion of lignocellulosic feedstocks and high water content of resulting digestates
from anaerobic digestion, hydrothermal carbonization (HTC) has been particularly suitable for processing of
the digestates. Hydrothermal carbonization is defined as a thermochemical transformation process for low
value wet biomass to a solid product termed as hydrochar. Hydrochar has been reported as a coal-like
powder which has the potential for soil amendment and energetic use.
In this project, the resulting digestates will be hydrothermal carbonized into carbon-rich and stable lignitelike hydrochar by various conditions and catalysts. The hydrochar addition during anaerobic digestion and
the anaerobic digestion of process water have been investigated by previous researches; however, it is not
clear about the degradation of the phytotoxic compounds of fresh hydrochar and process water during
anaerobic digestion. Therefore, the effect of integration of hydrochar and process water in anaerobic
digestion is also interesting to understand. Further applications of hydrochar and process water involve soil
amendment, activated carbon, and nutrient recovery. Another goal is the identification of the economic
feasibility and energy efficiency of the overall procedures under respective process conditions.
The anaerobic digestion experiments will be performed in cooperation with State Institute of Agricultural
Engineering and Bioenergy at the University of Hohenheim and a part of experiments and analyses are
going to be carried out in Karlsruhe Institute of Technology.
Fig. Symbiosis: Anaerobic Digestion and Hydrothermal Carbonization (HTC)
Project Title:
Combination of Hydrothermal Carbonization (HTC) and Biogas Production
Institution(s):
University of Hohenheim, Institute of Agricultural Engineering, Department
of Conversion Technology and Life Cycle Assessment of Renewable
Resources
Research group:
Prof. Dr. Andrea Kruse, Zebin Cao
Funding:
Contact:
Chinese Scholarship Council
Zebin Cao <[email protected]