Effect of residence time during hydrothermal carbonization of biogas digestate on the combustion characteristics of hydrochar and the biogas production of process water.
The biogas digestate from anaerobic digestion of cow manure and energy crops was treated by hydrothermal carbonization (HTC) at 210 °C for 0.5 to 5 h to understand the effect of HTC residence time on the combustion characteristics of hydrochar and the biogas production of process water. The increase in HTC residence time slightly reduced the higher heating values (16.3-16.0 MJ/kg) but improved most slagging and fouling indices of the hydrochar. However, the slagging and fouling during hydrochar combustion were almost impossible to avoid. The specific methane yield of the process water was not significantly influenced by the HTC residence time. Energy assessment demonstrated that HTC for 0.5 h achieved the highest process efficiency and net energy gain when the combustion energy was obtained from hydrochar and CH4 (from process water). Therefore, the HTC condition of 210 °C, 0.5 h is suggested to valorize biogas digestate for energy production.
['Cao|Zebin|Z|', 'Hülsemann|Benedikt|B|', 'Wüst|Dominik|D|', 'Oechsner|Hans|H|', 'Lautenbach|Armin|A|', 'Kruse|Andrea|A|']
D000818:Animals D056804:Biofuels D002244:Carbon D002417:Cattle D005260:Female D008372:Manure D008697:Methane D013696:Temperature D014867:Water
Hydrothermal carbonization Biogas digestate Combustion characteristics Anaerobic digestion Bioeconomy