Can hydrothermal carbonization be used as a mean to increase the circularity of existing food waste anaerobic digestion plants?

for the light rejects) or as a soil amendment, the process water can be converted into additional methane. For every reject fraction considered, an increase in the methane potential of the process water was shown, when compared to the initial fraction, showing a solubilization of the organic materials. This high methane potential leads to an additional production of energy for anaerobic digestion facility. Overall, the conversion of the reject fractions by hydrothermal carbonization improves the environmental performance of anaerobic digestion plants for every scenario considered (1.2- to 1.6-fold reduction for climate change impact category), with the biggest gain when the hydrochar is used as a fuel to substitute coal.