Pyrolysis or hydrothermal carbonisation for anaerobic-digested sewage sludge? A comparison of pyrochar and hydrochar structure and stability: data

Thermochemical conversion of sewage sludge was proven as a useful method for waste management. HTC showed the greatest potential to produce a material with higher adsorption capacity (100 cm3 /g for H180-4) but all chars should be subjected to an activation process to be able to compete with other kinds of feedstocks. The reduction of the H:C and O:C from the original SS after the treatments indicated a greater carbonisation degree, but a general reduction of the high heating value (HHV) from 17.94 MJ kgˆ’1 in SS to (14.93 MJ kgˆ’1 ). The torrefied char and hydrochars could be an attractive option to reduce energy of the process and drying stage in the case of HTC.