Performance Evaluation of Hydrothermal Carbonation Treatment to Biogas Production from Anaerobic Digestion of Organic Waste

The most problems in the field of municipal waste management are related to the organic fraction of municipal solid waste (OFMSW). In this experimental study, the effect of hydrochars produced at 150, 190, and 230 °C on AD process was analyzed with a sample of the OFMSW of Tehran. Due to the hydrothermal carbonization process, with increasing temperature, the hydrochar yield decreased and due to the increase in thermal value, the energy yield in hydrochar-190 was maximum. The effect of hydrochars on biogas production was variable and in hydrochars-150 and 190, 23.25 and 41.3% increase in biogas production was observed, respectively. This phenomenon was due to the destruction of the hard structure of the OFMSW. On the other hand, in hydrochar-230, there was a 30.63% reduction in biogas production, which was due to the production of inhibitor products such as phenol and furfural in the hydrothermal carbonation process. According to the results, the best conditions for the maximum production of biogas in the produced hydrochar at temperature of 190 °C and a retention time of 40 minutes. Also, the percentage of methane production in this condition was 63.25%.