Hydrothermal carbonisation of poultry litter: Effects of treatment temperature and residence time on yields and chemical properties of hydrochars

•HTC of PL was performed from 150°C to 300°C and from 30 to 480min.•Influences of treatment temperature and time on carbonisation were evaluated.•The HHV of produced hydrochar was increased to 25.17MJ/kg.•The hydrochar properties were highly dependent on treatment temperature. In this study, hydrochars were prepared by hydrothermal carbonisation (HTC) of poultry litter (PL) at temperatures between 150–300°C with residence times of 30, 120 and 480min. The effects of treatment temperature and residence time on the yield and composition of hydrochar were investigated. Both treatment temperature and residence time effects were observed however, the effect of residence time was lower. The results indicated that the HHV was improved by up to 25.17% and the overall ash in hydrochar was significantly lower compared to PL, however this coincided with a lower hydrochar yield.