Fuel properties and combustion kinetics of hydrochar prepared by hydrothermal carbonization of bamboo

•Hydrothermal carbonization was employed to pretreat bamboo for hydrochar preparation.•Hydrothermal carbonization could elevate the fuel properties of bamboo.•Combustion kinetics of hydrochars could be expressed by a simple Arrhenius equation.•Hydrothermal carbonization affected the combustion kinetic parameters of bamboo. Hydrothermal carbonization, an environmental friendly treatment method was employed to pretreat bamboo for hydrochar preparation in the present study. Hydrothermal carbonization could elevate the fuel properties and combustion behavior of bamboo. The combustion kinetic parameters of raw bamboo and hydrochars were calculated by a simple Arrhenius equation based on the thermogravimetric curves. Two distinct zones were observed for raw bamboo and hydrochars. The activation energies of raw bamboo in zone 1 and zone 2 were 109.5kJ/mol and 46.6kJ/mol, respectively, in the heating rate of 20°C/min. The activation energy of hydrochar in zone 1 increased at the hydrothermal carbonization temperature under 220°C and then decreased at higher hydrothermal carbonization temperature, due to the decomposition of relative reactive compounds in bamboo, and destruction of cellulose and hemicellulose structures, respectively. The activation energies of hydrochars in zone 2 were among 52.3–57.5kJ/mol, lower than that of lignin extracted from bamboo.