Autoclaving treatment of wasted disposable bamboo chopsticks

•Dry-basis reductions of bamboo chopstick BC and its combustibles increase with autoclaving time and temperature.•For mild autoclaving, large portions of combustibles CBs are still kept, maintaining the utilization properties of BC.•Autoclaving of BC at 428K and 60min is proper, preserving 84.11wt.% CBs.•The energy densitification ratio of BC mildly increases to 1.06–1.17 after autoclaving.•The pyrolysis characteristics of autoclaved BCs under the conditions of this study are closed to that of un-autoclaved BC.