Production of xylooligosaccharides from Camellia oleifera Abel fruit shell using a shell-based solid acid catalyst

[Display omitted] •A shell-based solid acid was prepared from Camellia oleifera Abel fruit shell.•Shell-based solid acid showed excellent performance to produce xylo-oligosaccharides.•The optimal xylo-oligosaccharides (XOS) yield of 51.41% was achieved.•The usage of solid acid was 0.2 g/g, which could be recycled six times by sieving.•Shell-based solid acid was suitable for typical lignocelluloses to produce XOS. This study aimed to produce xylooligosaccharides (XOS) from Camellia oleifera Abel fruit shell (CFS) using a shell-based solid acid derived from CFS (CFS-BSA). CFS-BSA preparation was optimized by incomplete carbonization at 450 °C for 1 h, followed by sulfonation at 130 °C for 8 h to yield a -SO3H functional group concentration of 1.04 mmol/g. When CFS-BSA was used to hydrolyze CFS with a 1:5 ratio of CFS-BSA to CFS at 170 °C for 20 min, a maximum XOS yield (X2-X5) of 51.41 % was achieved, which was notably higher than when using subcritical H2O solely. CFS-BSA can be recycled and reused at least six times by sieving without a substantial loss in its catalytic activity. CFS-BSA can also be used to produce XOS from other lignocellulosic materials such as corncob (41.04 %), sugarcane bagasse (45.03 %), corn stalk (45.89 %), birchwood (46.05 %), and poplar (40.10 %).