Effects of metal ions on the hydrolysis of bamboo biomass in 1-butyl-3-methylimidazolium chloride with dilute acid as catalyst.

In this study, the effects of six metal ions including Na+, K+, Mg2+, Ca2+, Cu2+ and Fe3+ on hydrolysis of bamboo biomass by diluted hydrochloride acid (HCl) in ionic liquid [C4mim]Cl under mild conditions was investigated. These metal ions as co-catalysts exhibited significant effects on accelerating the hydrolysis process and improving the yield of total reducing sugar compared to single diluted hydrochloride acid hydrolysis in [C4mim]Cl at the same conditions. The most effective ion was Cu2+ and the total reducing sugar yield of 67.1% was achieved at 100 °C with CuCl2 as co-catalyst after 4-h reaction. The total reducing sugar yield was increased by about 7% and the reaction time was decreased by 3 h. The kinetic model was also investigated to give an insight into the mechanism of hydrolysis process.