Ozonolysis of alkaline lignin and sugarcane bagasse: Structural changes and their effect on saccharification

Alkaline lignin (AkL) and sugarcane bagasse (SCB) were pretreated by an ozonification process with the aim to study its effect on the solubilization of lignin. We study the ozonification of Alkaline lignin (AkL) and sugarcane bagasse (SCB) with the aim to understand its effect on lignin solubilization and its effect on further acid and enzymatic saccharification. Here, infrared spectroscopy permitted to elucidate the structural changes on the ozonated materials. Indeed, the spectra analysis showed that AkL suffered evident oxidation after 60 min and the corresponding soluble lignin from SCB was observed within 30 min of the ozonification reaction. The total (TS) and reducing sugars (RS) produced from ozonized SCB in acid hydrolysis were 30.83 and 27.17%; while enzymatic hydrolysis resulted in 18.41 and 13.43% after 120 min of ozonation. Furthermore, there is apparently no pH effect on the solubilization of lignin and biomass saccharification. Nevertheless, the highest values of AkL, TS and RS, 0.97, 24.0 and 20.5% were obtained at pH 7, respectively. The ozone is a potential oxidizing agent to remove lignin from lignocelullosic biomass.