Valorización integral del tagasaste (Chamaecytisus prolifereus L.F. ssp palmensis) mediante pretratamiento hidrotérmico y pasteado con etanol

Abstract

Chamaecytisus proliferus L.F. ssp. palmensis (tagasaste), due to its chemical characteristics, can be an alternative raw material for pulp production, although lower yields than eucalyptus can be expected due to its higher extractive content. This study investigates the influence of a hydrothermal pretreatment, prior to pulping tagasaste prunings, which removes extractives from the pulp and yields a valuable liquid phase and a solid product suitable for pulp and paper production. The pulp and paper obtained after these processes are also characterized. The hydrothermal treatment shows increased solubilization with increasing temperature, with maximum concentrations of xylose and acetic acid occurring at temperatures near 195 °C. At these temperatures, the cellulose undergoes minimal degradation, and the oligomer extraction rate reaches 9.43%. During organosolv pulping, the overall process yields combining hydrothermal treatment and ethanol pulping (60.15% and 52.95%) are higher than the yield obtained when the lignocellulosic material is subjected solely to ethanol cooking (47.6%). The hydrothermal treatment has a positive effect on the kappa index of the resulting pulp, although a slight negative effect on viscosity. Under the most severe conditions (195 °C), a kappa index of 28.79 and a viscosity of 755 mL/g are obtained. The temperature increase during the hydrothermal pretreatment has a negative effect on the physical properties of the resulting paper. This decrease is particularly noticeable in the bursting index.