Modelling of the hydrolysis of sorghum straw at atmospheric pressure

Sorghum straw is a renewable, cheap and widespread resource. The acid hydrolysis of sorghum straw to obtain xylose solutions could be a good alternative for this abundant resource. The H 2 SO 4 hydrolysis of sorghum straw at two different temperatures (80 and 100°C) and three H 2 SO 4 concentrations (2, 4 and 6%) using a solid/liquid ratio of 1:10 (wlw) was studied. Kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, acetic acid and furfural were determined. The activation energy of the release reaction was 183.3 kJ mol -1 for xylose and 185.8kJ mol -1 for glucose. The optimal conditions found were 6% H 2 SO 4 at 100 °C for 60min, which allow one to obtain a solution with 18.27 g xylose l -1 , 6.78 g glucose l -1 , 0.7 g furfural l -1 and 1.35 g acetic acid l -1 . It is concluded that this process has potential for utilisation of this renewable lignocellulosic resource. La paille de sorgho est une ressource renouvelable, pas chere et repandue et pourrait etre traitee par hydrolyse acide pour obtenir des solutions de xylose. L'objectif de cette etude est d'evaluer l'hydrolyse par H 2 SO 4 de paille de sorgho a pression atmospherique. Les parametres cinetiques de 2 modeles mathematiques pour predire les concentrations de xylose, glucose, acide acetique et furfural sont determines. Les resultats montrent le potentiel de ce procede pour l'utilisation de cette ressource lignocellulosique.