Modelling of the hydrolysis of sorghum straw at atmospheric pressure

Abstract

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 H2SO4 hydrolysis of sorghum straw at two different temperatures (80 and 100degreesC) and three H2SO4 concentrations (2, 4 and 6\%) using a solid/liquid ratio of 1:10 (w/w) 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 185.8 kJ mol(-1) for glucose. The optimal conditions found were 6\% H2SO4 at 100degreesC for 60 min, which allow one to obtain a solution with 18.27g xylose l(-1), 6.788 glucose l(-1), 0.7g furfural l(-1) and 1.35g acetic acid l(-1). It is concluded that this process has potential for utilisation of this renewable lignocellulosic resource. (C) 2002 Society of Chemical Industry.