Kinetic Study on the Acid Hydrolysis of Cenchrus ciliaris Particles for the Production of Xylose and Other Monosaccharides

An experimental study on the acid hydrolysis of Cenchrus ciliaris particles was conducted. Input variables included particle size of the raw material (<0.053 mm and 0.16 mm), sulfuric acid concentration (0.05 and 0.15 M), and reaction temperature (120-150°C). Output variables included the concentrations of xylose, glucose, arabinose, and furfural in the aqueous solution. Five chemical reactions involving the hydrolysis of the Cenchrus ciliaris particles and the decomposition of the monosaccharides were proposed, and a pseudohomogeneous model consisting of five ordinary differential equations was developed. By means of numerical techniques, the values of the parameters of the Arrhenius equation for all chemical reactions were determined. Good agreement between the model predictions and the experimental data was obtained. The hemicellulose in the Cenchrus ciliaris particles was represented by an empirical formula containing 55 units of xylan, 25 units of glucan, and 19 units of arabinan oligomers.