Kinetic analysis of wet process phosphoric acid hydrolysis of corncob

Corncob has a high yield and contains a large number of cellulose substances. Wet phosphoric acid hydrolysis of corncob is of great significance to the utilization of organic waste, and provides theoretical support for the development of sugar-containing synergistic phosphorus fertilizers. In this study, the kinetics of hydrolysis of corncob by wet process phosphoric acid was investigated. The time evolution of total sugar, xylose and furfural formation during a 12-h hydrolysis was simulated by Saeman and biphasic models within differential acid concentrations and temperatures. The formations of both total sugar and furfural coincide a first-order irreversible reaction, which was not applicable to the Saeman model nor the biphasic model. Meanwhile, xylose formation was more suitable for the Saeman model. The optimal conditions for xylose are: a temperature of 100 °C, a reaction time of 720 min, an acid concentration of 55.6% (w/w). The xylose yield of corncobs was 0.15 g/g in the optimal conditions. Graphical abstract