Kinetics of the Formation of Saccharides and Fermentation Inhibitors during the Hot-compressed Water Pretreatment of Cassava Residue

Abstract

A mathematical description was developed for production of saccharides and fermentation inhibitors during the hot-compressed water pretreatment of cassava residue. Pretreatment was conducted at 150 °C, 160 °C, 170 °C, and 180 °C, and reaction times ranged from 0 to 70 min. The formation of saccharides and four main inhibitors (furfural (F), hydroxymethylfurfural (HMF), acetic acid, and formic acid) were studied. A model for predicting the concentrations of F and HMF (CF and CHMF, respectively) as functions of H + concentration was established. Furthermore, kinetic models were built after introducing the hydrogen ion concentration index mi. Hydrogen ion concentration had a dramatic effect on the dissolution of pentosan but did not greatly affect the dissolution of hexosan or the degradation of hexose or pentose. Additionally, the activation energies for the formation of pentose or hexose were lower than the degradation energies. The coefficients of determination (R 2 ) of the kinetic models for predicting the yield of the four compounds (pentose, hexose, furfural, and HMF) were higher than 0.923. These kinetic models provided a theoretical foundation and technical support for controlling the production of the main carbohydrates and fermentation inhibitors.

Influence of the pretreatment method on the hydrolysis of cassava starch factory residue

“…As such, to effectively utilize CSFR and further enhance subsequent biofuel yields, a number of pretreatment technologies based on biological , physical , chemical , and biochemistry methods have recently been reviewed . However, few studies have been reported on the optimum pretreatment conditions for obtaining maximum biofuel yields and without comparative analysis.…”