Characterization of depolymerized cellulosic residues

Abstract

It is known that dilute acid hydrolysis of cellulose results in yields not exceeding 60–65% of the potential glucose. All the models presented in the literature are based on the sequence cellulose→glucose→degradation products. The underlying assumption of this sequence is that the unconverted cellulose retains its chemical integrity with the extent of the hydrolysis reaction. In this paper we show that the unconverted cellulose is indeed modified during the hydrolytic treatment and cannot be chemically identified as cellulose as the reaction proceeds. This obviously limits the glucose yields and results in a major modification of the reaction sequence via dilute acid hydrolysis. Thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and diffuse reflectance infrared (DRIFT) have been used to study the structural and chemical changes of the cellulosic residues as a function of the extent of hydrolysis.