Kinetic analysis of cellulose extraction from banana pseudo-stem by liquefaction in polyhydric alcohols

The objective of this work is to track the composition changes in the process of liquefaction of banana pseudo-stem (BPs) and to maximize the cellulose fraction in the liquefied residue. Typical kinetics parameters of raw BPs and its three major components (lignin, hemicellulose and cellulose) were determined using kinetic models and transition-state theory. The results showed that cellulose had the highest activation energy and lowest reaction rate. The liquefied polyols were separated by water and acetone, and the functional groups, molecular weight distribution, acid values and hydroxyl values of different soluble parts were analyzed, providing an overall insight into the liquefaction behavior of BPs. The most suitable liquefaction conditions to avoid polycondensation and maximize cellulose content in the residues was at 150 degrees C with a reaction time of 90 min. Cellulose-enriched residues were readily purified by subsequent bleaching treatments. Based on the results of SEM, XRD, FTIR, TG and wet chemistry analyses, a mechanism of cellulose micro-fibril extraction from solid liquefied residues was proposed.