Producing bleached microcrystalline cellulose by two-stage dilute acid hydrolysis

Abstract

This study investigates the process of producing microcrystalline cellulose (MCC) through two-stage acid hydrolysis with intermediate washing and removal of dissolved sugars. The temperature–time dependence shows fast xylose extraction in the initial phase of the process, while the glucose increases slowly and permanently over the period. After the second stage of hydrolysis, a cleaning effect and an increase in pulp brightness is observed. This method allows obtaining MCC, with high brightness and properties appropriate for usage in the pharmaceutical, cosmetics and food industries, as well as in the chemical industry, from paper grade pulp, which contains large amounts of hemicelluloses.