Optimization of the production of nanocrystalline cellulose, enzymatic pathway, from mechanically pre-treated cellulosic pulp

Abstract

Nanocrystalline cellulose (CNC) is a high value-added nanomaterial with an increasing number of applications in various industrial sectors. Traditionally, it is extracted from cellulosic materials by degrading non-crystalline cellulose domains by hydrolysis with concentrated sulfuric acid. However, the high concentration of acid used has negative environmental and economic consequences. Also, CNC through put with this method is typically low. Enzymatic hydrolysis, on the other hand, is environmentally friendly and its milder reaction conditions facilitate the control of the characteristics of the nanocrystal produced, however, the yield generally obtained is still unsatisfactory, typically less than 20%. In order to increase the accessibility of cellulose to enzymes, thus improving the efficiency of the enzymatic reaction for CNC production, the combination of mechanical defibrillation followed by enzymatic treatment of cellulose fibers has the potential to be a more sustainable route to obtain of CNCs with higher yields. Thus, this project aims to optimize this process through the search for greater efficiency in increasing surface area and enzymatic hydrolysis. This will be done with the help of Design of Experiments (DOE), an important statistical methodology for data collection and analysis. In this way, it will be evaluated how the process parameters (severity of mechanical pretreatment, solids content, enzymatic load and hydrolysis time) affect the performance and properties of the rod-type CNC produced for an application of this nanomaterial as a reinforcement material. In polymeric nanocomposites with the enzymatic method, aiming at the optimization of the CNC production process.