Nanocrystalline cellulose isolation via acid hydrolysis from non-woody biomass: Importance of hydrolysis parameters

The use of nanocrystalline cellulose (NCC) as a renewable and green biomaterial in diverse value-added applications has roused substantial interest. Sourcing NCCs from the abundantly available non-woody biomass becomes attractive due to its high cellulose content and low cost. Acid hydrolysis using mineral acids has been widely explored as a facile, low-cost, and efficient way of isolating NCCs. Still, the technical aspect of the extraction procedure is lacking. This review gathers the available knowledge on the NCC extraction using hydrolysis with mineral acids from non-woody biomass and provides a critical overview of the extraction parameters to be considered from the feedstocks and related pretreatment to the final hydrolysis procedure. To fulfill an operationally feasible production of NCCs, this review shares considerations and challenges on the biomass characteristics and pretreatment as well as hydrolysis parameters for optimizing NCC production and tailoring its application.