A review on cellulose nanocrystals production and characterization methods from Elaeis guineensis empty fruit bunches

Cellulose nanocrystals with various functionalities have received significant interest in recent years due to their wide applications. Elaeis guineensis empty fruit bunches (EFB) have been explored by researchers as one of the potential sources for cellulose nanocrystals extraction in recent years. However, cellulose nanocrystals extraction methods using EFB as raw materials are yet to be evaluated based on technical, economic and environmental aspects. Thus, this study aims to assess the effect of EFB pretreatment methods, cellulose nanocrystals isolation methods, with or without any post-treatment, towards the final properties of cellulose nanocrystals. Characterization methods suitable for evaluating the properties of cellulose nanocrystals extracted from EFB are suggested and supported with data from other similar studies. In brief, sulphuric acid hydrolysis exhibits a more significant advantage in cellulose nanocrystals conversion yield and stable suspension than other treatments when empty fruit bunch fibres are used as the cellulose source. By evaluating the benefits or limitations of extraction and characterization methods, future studies on the cellulose nanocrystals extraction from EFB could be further enhanced to prepare a more efficient cellulose nanocrystals extraction from EFB at a commercial scale