Production of cellulose nanofiber (CNF) from empty fruit bunch (EFB) via mechanical method

Nanocellulose fibre is comprised of nanosized cellulose fibrils that can be isolated from plants due to the lignocellulosic components. Empty fruit bunch (EFB) is a waste product that produced after the sterilization process of the fresh fruit bunches, which contributes around 24 wt.% of the solid waste in oil palm mill and it has high cellulose content. Therefore, the isolation of cellulose nanofiber (CNF) from EFB can increase the value of EFB for high end product. CNF has high specific strength and stiffness, high aspect ratio, large specific surface area and high reinforcing potential. In this work, the characteristics of the CNF isolated from EFB through nano-grinding treatment will be investigated. The cellulose was firstly extracted from the EFB through thermal-chemical process before undergoing nano-grinding treatment to isolate the CNF. The morphology, chemical composition, thermal stability and crystallinity of the cellulose, and CNF were analysed using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray Diffraction (XRD). From the morphology analysis, nano-dimensioned cellulose fibers can be observed, with a reduction of mean diameter of cellulose from 8.25 μm to CNF; which is approximately 17.85 nm. Based on the chemical composition; such as COC stretching of pyranose ring and thermal analysis (Tmax of degradation =354 °C) of the CNF, the nano-grinding treatment does not give significant changes on chemical and thermal behaviour compared to cellulose. The crystallinity of the fibre shows a minimum increment after the mechanical treatment. Thus, the isolated CNF from EFB shows a promising characteristic and nano-grinding treatment is a potential method for the CNF isolation.