Effect of subcritical water (sub-CW) on oil palm mesocarp fibre (OPMF) structure and cellulose conversion to obtain useful components was studied to reduce production of mesocarp fibre as waste in excessive amount. The decomposition of OPMF was carried out at temperatures ranging from 200°C-300°C and with a constant reaction time of 5 min using a batch stainless-steel tube reactor (reactor volume: 7.3 cm3 ). The pressure inside reactor was equal to the saturated vapour pressure at the experimental temperature. Microscope images indicated sub-CW broke down the OPMF walls becoming smaller particles. Scanning electron microcopy (SEM) images showed that the particle size of OPMF was highly porous when treated at 240°C but was disrupted when treated above 250°C. From sugar analysis using high performance liquid chromatography (HPLC), the highest amount of monosaccharides was 22.2 mg g–1-dry OPMF at 240°C. The yield of sugar was reduced to 2.5 mg g–1-dry OPMF at 300°C as cellulose and hemicellulose were degraded due to pyrolysis. The particle size of OPMF, when subjected to sub-CW, showed a good relationship with the yield of sugars. The OPMF particle became disrupted above 260°C due to the pyrolysis activity. The solid residue from OPMF was reduced significantly using sub-CW.

Mahandran, S., Sabli, N., Ismail, M. H. S., Yoshida, H., & Izhar, S. (2020). Structural transformation of oil palm mesocarp fibre (OPMF) in water at subcritical state. Journal of Oil Palm Research, 32(4), 590-598. doi:10.21894/jopr.2020.0054