Review of the fuel properties, characterisation techniques, and pre-treatment technologies for oil palm empty fruit bunches

The valorisation of oil palm empty fruit bunches (OPEFB) in the palm oil industry is hampered by major challenges due to its poor fuel properties, which require comprehensive characterisation and pre-treatment. This paper presents an overview of the various technologies currently employed for the fuel characterisation and pre-treatment of OPEFB in the literature. Furthermore, the paper presents the current challenges and prospects of OPEFB characterisation and pre-treatment techniques. The reviews indicate that OPEFB characterisation studies in the literature are limited to the chemical, thermal, kinetic, and thermodynamic fuel properties. The authors opine that future characterisation studies are required to examine the physical, morphological, and microstructural properties of OPEFB. The paper also notes that drying, size reduction, and pelletisation are the most common pre-treatment techniques for OPEFB. The various characterisation and pre-treatment techniques highlighted are prone to various limitations, which indicate that more effective strategies are required to save the energy, time, and cost for future OPEFB valorisation. The design, implementation, or adoption of hybrid biomass pre-treatment and conversion systems could effectively address the issues of poor OPEFB fuel properties, operational challenges, and product distribution.