Resumen
Carbon fibre has an increasing demand in application of current technology. The limited supply of current fossil-fuel based precursor from pitch and polyacrylonitrile (PAN) causing the carbon fibre to become expensive. The newest technology is by using lignin precursor for carbon fibre. Lignin can be found within the composition of biomass where the largest composition is cellulose followed by lignin and hemicellulose. The primary function of lignin act as supporting mechanism where it enhances the binding between cellulose and hemicellulose producing a rigid wall. Therefore, the lignin is suitable as the precursor of carbon fibre where it can improve the binding of carbon fibre structure. In Malaysia, the largest biomass resource is from palm oil biomass since Malaysia is the second largest palm oil industry in the world. Therefore, the waste from the palm oil such as empty fruit bunches (EFB), oil palm frond (OPF), and palm oil mill effluent (POME). The study focusses on the availability of the lignin in the EFB whether it suitable to be a precursor for carbon fibre. By using the subcritical fluid technology (SFT), the lignin extraction was done by reacting 10 g of EFB with 70 ml of subcritical phenol at 260 °C, 280 °C, 300 °C at different reaction time of 1 min, 5 min and 10 min. The characteristics of lignin have been analysed were lignin purity, glass transition temperature (Tg), volatile matter and ash content. The analysis results were compared with the standard sets by the Oak Ridge National Laboratory (ORNL) to check the lignin suitability to act as carbon fibre precursor.