Chang, Siaw Sang creator author. text my 2025 2025 monographic eng xiii, 166 pages : illustrations; 30 cm. + 1 CD-ROM. Oil palm solid wastes (OPSW) are the most abundant biomass waste in Malaysia which have high potential to be the source of renewable energy. However, raw OPSW that poses hydrophilic nature and low heating values have preventing them to become tradable commodity as fossil fuel. Combination of torrefaction and co-pelletization process can significantly improved characteristics of the raw oil palm solid wastes. Torrefaction process not only improve heating values of raw HHV, but also inhibiting rotting behaviour of the raw OPSW. On the other hand, co-pelletization process blends different type of torrefied OPSW and transform brittle and shatter torrefied OPSW into pellets that are compact and uniform in size. Hence, the objectives of this work were to study the effect of torrefaction process on different type of oil palm solid waste and factors that affecting co-pelletization of different types of torrefied oil palm waste with torrefied palm kernel shell (TPKS). Four different types of OPSW which were oil palm frond (OPF), mesocarp fibre (MF), empty fruit bunch (EFB) and palm kernel shell (PKS) were torrefied at 250°C for 30 mins. The solid product were analysed in order to obtain the mass yield, energy yield as well as physical and chemical changes. Among the OPSW, PKS was most suitable feedstock for torrefaction process which yields highest mass and energy. TPKS was the most ideal OPSW to be blended with other torrefied OPSW as it poses highest higher heating value (HHV) and lowest ash content which were 23.10±0.09 MJ/kg and 1.34±0.10 wt.%, respectively. TPKS were then blended with TEFB at different compositions (0 – 100 wt.%). The blended samples were pelletized at different temperatures (80-150 °C). Pellets formed at 130°C showed the better pellet quality in terms of higher heating values, durability, tensile strength and density. Then, co-pelletization process were carried out at 130°C to study the effect of composition of TPKS on different type of torrefied OPSW, namely torrefied mesocarp fibre (TMF), torrefied oil palm frond (TOPF) and torrefied empty fruit bunch (TEFB) pellets. Among torrefied OPSW, pellets formed from blending of TMF and TPKS showed better characteristics which are suitable to be used as solid biofuel. TMF pellets blended with 60 wt.% of TPKS showed the highest durability and HHV which were 98.24% and 18.95 MJ/kg, respectively. Performance of torrefied pellets during combustion process were observed and evaluated. Based on the experimental results, combustion process comprised of three stages: gasification, flame burning and char burning. Addition of TPKS lengthen the gasification and char burning phase. In other words, addition of TPKS increase difficulties of ignition process, but improve sustainanbility of torrefied pellets. Thermogravimetric analyses results showed that mean reactivty and activation energy of combustion process reduced when blending TMF, TOPF and TEFB with TPKS. Overall, blended torrefied pellets formed at 130°C with 40TMF/60TPKS showed comparatively better characteristics in terms of HHV, ash and moisture contents, density, tensile strength and durability. Besides that, combustion process with blended pellets was long-lasting and required lesser energy to initiates. specialized Chang Siaw Sang Faculty of Chemical and Process Engineering Technology Thesis (Master of Science) -- Universiti Malaysia Pahang - 2025 Includes bibliographical references Faculty of Chemical and Process Engineering Technology Dissertations Universities and colleges Dissertations Theses Dissertations THE0010365 (Local) UMPSA 260223 20260223121653.0 eng