Effect of Low-Temperature Heat Treatment on Surface Morphology and Elemental Composition of Empty Fruit Bunch (EFB) Biomass Analyzed by SEM-EDS

Abstract

This study investigates the effect of low-temperature heat treatment on the surface morphology and elemental composition of Empty Fruit Bunch (EFB) biomass using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). EFB samples were heated at various temperatures ranging from 150°C to 200°C to observe structural changes and the distribution of elements on the biomass surface. SEM analysis revealed that at 150°C, the EFB surface exhibited a rough and porous texture with visible fibres. Increasing the temperature to 190°C and 200°C resulted in smoother surfaces with denser and more compact morphologies due to thermal degradation and particle fusion. EDS results identified the dominant elements present, including Carbon (C), Oxygen (O), Potassium (K), Calcium (Ca), and smaller amounts of Magnesium (Mg), Phosphorus (P), Silicon (Si), and Chlorine (Cl). At 150°C, Carbon content was recorded at 51.43%, while Oxygen was 33.21%. As the temperature increased to 200°C, Carbon slightly increased to 53.77%, and Oxygen decreased to 30.84%, indicating partial carbonization. Furthermore, the presence of potassium and calcium somewhat reduced from 4.39% and 3.37% at 150°C to 3.17% and 3.08% at 200°C, respectively, which suggests mineral volatilization during heating. These findings demonstrate that temperature significantly influences the physical and chemical characteristics of EFB biomass, with the 190–200°C range showing the most notable changes in surface compaction and elemental reduction. This research provides valuable insights into optimizing EFB as a precursor material for bio-based applications through controlled thermal treatment.