Breaking Barriers for a Green Future: A Comprehensive Study on Pre-treatment Techniques for Empty Fruit Bunches in the Bio-Based Economy

This review article provides a comprehensive summary of the chemical and biological approaches for pretreating empty fruit bunches (EFBs), a byproduct of the palm oil industry that can be used as a feedstock for biofuels and biochemicals. However, the presence of alkali metals and alkali earth metals (AAEMs) can reduce EFB quality and limit their usage. To improve EFB quality, acid washing and biological pretreatment methods are commonly used. The different types of acids used for washing, such as sulfuric acid, hydrochloric acid, and citric acid, are evaluated for their effects on EFB quality under various concentrations and washing conditions, and the pros and cons of each acid-washing method are discussed. Additionally, the application of biological pretreatment techniques, such as fermentation using fungi and bacteria, is explored to improve the quality of EFBs. The impact of different fermentation conditions and microbial strains on EFB quality is assessed, and the benefits and drawbacks of each biological pretreatment method are analyzed. This review article provides a comprehensive understanding of the acid washing and biological pretreatment methods for EFBs and their impact on feedstock quality. The knowledge gained from this research can be used to optimize the pretreatment process and increase the efficiency of EFB utilization, promoting the development of a sustainable and circular bioeconomy.