Evaluation of chemical and biological treatments to degrade oil palm empty fruit bunches (Elaeis guineensis Jacq.) and their potential use

The exploitation of oil palm generates lignocellulosic wastes, also known as oil palm empty fruit bunches (EFB), which are difficult to biodegrade and are mainly composed of cellulose, hemicellulose and lignin. The presence of lignin impedes the use of the cellulose from this biomass in industrial processes. This study evaluated the effect of different chemical and biological treatments to remove the lignin present in the EFB from oil palm. The conventional kraft method, the soda-anthraquinone pulping process, microwaveassisted hydrogen peroxide degradation and the peroxy-monophosphoric acid method were the chemical treatments evaluated. Meanwhile, the four biological treatments were tested using different lignocellulolytic native fungi from the genera Xylaria, Psilocybe and Agrocybe. The results showed a greater reduction of the lignin content with an enrichment of cellulose using the kraft method and the soda-anthraquinone pulping process. For the biological treatments, the fungus Agrocybe sp. showed a selective delignification, exhibiting a remarkable potential for the utilisation of cellulose present in this type of waste. In contrast, the fungus Psilocybe sp. showed high non-selective fibre degradation, which could be used for bioremediation and composting systems.