CHARACTERIZATION OF LIGNOCELLULOSIC BIOMASS COMPLEX FOR UNLOCKING THE POTENTIAL OF SUSTAINABLE BIOFUEL PRODUCTION

The present study investigates the chemical composition and delignification efficiency of various lignocellulosic biomass types as feedstock for bioethanol production. Agricultural residues and dedicated energy crops were identified as the most promising substrates due to their high cellulose (exceeding 40 %) and hemicellulose content (20–28 %), which are crucial for fermentable sugar yield. Non-fibrous biomass with higher lignin content, such as apricot and walnut shells (43–44 % lignin), exhibited structural resistance that hinders the effectiveness of pretreatment. Peracetic acid pretreatment was applied as a selective delignification method, demonstrating significant lignin removal while minimizing polysaccharide degradation. The optimal duration of pretreatment was established to be between 90 and 120 minutes, which provides a balance between preserving substrate yield and maximizing lignin reduction. Despite diffusion limitations in shell biomass, leading to higher residual lignin content, these substrates retained a significant proportion of polysaccharides, highlighting their potential for further use after process optimization. The findings provide critical insights into biomass-specific pretreatment strategies, facilitating enhanced enzymatic hydrolysis and subsequent biochemical conversion to bioethanol.