Assessment of Prosopis juliflora feedstock for bioethanol production potential via hydrolysis and physicochemical analysis

Abstract

Prosopis juliflora is a promising lignocellulosic resource for sustainable bioethanol production. This study experimentally investigated and characterized different anatomical parts of P. juliflora to assess their suitability as feedstock for fermentable sugar production. Wood and pod samples collected from northeastern Brazil were analyzed for their physicochemical and thermal properties. Analytical methods included determination of moisture, ash, elemental composition (C, H, N, S, O), metal content, and structural carbohydrates (cellulose, hemicellulose, lignin), along with thermogravimetric analysis conducted between 40 °C and 900 °C. Biomass hydrolysis was performed using dilute sulfuric acid and cellulase to compare catalytic efficiency. The results of this study demonstrate that P. juliflora biomass exhibits low moisture content (5.1–10.1 %) and high carbon levels (43.9–46.4 %), indicating favorable energy properties and potential for pyrolysis. The stem bark contained the highest levels of cellulose (48 %) and hemicellulose (17 %), although its relatively high lignin content (28 %) may hinder saccharification. Hydrolysis of untreated biomass yielded up to 21 % glucose using acid and 11 % using enzymes, confirming the presence of accessible fermentable sugars. The wood biomass of P. juliflora from the Brazilian semiarid region has a high cellulose content and moderate levels of lignin, making it the most promising and efficient fraction for ethanol production. These findings confirm that P. juliflora biomass has substantial potential for reducing sugar production, supporting its use in second-generation bioethanol production. However, the recalcitrant lignin fraction highlights the need for pretreatment to enhance holocellulose accessibility and sugar release. This study contributes novel experimental data that supports the valorization of P. juliflora as a renewable feedstock for sustainable biofuel applications in semiarid regions.