Title
Statistical optimization of NaOH pretreatment of pine needles using Box-Behnken design for bioethanol production
Authors
MUHAMMAD IRFAN, MISBAH GHAZANFAR, HAFIZ ABDULLAH SHAKIR, MUHAMMAD KHAN, MOHMMED AHMED A. ASIRI, SHAUKAT ALI, IRFAN AHMAD and MARCELO FRANCO

Received May 31, 2023
Published Volume 57 Issue 9-10 September-December
Keywords pretreatment, pine needles, NaOH, fermentation, bioethanol

Abstract
In this study, pine needles were exploited for bioethanol production. Pretreatment is the first and foremost step towards better yield of bioethanol from lignocellulosic biomass. In this study, NaOH pretreatment of pine needles was optimized by the Box Behnken design. Substrate characterization was done by using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Maximum cellulose (90%) and total phenolic compounds (51.03 ± 0.002 mM) were recorded under optimized conditions, and structural analysis also revealed the significance of the pretreatment. High F and R2 values and low P values indicated the accuracy and validity of the model. Pretreated biomass was further subjected to saccharification using commercial, as well as indigenous cellulase. Maximum saccharification (49.2%) was observed with commercial cellulase, which led to a 7% ethanol yield employing Saccharomyces cerevisiae. Maximum ethanol yield (7%) was observed in NaOH pretreated biomass. Results proposed that Pinus spp. needles could be potential cellulosic biomass for bioethanol production.