Process Optimization for Ionic Liquid Tetrabutylammonium Hydroxide Pretreatment of Waste Particleboard to Heighten Enzymatic Hydrolysis Saccharification

Abstract

The dense lignocellulosic structure inherent in particleboard poses a challenge to its efficient energy utilization, necessitating pretreatment prior to use. This study is aimed at exploring an optimal ionic liquid pretreatment process to enhance the utilization efficiency of waste particleboard. Response surface methodology (RSM) and analysis of variance (ANOVA) were employed to investigate the effects of various parameters, including reaction time, temperature, and concentration of tetrabutylammonium hydroxide ([TBA] [OH]) solution on glucose production during the lignocellulosic hydrolysis process. Under the optimal pretreatment conditions (68 min, 65 °C, and 11.44% [TBA] [OH] concentration), the glucose yields from enzymatic hydrolysis of waste particleboard reached 324.48 mg/g, exhibiting a remarkable 34.75% increase compared to untreated samples. Scanning electron microscope (SEM) analysis revealed the disruptive effects of pretreatment on the lignocellulosic structure. Fourier transform infrared spectroscopy (FT-IR) demonstrated the removal of hemicellulose, as evidenced by the disappearance of the peak at 1740 cm⁻¹. X-ray diffraction (XRD) analysis indicated a 5.08% increase in the crystallization index of the pretreated biomass. Composition analysis further confirmed the partial removal of hemicellulose and lignin, resulting in the enhanced exposure of cellulose and subsequently increasing the accessibility of cellulase. This improvement ultimately led to an enhancement in enzymatic hydrolysis efficiency.