Production of furfural from regenerated hemicellulose via solid acid catalysis, ultrasonic pretreatment and microwave irradiation.

This study focused on the valorization of Pinus koraiensis seed scale residues for furfural production from regenerated hemicellulose via solid acid catalysis. The optimized process included solid acid catalysis, ultrasonic pretreatment, and microwave-assisted processing, and the optimal conditions were 50 % ethanol (30:1 mL/g), 80 W of ultrasonic power (10 min, 40 °C), 3 % solid acid, and 385 W of microwave power (20 min), resulting in a theoretical furfural yield of 10.50 mg/g and an actual yield of 10.36 mg/g (conversion rate of 31.49 %). The recovered solid acid exhibited similar catalytic performance to the fresh solid acid (yield of 10.23 mg/g and conversion rate of 31.11 %). Kinetic analysis revealed that reaction equilibrium was reached within 10 min, with activation energies of 11.96 kJ/mol at 30-40 °C and 25.24 kJ/mol at 40-50 °C, indicating inhibition at higher temperatures. Characterization confirmed the acidity, high thermal stability and excellent reusability of the acid despite slight deactivation after recovery. Future research will focus on optimizing the efficiency and reusability of solid acid catalysts and exploring the use of regenerated hemicellulose derivatives in biobased chemical and sustainable material applications. As renewable and biodegradable resources with tunable structures, hemicellulose derivatives offer great potential for producing biobased chemicals, ecofriendly materials, and catalysts, advancing the biobased economy while reducing fossil fuel dependence and environmental impacts.