Continuous High-Pressure Screw Reaction System for Scalable Hydroxycinnamic Acid Production

Abstract

Hydroxycinnamic acids (HCAs), including ferulic acid (FA) and p-coumaric acid (p-CA), are bioactive compounds with antioxidant, anticancer, and antiviral properties. Sugar cane bagasse (SCB), an underutilized agro-industrial byproduct from the sugar industry, is a promising feedstock for HCA extraction due to its high abundance. However, conventional alkaline hydrolysis methods for HCA extraction are hampered by prolonged processing times and oxidative product degradation. Herein, we address these limitations with a continuous anaerobic alkaline hydrolysis process employing a high-pressure screw reaction (HPSR) system. Operating under pressurized inert conditions, the HPSR system eliminates oxidative degradation while achieving rapid reaction kinetics. Instant heating and cooling allowed efficient production of HCAs (28 mg/g, ∼59% of the total extractable HCAs) in just 4 min, achieving a production rate of 8.33–11.07 mg/g biomass/min within 2 min─an order of magnitude higher than conventional batch systems. Integrating high solid-to-liquid ratio (1:10 w/v) production and downstream purification, the process achieved the scalable production of high-purity (93%) HCAs, enhancing the industrial relevance of this continuous process. To sum up, this work establishes a scalable, energy-efficient platform for valorizing lignocellulosic waste into high-value products, bridging a critical gap between laboratory-scale innovation and industrial implementation.