Pressurized Screw Feeding Reactor Promoted Continuous and Scalable Production of Hydroxycinnamic Acids

The valorization of agricultural waste into high-value hydroxycinnamic acids (HCAs) is critical for advancing sustainable biorefineries. However, traditional batch alkaline hydrolysis processes are hindered by cost-prohibitive downtime, labor-intensive operations, and inefficient heat-mass transfer, limiting their industrial applicability. This study presents a continuous high-pressure screw reactor (HPSR) system that integrates intensified mechanical shear, enhanced material mixing, and improved process controllability. These features collectively accelerate reaction kinetics while significantly suppressing product thermal degradation, enabling a high yield of HCAs (25.46 mg/g) and lignin removal (93.6%) within a time scale of minutes. The production efficiency reaches 11.40 mg/g biomass/min, one magnitude higher than that of the batch mode. Further, a high solid/liquid ratio strategy amplifies product stream concentration, coupled with a cascade purification involving adsorption, extraction and crystallization, yielding high-purity (91.04%) p-CA product. In summary, this work demonstrates an efficient conversion strategy to convert herbaceous biomass into HCAs and other industrially relevant components in a continuous fashion.