Technoeconomic analysis of alkaline extraction of corn stover for hydroxycinnamic acids production in a continuous reaction system

This is the authors' abstract. We don't add key points for this paper.

Alkaline extraction of lignocellulose offers a sustainable route to hydroxycinnamic acids (HCAs), particularly p-coumaric acid and ferulic acid, while preserving the cellulose-rich solid fraction. Industrial implementation, however, is constrained by batch processing, which requires prolonged heating and cooling, limits throughput, and increases operating cost. In this study, we integrate pilot-scale continuous extraction, downstream purification, and techno-economic analysis using a high-pressure screw reactor (HPSR) for corn stover under compressed air. The system's instantaneous heating and enhanced mass transfer effectively generates HCA yield of up to 21.08 mg/g corn stover within 10 min, approaching the batch maximum while dramatically compressing the extraction window. Multistage membrane separation, extraction, and crystallization produced p-CA-rich crystals with 94.7% purity and 56.9% overall recovery, while preserving a cellulose-rich pulp coproduct. At a design capacity of 1 t h −1 corn stover, continuous operation reduced total utility-energy demand from 13.23 to 6.69 GJ h −1 and lowered capital and operating costs relative to the batch process. The resulting minimum selling price was USD 42.63 kg −1 , compared with USD 51.84 kg −1 for batch operation, with a positive NPV of USD 5.15 million, 14.7% IRR, 15.5% ROI, and a 6.45-year payback period. Sensitivity and Monte Carlo analyses identified HCA production rate, operating expenditure, discount rate, and capital investment as the dominant economic drivers, with 84.1% of simulated scenarios yielding an MSP below USD 50 kg −1 . These results establish HPSR processing as a process-intensified platform linking rapid biomass fractionation, integrated coproduct recovery, and improved industrial economics.