Shortening Protein Total Residence Time to Improve High-Cycle Purification Efficiency in Integrated Continuous Biomanufacturing.

Amid the growing demand for therapeutic protein production, improving the efficiency of downstream purification has become increasingly critical. In this study, an automated downstream purification strategy was developed that is compatible with both continuous and batch-mode upstream processes. As a demonstration, a 50-L end‑to‑end continuous bioprocess was implemented. A novel analysis method, Ensemble Residence Time Distribution (ERTD) analysis, was applied to characterize the flow pattern of the integrated upstream and downstream process. Through systematic simulation, the ERTD framework quantifies the overall turnaround time (TAT) and residence time distribution across individual unit operations, providing a framework for evaluating downstream performance. The simulation results constitute the primary focus of the study, while the 50-L continuous process provides an industrially relevant experimental case study for demonstrating the proposed framework. The key contributions of this work are as follows: (1) A practical automated framework that leverages existing facilities and equipment, enabling broad industrial applicability; (2) A flexible downstream process intensification strategy compatible with both batch and continuous upstream operations, which offers effective solutions to meet stringent downstream efficiency demands while addressing potential regulatory concerns; (3) The implementation of the novel ERTD modeling that uses overall average residence time as a quantitative indicator for downstream efficiency evaluation, deepening mechanistic understanding of the holistic downstream process and identifying its bottleneck unit operations.