Enabling Bioprocess Development using Virtual Plant Technology

Dynamic process modeling is a valuable tool for understanding process behavior and testing new ideas in a safe and secure environment. It can be used to identify and test new operating conditions, process configurations, control strategies, or operating procedures that increase yield, reduce costs, or impact other important performance indicators. Dynamic models can also be extended in order to train new and existing operators on unusual or emergency conditions, reducing operator error, improving operational consistency, and making hazardous processes inherently safer to run.

Over the last several years, DuPont has made a clear, long-term commitment to developing and operating bioprocesses. Enabling the DuPont strategic direction in biotechnology depends on Virtual Plant Technology. Virtual Plant Technology refers to the application of dynamic modeling to address the needs of the project development cycle, including evaluation and testing of process alternatives during design, operability studies, control structure design and testing, DCS configuration testing, and operator training. Dynamic modeling and simulation are often more critical in bioprocess development than in traditional chemical processes. Bioprocesses may have complex flowsheets and make extensive use of batch or combined batch / continuous processing. Because many bioprocesses have high water loads, water recycle and inventory management can become problems in such an environment. Further, plant-wide batch automation may be challenging, requiring synchronization of different batch unit operations, arbitration of shared equipment, and coordination with the continuous processing units, while maintaining the operating conditions at their targets and within constraints. Additionally, steady state process models may not accurately determine variability and maximum or minimum loads on equipment and utilities. Therefore, dynamic simulation is an important tool to understand the inherently complex dynamic behavior of the integrated bioprocess, the use of which translates into better design, operating policies, understanding of constraints, and process control, and opens the door for significant financial benefits.

DuPont™ TMODS, a proprietary dynamic modeling software package developed and maintained by the Dynamic Simulation, Control, and Optimization Group in DuPont Engineering Research and Technology (DuET), is by far the most commonly used dynamic simulation tool in DuPont. As such, the modeling capability in DuPont™ TMODS is highly leverageable, and the tool has very broad use and acceptance across DuPont. DuPont™ TMODS and dynamic modeling are key components of Virtual Plant Technology as practiced in DuPont. For the last two decades, Virtual Plant Technology has been used throughout DuPont’s chemical and polymer businesses to improve process understanding and make processes more profitable. This talk will focus on how Virtual Plant Technology is being used in DuPont to support the development of bioprocesses. For example, it has been used to study process alternatives, such as the effect of different bioreactor designs or the use of perfusion and cell recycle, and to support the process economic evaluation of those alternatives. It has also been used to develop control strategies and study process operability, especially with regard to the large water flows, recycle streams, and inventories typical of bioprocesses, leading to important changes in process design. Virtual Plant Technology has also played a vital role in bioprocess commercialization, including operator training simulators, control system functional description development, and control system configuration and checkout.