(556a) Design of Process Monitoring and Analysis Systems

In the manufacturing industry, for example, the pharmaceutical industry, obtaining a consistent end-product quality is mandatory. A thorough understanding of the process as well as a properly designed monitoring and analysis system are required to obtain the desired end-product properties. This work focuses on developing a systematic approach for the design of the process monitoring and analysis systems. The design of a process monitoring and analysis system is a step-wise procedure consisting of the selection of critical process variables, followed by the proper selection and placement of suitable monitoring and analysis equipments to keep track on the behavior of these critical process variables, and finally, also including the coupling of the monitoring and analysis system to a control system to ensure that critical process variables can be controlled.

A model library and a knowledge base are two important supporting tools which will help to obtain the proper monitoring and analysis system. The model library contains the set of models for each unit process. These models relate the process variables. These models will support the process analysis and will generate the additional or missing data needed to obtain the final design. For example the model library provides the sensitivity analysis through which the effect of process variables on the final product properties can be analyzed and thus critical control variables can be identified. It also provides the interdependency analysis through which the appropriate actuators for each control variable can be selected. The model library also has the option for closed-loop simulation through which the effectiveness of the selected pairs of critical control variables and actuators can be analyzed. The knowledge base provides the necessary data during the design. It contains information related to process monitoring and analysis systems and includes for each unit process, a list of critical process variables that should be monitored, a list of the corresponding manipulating variables (actuators), and the corresponding equipments typically used for their measurement (including data related to accuracy, robustness, time, etc.). A design algorithm has been developed which will relate the available information in terms of product quality specifications and process specifications with the developed supporting tools and will provide the proper monitoring and analysis system. Optimization of the design can be achieved in terms of product data analysis time, cost of monitoring equipment subject to the maintenance of the desired product quality.

The objective of this paper is to highlight the model-based approach for design of process monitoring and analysis systems. A collection of the necessary process operational models have been created through a computer-aided modeling tool. The design of process monitoring and analysis systems through the systematic approach will be illustrated through two case studies: a fermentation process and a crystallization process.