Transferring materials through the pipeline network is a basic operation in almost every batch chemical plant. Traditionally, the tasks for conjecturing the needed operation steps are carried out manually on an ad hoc basis. This approach is often time-consuming for the multi-task and multi-stage industrial processes and, furthermore, the resulting recipe may be error-prone. The aim of this study is thus to develop a systematic strategy to generate the optimal operating procedures with Petri-net based integer programs. The Petri-net representations of system structure and also equipment states can be constructed systematically by following the procedure developed by Chou and Chang (2005). The logic constraints of this integer program are then formulated according to the token movements in Petri-net model. The resulting optimal operating procedure can be generated on the basis of any given objective function, e.g., the total length of all material-transfer routes, the total number of operation steps and the total operation time, etc. A realistic example concerning the beer filtration process will be presented to demonstrate the effectiveness and correctness of the proposed approach.

Reference: Chou, H. H., and Chang, C. T., “A Petri-Net Based Strategy to Synthesize the Operating Procedures for Cleaning Pipeline Networks,” Ind. Eng. Chem. Res. 44, 1, 114-123 (2005).