Computer-Aided Design and Simulation of Chemical Plants: PEETPACK, a Non-Proprietary Flowsheeting Program

Abstract

There are over thirty flowsheeting programs presently in use or at various stages of development in North America and in Europe, however very few of them are non-proprietary and of these none contains a sufficiently wide or general library of unit models and physical property data, or contains an efficient calculation order finder. Many programs suffer also from a poor data interface with the users which makes teaching or learning process difficult and time-consuming. PEETPACK (Process Engineering Evaluation Techniques Package) described in this thesis is a contribution towards fulfilling the need for a more flexible, complete and above all non-proprietary program. This program has been developed based on the author's experience with a wide variety of other flowsheeting programs, and it attempts to meet a number of criteria of acceptability through its careful programming on local resources to ensure its non-proprietary nature. PEETPACK is constructed in a highly modular form to facilitate its installation, further development and its ease of understanding by students and industrial users alike. It is composed of six sets of semi-independent programs: the data communicators, the calculation program, a library of general unit models, a library of physical property routines and a set of job control and command programs to link all the segments. Its data communicators are very flexible and allow the mixing of interactive and batch-mode data input. The library of models contains fifteen models of basic and essential unit operations and these make extensive use of thermodynamic and physical property evaluation routines for hydrocarbons based on well-documented theoretical and empirical methods. Its error tracing and trapping facilities should make its running smooth and help the user diagnose the error sources. The thesis presents a detailed analysis of three flowsheeting programs (PACER, GEMCS and CONCEPT) which helped in preparing this new program then describes in detail each of the six sections making up the PEETPACK package. The thesis concludes by presenting a new application of flowsheeting programs, that of actual plant-data reconciliation through an analysis of the error distribution in the data.