A HIERARCHICAL PROCEDURE FOR THE CONCEPTUAL DESIGN OF SOLIDS PROCESSES

A systematic procedure for the conceptual design of vapor-liquid-solid processes has been developed. In an evolutionary manner, it leads the user to select process units, to identify the equipment configurations and to determine the important design variables and the associated economic trade-offs. At present, the procedure is limited to low-molecular-weight solids and does not handle vapor solid processes. This hierarchical procedure has been implemented in a computer code to aid in the development of preliminary process flowsheets for solids processes. A number of case studies have been analyzed, including the manufacture of bis(beta-hydroxy ethyl)terephthalate from terephthalonitrile-selected for reporting in this article. Design variables unique to this solids plant-dilution ratio, wash ratio and crystallizer temperature-have been identified and their effect on overall plant economics quantified.