From Small Batch to Large-scale Continuous Processes

T he chemical process industries are probably the least understood of all manufacturing sectors, largely because few final products are sold directly to consumers. The chemical process industries are perhaps best summarized by the BASF ad: “We don’t make the products you buy, we make the products you buy, better.” A consumer who purchases an automobile generally has some appreciation for the sequence of steps involved in an assembly line to produce the vehicle. Most consumers, however, have a lesser understanding of the chemical processes involved in producing plastics for the dashboard, fabrics for the seats, glass for the windshield, and polymers for the tires. One goal of this special section, part II of the August 2006 special section, is to provide control engineers with a better understanding of various chemical processes and their control challenges. The August 2006 issue focused on biologicalbased chemical processes, with topics ranging from large-scale pulp and paper processes to crystallization operations with tight control over crystal size, shape, and structure. The topics covered in this issue range from small batch processes for specialty chemicals and pharmaceutical production to large-scale petroleum refineries with continuous processes. The first article by Bonvin, Srinivasan, and Hunkeler covers batch processes, which are IM A G E C O U R T E S Y O F D E N N IS S . B E R N S T E IN