Published September 2003
On-line process economics optimizers were developed in the oil refining industry, and have since been adopted by chemical producers who make primarily basic chemical building blocks.
The industry was made possible by process computer control, which began by using computer subroutines to control individual process variables in a chemical manufacturing operation. These were designed to maintain technical setpoints established by process design engineers. As the industry matured, it incorporated cascade control to optimize (at the technical level) a group of process variable parameters.
While technical process control optimization using computer subroutines was being employed within manufacturing plants, oil refiners developed off-line linear programming techniques (ex. PIMS) to optimize the economic performance of their refineries. Refiners later installed their linear programming computer models onto their process control computers, and would periodically run the linear program (once a day, once an hour) to manipulate the technical variables of the plant to satisfy an economic optimum objective function.
Chemical producers familiar with refining (ethylene producers) adopted the know-how employed by oil refiners in computer process economic optimization, and began expanding both the range of applications and the type of mathematics used, in order to provide more meaningful economic setpoints on a more frequent basis than the cumbersome linear programming models used in refining.
This study identifies the organizations that sell commercial economic optimization computer programs designed to run on process control computers. This study indicates what chemical applications (chemical products) optimizer routines have been developed for, the mathematical bases used in the routines, the types of algorithms used, and the commercial results claimed that justify the capital investment required, and the ongoing software support effort.
This study also provides case studies of several chemical manufacturers that actively employ economic optimizers, and reports upon the actual results obtained and the benefits actually achieved. Finally, it pinpoints areas of possible improvement in future developments.