EDGAR

R. Edgar and R. Snider, in D. E. Clark and co-workers, eds.. Microwaves Theory and Application in Materials Processing, American Ceramics Society, Westerville, Ohio, 1991. 

T. E. Edgar and D. M. Hinnelblau, Optimi tion of Chemical Processes McGraw-HiU Book Co., Inc., New York, 1988. 

Process Control Thomas F. Edgar, Cecil L. Smith, F. Greg Shinskey,... 

Edgar B. Blunder, Howard G. Mcllvried, HI, Gary J. Stiegel,... 

Thomas F. Edgar, Ph.D., Professor of Chemical Engineering, University of Texas, Austin, Texas (Section 8, Process Control)... 

Edgar B. Klunder, Ph.D., Project Manager, Energy Technology Center (Pittsburgh), U.S. Department of Energy (Section 27, Energy Resources, Conversion, and Utilization)... 

Edgar, T. F, and D. M. Himmelhlau. Optimization of Chemical Fr ocesses, McGraw-Hill (1988). 

Once the objective and the constraints have been set, a mathematical model of the process can be subjected to a search strategy to find the optimum. Simple calculus is adequate for some problems, or Lagrange multipliers can be used for constrained extrema. When a Rill plant simulation can be made, various alternatives can be put through the computer. Such an operation is called jlowsheeting. A chapter is devoted to this topic by Edgar and Himmelblau Optimization of Chemical Processes, McGraw-HiU, 1988) where they list a number of commercially available software packages for this purpose, one of the first of which was Flowtran. 

With many variables and constraints, linear and nonlinear programming may be applicable, as well as various numerical gradient search methods. Maximum principle and dynamic programming are laborious and have had only limited applications in this area. The various mathematical techniques are explained and illustrated, for instance, by Edgar and Himmelblau Optimization of Chemical Processes, McGraw-Hill, 1988). 

Edgar and Himmelblau (Optimization of Chemical Processes, McGraw-HiU, 524-550, 1988) supply many references to other problems in the literature ... 

General References Seborg, Edgar, and MeUichamp, Frocess Dynamics... 

Industries, McGraw-Hill, New York, 1994 Sehorg, Edgar, and MelBcPamp, Process Difnamrcs and Control, Wiley, New York, 1989. 

The PI controller is by far the most commonly used controller in the process industries. The summation of the deviation with its integral in the above equation can be interpreted in terms of frequency response of the controller (Seborg, Edgar, and Melhchamp, Process Dynamics and Control, Wiley, New York, 1989). The PI controller produces a phase lag between zero and 90 degrees ... 

McGraw-Hill, New York, 1988. Seborg, D. E., T. F. Edgar, and D. A. Mel-lichamp, Vrocess Dynamics and Control, Wiley, New York, 1989. McAvoy T. J., Interaction Analysis, ISA, Research Triangle Park, North Carohna, 1983. 

No single method or algorithm of optimization exists that can be apphed efficiently to all problems. The method chosen for any particular case will depend primarily on (I) the character of the objective function, (2) the nature of the constraints, and (3) the number of independent and dependent variables. Table 8-6 summarizes the six general steps for the analysis and solution of optimization problems (Edgar and Himmelblau, Optimization of Chemical Processes, McGraw-HiU, New York, 1988). You do not have to follow the cited order exac tly, but vou should cover all of the steps eventually. Shortcuts in the procedure are allowable, and the easy steps can be performed first. Steps I, 2, and 3 deal with the mathematical definition of the problem ideutificatiou of variables and specification of the objective function and statement of the constraints. If the process to be optimized is very complex, it may be necessaiy to reformulate the problem so that it can be solved with reasonable effort. Later in this section, we discuss the development of mathematical models for the process and the objec tive function (the economic model). 

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