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CLIFFTENT For Process Optimization
66 D E C E M B E R / 2 0 0 4 w w w. c o n t r o l g l o b a l . c o m
y first assignment as a newly hired control systems repre-sentative at IBM in 1961 was to evaluate the work beingdone at DuPont’s Repauno Works in southern New
Jersey. Being an IBM test site I was sent to see if the results ofour work there could help us sell our recently announced IBM1710 Industrial Computer Control System. The process beingstudied was a fixed-bed reactor for acrylonitrile synthesis. A prin-cipal control problem arose from the catalyst activity whichdegraded so steeply that parallel reactors were needed, one in
synthesis mode while the other was beingregenerated. Deciding when to switch soas to maximize productivity was an impor-tant objective.
A really talented team from IBMResearch (Jack Bertram, Dick Stillman, Dick Koepke plusothers) had modeled the synthesis process in a set of cou-pled, partial differential equations. Solving these equationsnumerically, however, required several minutes on an IBM7090 to simulate a few seconds of real-time. All went back tothe drawing board and the team reduced the theoreticalmodel to a set of easily solvable empirical relationships cov-ering the operating space of interest. Meanwhile, back atDuPont, researchers were also hard at work trying to identifyan improved catalyst that didn’t degrade significantly.
“Thank you very much,” said Dupont, “it was a great proj-ect. We learned a lot about our process and how to controlit. On further review we really don’t need the computer con-trol system as we had initially thought.”
I learned right from the start that process optimization wasa really tough way to sell control systems. We had recently dis-covered that paper-making was a very complex process thatcontrol computers could facilitate by making key perform-ance indicators available to the machine tender in real-time.Without recourse to higher mathematics, the control systemcould significantly improve overall machine productivity dur-ing paper-grade changes, upset recovery (e.g., sheet-break)and other transient conditions. Process optimization becamea future intangible that could close the deal if necessary.
During ISA/2004 in Houston, I had a long discussion overlunch with Pierre R. Latour, a recognized authority inprocess automation technology and successful entrepreneur
in several process control ventures. Latour began his careerin the early 1960s with DuPont and Shell Oil after receivinga PhD in Chemical Engineering at Purdue. He worked onthe first Shell computer control project (FCC–Deer ParkRefinery 1966). A two-year tour as a captain in the U.S. Armyfollowed at NASA’s Manned Space Flight Center managingthe Apollo Docking Simulator development. After musteringout, Latour co-founded Biles & Associates (later acquired byInvensys) and Setpoint (later acquired by Aspen Technology).
Latour served in a business development capacity as VicePresident at Aspen prior to launching his current consul-tancy–CLIFFTENT, Inc. ([email protected]).
Latour is nothing if not passionate about the value of theCLIFFTENT methodology (http://groups.msn.com/CLIFF-TENT ). His rapid-fire discourse barely allows for dialog andI’m certain that I have only a superficial understanding of thismethod of selecting the optimal set-points for maximum eco-nomic yield from a process or operation.
His quarrel with process control as currently practicedboils down to two points:1. No consistent, objective method exists for assessing the
economic value of improved dynamic performance.2. No incentive exists for control systems implementers to
deliver sustained performance improvements.Latour’s answer to the first is CLIFFTENT–a mathemati-
cal method for optimizing setpoints and measuring thefinancial value of reduced variance for any controlled vari-able or key performance indicator. His answer to the secondis SR2 (Shared-Risk, Shared-Reward)–a method for licens-ing technology solutions based on their performance asmeasured by CLIFFTENT.
This is a guy you ignore at your peril. He has demon-strated a deep technical knowledge of chemical process con-trol, as well as the ability to survive and prosper as a businessleader. If I were a chemical process manager, a control sys-tems technologist or a business entrepreneur in a related dis-cipline, I’d listen to Pierre Latour quite closely.
Terrence K. McMahon McMahon Technology Associates
C
MM
“CLIFFTENT–a mathematical method for optimizing setpointsand measuring the financial value of reduced variance for anycontrolled variable or key performance indicator.”
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