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HomeAuthorsFriedman, Y. Z.

Friedman, Y. Z.

Petrocontrol, New York, New York

Y. Zak Friedman is a Principal Consultant with Petrocontrol. He has practiced APC for most of his career, specializing in using first-principles models for inferential process control and has developed inferential models to fit many hydrocarbon processes. Dr. Friedman’s experience spans more than 50 yr, working with Exxon Research and Engineering, KBC Advanced Technology and Petrocontrol. He holds a PhD degree from Purdue University.

HP Control: Controlling the mundane naphtha stabilizer, Part 2

Hydrocarbon Processing / October 2007
Petrocontrol: Friedman, Y. Z.
Process Control

Part 1 of this editorial (September issue) discussed a debutanizer control strategy (Fig. 1). Given that feed composition varies with ambient conditions, one could argue that unless you have advanced ..

HP Control: Controlling the mundane naphtha stabilizer, Part 1

Hydrocarbon Processing / September 2007
Petrocontrol: Friedman, Y. Z.
Process Control

Consider the distillation column in Fig. 1. It is called a "stabilizer" and removes LPG from naphtha. Every refinery has at least three of them, and often five or more, one each in every crude unit, r..

Implementing coker advanced process control

Hydrocarbon Processing / June 2007
Petrocontrol: Friedman, Y. Z.
Ruhr Oel: Haseloff, V.
Process Control / Process Optimization

This project resulted in about a half-year payout

HP Control: What about reactor advanced process control?

Hydrocarbon Processing / June 2007
Petrocontrol: Friedman, Y. Z.
Process Control

The premise of advanced process control (APC) is that there is money to be made by pushing a unit against its limits while keeping the product qualities at target. This concept is easy to understand b..

HP Control: Inferential models that correlate but do not predict

Hydrocarbon Processing / March 2007
Petrocontrol: Friedman, Y. Z.
Process Control

A friend has asked me to help solve a dilemma. A neural net model developed in his plant had a near perfect fit against lab values but in spite of that the model's prediction ability was poor. I was s..

HP Control: Audit your APC applications

Hydrocarbon Processing / December 2006
Petrocontrol: Friedman, Y. Z.
Process Control

I was one of the first control industry whistleblowers, pointing out that half of the advanced process control (APC) applications implemented over the years do not work. We APC engineers have the resp..

HP Control: Jim Ford's views on advanced process control

Hydrocarbon Processing / November 2006
Petrocontrol: Friedman, Y. Z.
Process Control

C. F. Picou Associates, Inc. (CFPA), an affiliate of Maverick Technologies, was founded in 1974 by Dr. Courtney Picou. Originally aiming to provide process engineering consulting to the refining indus..

HP Control: What constitutes a real-time application?

Hydrocarbon Processing / September 2006
Petrocontrol: Friedman, Y. Z.
Process Control

I recently heard computer programs, mainly of the simulation variety, described as working in real time in service of the unit operators, inferring product properties and other unmeasured constraints ..

HP Control: Are there any good APC training programs out there?

Hydrocarbon Processing / August 2006
Petrocontrol: Friedman, Y. Z.
Process Control

I have written several articles and editorials warning about the failure rate of advanced process control (APC) applications. See for example my January 2006 editorial,1 which also references related ..

HP Control: Solomon Associates' advanced process control survey

Hydrocarbon Processing / June 2006
Petrocontrol: Friedman, Y. Z.
Process Control

Measuring advanced process control (APC) benefits is as important as it is difficult. We justify APC projects on estimations that the unit operation would improve. To the extent that these preproject ..