Saturday, November 07, 2015

Innovations in Advanced Process Control?

Over the years I have come to enjoy and appreciate Heinz P. Bloch's one page articles in Hydrocarbon Processing about reliability. They are always full of insight I can learn from whether the particular issue relates to the benefits of attending conferences or a specific maintenance issue, or a staff issue as in Octobers column titled "Hire or train a reliability professional?". This column was based on a question from a reader about how to satisfy the need for a reliability expert at the company. The answer was not a clear train or hire, but provided insight on the issues involved with either choice.

Turning the page, was like a cool shower. The next article was titled "APC technology adapts quickly to economic changes" and written by Tushar Singh from AspenTech. Finally a topic in HP on which I was not completely blank. When I started reading the article my initial enthusiasm turned wondering how knowledgeable the writer was about APC - and I really have not been active in the field for more than 20 years. Although I over the years have kept contact with active acquaintances.

The first paragraph except for mentioning the need to optimize operations is empty talk. The second claim companies are helped by ground-breaking innovations in APC. However, those ground-breaking innovations are not mentioned. I believe the ground-breaking innovations in APC occurred in the early nineties, when Henrik Brabrand at DTU developed MIMOSC - multi input multi output self tuning controller - and applied it to a heat integrated distillation column pilot plant of semi-industrial scale. At the same time Jacques Richalet of Adersa applied similar ideas to aluminium sheet metal production. Mr. Singh owes us to mention, which ground-breaking innovations he are writing about.

Mr. Singh goes on to claim APC is crucial to maximizing profitability. I wonder what definition of APC should be used here? Normally I think about APC as the layer between the business planing software on the mainframe and the single loop controllers in the plant. The business planing software maximize profitability and then tells the APC what to do to execute the plan.

The next section jumps to the very different question of the perceived skill shortage, and manage to write "If the controllers react in a manner, that the operators do not understand, the controllers could perform incorrectly and be turned off, as the controller model will not reflect the plant behavior at a particular point in time". I have no idea  what Mr. Singh means here. The author further states "..to align the controller objectives to tuning parameters". Again I have no idea what the meaning should be.

Finally there is a section related to the title of the article. The section heading is "Responding to changes in economic objectives". However, at the end of the first paragraph I am lost by the statement "..to keep pace with a highly competitive global landscape". I wonder what input the APC gets from the global landscape or why undesirable scenarios need to be accommodated?

Luckily articles as superficial and empty as this one is very rare in Hydrocarbon Processing, and I keep looking forward to each new issue. But what you think about vendors contributions to HP?