Distributed Control / PLCs & PACs

Valero's Good Examples

Automation in the Refinery of Today It's Not Business as Usual

By Jim Montague

I've already mentioned it was nice to attend ISA Automation Week after several years' absence, but I didn't realize how useful 2012's event would be until the final keynote. I'm no controls engineer, and because I'm not hip deep in process lines and PLCs all the time, it's good for me to be reminded how these fields actually work. Having that understanding gives me points of reference I can use to cover oil and gas and the other process industries.

So I sat in on Travis Capps' presentation, "It's Not Business as Usual Anymore: Automation in the Refinery of Today," at the Orlando Convention Center and got a bracing wake-up call about the critical importance of advanced process control (APC) and the huge gains it can deliver if users are willing to learn and invest in it. Capps is Valero Energy Corp.'s vice president of energy and gases.

Capps explained that principles for the "Refinery of Today" include a common management framework, occupational and process safety, sound environmental practices, stable and reliable operations, efficient supply chain management, profitability and growth—especially as North America again becomes a net exporter. Valero's framework is its Commitment to Excellence Management System (CTEMS), and its uniform expectations, practices and standards are the foundation of its refinery performance measures and assessments—particularly as it strives to achieve first-quartile performance in refining, mechanical availability and energy efficiency. Naturally, these goals lead straight to automation and process control and APC. 

"With stable and reliable process control in place, APC and real-time optimization (RTO) efforts can directly contribute to margin capture by using online measurements to optimize processing units and do product blending in real time," says Capps. "Compared to people, computers can track more information in real time and use this information to adjust operations more quickly to maintain the most profitable targets and rates. In general, process units have multiple limits, and to avoid violating limits, operators need to be conservative. However, APC can watch all these limits simultaneously and change unit operations to the most economic target as feedstocks, daily temperatures and other variables change. Essentially, as things change, APC can react more quickly to avoid violating operating limits."

So far, Capps reports Valero deployed APC on 110 process units out of 210 candidates by the end of 2011, and presently has 15 projects underway. "Typical benefits can be tens of millions of dollars per year for an average-sized refinery," adds Capps. "APC utilization has also increased from 55% on a smaller installed base to more than 80% on the larger installed base."

This isn't the first time Valero gave me a great story. I helped Valero's analyzer technology manager, Robert Sherman, write "Sample Conditioning Systems Need Love Too" for the December 2011 issue. In it, he stressed that process users and integrators must carefully design and match sample conditioning systems (SCSs) with application requirements, complete application data sheets and deploy climate-controlled shelters.

At the 2010 Honeywell Users Group meeting, I covered Valero's upgrade of the control systems, control room and networking infrastructure at its Benicia, Calif., refinery. Denise Plaskett, Valero's principal applications engineer for control systems, presented "Continuous Evolution: Layering Experion on Top of TDC," describing how she and her colleagues designed and carried out the renovation, including moving more than 2000 I/O points, testing new local control networks and dealing with timing issues that required all integration and cutover to the new system to be done on-line while working around unit turnarounds over several years. Pretty dramatic. Nothing like good stories.