Process application upgrades are never easy, but they can be less difficult, easier to justify and more successful with the right controls and software. Adam Edmonson, P.E., instrument engineer, and Michael Nassif, control systems engineer, both at Shell Chemical LP, reported learning this lesson when they recently migrated a six-train batch unit at their plant in Geismar, La., from Honeyell Process Solutions' (HPS) obsolete TotalPlant Batch (TBP) software running on C200 controllers to Experion Batch Management (EBM) software running on C300 controllers.
Securing project approval
Located on the Mississippi River about 20 miles south of Baton Rouge, the plant manufactures ethoxylate, which is a primary ingredient in soap products such as laundry detergents and dishwashing liquids. The unit processes batches that average 50,000 pounds, while the trains typically consist of two or three vessels, including a main reactor, tanks, pipelines and sub-trains. Edmonson and Nassif reported there were several reasons why they needed to upgrade, though their project was initially difficult to get approved.
"TBP was obsolete, but EBM couldn't run on C200, so we had to upgrade to C300," said Edmonson. "We tried obsolescence as a way to justify the migration, but that proposal was rejected by our capital projects committee, so we supplemented it with estimated gains in asset management and smart instrumentation. We determined the upgrade could save 10 seconds per batch step or about 300 seconds per batch. With six to nine batches per day, this could add up to some significant potential production savings." He added that migrating to EBM would also enable the batch unit to comply more closely with the ISA S88 batch management standard.
Edmonson and Nassif presented "TotalPlant Batch Migration to Experion Batch Manager” at Honeywell Users Group Americas 2017 on June 21 in San Antonio, Texas. They reported that Shell's ethoxylation unit had been upgraded from PLCs to Experion R201 with TotalPlant Batch and four C200 controllers in 2005.
Prepare to migrate
After securing approval to migrate the batch unit to EBM and C300s, Edmonson and Nassif also determined that about 70 graphics needed to be upgraded, and that they could perform cold cutovers of each train during planned shutdown periods. The project also included migrating the unit's high-level analog inputs (HLAI) and analog outputs (AO) to HPS Process Manager I/O (PMIO) talking HART communication protocol. These and other new components, as well as EBM and Sequential Control Module (SCM) software in Experion, also allowed the factory acceptance test (FAT) for the migration top be done on a virtual system using simulated controllers.
"EBM was also put on a live system using a simulator before live cutovers," said Nassif. "Operator training was done on a live system using a simulator, which let operators 'play' with batches on EBM before the actual cutovers.”
In addition, they worked with Precision Engineering Inc. (PEI), a system integrator in Mobile, Ala., to replicate and implement Campaign Manager, which is a customized function in EBM that could also save time. "This is a duplicate function for EBM and a custom solution for TPB that allowed us to run in continuous mode," explained Edmonson. "This means a new batch of the same recipe could start automatically on a train."
The batch unit's phased migration and loading to EBM, graphics, SCM, Campaign Manager and other components was performed by Shell's staff on two trains per day over a three-day period, with phone support from HPS as needed. The cutovers were completed in December 2016.
Nassif reported that one anticlimax of upgrading the batch unit was that it only produced time savings of 18 seconds for the catalyst, 23 seconds for the reactor, and 32 seconds for the soak process, which added up to a lot less than the savings of 300 seconds per batch that was originally expected. "The new system is running well, and operator acceptance is high, so we're still happy with how this migration turned out," he said.
Edmonson added, "Following the simulation training, we did have some problems with the first few actual batches. However, the rest since then have been smooth, and we've been home free."