Shutting down a continuous process can be risky business. Even if the shutdown has been planned in advance, many operators and maintenance technicians get the chance to stop, service and restart their processes only once every seven years or so. That lack of practice and familiarity with the required procedures leads to heightened chances of accidents and waste—especially if the operators and technicians become overwhelmed or distracted.
To reduce the risks, many facilities operating continuous processes are turning to various kinds of software to manage shutdowns and other abnormal situations. The software packages are helping workers size up the situation quickly, and then execute the proper procedures—leaving no valve unchecked.
According to investigations that the U.S. Chemical Safety Board has conducted of startup-related incidents, two common threads in these incidents are the inability to recognize risks and the lack of systems specifically designed for startups. For this reason, Eddie Habibi, founder and CEO of PAS, advocates deploying extant technologies to present the right information in a timely, concise and contextual manner so that the operations staff can make informed decisions. He also urges following industry standards such as ISA-18.2 for alarm management and ISA-101 for high-performance operator graphics.
In all, Habibi points to four key elements of a healthy, integrated operator-decision support system: alarm management, effective graphics that deliver adequate information on high-performance human-machine interfaces (HMIs), integrated operating procedures and integrated pre-startup and pre-shutdown checklists.
“The latest thinking on risk mitigation is to provide a robust, real-time information and event-management system that delivers clear, concise and actionable information relevant to the situation at hand,” Habibi explains. “Ultimately, the key to minimizing risk during startups and shutdowns is to empower the console operator to remain vigilant, identify emerging abnormal situations, and respond in a timely manner.”
For DSM Fibre Intermediates, a chemical producer in Sittard, Netherlands, operators were being flooded with alarms during abnormal situations at facilities producing caprolactam, a raw material for making nylon. To manage the alarms better and help the operators focus on the crux of the problem, the company turned to PlantState Suite from PAS.
Using a seven-step implementation procedure, the vendor’s engineering team identified the causes of the alarms that were placing undue stress on the operators and developed a plan to help DSM achieve its goals. The team was able to deploy the software two months after completing the initial analysis phase. “Now that PlantState Suite is up and running, we have been able to analyze the alarm and event statuses in our plants in a very efficient way,” says Udo Dehner, DSM’s senior process control engineer.
As a result, he and his colleagues have seen a 70 percent reduction in the number of alarms generated. Now that the operators no longer have to deal with nuisance and “second-tier” alarms, they can focus on the primary alarms triggered by the source of the problem at hand.
Boost downtime productivity
Not only can the technologies Habibi advocates improve safety during turnovers, but they can also improve the performance of the operators and therefore make the downtime more productive. Consider the gains during the periodic shutdowns for regenerating a catalyst in some reactors that Honeywell Specialty Materials uses at its plant making hydrofluoric acid and other products in Geismar, La.
The regeneration process was fraught with variability. Because it was a manual process that took a few days, it typically involved more than one operator. Its effectiveness, moreover, depended on how closely the operators regulated it, which might not be optimal if any of the operators were busy when it was time to act. Consequently, not only would the plant’s productivity suffer more than necessary if an operator were distracted by other tasks, but also the lack of attention could affect the regeneration and hurt the performance of the catalyst once it went back into service.
To avoid these problems, Geismar’s engineering staff turned to colleagues at a sister division, Honeywell Process Solutions (HPS), for help with automating the process. “Procedural automation can ensure the shutdown is done exactly as before, and either educate the operator or refresh his knowledge,” says Tom Williams, program manager for operator effectiveness at HPS. “We can clone the existing system, and then run the shutdown offline in the virtual world so the operators can see what is supposed to occur.” Cloning can be particularly helpful when no changes have occurred since the last shutdown.
At the Geismar facility, Procedural Operations workflow software from HPS was a key piece of the procedural automation deployed. The implementation team was able to use it to incorporate best practices, as well as operator check and trigger points, into an automated process. Not only are the various steps of the regeneration process now visible, but the software also alerts operators when the system is ready to advance to the next step. The result was less variation, which, in turn, led to greater efficiency and lower costs.
Tend to the details
Success for such projects depends on more than just checking what has been done in the past. Williams also recommends reviewing any changes—no matter how minor they might be—made to the raw materials, products, instruments and other equipment. “Automating a procedure requires a very detailed review of the current procedures to ensure their accuracy, adopting a good MOC [management of change] practice, and verifying the logic and displays with the operators,” he says.
The mechanism for reporting status must also tell operators how well the startup or shutdown is going via metrics they care about. “If the operators don’t trust the system or find it hard to use, they will turn it off or work around it,” Williams says.
To keep their confidence, automation vendors have developed virtual technology that streamlines the building, testing and verifying of automated procedures. “We’ve been building automated procedures not only for startups and shutdowns, but also for ‘safe parks’ that allow operators to put a system into a standby state while they work on solving a problem without going into a full shutdown,” Williams says. “This saves vital time and may reduce the wear and tear on the process equipment.”
Virtual technology also permits operators to practice ahead of time. “Simulators are a proven technology for both initial and ongoing operator training and competency,” PAS’s Habibi notes.
Simulations and other virtual technology should capture and reinforce best practices. Much work has been done in developing such practices over the past decade because of the growing awareness of the central role that standardizing workflows plays in getting consistent results, reports Honeywell’s Williams, who is also director of the Abnormal Situation Management (ASM) Consortium. “The ASM Consortium, for example, has studied procedural failures and published several articles describing how the observed failures can be eliminated,” he notes.
He also points to best procedural practices published by the Center for Chemical Process Safety at the American Institute of Chemical Engineers in New York. “The ISA [International Society of Automation] is also supporting the development of standards for automating procedures that leverage for the continuous process world some of what has been learned in the batch world,” he adds.
Avoid overwhelming operators
Another way to enforce best practices is to take care not to overwhelm operators and maintenance technicians by cramming more work into the scheduled downtime at the last minute. “When the scope deviates from what was planned, the risk increases because there is not enough time to properly mitigate the risk,” says Nikki Bishop, director of turnarounds at Emerson Process Management.
For this reason, she recommends early planning as a best practice. It gives you the time to identify the scope of the maintenance properly and marshal your resources beforehand. “As more companies choose to extend the time between turnarounds, it becomes even more critical to make sure that the correct scope of work is identified,” she says.
This, of course, requires data. In most cases today, the problem is not a lack of data, but data overload. “Most sites are data rich, but quality poor when it comes to getting information from the data available,” Bishop notes. What is needed in most facilities is help with sorting through the data to find the pieces useful for the task at hand.
In the case of planning for shutdowns, more facilities are turning to diagnostic technology and services from automation vendors. “Forward-thinking users are beginning to use advanced trending and pattern-recognition software where possible,” Bishop reports. “Such systems can identify multiple-variable scenarios that indicate developing problems so that they can be corrected before they result in failure.”
Advanced condition-monitoring software and hardware also automate the evaluation of the true health of equipment and the distribution of that information to the people who need it. Before a shutdown, advanced diagnostics can tell technicians what work needs to be done so they can incorporate it into their plans and have the parts and other resources standing by.
Technologies like Emerson’s wireless Mobile Worker can put plant diagnostics and process data at the fingertips of field technicians so they can make safe decisions. “Asset-diagnostics software not only allows technicians to make judgment calls about condition without taking assets apart, but it also lets them know that the equipment is functional prior to startup,” Bishop says.
Users are not the only ones exploiting these technologies to make sense of the overwhelming amount of data available in plants today. Automation vendors are, too. “Many times, user sites have an abundance of diagnostic data that their staffs either do not have the time or skills to use, or they are missing diagnostic data altogether,” Bishop explains. So a trend among users has been to seek outside experts for help capturing and mining the data necessary for planning and executing their turnarounds, especially as the skilled workforce continues to shrink.
In fact, this is why an Emerson analyst was on hand at a pharmaceuticals plant to find a defective ball bearing in a new vapor distillation unit being commissioned in June last year. An Emerson analyst discovered it when he detected some harmonics in the frequency spectrum of the vibration data taken with an Emerson CSI 2140 handheld data collector and analyzed with the vendor’s PeakVue software. As it turned out, a motor was assembled with the bad bearing, and the OEM’s vibration monitoring system had missed the warning signs.
For this reason, Bishop urges leaving enough time in the plan to deal with unexpected problems. “Integrating small capital projects into turnarounds is another best practice, but it must be done early and with careful coordination,” she says.
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