The commissioning of a newly constructed piece of equipment always is challenging. The task is even more daunting in a research environment because the operation is more novel, the process information and operation less defined, and the equipment performance often not as certain. Compared to a plant startup, the commissioning of a pilot plant unit generally is less well organized and certainly less fully staffed.
The University of Wisconsin offers a course “Pilot Plant Design, Construction, and Operation” that provides further information on commissioning pilot plants, laboratory units and research equipment in general. More details can be found here.
Based on my experience, here are the ten most common problems that afflict the commissioning of pilot plants:
1. Lack of a commissioning plan that lists in detail all the known tasks that must be done before operation. Most pilot-plant commissioning plans exist only in a researcher’s mind. The few that do get documented usually are shallow, cursory and full of logic gaps and missing elements. So, it’s hardly surprising that startups then take so long and go so poorly. A good commissioning plan should detail every task, and estimate the resources involved and the time required. It should assign each task to a specific person and set a target date. This sort of commissioning plan, while tedious to develop and time consuming to write, is critical to the success of the whole process.
2. Failing to review the design for commissioning problems before construction is complete. Many difficulties are blatantly obvious beforehand. Common examples include a flow meter that lacks a valve for calibration, a level sensor that has no way to see the level for calibration, a pump that has no means for venting, and a heat trace line that has few temperature indicators to confirm proper operation. All these and dozens more miscues are painfully common. An experienced pilot plant designer should conduct a detailed review of the proposed design prior to completion to develop a good commissioning plan well in advance of when the unit is finished. The number of small but time-consuming issues likely detected will amaze you; more importantly, addressing them during construction will save large chunks of commissioning time. These get overlooked during the design process because it has a different focus. You must look at the unit through another lens to catch all these small but important gaps. Few should exist in a well-designed unit by an experienced designer. Rarely will none arise.
3. Trying to commission a unit using personnel part time. My experience repeatedly has shown that when a group assigns personnel to the effort part time the startup takes inordinately longer. A team available only half time takes 3–4 times longer to complete the task than a full-time team. Yes, there will be days where time is lost for meetings, personal commitments and the odd crisis. However, an organization will suffer poorer results and a disproportionately longer commissioning time if it doesn’t find ways to commit the team full time. Otherwise, people on the team must remember where they were, pick up the tools and documentation, coordinate with the others involved (who may not be available at that moment) and get started again.
4. Having totally unrealistic expectations about the required resources and probable schedule. Most plans for pilot-plant commissioning grossly underestimate the effort involved and the time needed. I’ve seen plans that assume that leak-testing a brand new pilot plant will take a day, installing all the insulation will require another day, and performing all the calibrations will consume a day or perhaps two. In reality, each of these — and dozens more items — took significantly longer. Moreover, no contingency is allotted for problems. Understaffing exacerbates the underestimating. A task takes much, much longer because the necessary resources aren’t available at all, not available for long enough or not even planned to be available. This invariably leads to other problems due to resources having been committed elsewhere or other efforts now taking precedence. In addition, management pressure, based on totally unreasonable expectations from the badly underestimated plan, becomes intrusive and often disruptive.
5. Not reading the instruction and installation manuals in advance. Pilot plants always involve new equipment — either a novel unit for which there’s little actual operating experience or new in the sense that the organization has no familiarity with it. All too often, no one looks at the manuals until the equipment has problems. Only then does the need for different installation or calibration become apparent. Sadly and all too often, that’s also when it’s discovered that the equipment doesn’t really suit the unit’s specific operating conditions. All should have been addressed in advance.
6. Not considering the downside risk, particularly for new processes, designs or equipment. What if the brand new particle analyzer doesn’t work? What if the gas chromatograph (GC) doesn’t seem to give an accurate analysis? What if the pump clogs? Questions like these make researchers uncomfortable. They think to themselves: “If you keep asking what if everything fails, we’ll never get any research done!” Yet the effort to determine a fallback position in the event of a problem can save incredible amounts of time. Identifying another GC on-site to send a batch sample or an on-site expert in this type of analysis can save days if the problem arises. Leaving room for a larger pump in case the chosen less expensive or faster delivery model doesn’t work as expected can prevent large amounts of costly rework. Adding the valve, gage or thermocouple during construction is so much faster and cheaper than doing so during commissioning. Occasionally this effort also highlights the often overlooked problem that one key piece of equipment is essential to the unit’s proper operation. So, if the particle analyzer has no fallback, testing it in advance to verify it will work in your application may avoid incredible problems later.
7. Not systematically checking out the unit’s safety logic. Without a logic matrix that shows all the inputs and how they will affect all the outputs, checking out safety (and operating) logic is very hit or miss. It’s too easy to overlook simulating a given failure mode to confirm that the unit operates properly. (I once wound up standing in a pool of water after we decided to see what happens if someone pushed two buttons — one opening a drain to a bucket and the other starting the feed — at the same time. The senior operator commented, “Glad that we found that out with water.”) Developing these logic matrixes is tedious and time consuming; checking them is even worse. However, they are critical to ensuring a safe commissioning.
8. Failing to allot time for all the necessary documentation and reviews. Completion of operating and emergency response plans often are casually dismissed as “ongoing” or “as time permits.” Setting up a preoperational safety review, updating the required databases and completing all the organization’s forms take time and effort — and must have resources and time allotted. I’ve seen too many units ready to operate but held up for weeks for completion of these items. This usually stems from no one starting early enough or devoting sufficient attention (and resources) to them because the effort involved was never truly assessed.
9. Not listing all the tasks, even the minor ones, that must be completed as part of the commissioning. Making or ordering the valve tags, tracing all the piping, mounting all the signs, ordering the feedstocks, getting the gas cylinders, finding enough sample bombs, and numerous other small less-than-glorious tasks need doing. Most commissioning plans fail to address these chores, which then, invariably, fall by the wayside and are forgotten until they — needlessly — become critical path items. The commissioning plan must include every task, no matter how unglamorous and trivial. (How often have you walked to your car for a crucial trip only to have to scurry back to get your keys or your phone?)
10. Failing to approach task in an organized and logical manner. Checking loops haphazardly as they occur, failing to ring out all the thermocouples, calibrating equipment only when you think about it and many other tasks are approached too casually. Nothing goes as fast as something planned well and organized effectively. It takes discipline to tediously check all the inputs to a computer in order but it saves so much time and effort when a problem arises and you can know that “well it is wired right so that’s not the problem.”
If you take deliberate steps to avoid these ten problems, you’ll experience a smoother commissioning.
RICHARD PALLUZI is a pilot plant and laboratory consultant based in Basking Ridge, N.J. Email him at [email protected].