Many of us have experience with processing facilities of some kind. By this, I mean petrochemical plants, refineries, food processing facilities and distilleries (to name a few). How many of us are privy to the day-to-day frustrations from the Operating teams?
The seals on P-123 have failed again. I thought Engineering already put in tougher seals.
Product always goes off-spec when the plan calls for higher rates. Is there a buyer for off-spec, or do we need to re-run it?
I know the VP wants us to push the plant, but we just can’t run past 90% capacity. Does she want production or endless trips?
Turn that controller off. TC-483 has never worked and only causes problems.
These are symptoms of operability issues. Operability refers to the ability of a facility to operate reliably, in the way that it was intended, without hiccups.
These symptoms manifest as different problems in the plant:
Equipment damage. This is often caused by operating outside the acceptable range (i.e., running a pump off the end of the curve). The cost of equipment damage is not limited to repair: rate cuts or a plant outage may be necessary.
Variable product quality. A change in operating conditions (such as flow rate) can hamper the effectiveness of a unit operation, which leads to excursions in product quality. To combat this, the facility targets a higher product quality to keep the expected excursions within allowable limits. However, over-processing eats into plant capacity.
Unstable operation at high rates or low rates. Operating teams often refer to a “sweet spot” where the facility operates most reliably, and the facility does not run smoothly at lower or higher rates. The implications can be a difficult startup, instability at high rates, or both.
The implications of operability problems are (almost) always:
Lost opportunity for increased capacity,
Increased operating expenses.
Plus the added stress on the Operating teams for the constant attention to put out the never-ending daily fires.
The payoff for solving the problems sounds too good to be true. Increased plant capacity, less off-spec product, less equipment damage, less grey hair and whiter teeth (OK, the last one may be pushing it). Even better, the solutions do not usually require spending capital and can be implemented fairly quickly.
Before you consider a debottleneck to increase plant rates, look for symptoms of operability problems. If the alarm rates are below the benchmark of 5 per 10 minute interval, and controllers are rarely placed in MANUAL, and the Operations teams are not putting out daily fires, then the plant is operating effectively. A debottneneck makes sense, and the full capacity of additional capital can be realized. But if these symptoms exist in your facility, then invest a few dollars to identify and address operability problems. You won’t be disappointed.
