How does your plant make money?

How can you operate a plant without knowing how your products are sold? Apparently this happens more often than you would think. I walked into a plant once that was shut down by the company operating the liquids pipeline. They forced the plant to shut down due to high ethane content in a propane plus product.

I started collecting information; personnel, including the plant engineer, believed their plant chromatograph was out of calibration. They then went on to explain that they fed a line along with several other plants which may have been diluting their product. The other plants went down for one reason or another, and it was at that point that the pipeline company saw the high ethane product coming from the only plant putting liquids into the line. They believed that this was the direct cause of their plant shut down.

It boggled my mind. I asked them how the pipeline company would have adjusted their payments according to the actual composition of their liquid product. They thought the company may have been copied on their daily report which indicated the composition of the liquid product for that day. I think most companies live less by “trust” and more by “trust but verify”!

Sure enough the pipeline representative confirmed to me they had a continuous sampler on their meter station at the plant outlet. The sample was pulled every 7 days and analyzed for composition. This was the basis for their payments to the plant. This was also the basis for shutting down the plant when one 7 day sample contained too much ethane.

No one in the plant knew how their plant made money. This included the plant engineer.

Plant Engineer

I had been asked late in the afternoon to travel to a plant that was shut down due to liquid off specification. The next morning they were supposed to start up, they had 4 hours to get on specification. I had never heard of the plant before. I was given P&IDs and a map to the plant. I set off that evening without knowing the owner or anything about the plant.

That evening in the motel I started to review the P&IDs. They were an issue well before issued for construction. And yet this plant was in operation and had been for years. A HAZOP must have been done on faith.

I walked into the control room that was gripped with a sense of crisis. The plant engineer introduced himself but said he was busy with their consultants. A local firm that took care of plant modifications, mainly from the construction side. I listened to them for a while, and realized they were upset that there was water in the Flare Knock-Out. They were trying to figure out how water could have been in the Flare Knock-Out. I told them where it came from, they could not believe it but when they looked they saw I was right. The regeneration gas scrubber dumped water into the flare knock-out. Like most plants. I was not smart or prescient, I had just seen a lot of plants. They immediately went into design modification. How could they keep water out of the flare knock out so that in the future they could dump NGL into the drum without freezing up. I tried to tell them that the plant had been operating for years without a problem. If they didn't drain NGL into the flare drum they would make more money and not have a problem.

I told them of alternatives, if you insist on draining your product to the the drain, drain water off as low as you can, add methanol, and then drain your profit off. This was not acceptable, they needed a separate drain system for water. They added that for $1 million dollar plus. In the future when an engineer decides to throw away their product, it won't freeze up.

That sounds like if you invest $1 million+ now, you can protect your self from engineers like that.

Engineer saves me money!!!

Do you need a plant engineer? In most cases I would say yes. But the choice you make determines if they make you money or cost you money. Of course this is true for any position you fill, but a good plant engineer will make you money.

At one time most plants had a dedicated engineer. The drive over the years to reduce operating costs has led to the area engineer. Instead of being responsible for one plant, they are now responsible for an area that may include 5 or more plants. This has put a time constraint on how much time an engineer can dedicate to any one plant. Drive time alone can be a significant portion of an engineer’s time. Then there are the inevitable reports that must be written. There must be accountability, and some measure of progress or success, but this should be balanced against time required to prepare a report and the actual usefulness of that report. It has been my experience that the time required is underestimated because the request comes from someone who has not tried to complete a similar report.

I guess one of my points is that you can have a very good plant engineer, but if he spends his time driving and writing reports and maybe managing million dollar projects on the side, he may not have the time to sit down and work with operations to improve plant performance.

On the other hand, there are times when the plant engineer truly costs you money. Take for instance the cryogenic gas plant that is shut down because the liquid product is off specification. The NGL is supposed to be a propane plus product, but due to high ethane content, the liquids pipeline company has shut down the plant. Now what is one to do with a NGL surge tank full of off specification product? One engineer decided the best thing to do would be to drain all of that liquid to the flare prior to the restart of the plant.

Aside from all of the problems created by draining this liquid to flare, (surprise, there is water in the flare knock out drum that he should have known about and NGL tends to get colder than ice when vented to atmospheric pressure), this is simply money down the drain. A better alternative would have been to vent the surge drum to flare until the vapor pressure was decreased to a salable product. The volume would be reduced by the vented volume, but the remaining liquid could have been sold for real revenue.

Assume a standard bullet with 18,000 gallons total capacity half full. That is 9,000 gallons of liquid down the drain, or, if we assume 10% of volume vented off, 8,100 gallons of product. If I assume the NGL is worth $2 per gallon, about half the price of oil at $90 per barrel, then you either lose $18,000 or you make $16,200. That is the kind of money a good engineer can make you in a plant!

There are other more complex solutions to the issue that could have saved even the vented gas, but nothing simple that could be easily done in the few days between plant shut down and planned restart of the plant.