El Dorado’s Frontier Refining Company is currently barreling through an expansion project, likely the largest of its kind in this plant since the 1970s. The refinery’s crude unit is currently shut down so workers can tie in more than 500 new connections that will be used to get the latest $146 million additions online.
The crude unit is the first unit in a refinery and it processes the raw material which comes over to Frontier from the Enbridge tank farm nearby. The bulk of the crude – which mostly comes from West Texas – is pumped to that facility via the Osage Pipeline that comes from Cushing, Okla., the “pipeline crossroads of the world.”
Once the raw materials enter the crude unit, it is separated into various parts through a boiling process combined with fractionation.
“If you look at crude oil, it’s a huge cocktail of everything from methane, very light hydrocarbons to asphalt, and it’s all mixed into one component,” said Jim Stump, refinery manager. “[The crude unit] separates it into stuff that’s going to be gasoline, stuff that’s going to be diesel, a component we call gas oil – which is like grease – and asphalt.”
All of the resulting ingredients – with the exception of a small amount of the asphalt – are intermediate products that will need further treatment throughout the refinery.
“Everything else in the refinery takes the stuff that the crude unit produces and further processes it,” Stump said. “But the crude unit is the first step. It’s always been the bottleneck of the refinery.”
A catalytic cracker, or “cat cracker,” is the basic gasoline-making process in a refinery. The cat cracker uses high temperatures, low pressure and a catalyst to create a chemical reaction that breaks heavy gas oil into smaller gasoline molecules. With a cat cracker, more of each barrel of oil can be turned into gasoline.
Frontier El Dorado produces about 35,000 barrels (1,470,000 gallons) of gas oil each day from the 110,000 barrels of crude oil being processed.
“About a third of the crude is grease (gas oil),” Stump said. “Of course, the world doesn’t need that much grease. So what the cat cracker does with that grease is it converts all of that into gasoline and diesel.”
A coker unit heats the asphalt – which comprises nearly 20 percent of the crude – to about 900 degrees until it thermally cracks the long chain hydrocarbon molecules in the residual oil feed into shorter chain molecules, resulting in more gasoline, diesel and the by-product petroleum coke.
“The two big money-makers in this refinery are that cat cracker and that coker,” Stump said.
In January 2007, Frontier also began dealing in cheaper Canadian crude supplies that naturally contain more of the heavier elements of crude like asphalt and gas oil.
“If you’re going to buy a lot of that stuff, you’re going to need plenty of cat cracker capacity, which we already had – the cat’s never run full,” Stump said.
The coker unit, however, is being augmented with two new drums to increase its capacity. This $60 million project is on schedule for completion in June.
The “centerpiece” of the construction, though, is the addition of a 200-foot-tall vacuum tower which facilitates boiling the grease out of the asphalt by affecting the atmospheric pressure acting on the elements.
“Just like a pot of water boils at a cooler temperature up in the mountains because the atmospheric pressure is lower,” Stump said, “the same thing happens in that vacuum tower. We pull a perfect vacuum on it and that allows us to separate that grease from that asphalt at, like, 700 degrees instead of 1,300 degrees.”
Keeping the temperature lower prevents the intermediate products from cracking into gasoline and diesel before the proper time. The refinery is using this new vacuum tower to replace a smaller and ultimately less effective version.
“Because [the old vacuum tower] is too small, we haven’t done a good job getting the grease out of the asphalt,” Stump said. “So the cat’s always run without enough feed and the coker’s always had too much feed. That grease stays in the asphalt and we can’t separate it to get it in the cat and we end up pushing it in the coker where we don’t really want it.
“This whole huge vacuum tower is a key part of our whole expansion effort. It allows us to run more heavy crude.”
Where the refinery could process 105,000 barrels of crude per day, Stump expects this expansion will increase daily capacity to about 120,000 barrels per day.
“The cost of our crude goes down because we can buy more cheap crude, our total throughput goes up,” Stump said, “and we get this gas oil into a better place to process it, so our yields get better, too.”
On-site field construction for the crude unit began in late fall 2006. The month-long turnaround (shutting the unit down) began March 1. In the second week of February, though, turnaround work began on about eight different process units in the plant, Stump said.
“It’s just a huge amount of work in a very quick unit of time,” Stump said. “That’s what a turnaround is all about. By a year ahead of the turnaround date, we already have the scope defined, the budget defined, everything kind of locked in. We spend that year before turnaround getting ready for the turnaround.
“We’re running zero crude in the month of March. Because that’s such a huge penalty, you spend a ton of effort making sure you understand every detail, every work plan, find every contingency, so that when you start that turnaround, it is absolutely as efficient and safe as you can possibly make it.”
Beginning in December, Frontier began storing up more than 1 million barrels of crude intermediates to keep the cat cracker and coker stocked during the turnaround. This prevents having to stop production and causing unnecessary wear and tear on the machines. It also keeps product coming out of the refinery so its customers aren’t left empty-handed while the crude unit is halted.
Despite the best-laid plans, if the project were to run four or five days late, there’s no contingency plan to keep production rolling. But Stump said the refinery even takes finicky Kansas weather into account, so they appear to be on schedule for an early finish.
To get this project done, there are about 1,200 extra contract workers buzzing around the refinery right now. Stump estimates at least 800 of those workers are travelers who fill El Dorado hotel rooms, camp out at the lake and get about $100 per diem to spend in town.
“Right now some of them are having to stay in Augusta and Wichita because there’s no more room in El Dorado,” Stump said.
Frontier has even tapped its neighbor, the Star Vu drive-in, renting the theater’s parking lot to accommodate the excess of vehicles.
Stump said he’s frequently asked what the economic impact of these peak turnarounds is on El Dorado, but he’s never tried to quantify it.
“I would imagine the daily spend for 1,200 people is between $100 and $150 per day,” Stump said. “If you think about it, that’s about $150,000 a day in revenue stream just from people living in the town of El Dorado.”
In addition to the major construction, Frontier is spending about $30 million on a number of smaller capital projects.
In fall 2009, the refinery will also be completing upgrades to its gas oil cat feed hydro-treater to keep up with Environmental Protection Agency standards. The cat cracker will also see revamps then, resulting in another peak turnaround period. Those two projects will cost about $160 million.
El Dorado, Kan. —
