Step Four -- Oil Refining

From oil to gasoline:

a series illustrating oil processing steps

The 75th anniversary emblem on a product tank

The Union HQ, right across the freeway from the main gate.

A panorama of the facility from the SW. The tanks on the left are for feedstocks; there is another tank farm on the east side for products.

The Big Spring refinery went online in 1929. It was built by Cosden for fuel production. Most early refineries were fuel producers of one kind or another (gasoline, diesel, kerosene -- still used for lanterns in those days, and heating oil. This form of specialized production created a huge waste stream: natural gas, asphalt, and heavy oils, as examples.

Instead of building new plants, refiners just keep adding on to existing ones for two reasons: the old stuff can keep being reconditioned and emission laws allow old plants to pollute more whereas new ones have stricter rules. As long as enough oil can be supplied, they can grow indefinitely. This one now has a capacity of 70,000 barrels of oil per day, a small refinery by Texas standards and refines sour (acid carrying) West Texas crude. It produces 22,500 bpd of gasoline.

So this refinery has sprawled all over the hilltop east of town where Cosden located the original plant. The oil arrives largely via 500 miles of pipelines from the wells in all directions but the rail yard in downtown Big Spring always has a lot of oil tankers coming here as well. This refinery is a large producer of asphalt.

The plant is now owned by AlonUSA Energy Inc., a subsidiary of Alon Israel; Petrofina, a Belgian company, sold the refinery, the marketing outlets (stations), and the use of the Fina name in the USA after acquiring it in a larger purchase. One of the storage tanks has a Fina emblem on it.

The old cracking retort is still the central part of the refinery. From it, fractions of hydrocarbons go to the various sections as feedstocks.. The big box in the middle is an electrostatic precipitator to collect solid particles in the stack gases before they go up the chimney on the side of it.

The black cylinders are chimneys. The flared bottoms are the discharge ducts of the induced draft fan which pulls the flue gases out of the the combustion chambers. The top part with the framework is a heat exchanger which works like a boiler to make steam or to heat other process liquids. The little platforms around each chimney is for the monitors for emissions: particulates, NOx, SOx, etc. Much of the oil which enters the plant eventually becomes fuel for the operation of the plant.

The railroad to the north of the plant. The product tanks are on the left.The tank cars on the siding on the left are for sulfur; sour crude yields a lot of sulfur which, due to emission standards, becomes another byproduct. (If you get downwind of this plant, you'll know not all the sulfur ends up in these cars!) I have no idea what the hopper cars on the right are for or if they have anything to do with the refinery.

The tall, skinny pipes are flare towers for burning escaping combustible gases. This happens during upsets when the pressure in a reactor is excessive. The towers at center are reaction towers for making specialized chemicals.

This is the biggest compressor I have ever seen (The dark thing at bottom center)! And it isn't for air: the lines both in and out are insulated. The copper line is cooling water. The odd tower to its right is the electric motor to drive the thing! The pipes in and out go back into the yard behind the compressor; the tower on the left is unrelated to the compressor. The valve on top of the supporting structure is a desuperheat (cooling) regulator. As the compressed gases come out, they have been heated by the compression; this regulator injects a measured amount of liquid into the flow, cooling it as it evaporates to the desired temperature.

The big cylindrical tank on its side is a surge tank between processes. I have no idea what the hanging hoppers next to it are but seem to be for some kind of solid product. The tower with the skinny top is some kind of reflux tower. Since the only pipe entering is at the top of the wide portion, the top is like a surge volume. Notice the flare burning; this flare kept going off as I was photographing but this was the only time I caught it burning!

Refineries look like a bunch of tall columns but there is actually more volume in all the piping than the tanks. Some of the piped stuff includes: compressed air, steam, feedstuffs, reactants, gases (O2, Cl2, H2), and reaction products. Producing the required gases for refineries is an industry unto itself!

The towers all seem similar; they were probably all part of one addition to the plant for specialty products. Or even all for the same product. With different reagent addition and reaction conditions (temp, press, etc), a process can actually be used for more than one similar product. Much as diesel and heating oil use the same facilities. Note the tiny human crossing the street.

Different types of reaction vessels. The leftmost one sprays reactants into a stream of something introduced at the top. The rocket-looking one is really a fractionating still. and the tall one injects several streams (three at the top, two in the middle, and three at the lower injection ports). The insides of these towers are usually a series of trays, one above the other, for the liquid to cascade over as it reacts.

I passed this refinery outside Amarillo, TX. It caught my eye for two reasons: the towers all seemed short and they were all in pairs. It turns out this is a Monsanto specialty product refinery: solvents and other industrial stuff. The "balls" on the right are gas storage tanks. This was taken across a railroad track and a highway.




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