Monday, June 10, 2013 | Posted By Karen Axelrod in Factory Tours
Although manufacturing is our primary theme here at Watch It Made in the U.S.A., the naturally occurring resources that exist on and under American soil have always been one of the country's greatest strengths; without them, of course, much of our manufacturing would never have been possible. If you are interested by geological subjects in particular, and if your summer vacation will swing through the heartlands of the US, the two tours described below may be of interest.
Kansas Underground Salt Museum
Kansas is often considered to be the archetype of a place as far as possible from the ocean. About 275 million years ago, however, a large inland sea spread over this region. While that sea disappeared long ago over the course of geological time, its remnants persist in the form of thick, extensive salt beds deep below ground. In Hutchinson, you can explore one part of these ancient deposits at the Kansas Underground Salt Museum (recently restyled with the name "Strataca"). Here you ride 650 feet down to spacious, comfortable subterranean galleries excavated by salt-mining operations during the 20th century.
Deposited over many thousands of years as the ancient sea dried up, the layer of salt underneath Kansas varies in thickness between 100 and 500 feet and extends throughout most of the central and western parts of the state. After the salt beds were discovered in 1887, the first salt mines in Kansas were operating only a few years later. As in coal mines, workers descended in dangerous conditions to excavate minerals from deep chambers. The first salt mine in Hutchinson opened in 1923, and mining for road salt still occurs in the area.
The Kansas Underground Salt Museum is a truly remarkable experience. In the visitor center on the surface, you don the mandatory hard hat and then enter the mine's solidly built industrial elevator (or "hoist"). The descent of 650 feet takes a mere 90 seconds. You then emerge into a spacious, low-lit subterranean otherworld carved out of densely packed salt. The museum, fashioned in the disused mine itself, sprawls through an amazingly vast series of softly lighted salt-walled galleries with high ceilings. Indeed, the space feels more like a giant indoor sports facility than a manmade cave—no possibility of claustrophobia here. At a perpetual 68 degrees and 45% relative humidity, the environment could not be more comfortable. Explaining both the geological and the industrial histories of the Kansas salt deposits, the museum exhibits stretch extensively throughout the galleries, while a small train and a tram (called the "Dark Ride") convey visitors through other parts of the old salt mine.
Great Plains Synfuels Plant
Rising amid clouds of steam from the quiet prairie farmlands that cover western North Dakota, the Great Plains Synfuels Plant does something unusual. It makes natural gas. While natural gas (technically methane) is normally drilled from subterranean deposits, it is also possible to synthesize it from coal through a process called gasification. The Synfuels Plant is the only commercial-scale coal-gasification facility in the United States. Completed in 1984 and run by the Dakota Gasification Company, the plant now makes 145 million cubic feet of natural gas every day. Via pipeline, this resource is distributed throughout the eastern United States.
Although the plant's product is sent to distant places, its natural resources are local. Nearby deposits of lignite coal, the remains of peat swamps that existed 55–65 million years ago, are mined and delivered to the Synfuels Plant, which gasifies about 18,000 tons of coal per day. Meanwhile, the carbon dioxide generated in gasification is not spewed into the atmosphere, where it would add to greenhouse-gas pollution. Instead, it is piped north to oilfields in Saskatchewan, Canada, where a storage operation permanently sequesters the carbon dioxide underground. This environmentally friendly aspect of gasification at the Synfuels Plant is considered a model for the benign use of the abundant coal that the US has under its own soil. To many people, using this coal in a relatively clean way offers a sensible means to help the US become less dependent on foreign energy resources.
For obvious reasons, the work of the Great Plains Synfuels Plant is important to American national interests, and Homeland Security rules mean most of it is off limits to the public. Instead, the general tour at the visitors' center shows you an intricate scale model of the facility with interpretive displays and videos to illustrate how gasification works. The heart of the plant consists of its 14 giant gasifiers: cylindrical pressure vessels that tower 40 feet high and have an internal diameter of 13 feet. Gasification involves dismantling the molecular structure of coal through combustion: in the gasifiers, steam and oxygen are injected into the bottom of the coal to cause intense burning at 2,200 degrees. The hot gases dismantle the molecular bonds of coal and steam, releasing carbon, hydrogen, sulfur, nitrogen, and other substances to form a raw gas. This leaves the gasifiers and is cooled. Tar, oils, phenols, ammonia, and water co-products are condensed from the cooling gas, purified, and diverted. The gas enters a cleaning area, where it is scrubbed of other impurities, and then passes over a nickel catalyst that causes carbon monoxide and the remaining carbon dioxide to react with free hydrogen. This forms methane (i.e. what we call natural gas). The carbon dioxide is removed and sent on its way to Canada. After being cooled, dried, and compressed, the methane enters the gas pipeline—possibly on its way to you.
These tours may be featured in the next edition of Watch It Made in the U.S.A. Meanwhile, you can read about other tours in the current edition of the book.
Posted By Karen Axelrod at 3:58 PM in Category:Factory Tours
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