by Dr. Ralph Longsworth, retired, APD Cryogenics, ralphlongs@aol.com
A very interesting insight into the evolution of helium production and personal insights into the life and contributions of H. P. Cady was presented by his grandson, Dr. Ralph Cady Longsworth, retired from APD Cryogenics, in a paper entitled “100th anniversary of the discovery of helium in natural gas,” presented at the Cryogenic Engineering Conference in 2005. This article is excerpted from that paper with the author’s permission. Dr. Longsworth also included interesting family history and details of Cady’s life in this paper.
December 7, 2005, marked the 100th anniversary of the discovery of helium in natural gas by H. P. Cady and D. F. McFarland at the University of Kansas (KU). The work was done in the chemistry building, Bailey Hall, built in 1900 and designated as a National Historic Chemical Landmark in 2000. An early air liquefier was installed in 1903 and in the same year McFarland used the liquid air to analyze a sample of natural gas that wouldn’t burn. It took two years to assemble the apparatus that Cady used to see the helium spectrum in the residual gas.
In 1968 a symposium was organized by the US Bureau of Mines to celebrate the discovery of helium in the sun in 1868. The proceedings of this symposium provide much information about the history of helium and its applications up to 1968. The paper by Farber [1] has a very comprehensive description of the early history relating to helium, with an extensive list of references. Seibel, who played a principal role in the development of the production of helium while he worked for the US Bureau of Mines, has provided descriptions from the discovery of helium in natural gas through the helium conservation program authorized in 1960, [2, 3]. Katz [4] has a fascinating description of the correlation of helium with different geological formations and other gases, particularly nitrogen.
The discovery of helium in the sun required only one piece of scientific equipment, a spectrometer. The discovery of helium in natural gas, on the other hand, required many additional technologies that were developed in the latter part of the 19th century in Europe. Chief among these were developments in cryogenics. In 1903, the scene shifts to the University of Kansas in the US, where a sample of gas that would not burn was found to have 71% nitrogen, some methane and a residual amount that could not be condensed in liquid air. In 1905 it was found that the residual gas contained helium. The story of the discovery at KU and subsequent contributions by Cady and Seibel to the production of helium from natural gas should be of interest to people working in cryogenics today.
In 1889 Hildebrand, who was with the US Bureau of Mines, found nitrogen in uraninite from Connecticut. Later research findings led to the primary source of helium being from heating uranium ores until 1918, when helium was made available from natural gas.
The first liquefaction of helium in 1908 by H. Kamerling Onnes at Leiden is a remarkable feat. Working with 22 liters of helium gas that he obtained from uranium ore, he used a counterflow JT heat exchanger with the high pressure helium precooled to 14K by pumping on liquid hydrogen to liquefy it.
While a spectrometer was sufficient to identify helium in the sun, Geissler tubes, electricity and chemical separation of oxygen and nitrogen from gas samples were needed to confirm its presence on earth. The discovery of helium in natural gas used additional technologies familiar to those who work in cryogenics: the liquefaction of air, vacuum technology, dewars and charcoal adsorption.
H. P. Cady graduated in 1897 from KU, spent two years at Cornell University and returned to KU in 1900 as an instructor while working on his PhD. D. F. McFarland had earned a masters degree at Yale and returned to KU in early 1903.
In May 1903 a crew drilling for oil in Dexter, in southeast Kansas, hit a gas pocket that blew nine million cubic feet of gas a day for days before it was capped. Stock was sold in a gas company and a celebration organized at which gas from the well would be lit. The crowd that gathered for the celebration was aghast when, despite many tries, the gas would not burn. A sample was sent to KU.
Using liquid air from a liquefier, Cady and McFarland found that the gas had only 15% methane plus 72% nitrogen and 12% of an inert residue. They then set about to assemble the equipment needed to analyze the residual gas. This included a spectroscope, charcoal traps and Geissler tubes. The KU archives include the calibration data that Cady measured for the spectroscope. The charcoal traps were used to remove as much of the residual gas as possible, and then a Geissler tube was filled with the remaining gas.
On December 3, 2005, a spectrographic analysis was done on the gas in the Geissler tube. Results showed the spectrum of helium very clearly. A subsequent analysis of the gas that was trapped in the charcoal showed hydrogen and a trace of nitrogen. On December 11, the helium concentration was measured at 1.84%. The finding of helium in natural gas was reported in a paper prepared by Cady and McFarland and presented by Professor E. H. S. Bailey at the American Chemical Society meeting in New Orleans in January 1906.
Cady and McFarland followed up the initial finding by getting gas samples from 44 wells in Kansas and analyzing the composition, including the concentration of helium. The results were published in 1907 [5]. This was the first survey of the composition of natural gas. McFarland returned to Yale and completed his PhD in 1909. He spent the rest of his career teaching chemistry, first at the University of Illinois and then at Penn State University, retiring in 1945. Cady earned his PhD in 1903, the third ever granted by KU. He became a full professor in 1911 and department chairman in 1920, succeeding Bailey, and serving until 1939. One of his passions was to get young people interested in science. He introduced his grandson, the author, to experiments in his laboratory. He died in 1943, mercury poisoning being a contributing factor.
During both World Wars, the US government had an interest in helium production, primarily to provide helium-filled airships. It was also found that mixing helium and oxygen made a good diving gas and was effective in treating asthma. Many new uses were found after WWII and the production rate grew. The government efforts at helium conservation, the role of the Bureau of Mines and subsequent legislation arose out of these beginnings.
References
- Farber, E., Helium Symposia Proceedings in 1968—A Hundred Years of Helium, information circular 8417, US Bureau of Mines, 1968, pp. 199-228
- Seibel, C. W., Helium Symposia Proceedings in 1968—A Hundred Years of Helium, information circular 8417, US Bureau of Mines, 1968, pp. 229-241
- Seibel, C. W., “Helium, Child of the Sun,” University Press of Kansas, 1968
- Katz, D. L., Helium Symposia Proceedings in 1968—A Hundred Years of Helium, information circular 8417, US Bureau of Mines, 1968, pp. 242-255
- Cady, H. P. and McFarland, D. F., “The Occurrence of Helium in Natural Gas and the Composition of Natural Gas,” J. Amer. Chem. Soc., vol. 29, No. 11, 1907, p. 1523
