Helium From Natural Gas

Helium from Natural Gas. Recovery of helium from a given natural-gas stream depends almost entirely on the total economic picture of the stream. In the United States, the lowest practical helium level that is recovered is most frequendy 0.3 vol %, although helium is frequendy ignored, and hence wasted, in streams containing somewhat high concentrations. In other parts of the wodd where political considerations sometimes interact with the economic, the use of helium concentrations lower than 0.3 vol % maybe dictated. 

Natural-gas components include water vapor, carbon dioxide (qv), sometimes hydrogen sulfide, heavier hydrocarbons (qv), methane, nitrogen, small amounts of argon, traces of neon and hydrogen, and helium. The production of pure helium from natural gas requires three basic processing steps (73). 

Relatively new methods for separating helium from natural gas use pressure swing adsorption (PSA) processes to recover helium at better than 99.99% purity. This type of process is probably less costiy for the production of gaseous helium but might be uneconomical for liquefied helium production. The PSA process is widely used to produce specification pure helium from 85+% cmde helium in conjunction with cryogenic enrichment of the ca 50% helium raffinate. 

Why do you think that it is more profitable to obtain gases like helium from natural gas ... 

Plate-and-frame modules were one of the earliest types of membrane system. A plate-and-frame design proposed by Stem [110] for early Union Carbide plants to recovery helium from natural gas is shown in Figure 3.38. Membrane, feed spacers, and product spacers are layered together between two end plates. The feed mixture is forced across the surface of the membrane. A portion passes through the membrane, enters the permeate channel, and makes its way to a central permeate collection manifold. 

Figure 3.38 Early plate-and-frame design developed by Stern et al. [110] for the separation of helium from natural gas. Reprinted with permission from S.A. Stem, T.F. Sinclaire, P.J. Gareis, N.P. Vahldieck and P.H. Mohr, Helium Recovery by Permeation, Ind. Eng. Chem. 57, 49. Copyright 1965, American Chemical Society and American Pharmaceutical Association...

A Bureau of Mines system for the separation of helium from natural gas is shown in Fig. 11-119. Since the major constituents of natural gas have boiling points very much different from that of helium, a distillation column is not necessary and the separation can be accomplished with condenser-evaporators. 

Membranes have been suggested for use in the separation of helium from natural gas [Spillman, 1989] which typically contains 85% methane and 10% ethane. While no test data using real or simulate natural gas is available, there is some information on the separation of helium and ethane using alumina and silica membranes [Havredaki and Petropoulos, 1983], Table 7.16. Clearly, Knudsen diffusion is dominant in the these limited tests. Thus no promising separation performance has been demonstrated. 

Analyses of cryogenic processes, such as air separation or the separation of helium from natural gas, have found that a combination of pressure drops involving heat exchangers and compressors was most economical from the standpoint of capital invested and operating expenses. 

An estimated 78 percent of the world s helium was produced in the United States in 2008. Other producers included Algeria, Qatar, Russia, and Poland. Nineteen U.S. plants extracted helium from natural gas. Those plants were located in Colorado, Kansas, New Mexico, Oklahoma, Texas, Utah, and Wyoming. According to the U.S. Geological Survey (USGS), between 2009 and 2015, about nine new helium plant projects are slated to begin work worldwide. Such plants will be located in the United States (2), Algeria, Australia, China, India, Indonesia, Qatar, and Russia. 

Use To form a protecting layer of the tiny spheres over liquid surfaces, such as oils in big tanks, to reduce evaporation to separate helium from natural gas because of the wide difference in relative rates of diffusion through the spheres as an extender in plastics to achieve low density. 

The separation of helium from natural gas is a potential application of membrane technology. Using a membrane with a He/CH. selectivity of 190 and a feed with only 0.82 percent He, half of the helium can be recovered in a single stage, giving a permeate 30 times richer than the feed, ... 

Separation of Helium from Natural Gas, A typical composition of a natural gas... 

A novel method to separate helium from natural gas was proposed. It was noted that Pyrex glass is almost impermeable to all gases but helium. The diffusion coefficient of helium is 25 times the diffusion coefficient of hydrogen. Consider a Pyrex tubing of length L and... 

First extraction of helium from natural gas in Hamilton, Canada... 

Since the 19th century it has been known that certain polymer membranes can separate gases by permeation. As early as 1831, Mitchell reported that different gases permeate membranes at different rates. Graham, in 1866, discussed the mechanism of permeation and demonstrated experimentally that mixtures of gases can be separated using rubber membranes. In 1950, Weller and Steiner reported on permeation processes of industrial importance, the separation of oxygen from air and the recovery of helium from natural gas. However, the selectivity and production rates of the membranes available at the time were poor... 

All industry relies on the recovery of natural resources, and the cryogenic industry is no exception. For instance, helium, critical to the cryogenic industry, is a very limited natural resource. It is found as a minor component in some natural gas supplies of Kansas, Texas, Wyoming, and Arizona and would normally be wasted, vented to the atmosphere from gas burners. Since 1917, the U.S. Bureau of Mines has separated helium from natural gas. The early use of the high-purity helium was primarily in noncryogenic gaseous... 

Air contains 0.000524% He, 0.001818% Ne, and 0.934% Ar, by volume. The proportion of Kr is about 1 ppm by volume, and that of Xe, 0.05 ppm. The atmosphere is the only source of all these gases except helium. The main source of helium is certain natural gas wells in the western United States that produce natural gas containing up to 8% He by volume. It is cost-effective to extract helium from natural gas even down to levels of about 0.3%. Underground helium accumulates as a result of a-particle emission by radioactive elements in Earth s crust. Whereas the abundance of He on Earth is very limited, it is second only to hydrogen in the universe as a whole. 

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