Noble Gas: The elements found on the right side of the periodic table i.e group 18 is known as a noble gas. Noble gases are non-reactive. The outer most shell of the noble gas is full. A Noble Gas does not need to have eight electrons to be classed as such - it simply must have a full outer shell. The first shell can only hold two electrons, which is what helium has, so helium. Helium is a noble gas. It has the noble gas configuration.

• Helium Is A Noble Gas Whereas Beryllium Is A Metal
• Is Neon A Noble Gas
• Helium Is A Noble Gas Found
• Helium Is A Noble Gas Without
• Are Noble Gases Reactive

Chemists describe “noble” as those substances that bind to other substances only with relative difficulty; this applies to noble metals like platinum and gold and also to noble gases like helium. Most people, on the other hand, understand “noble” to mean valuable—and they wouldn’t be wrong: Platinum is known to be considerably more expensive than, for example, iron. And one cubic meter of gaseous helium costs between €8 and €30 depending on the purchase quantity and the purity, among other factors. By comparison, one cubic meter of natural gas is available to a private customer for only about 60 euro cents.
One reason for the high price of helium is its high demand. The gas is used to cool magnetic resonance tomographs (MRTs) in hospitals and to fill balloons and airships. It is also used in glass fiber production, welding, and the electronics industry, and in leak detection for systems and equipment. But helium is rare. It has been extracted from the few natural gas sources worldwide where it is present in proportions between two and eight percent. The world market is currently divided between the producing countries: the USA, Algeria, Qatar, Russia, and Poland.
Membrane technology for Canada
Since August 2016 Canada has also been producing helium. A unique plant has come on stream in Mankota, which extracts 99.999 percent helium fully automatically from the 250,000 cubic meters of gas produced daily. The plant was built by the Engineering Division of the Linde Group. Its distinguishing feature is that Linde has combined an established gas-separation process with Evonik’s new SEPURAN® Noble membrane technology. This hybrid process allows particularly efficient enrichment of helium in the Canadian gas source, where the helium content is well below two percent. Linde was thus able to make a persuasive case to Weil Group Resources, the owner of the gas source, and to come out ahead in global
competitive bidding.
SEPURAN® membranes consist of polyimide, a high-performance polymer whose resistance to high temperatures and aggressive chemicals has been proven over many decades. For example, the polyimide is also used in hot-gas filtration in cement and steel smelting plants. Spinning systems at Evonik’s site in Schörfling (Austria) produce the material in the form of fibers with a very special architecture: Their interiors are hollow. The material is highly porous all the way up to this cavity. The pores become progressively smaller toward the exterior. A relatively dense shell, less than 100 nanometers thick, forms the surface of the fibers.
Gases whose molecules are very small (kinetic diameter) can permeate this skin faster than those whose particles are larger. In this way the skin can distinguish between, for example, carbon dioxide and methane, or helium and methane. The remaining porous part of the fiber does not help in gas separation because the pores are too large for this purpose; it serves as a supporting element, lending the material mechanical stability. Evonik bundles tens of thousands of these hollow fibers into a membrane module in a stainless steel housing.
The SEPURAN® Green membrane modules currently in use for biogas upgrading in more than 100 facilities worldwide are not perfectly suited for extracting helium: Due to the low proportion of helium in natural gas, SEPURAN® Green membranes do not upgrade the noble gas to the desired extent. What is needed is a membrane that can select helium from the rest of the gas even more effectively than SEPURAN® Green. Evonik’s specialists have succeeded in producing such a membrane by modifying the spinning process for fiber production. Evonik markets this membrane under the name SEPURAN® Noble.
Customized hollow fibers
If you now think that a higher separation efficiency than that offered by SEPURAN® Green would also work for methane and carbon dioxide, and could thus also improve biogas upgrading, you wouldn’t be wrong. But SEPURAN® Noble would not allow sufficient permeation of either gas: The higher selectivity of this SEPURAN® variant comes at the cost of lower productivity.
In the case of helium this is not critical, however, because it can pass through the membrane much faster than, say, carbon dioxide. The skill of the SEPURAN® team thus lies in customizing the properties of the hollow fiber membranes for the application in question. In this way it fully exploits the already very good gas separation properties of polyimide.
In the hybrid reference plant in Mankota, SEPURAN® modules upgrade the crude gas to a helium content of about 50 percent. From the resulting gas mixture, almost pure helium is then obtained by pressure swing adsorption (PSA). In this well-established method, the pressurized gas mixture is passed through a solid bed. Helium remains almost totally unadsorbed on this solid while the other gas components are deposited on or in it. As soon as the adsorption capacity of the solid is exhausted, it is regenerated by reducing the pressure. Two solid beds are operated concurrently so that PSA continuously provides helium; while one of these is in the adsorption mode, the other is being regenerated.
The PSA process only functions well with a helium content of at least 25 percent, and its effectiveness increases with the helium content. This is why initial upgrading of the crude gas by SEPURAN® membranes is necessary. The two processes complement each other perfectly because the membrane process produces an unpressurized helium gas mixture that is subjected to pressure by PSA. The pure helium finally obtained is thus also under pressure, which reduces transportation costs.
Collecting and upgrading used helium
Helium is expensive, and large users may find it worthwhile to recover the used noble gas; they too can benefit from SEPURAN® Noble. These large users include producers of optical fibers transmitting internet data and phone calls. The helium is particularly effective for cooling the glass fibers as these are drawn from the hot melt. This increases production speed: A single plant can produce more than two kilometers of fiber per minute. But helium cooling is costly: Many glass fiber production facilities spend hundreds of thousands of euros on helium annually.
Nextrom, a leading global plant engineering firm for the glass fiber industry, has now developed a solution for fiber producers that is based on SEPURAN® Noble. It offers a system in which the used helium is collected, cleaned, and re-used for cooling. As much as 90 percent of the helium can be recovered in this way.
A mere two years after market launch, SEPURAN® Noble has now become established in the glass fiber industry; the SEPURAN® team owes this success partly to the support of their colleagues from Silanes, who are familiar with this sector. Moreover, membrane technology can be very easily integrated into glass fiber production because the upgraded helium need not be liquid nor ultrapure. But this is not the case for other helium applications, such as magnetic resonance tomography, where it will take somewhat longer for SEPURAN® Noble technology to gain a foothold. Membrane experts are nonetheless convinced that the technology will also establish itself in applications other than optical fibers.
Also valuable for hydrogen
Hydrogen passes through membranes as easily as helium: Although hydrogen consists of diatomic molecules, these are not much larger than a single helium atom. SEPURAN® Noble modules can therefore also be used to separate hydrogen from carbon monoxide and other gases. Carbon monoxide and hydrogen are the main components of synthesis gas, obtained for example from coal but increasingly also from biomass and waste. Synthesis gas can be processed further in specific ways to yield a very wide range of products such as liquid
gasoline-like fuels or methanol. The proportion of CO and H2 in synthesis gas must be adjusted according to the product desired; this is done by using membranes.
SEPURAN® Noble membranes also allow hydrogen to be recovered from nitrogenhydrogen mixtures. This is important in, for example, the synthesis of ammonia, which is the starting material for nitrogenous fertilizers, because in the Haber-Bosch process the reaction between nitrogen and hydrogen to yield liquid ammonia does not go to completion. The remaining gas mixture is fed back into the process after the hydrogen content has been increased by membrane methods. Here, as in the upgrading of synthesis gas, the use of membranes is well established. But, thanks to its superior gas separation properties, SEPURAN® Noble could potentially replace the membranes currently being used.

Helium is at the top of the noble gas group (which also contains neon, argon, krypton, xenon, and radon) and is the least reactive element. Helium has many interesting characteristics, such as making balloons float and raising the pitch of one's voice; these applications are discussed below.

Introduction

Helium is the second most abundant element in the universe, next to hydrogen. Helium is colorless, odorless, and tasteless. It has a very low boiling point, and is monatomic. Helium is small and extremely light, and is the least reactive of all elements; it does not react with any other elements or ions, so there are no helium-bearing minerals in nature. Helium was first observed by studying the sun, and was named after the Greek word for the sun, Helios.

Occurrence and production

Helium is one of the most abundant elements in the universe. Large quantities are produced in the energy-producing fusion reactions in stars. Previously, helium was rarely used, because only .0004% of Earth's atmosphere is helium—that equates to one helium molecule for every 200,000 air molecules, including oxygen, hydrogen, and nitrogen. However, the discovery of helium-rich wells in Texas, Russia, Poland, Algeria, China, and Canada has made helium more accessible.

Helium is produced in minerals through radioactive decay. Helium is extracted from natural gas deposits, which often contain as much as 10% helium. These natural gas reserves are the only industrially-available source of helium. The total world helium resources theoretically add up to 25.2 billion cubic meters; the United States contains 11.1 billion cubic meters. The extracted gas is subjected to chemical pre-purification, using an alkaline wash to remove carbon dioxide and hydrogen sulfide. The remaining gas is cooled to -200°C, where all materials, except helium gas, are liquefied.

History

Helium was first discovered in 1868 by the French astronomer P. J. C. Jenssen, who was studying the chromosphere of the Sun during a solar eclipse. He used a spectrometer to resolve the light into its spectrum, in which each color represents a different gaseous element. He observed a new yellow light, concluding that it indicated the presence of an element not previously known. In 1895, the existence of helium on Earth was proved by Sir William Ramsay. Heating cleveite (a radioactive mineral) released an inert gas, which was found to be helium; this helium is a by-product of the natural decay of radioactive elements. The chemists Norman Lockyer and Edward Frankland confirmed helium as an element and named it after helios, the Greek word for the Sun.

Helium Is A Noble Gas Whereas Beryllium Is A Metal

Applications and hazards

Helium has a number of applications due to its inert nature. Liquefied helium has cryogenic properties, and is used to freeze biological materials for long term storage and later use. Twenty percent of industrial helium use is in wielding and industrial applications. Helium protects the heated parts of metals such as aluminum and titanium from air. Mixtures of helium and oxygen are used in tanks for underwater breathing devices: due to its low density, helium gas allows oxygen to stream easily through the lungs. Because helium remains a gas, even at temperatures low enough to liquefy hydrogen, it is used as pressure gas to move liquid hydrogen into rocket engines. Its inert nature also makes helium useful for cooling nuclear power plants.

The most commonly known characteristic of helium is that it is lighter than air. It can levitate balloons during parties and fly blimps over sports stadiums. Helium has 92% of the lifting power of hydrogen; however, it is safer to use because it is noncombustible and has lower rate of diffusion than that of hydrogen gas. The famous Hindenburg disaster is an example of the hazards of using combustible gas like hydrogen. Because helium was previously very expensive only available from natural gas reserves in U.S., Nazi Germany had only hydrogen gas at its disposal. The consequences were devastating, as shown below:

Currently, helium is found in other natural gas reserves around the world. The cost of helium has decreased from $2500/ft³in 1915 to $0.15/ft³in 1989. Helium is what keeps the Goodyear blimps afloat over stadiums.

Helium is often inhaled from balloons to produce a high, squeaky voice. This practice can be very harmful. Inhaling helium can lead to loss of consciousness and cerebral arterial gas embolism, which can temporarily lead to complete blindness. This occurs when blood vessels in the lungs rupture, allowing the gas to gain access to the pulmonary vasculature and subsequently the brain.

Characteristics

Gas and plasma phases

Helium is naturally found in the gas state. Helium is the second least reactive element and noble gas (after neon). Its low atomic mass, thermal conductivity, specific heat, and sound speed are greatest after hydrogen. Due to the small size of helium atoms, the diffusion rate through solids is three times greater than that of air and 65% greater than that of hydrogen. The element is inert, monatomic in standard conditions, and the least water soluble gas.

At normal ambient temperatures, helium has a negative Joule Thomson coefficient. Thus, upon free expansion, helium naturally heats up. However, below its Joule Thomson inversion temperature (32-50 K at 1 atm), it cools when allowed to freely expand. Once cooled, helium can be liquefied through expansion cooling. Helium is commonly found throughout the universe as plasma, a state in which electrons are not bound to nuclei. Plasmas have high electrical conductivities and are highly influenced by magnetic and electric fields.

Solid and liquid phases

Helium is the only element that cannot be solidified by lowering the temperature at ordinary pressures; this must be accompanied by a pressure increase. The volume of solid helium, ³He and ⁴He, can be decreased by more than 30% by applying pressure. Solid helium has a projected density of 0.187 ± 0.009 g/mL at 0 K and 25 bar. Solid helium also has a sharp melting point and a crystalline structure. There are two forms of liquid helium: He⁴I and He⁴II.

Helium I

Is Neon A Noble Gas

Helium I is formed when temperature falls below 4.22 K and above the lambda point of 2.1768 K. It is a clear liquid that boils when heat is applied and contracts when temperature is lowered. Below the lambda point, helium does not boil, but expands. Helium I has a gas-like index of refraction of 1.026 which makes its surface difficult to see. It has a very low viscosity and a density 1/8th that of water. This property can be explained with quantum mechanics. Both helium I and II are quantum fluids, displaying atomic properties on a macroscopic scale due to the fact that the boiling point of helium is so close to absolute zero.

Helium II

At 2.174 K, helium I forms into helium II. Its properties are very unusual, and the substance is described as superfluid. Superfluid is a quantum-mechanical state of matter; the two-fluid model for helium II explains why one portion of helium atoms exists in a ground state, flowing with zero viscosity, and another portion is in an excited state, behaving like an ordinary fluid. The viscosity of He⁴II is so low that there is no internal friction.

He⁴II can conduct heat 300 times more effectively than silver, making it the best heat conductor known. Its thermal conductivity is a million times that of helium I and several hundred times that of copper. The conductivity and viscosity of helium II do not obey classical rules, but are consistent with the rules of quantum mechanics. When temperature is lowered, helium II expands in volume. It cannot be boiled, but evaporates directly to gas when heated.

In this superfluid state, liquid helium can flow through thin capillaries or cracks much faster than helium gas. It also exhibits a creeping effect, moving along the surface seemingly against gravity. Helium II creeps along the sides of a open vessel until it reaches a warmer region where it evaporates. As a result of the creeping behavior and the ability to leak rapidly through tiny openings, helium II is very difficult to confine. Helium II also exhibits a fountain effect. Suppose a chamber allows a reservoir of helium II to filter superfluid and non-superfluid helium. When the interior of the container is heated, superfluid helium converts to non-superfluid helium to maintain equilibrium. This creates intense pressure on the superfluid helium, causing the liquid to fountain out of the container.

Isotopes

Helium has eight known isotopes but only two are stable: ³He and ⁴He. ³He is found in only very small quantities compared to ⁴He. It is produced in trace amounts by the beta decay of tritium. This form is found in abundance in stars, as a product of nuclear fusion. Extraplanetary materials have trace amounts of ³He from solar winds. ⁴He is produced by the alpha decay of heavier radioactive elements on Earth. It is an unusually stable isotope because its nucleons are arranged in complete shells.

Helium Is A Noble Gas Found

References

1. Banks, A. (1989). 'Helium.' Journal of Chemical Education 66(11): 945.
2. Draggan, S. (2008). 'Helium.'
3. Eagleson, M. (1994). Concise encyclopedia chemistry, Walter De Gruyter Inc.
4. Enghag, P. (2004). Encyclopedia of the elements.
5. Moore, P. and D. Josefson (2000). 'Type 2 diabetes is a major drain on resources.' Annals of Emergency Medicine 35: 300-303.
6. Rosendahl, C. (1938). 'New Zeppelin Is Described by American Airship Expert.' The Science News-Letter 33(18): 281-283.
7. Weast, R. and C. R. Company. (1988). CRC handbook of chemistry and physics, CRC press Boca Raton, FL.

Outside Links

• en.Wikipedia.org/wiki/Helium
• en.Wikipedia.org/wiki/Goodyear_Blimp

Problems

1. What happens when a lit cigarette is thrown at a leaking, high-pressured helium cylinder?

a). nothing

b). the cigarette is incinerated before touching the cylinder

c). the cylinder explodes

d). the cylinder becomes a flame thrower

2. How many isotopes of helium are known? ______
3. (Helium gas, or helium II liquid) leaks faster than the other when stored in a opened cylinder (at STP).
4. What happens when a section of divided petri dish is filled with helium II at 2.173K?

a). It starts boiling.

b). It starts 'creeping' over the divider, soon filling up the other sections of the dish.

c). It evaporates and soon leaves the dish.

d.) It solidifies and expands, breaking the dividers of the petri dish, and filling up the whole dish.

5. Helium was first discovered through ________.

Helium Is A Noble Gas Without

Contributors and Attributions

Are Noble Gases Reactive

• Jun-Hyun Hwang - University of California, Davis