Shrinking helium reserves may threaten more than kids’ play
Jan 11,2008 00:00 by Bend_Weekly_News_Sources

Helium, the el­e­ment that lifts things like bal­loons, spir­its and voice ranges, is be­ing de­plet­ed so quickly that the world’s larg­est re­serve of it is ex­pected to run out by 2015, sci­en­tists say.

That would de­flate more than the Good­year blimp and par­ty fa­vors. Its larg­er im­pact is on sci­ence and tech­nol­o­gy, ac­cord­ing to Lee So­bot­ka of Wash­ing­ton Un­ivers­ity in St. Lou­is.

Courtesy Washington University in St. Louis

“He­li­um’s use in sci­ence is ex­tremely broad, but its most im­por­tant use is as a coolan­t,” said So­bot­ka, a spe­cial­ist in nu­clear chem­is­try and phys­ics who works at sev­er­al na­t­ional lab­o­r­a­to­ries. Larg­er he­li­um con­sumers, such as these, gen­er­ally are equipped to re­cy­cle it, So­bot­ka said; not so for many smaller-scale users.

Yet “he­li­um is non-renewable and ir­re­place­able,” as it can’t be ma­n­u­fac­tured in sig­nif­i­cant amounts, So­bot­ka said. “All should make bet­ter ef­forts to re­cy­cle it.” He­li­um’s ap­plica­t­ions, he added, in­clude nu­clear mag­net­ic res­o­nance, mass spec­tros­co­py, weld­ing, fi­ber op­tics and com­put­er mi­crochip pro­duc­tion. NA­SA uses large amounts to pres­sur­ize space shut­tle fu­el tanks. 

Drift away

The he­li­um on Earth has built up over bil­lions of years from the de­cay, or dis­in­tegra­t­ion, of the nat­u­ral el­e­ments ura­ni­um and tho­ri­um, So­bot­ka said. The pro­cess oc­curs in supe­r-slow mo­tion, he added. For ex­am­ple, the ura­ni­um var­i­ant, or iso­tope, ura­ni­um-238 is par­tic­u­larly im­por­tant for he­li­um pro­duc­tion. In Earth’s en­tire life­span, So­bot­ka said, only half of the ura­ni­um-238 atoms have de­cayed, each yield­ing eight he­li­um atoms.

As ura­ni­um and tho­ri­um de­cay, some of the he­li­um is trapped along with nat­u­ral gas de­posits in cer­tain ge­o­log­i­cal forma­t­ions, So­bot­ka said. Some of the pro­duced he­li­um seeps out of the Earth’s man­tle and drifts in­to the at­mos­phere, where there is about five parts per mil­lion of it. This he­li­um, along with any let in­to the at­mos­phere by users, drifts up and is even­tu­ally lost to Earth.

“When we use what has been made over the ap­prox­i­mate 4.5 bil­lion of years the Earth has been around, we will run out,” So­bot­ka said. “We can­not get too sig­nif­i­cant quan­ti­ties of he­li­um from the sun — which can be viewed as a he­li­um fac­to­ry 93 mil­lion miles away — nor will we ev­er pro­duce he­li­um in an­ywhere near the quan­ti­ties we need from Earth-bound facto­ries.” Nu­clear re­ac­tors can make some he­li­um, but not nearly enough, he added; sci­en­tists haven’t even ap­proached min­ing he­li­um out of the air be­cause costs are pro­hib­i­tive.

Un­like any oth­er el­e­ment, or­di­nary he­li­um, which con­tains two pro­tons and two neu­trons, be­co­mes a liq­uid be­low the tempe­rature 4.2 Kel­vin. That’s just four Cel­si­us de­grees above the low­est tempe­rature pos­si­ble, ab­so­lute ze­ro. When one puts an ob­ject next to liq­uid he­li­um, en­er­gy is ex­tracted from the ob­ject, mak­ing it colder. The en­er­gy ex­tracted from the ob­ject va­por­izes the he­li­um. It is this he­li­um va­por which, So­bot­ka claims, should al­ways be re­cap­tured, to be re­cy­cled for fu­ture use.

Much of the world’s he­li­um supply lies in a re­serve out­side Am­a­ril­lo in the Tex­as Pan­han­dle. It’s an ar­ea bet­ter known for the lo­cales of Lar­ry Mc­Murtry’s nov­els, such as “The Last Pic­ture Show,” and “Tex­asville,” than as an el­e­mental fac­to­ry farm. 

A reb­el, a lon­er

Both hy­dro­gen and he­li­um, the first two el­e­ments on the Per­i­od­ic Ta­ble of El­e­ments, are abun­dant in the un­iverse (a­bout 92 pe­rcent and about 8 pe­rcent of the atoms, re­spec­tive­ly). But he­li­um is rare on Earth. That’s be­cause he­li­um is a reb­el, a lon­er that does­n’t nor­mally com­bine with oth­er atoms, as hy­dro­gen does, So­bot­ka said.

Helium is “the most ‘no­ble’ of gas­es, mean­ing it’s very sta­ble and non-reactive for the most part,” So­bot­ka said. El­e­ments com­bine by shar­ing elec­trons, the sub­a­tom­ic par­t­i­cles that car­ry elec­tric charge. But he­li­um is “a very tightly bound atom” that clings closely to its elec­trons, pre­venting such part­ner­ships, he ex­plained.

In ad­di­tion to the Tex­as pan­han­dle, he­li­um can be found in small re­gions of Col­o­rad­o, Kan­sas and Ok­la­ho­ma, So­bot­ka said. It’s mar­keted in Aus­tral­ia and Al­ge­ria. And Rus­sia has the world’s larg­est re­serves of nat­u­ral gas, where he­li­um cer­tainly ex­ists. But there is no push to mar­ket it, as for the short term, sup­plies are ad­e­quate, though in­creas­ingly cost­ly. So­bot­ka be­lieves that Rus­sia will be the world’s ma­jor source in 30 years.

Liq­uid he­li­um costs about $5 per li­ter, hav­ing gone up more than 50 pe­rcent over the past year as de­mand grad­u­ally out­strips the sup­plies, he said. He cit­ed the with­draw­al of some com­pa­nies from the mar­ketplace, and the emer­gence of oth­ers not yet in pro­duc­tion, as the driv­ing force be­hind high­er prices.

He­li­um cap­ture in the Un­ited States be­gan af­ter World War I, when its main use was for di­ri­gi­bles. Be­cause he­li­um is non-flammable, its use pre­vented a re­peat of the 1937 Hin­den­burg trag­e­dy, in which a hy­dro­gen-filled Ger­man air­ship burst in­to flames. The U.S. go­vernment ran the he­li­um in­dus­try for 70 years, but since the mid-’90s it has been in the do­main of the oil and nat­u­ral gas in­dus­tries, So­bot­ka said.

Tell it like it is

“The go­vernment had the good vi­sion to store he­li­um, and the ques­tion now is: Will in­dus­try have the vi­sion to cap­ture it when ex­tract­ing nat­u­ral gas, and con­sumers the wis­dom to cap­ture and re­cy­cle?” So­bot­ka said. “This takes long-term vi­sion be­cause pre­s­ent mar­ket forc­es are not suf­fi­cient to com­pel pru­dent prac­tice.”

He­li­um plays sec­ond fid­dle to mar­keting oil and nat­u­ral gas, So­bot­ka con­tin­ued: much of it is lost in a pro­cess that re­moves non­com­bus­ti­ble ni­tro­gen and he­li­um from the prod­uct of prime in­ter­est.

“When they stick that straw in­to the ground to suck out oil and gas, the he­li­um comes out, and if it does­n’t get cap­tured it drifts in­to the at­mos­phere and is lost,” So­bot­ka said. “He­li­um pro­duc­tion is a side in­dus­try to oil and nat­u­ral gas, an en­deav­or that no­body wants to lose mon­ey on.”

Lab­o­r­a­to­ries world­wide could make bet­ter at­tempts at con­serv­ing he­li­um, he said. They can ei­ther use costly machines called liq­ue­fiers that can cap­ture, store and re­liq­ue­fy he­li­um on site; or re­search­ers can take cap­tured he­li­um as gas, re­turn it to the company that sold it to them and get a mon­e­tary re­turn, just as in a de­pos­it on a bot­tle. “We have to be think­ing of these things,” he said. “Up to now, the is­sue of­ten has­n’t ris­en to the lev­el that it’s im­por­tant. It’s a prob­lem for the next genera­t­ion of sci­en­tists.”

Courtesy Washington University in St. Louis and World Science staff