energies
Article
Separation of
3
He Isotope from Liquid Helium with the Use of
Entropy Filter Composed of Carbon Nanotubes
Jakub Niechcial
1,
* , Wojciech Kempi ´ nski
1,
* , Leszek Stobi ´ nski
2,3
, Zbigniew Trybula
1
, Piotr Banat
1
,
Maciej Chorowski
4
, Jaroslaw Poli ´ nski
4
, Katarzyna Cholast
5
and Andrzej Kociemba
5
Citation: Niechcial, J.; Kempi ´ nski,
W.; Stobi´ nski, L.; Trybula, Z.; Banat, P.;
Chorowski, M.; Poli ´ nski, J.; Cholast,
K.; Kociemba, A. Separation of
3
He
Isotope from Liquid Helium with the
Use of Entropy Filter Composed of
Carbon Nanotubes. Energies 2021, 14,
6832. https://doi.org/10.3390/
en14206832
Academic Editor: Muhammad Aziz
Received: 5 August 2021
Accepted: 15 October 2021
Published: 19 October 2021
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1
Institute of Molecular Physics, Polish Academy of Sciences, 60-179 Pozna ´ n, Poland;
trybula@ifmpan.poznan.pl (Z.T.); banat@ifmpan.poznan.pl (P.B.)
2
Faculty of Chemical and Process Engineering, Warsaw University of Technology, 00-645 Warszawa, Poland;
lstob50@hotmail.com
3
Nanomaterials, Leszek Stobinski, 03-337 Warsaw, Poland
4
Department of Cryogenics and Aerospace Engineering, Wroclaw University of Science and Technology,
50-370 Wroclaw, Poland; maciej.chorowski@pwr.edu.pl (M.C.); jaroslaw.polinski@pwr.edu.pl (J.P.)
5
Polish Oil and Gas Company—Odolanów, 63-430 Odolanów, Poland; katarzyna.cholast@pgnig.pl (K.C.);
andrzej.kociemba@pgnig.pl (A.K.)
* Correspondence: jakub.niechcial@ifmpan.poznan.pl (J.N.); wojkem@ifmpan.poznan.pl (W.K.)
Abstract: The
3
He isotope finds applications in many areas of science and industry, the most impor-
tant of which are cryogenics, where
3
He allows for achieving millikelvins in dilution refrigerators,
and public security with
3
He detectors of radioactive materials at airports and important buildings.
3
He is also used in medicine for lung tomography. One of the most extraordinary future applications
is the use of
3
He in fusion reactors for clean energy.
3
He is currently very expensive, with prices
reaching USD 2750 for 1 liter of gas in normal conditions; thus, more effort is put into finding econom-
ically viable methods to acquire this isotope. The article shows research results of acquiring the
3
He
isotope from liquid helium by a quantum separation method with the use of entropy filters based on
new carbon nanomaterials: purified multiwall carbon nanotubes (MWCNTs) and purified multiwall
carbon nanotubes decorated with ZrO
2
nanoparticles. MWCNTs were bundled and applied in the
form of pressed tablets with fixed sizes. The research was conducted at the low-temperature region,
where helium exhibits its quantum properties by undergoing a phase transition to the superfluid
phase at the lambda temperature: T
λ
= 2.18 K. Entropy filters work below this temperature.
Keywords: entropy filter; carbon nanotubes; quantum filtration; isotope separation;
3
He isotope
1. Introduction
From the end of the 1960s, the annual global energy consumption increased almost
3.5 times [1], leading us to look for sources that both supply stable and safe energy production,
and are also in line with the sustainable development of the global economy. EU restrictions
on traditional energy sources based on Earth gas and coal enforce solutions that satisfy both
the economical calculation and pro-ecological regulations [2]. One of the solutions that could
fulfill these requirements is fusion power, where
3
He is expected to be useful as a fusion
fuel [3,4]. Thus, it is of utmost importance to obtain this isotope as effectively and economically
as possible. The development of an industrial method for the separation of
3
He and
4
He
isotopes in liquid helium (LHe) was mentioned in a U.S. Congress report as an important
method from the viewpoint of energetics based on the production of clean energy [5,6].
Methods for the separation of
3
He-
4
He mixture have been used for a long time [7–9], but
the most interesting are those conducted at low temperatures [10–12], utilizing quantum
effects occurring in superfluid helium that allow for the use of entropy filters composed of
various materials [13,14]. In our case, these are modern carbon nanomaterials: pure and
ZrO
2
-decorated bundled multiwalled carbon nanotubes (MWCNTs) in the form of pressed
tablets of a certain size.
Energies 2021, 14, 6832. https://doi.org/10.3390/en14206832 https://www.mdpi.com/journal/energies