Separation of 3He Isotope from Liquid Helium with the Use of Entropy Filter Composed of Carbon Nanotubes

Abstract

The 3He isotope finds applications in many areas of science and industry, the most important of which are cryogenics, where 3He allows for achieving millikelvins in dilution refrigerators, and public security with 3He detectors of radioactive materials at airports and important buildings. 3He is also used in medicine for lung tomography. One of the most extraordinary future applications is the use of 3He in fusion reactors for clean energy. 3He is currently very expensive, with prices reaching USD 2750 for 1 liter of gas in normal conditions; thus, more effort is put into finding economically viable methods to acquire this isotope. The article shows research results of acquiring the 3He 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 ZrO2 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: Tλ= 2.18 K. Entropy filters work below this temperature.

Mechanical Mechanism of Ion and Water Molecular Transport through Angstrom-Scale Graphene Derivatives Channels: From Atomic Model to Solid-Liquid Interaction

“…is particularly interesting, because these carbon-based materials can be obtained in various forms and their microstructures can also be controlled manually [ 30 ]. J. Niechcial et al [ 31 , 32 ] proposed an effective separation technique for He4/He3 through an entropy filter composed of carbon nanotubes based on the principle of atomic scale channels.…”

AI versus Classic Methods in Modelling Isotopic Separation Processes: Efficiency Comparison

“…The analysis of the isotopic composition of the meteorites represents a modern method for the space exploration. The 18 O isotope for the 18 F production used in the positron emission tomography, respectively, the 13 C and 14 C isotopes, which are used in the respiratory tests, plays an important role in medicine nowadays. Another important domain in which the stable isotopes of 18 O, 15 N, and 13 C are used as tracer agents in agriculture [5], improving the usage of the chemical fertilizer.…”

“…The 18 O isotope for the 18 F production used in the positron emission tomography, respectively, the 13 C and 14 C isotopes, which are used in the respiratory tests, plays an important role in medicine nowadays. Another important domain in which the stable isotopes of 18 O, 15 N, and 13 C are used as tracer agents in agriculture [5], improving the usage of the chemical fertilizer. The most frequent stable isotopes separation methods use the distillation procedures of the compound that contains the followed isotope in liquid or in gaseous phase, respectively, the isotopic exchange in countercurrent on columns with packing.…”

“…The separation of the isotopes is carried out using separation columns with specific equipment having a complex structure and operation [7][8][9][10][11][12][13][14]. The separation columns are operated as a refluxing system, the pipes being positioned at the columns two edges.…”

“…The processes of separation of stable isotopes on columns with packing differ from one isotope to another by: the elementary separation factor, the speed with which the isotopic exchange between the liquid and the gaseous phase takes place (kinetics of isotopic exchange), the size of fluid flows in countercurrent in the column, the chemical concentration of the liquid phase in chemical equilibrium with the gaseous one, the column temperature and the operating pressure. The proposed model can be successfully applied for other stable isotopes ( 15 N, 13 C, and 10 B) if the separation process parameters are known (flow rates and nature of fluids in the column, their concentration, operating pressure of the column, working temperature) leading to the determination of the constructive characteristics of the separation cascade (number of columns to achieve a desired separation, height, inside diameter, type of packing in the separation column (stainless steel wire Helipak, Berl ceramic saddles, glass balls, copper wire mesh, and connection mode of columns in series or parallel)).…”