Change in Isotopic Composition of Oxygen in Air Separation Process
- PDF / 164,141 Bytes
- 4 Pages / 594 x 792 pts Page_size
- 110 Downloads / 217 Views
CHANGE IN ISOTOPIC COMPOSITION OF OXYGEN IN AIR SEPARATION PROCESS M. A. Bilalov, A. A. Kazakova, and Yu. V. Nikiforov
UDC 621.593
The paper describes the main components of atmospheric air. The main air separation methods are considered. The main methods for producing isotopes are described; data on the quantitative composition of oxygen isotopes are given. A description of an experimental apparatus for measuring oxygen isotopes based on an inductively coupled plasma mass spectrometer is given and its operation principle is described. A methodology for estimating the error of measurement results is given. The isotopic composition of oxygen samples produced by various methods has been determined. Keywords: oxygen, oxygen isotopes, distillation, pressure swing adsorption, membrane air separation.
Atomic oxygen consists of three stable isotopes (16O, 17O, 18O) [1], which are stable varieties of atoms with the same nuclear charges, but with different numbers of neutrons in them and, accordingly, with different nuclei mass. Oxygen isotopes are widely used in various fields of science and technology. The analysis of oxygen isotope ratios is one of the main methods for investigating natural compounds; it allows solving wide range of problems: from the study of the evolution of terrestrial and cosmic bodies to the search for minerals. For example, the method of analyzing oxygen isotope ratios in oceanic and sea waters is used to obtain data on the conditions of the formation of various minerals [2]. In addition, oxygen isotopes are used in medicine. One of the promising directions is the use of compounds “labeled” with the heavy oxygen isotope 18O, that makes it possible to establish the causes of many diseases of the nervous and cardiovascular systems, to diagnose oncology diseases, to determine the effectiveness of using certain pharmaceutical products for the treatment of brain diseases. The largest application of the isotope 18O is in one of the modern medical diagnostic methods — the positron emission tomography. In the process of extracting oxygen from the air, due to the difference in the properties of isotopes or their compounds, the amount of certain oxygen isotopes can also vary in comparison with their content in the atmospheric air. It can be assumed that the oxygen isotopic composition will depend on the method of producing oxygen. The objective of this research is to determine the isotopic composition of oxygen (according to the developed technique using a quadrupole inductively coupled plasma mass spectrometer) for various methods of producing oxygen from air. The mass fraction of oxygen, which is the second in concentration chemical element in the Earth’s atmosphere, in relation to other components of the atmosphere is 23.15%. The oxygen isotopic composition of the Earth’s atmosphere is [3]: 99.758% of isotope
16
O,
Bauman Moscow State Technical University, Russia; e-mail: [email protected], [email protected]. Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, Vol. 56, No. 5, pp. 21–22,
Data Loading...
