Thermophysical property measurements on tetrabutylphosphonium sulfate ionic semiclathrate hydrate consisting of the bivalent anion

Yuta Arai, Ryo Koyama, Fuyuaki Endo, Atsushi Hotta, Ryo Ohmura

Research output: Contribution to journalArticle

3 Citations (Scopus)


To develop the “hydrate thermal energy storage technology” it is desired to reveal the mechanism of the thermophysical property manifestation on ionic semiclathrate hydrate. The influence of valence on thermophysical properties has not been investigated so far. In the present study, the phase equilibrium temperatures and the dissociation heats of tetrabutylphosphonium sulfate ((TBP)2SO4) ionic semiclathrate hydrate were experimentally studied. (TBP)2SO4 hydrate consists of the bivalent anion, SO4 2−. The highest phase equilibrium temperature was 6.5 °C at the mass fraction range from 0.363 to 0.384. The largest dissociation heat was (168.8 ± 2.4) kJ·kg−1 at the mass fraction 0.374. These values of the phase equilibrium temperature and the dissociation heat were respectively lower and smaller than those of the ionic semiclathrate hydrates with the monovalent anion. As a new choice for thermal energy storage medium, (TBP)2SO4 hydrate would be suitable to the automotive air conditioner and the cold chain for blood or perishable foods.

Original languageEnglish
Pages (from-to)330-335
Number of pages6
JournalJournal of Chemical Thermodynamics
Publication statusPublished - 2019 Apr 1



  • Bivalent anion
  • Dissociation heat
  • Ionic semiclathrate hydrate
  • Phase equilibrium temperature
  • Tetrabutylphosphonium sulfate hydrate
  • Thermal energy storage

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Physical and Theoretical Chemistry

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