Work

Tetra-n-butylammonium Tricarboxylate Semiclathrate Hydrates as Phase Change Materials: Phase Equilibrium Relations and Memory Effect in Reformation

Year: 2025

Type: article

Abstract: Semiclathrate hydrates (SCHs), one of the phase change materials for cold energy storage, are crystalline compounds consisting of host water molecules and appropriate guest substances. The typical guest substances of SCHs are tetra- n -butylammonium (TBA) salts. In the present study, we investigated the phase equilibrium relations of (TBA) 3 tricarboxylate SCHs, where citrate (−Cit) and 1,2,3-propanetricarboxylate (−123Pro) were used as environmentally friendly tricarboxylate anions. The maximum equilibrium temperatures of (TBA) 3 -Cit and (TBA) 3 -123Pro SCHs, whose phase diagrams exhibited a congruent-type phase behavior, were 286.02 ± 0.05 and 286.34 ± 0.05 K, respectively. Their dissociation enthalpies were 186 ± 3 and 193 ± 3 kJ/kg, respectively, which are as large as that of TBA-bromide SCH that has been put to practical use in cold energy storage applications. As an index for suppressing the degree of supercooling in SCH reformation, we have focused on the memory effect. The ability to retain the memory effect in the (TBA) 3 -Cit and (TBA) 3 -123Pro SCHs was relatively large. The (TBA) 3 -Cit and (TBA) 3 -123Pro SCHs would be superior phase change materials for cold energy storage.

Source: Energy & Fuels

DOI: 10.1021/acs.energyfuels.5c00502

Authors: Kazuhiro Minamikawa, Jin Shimada, Takeshi Sugahara, Takayuki Hirai

Institutions: The University of Osaka, Japan Society for the Promotion of Science

Language: English

Topic: Phase Change Materials Research

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action

Open Access status: green

Funders: Osaka University, Japan Society for the Promotion of Science