Experimental Study of Semiclathrate Hydrates Formation TBAOH, TBAF, and TBAC in the Presence of SDS and Tween Surfactants as a Cold Thermal Energy Storage System for Air Conditioning Applications

Abstract

Over the past decades, the increasing use of air conditioning systems has been one of the main drivers for reducing the peak of electricity consumption. PCMs (phase change materials) for cold thermal energy storage (CTES) allow us to achieve a heat capacity for future use. Hence, CTES has been suggested to reduce power demand problems. In this study, to obtain the phase change temperature and formation temperature of TBAF, TBAC, and TBAOH semiclathrate salts as CTES for air conditioning applications, the experiments were performed from 10 to 50 wt %. Also, the effect of two additives, Tween 80 and SDS, at three weight percentages (0.1, 0.3, and 0.5 wt %) on formation temperature and phase change temperature was investigated. Furthermore, the effects of SDS and Tween mixtures using Design Expert software and Analysis of Variance (ANOVA) were analyzed and optimized. The results showed that, in general, TBAF hydrate solution had a higher phase change temperature and formation temperature than TBAC and TBAOH salt semiclathrate. The highest phase change temperature for all salts TBAF, TBAC, and TBOAH occurred at approximately 35 wt %, and their temperatures were 24.6 °C, 14.1 °C, and 12.8 °C, respectively. Using SDS and Tween additives, the phase change temperature and hydrate deflection time of TBAC, TBAF, and TBAOH were 21.73 °C, 26.08 °C, and 28.84 °C and 32.31 min, 25.92 min, and 20.20 min, respectively. With the Design Expert software, a model for the phase change temperature and deflection time of each hydrate was obtained. In the optimization section, a condition of the optimal hydrate formation was proposed.

Review of Ionic Semiclathrate Hydrates as Thermal Energy Storage Materials: Properties and Applications

“…Their conclusion was consistent with the theoretical relationship between the viscosity and solid fraction of the slurry reported by Graham et al The addition of an inhibitor of hydrate formation, such as a surfactant, is effective in suppressing the viscosity of a slurry. − Most recently, it was found that adding amino acids to a hydrate slurry reduces its viscosity, thereby reducing the pumping power consumption . Although representative surfactants such as sodium dodecyl sulfate and Span 80, which are not encapsulated in hydrate cages, serve as kinetic promoters for hydrate formation, the phase equilibrium temperature of hydrates undergoes very little change when adding the above surfactants to hydrate formation systems. , Conversely, adding additional guest compounds such as tetrahydropyran alleviate the phase equilibrium conditions …”

“…90 Although representative surfactants such as sodium dodecyl sulfate and Span 80, which are not encapsulated in hydrate cages, serve as kinetic promoters for hydrate formation, 93 the phase equilibrium temperature of hydrates undergoes very little change when adding the above surfactants to hydrate formation systems. 94,95 Conversely, adding additional guest compounds such as tetrahydropyran alleviate the phase equilibrium conditions. 96 Understanding the crystal growth characteristics of hydrates is crucial for elucidating the fundamental principles of the rheological properties of slurries.…”

Zeolitic ice: A route toward net zero emissions

“…• C), thermal stability (melting point can vary from -66 up to 31 • C), latent heat of fusion (190-220 kJ/kg) and relatively better heat transfer efficiency compared to clathrate hydrates [32,206] which is suitable for various cooling requirements [207]. The process usually starts with cooling the system to form a hydrate, which is an exothermic process.…”

Fast Formation of Hydrate Induced by Micro-Nano Bubbles: A Review of Current Status

“…At present, the most commonly used methods to strengthen hydrate formation are "mechanical methods [13][14][15][16][17][18]" and "additives [19][20][21]". The mechanical methods (e.g., stirring, spraying, and gas bubbling) introduce external energy, which significantly in-creases energy consumption, while hydrate formation can hinder the stirring.…”