Hydrophilic modification of expanded graphite to develop form-stable composite phase change material based on modified CaCl2·6H2O

Zou, Ting; Fu, Wanwan; Liang, Xianghui; Wang, Shuangfeng; Gao, Xuenong; Zhang, Zhengguo; Fang, Yutang

doi:10.1016/j.energy.2019.116473

Cited by 75 publications

(12 citation statements)

References 34 publications

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“…Also, the wide and weak peak at 2150 cm −1 represented the characteristic band of CaCl 2 . 59 The pattern of EP/Ca@C-0.25 was similar to that of EP/Ca, indicating that there was no chemical interaction between the carbon shell and the core material.…”

Section: Resultsmentioning

confidence: 81%

“…For EP/Ca, the peaks at 3450 and 1628 cm –1 were significantly enhanced due to the −OH stretching vibration of crystal water from calcium chloride hydrate. Also, the wide and weak peak at 2150 cm –1 represented the characteristic band of CaCl 2 . The pattern of EP/Ca@C-0.25 was similar to that of EP/Ca, indicating that there was no chemical interaction between the carbon shell and the core material.…”

Section: Resultsmentioning

confidence: 84%

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Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

et al. 2021

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The sorption heat storage based on composites with salt hydrates enables the efficient utilization and trans-seasonal storage of solar energy. Nevertheless, the limitation of heat and mass transfer of salt hydrates has restricted the implementation of this technology. Here, a novel strategy is proposed to synthesize a multistage core–shell sorbent, where salt hydrates are dispersed in the macropores of the expanded perlite (EP) before being coated with a carbon layer outside the EP/Ca particles. The abundant macropores in the matrix are beneficial to the high salt loading and efficient mass transfer. Moreover, the carbon shell significantly enhances the light-to-heat conversion performance of the sorbent, and the heat can be directly transferred from the shell to the internal salt hydrates for desorption, thus realizing the absorption, conversion, and storage of solar energy in the multistage core–shell sorbent. The sorption capacity of EP/Ca@C-0.25 is determined to be 1.22 g-H2O/g-sorbent under the conditions of 20 °C and RH 80%, and 84% of the water can be desorbed after irradiation under the 1 kW/m2 simulated sunlight for 2 h, with a heat storage density of 1698 J/g-sorbent in the heat storage process. Additionally, we also studied the performance of EP/Ca@C-0.25 in a solar-driven thermal energy storage system. In summer, the sorbent is placed outdoors and desorbed under sunlight within 2 h to achieve heat storage. In winter, the sorbent is placed in a fixed bed for adsorption, and the heat released during adsorption increases the air temperature by 5 °C for 10 h. Typically, the multistage core–shell sorbent demonstrates a potential sorbent for large-scale use in solar-driven thermal energy storage for practical purposes.

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Section: Resultsmentioning

confidence: 81%

Section: Resultsmentioning

confidence: 84%

Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

et al. 2021

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“…Comparing Figures 13,14, and 15, it may be interpreted that the presence of the composite always suppresses the stiff rise in room temperature even in the presence of the heat source (due to switching the lamp on). Comparing the rate of temperature rise (rise in temperature against duration), it appears that the delay in attaining the stiff rise in temperature was proportional to the PCM content or the enthalpy content available in the composite.…”

Section: Application Of the Pcm Composite In Amentioning

confidence: 91%

“…The time needed to attain 30 °C was 2763 s for plasterboards without the PCM composite, which became 4467 s with the PCM composite. Though many salt hydrates (inorganic PCMs) were explored as suitable building materials, organic PCMs are preferred over inorganic PCMs due to behavioral irregularities with salt hydrates, i.e., phase separation, supercooling, and cyclic instability . Different organic PCMs, e.g., paraffin, fatty acids, esters, and alcohols, were also reported in building applications. − The leakage/contamination with the surroundings issue of PCMs once melted was resolved by forming EP-based composites.…”

Section: Introductionmentioning

confidence: 99%

Thermal Buffering Performance of a Propyl Palmitate/Expanded Perlite-Based Form-Stable Composite: Experiment and Numerical Modeling in a Building Model

et al. 2021

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A phase change material (PCM) composite was prepared by impregnating propyl palmitate in expanded perlite (EP, as a support matrix), and its thermal buffering performance was tested in building applications. Five composites with varying PCM contents, i.e., 60, 55, 50, 45, and 40%, were prepared, and the composite with 55 wt % (EP-55) was chosen for thermal buffering performance analysis. All composite samples showed melting between 18.5 and 18.8 °C (as a PCM), while attenuated total reflection-infrared spectroscopy analysis confirmed simple physical adsorption occurring between the PCM and EP. Differential scanning calorimetry measurements (EP-55) showed a phase change enthalpy of 81.98 ± 1 J g −1 , and stable performance during 1000 thermal cycles with the EP-55 composite confirmed appreciable thermal stability and reliability. The thermal buffering performance of the composite was tested in a building model, which was simulated using COMSOL Multiphysics 5.5. The unsteadystate energy (conduction/convection/radiation and latent heat of a PCM) transport from a source to the building was expressed mathematically along with its boundary conditions. The model was validated using a blank and with a composite, which was later applied to predict another unknown case. The model-predicted temperatures could very closely match (< ±4.0%) with experimental values.

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“…Due to the outstanding characteristics of the phase transition process, the latent thermal storage using phase-change materials (PCMs) is preferred. The PCMs can store and release a certain amount of latent energy [1][2][3] at an almost constant temperature during its phase transition, effectively preventing rapid thermal fluctuations during phase transitions and ultimately improving indoor thermal comfort by stabilizing the indoor surface temperature. To meet the requirement of a living environment, the phase transition temperature shall be kept in 22-26°C.…”

Section: Introductionmentioning

confidence: 99%

Preparation and thermal properties of modified binary paraffin - Hexadecylamine shaped composite phase-change energy storage materials

Hao

Jiang

et al. 2022

Journal of Thermoplastic Composite Materials

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Binary paraffin has attracted much attention because it can control the phase change temperature range and has good flexibility. To improve the latent heat effect, a modified binary paraffin—hexadecylamine—ceramsite shaped composite phase-change energy storage material was prepared in this study through eutectic mixing and vacuum adsorption method. With eutectic binary paraffin—hexadecylamine as the core material, ceramsite as the carrier shell material and nano aluminum nitride (AlN) as the heat conduction enhancer. The thermal stability of the composites was characterized using a temperature recorder, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results showed that the optimal mass ratio of the eutectic phase-change material was solid paraffin: liquid paraffin: hexadecylamine = 50: 18: 32. The optimal mixture has a phase-change temperature of 26.5°C and a latent thermal value of 204.50 J/g, indicating that it has good heat storage performance. The phase-change temperature was 1.2°C earlier after the addition of 0.5% AlN, and the heat rate of storage was also improved. The mass ratio of the composite phase-change materials and ceramsite was 27.5: 72.5 is achieved by vacuum adsorption into the ceramsite. The phase-change materials are evenly dispersed and the ceramsite is well wrapped. It has good thermal stability, as verified by a 500 accelerated heating-cooling circulations below 60°C, and has great potential for the development of new building energy storage materials.

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Hydrophilic modification of expanded graphite to develop form-stable composite phase change material based on modified CaCl2·6H2O

Cited by 75 publications

References 34 publications

Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

Thermal Buffering Performance of a Propyl Palmitate/Expanded Perlite-Based Form-Stable Composite: Experiment and Numerical Modeling in a Building Model

Preparation and thermal properties of modified binary paraffin - Hexadecylamine shaped composite phase-change energy storage materials

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Hydrophilic modification of expanded graphite to develop form-stable composite phase change material based on modified CaCl2·6H2O

Cited by 75 publications

References 34 publications

Scalable Production of EP/CaCl2@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

Scalable Production of EP/CaCl2@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

Thermal Buffering Performance of a Propyl Palmitate/Expanded Perlite-Based Form-Stable Composite: Experiment and Numerical Modeling in a Building Model

Preparation and thermal properties of modified binary paraffin - Hexadecylamine shaped composite phase-change energy storage materials

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Product

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Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application

Scalable Production of EP/CaCl₂@C Multistage Core–Shell Sorbent for Solar-Driven Sorption Heat Storage Application