Thermal and microstructural properties of paraffin/diatomite composite

Alleg, S.; Mebrek, Alima; Suñol, J.J.

doi:10.1016/j.vacuum.2018.08.044

Cited by 39 publications

(15 citation statements)

References 37 publications

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“…Moreover, the DM shows excellent compatibility with energy storage system, low cost, and high specific surface area, which is the suitable choice for matrix materials of CPCMs. At present, DM‐based organic CPCMs, such as PEG/DM, paraffin/DM, and fatty acid/DM, are widely studied; in contrast, the researches of encapsulating inorganic hydrated salts with DM are relatively lacking. As we all know, the low thermal conductivity and high supercooling degree of DM‐based encapsulated hydrated salt CPCMs are the unfavorable factors that affect the performance, so it is urgent to prepare novel excellent CPCMs with high thermal conductivity and low supercooling degree.…”

Section: Introductionmentioning

confidence: 99%

Design of diatomite-based hydrated salt composites with low supercooling degree and enhanced heat transfer for thermal energy storage

Yang

et al. 2019

Int J Energy Res

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Summary In this work, diatomite (DM) was calcined at 400°C to obtain the pure surface and pores (DM‐1); then, the three kinds of shape‐stable composite phase change materials (ss‐CPCMs) of CaCl2·6H2O (CCH)/DM‐1, CH3COONa·3H2O (SAT)/DM‐1, and Na2SO4·10H2O (SSD)/DM‐1 were prepared by impregnation method. The hydrated salts were uniformly adsorbed on the surfaces and into the pores of DM‐1 by capillary action and surface tension. The addition of nucleating agent effectively reduced the supercooling degrees of hydrated salts, and the heterogeneous nucleation mechanism was employed to explain the supercooling suppression. The results showed that the supercooling degrees of the three hydrated salt ss‐CPCMs with optimal nucleating agent were less than or equal to 0.6°C. Moreover, the thermal conductivities of ss‐CPCMs were significantly improved by adding graphite, and the addition of 10 wt% graphite could increase the thermal conductivity of hydrated salt ss‐CPCMs by at least 70%. The package capacity of CCH, SAT, and SSD in three ss‐CPCMs with appropriate contents of nucleating agent and graphite was 58.1, 56.1, and 56.3 wt%, respectively. The DSC results showed that the phase change temperatures of the three ss‐CPCMs were approximately 28.8 to 57.8°C, and the latent heat was approximately 108.7 to 149.4 J/g. The XRD and FT‐IR results exhibited that the three ss‐CPCMs indicated understanding chemical compatibility. In addition, the results of 200 melt‐solidification cycles demonstrated that the ss‐CPCMs had excellent thermal cycle reliability. Thus, the hydrated salt/DM‐1 ss‐CPCMs showed great potential as heat storage materials for various heat storage applications.

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Section: Introductionmentioning

confidence: 99%

Design of diatomite-based hydrated salt composites with low supercooling degree and enhanced heat transfer for thermal energy storage

Yang

et al. 2019

Int J Energy Res

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“…Different organic and inorganic PCMs were used in PCM/diatomite composites, such as stearic acid, palm oil, palmitic acid‐capric acid eutectic mixture, decanoic acid, dodecanoic acid, eutectic mixtures of hexadecanoic acid and octadecanoic acid, polyethylene glycol, octadecane, potassium nitrate, sodium sulfate, lithium nitrate, sodium nitrate, and magnesium nitrate hexahydrate . However, the most widely used PCM is paraffin …”

Section: Introductionmentioning

confidence: 99%

“…40 However, the most widely used PCM is paraffin. 10,11,18,[41][42][43] To improve the absorbability, purity, and other properties, researchers have modified diatomite samples with different methods before use. 6 Calcination is the most common method for modification of diatomite before compounding to increase the PCM ratio in the composites.…”

Section: Introductionmentioning

confidence: 99%

“…Calcination is the most common method for modification of diatomite before compounding to increase the PCM ratio in the composites. Sun et al and Benayache et al prepared paraffin composites with calcined diatomite, and the PCM ratios of the composites were found to be 61 wt% and 50.62 wt%, respectively. High temperatures such as 450°C to 650°C and a duration of 2 hours are needed for optimal calcination of diatomite to completely eliminate the inorganic impurities and carbonate compounds in diatomite samples .…”

Section: Introductionmentioning

confidence: 99%

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Development of pentadecane/diatomite and pentadecane/sepiolite nanocomposites fabricated by different compounding methods for thermal energy storage

2019

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Summary Global warming is one of the most important consequences of excess energy consumption. Phase change materials (PCMs) have prominent advantages in thermal energy storage owing to their high latent heat capacities and small temperature variations during the phase change process. However, leakage is a major problem that limits the use of PCMs. Leakage may occur in encapsulated PCMs or in composites where the PCM is attached to the surface of a supporting material or within the pores of that material. In this study, pentadecane/diatomite and pentadecane/sepiolite nanocomposites were fabricated by using unmodified and microwave‐irradiated diatomite and sepiolite samples and by using different compounding processes, such as direct impregnation, vacuum impregnation, and ultrasonic‐assisted impregnation methods. The microstructures and the chemical and thermal properties of the composites were characterized by scanning electron microscopy, Fourier‐transform infrared spectroscopy, and differential scanning calorimetry. Subsequently, the thermal reliability and stability and the thermal conductivity of the PCM composites were also investigated. A melting temperature of 9.25°C and a latent heat capacity of 58.73 J/g were determined for the pentadecane/diatomite composite that was prepared with the direct impregnation method using a microwave‐treated diatomite sample. The pentadecane/sepiolite composite prepared in the melting temperature range 7.98°C to 8.53°C and latent heat capacity range 41.05 to 46.02 J/g. The results of the thermal analysis indicate that fabricated diatomite‐based or sepiolite‐based PCM composites have good potential as thermal energy storage materials.

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“…Например, производство фильтровальных порошков, красок и лаков, высококачественной бумаги, тонких абразивов, высокопрочной резины. Также диатомиты можно использовать в медицинской, фармакологической и пищевой промышленности как полезные композитные и нанокомпозитные материалы, биостимуляторы, адсорбенты, кондиционные добавки [5][6][7][8][9][10].…”

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Микроэлементный Состав Водных Экстрактов Некоторых Образцов Диатомитов И Лидитов Карелии

Feoktistov¹,

Медведев²

2020

IZVESTIYA

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Актуальность исследования обусловлена необходимостью получения достоверной информации об элементном составе водных экстрактов диатомитов и лидитов. В настоящее время диатомиты используются в различных отраслях промышленности, в том числе медицинской и фармацевтической. Однако детального изучения состава их водных экстрактов практически не проводилось. Цель: изучить микроэлементный состав водных экстрактов нескольких образцов диатомитов и лидитов. Объекты: три образца диатомитов и два образца лидитов территории Республики Карелия. Методика: лабораторный эксперимент, водная экстракция, масс-спектрометрия с индуктивно-связанной плазмой (ICP MS). Результаты. Изучен элементный состав водных экстрактов нескольких образцов диатомитов и лидитов территории Республики Карелия методом ICP MS. Во всех исследованных экстрактах образцов диатомитов и лидитов преобладающими элементами являются Mg, Na, Ca, K и Al (до нескольких тысяч мкг/л). Экстракты образцов диатомитов имеют однородный состав. Максимальные содержания в них других, наиболее значимых, элементов составляли: P – до 650, Fe – до 1700 (образец № 1) и Mn – до 3300 (образец № 3) мкг/л. Концентрации в диапазоне от 10 до 100 мкг/л характерны для ряда элементов (Li, B, Ti, Cr, Co, Ni, Cu, Zn, Sr, Y, Zr и Ba) в экстрактах всех образцов диатомитов. Экстракты образцов диатомитов № 1 и 2 имели максимальные концентрации легких редкоземельных элементов (РЗЭ): Nd (до 247), Ce (до 230), La (до 156 мкг/л). Химический состав экстрактов образцов лидитов заметно отличался, как между собой, так и от экстрактов диатомитов. Кислая среда (рН 4,5–4,6) экстракта образца № 4 способствовала накоплению ряда элементов: Ni, Sr, Be, Mn, U, Tl, и особенно V, Co, Cu, Zn, Y, Ba. В то же время в экстракте образца № 5 в слабощелочных условиях (рН 7,4–7,5) наблюдались максимальные концентрации Mo, W, Zr, Hf. В исследованных экстрактах образцах диатомитов и лидита № 4 концентрации Al, Mn, Fe, Co, Ni, Cu, Zn превышали значения предельно допустимых концентраций (ПДК) рыбохозяйственных водоемов. Водные экстракты образцов диатомитов показали значительное содержание элементов, которые могут оказать влияние на формирование состава маломинерализованных карельских вод. При этом содержание ряда полезных для развития растений микроэлементов (Ca, Mg, К, Р, Cu, Zn, V, Mn, Sr, Y, Zr) предполагает возможность их использования как «мягких» удобрений (или добавок к минеральным удобрениям).

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Thermal and microstructural properties of paraffin/diatomite composite

Cited by 39 publications

References 37 publications

Design of diatomite-based hydrated salt composites with low supercooling degree and enhanced heat transfer for thermal energy storage

Design of diatomite-based hydrated salt composites with low supercooling degree and enhanced heat transfer for thermal energy storage

Development of pentadecane/diatomite and pentadecane/sepiolite nanocomposites fabricated by different compounding methods for thermal energy storage

Микроэлементный Состав Водных Экстрактов Некоторых Образцов Диатомитов И Лидитов Карелии

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