Preparation and Characterization of Inorganic PCM Microcapsules by Fluidized Bed Method

The literature shows that inorganic phase change materials (PCM) have been very seldom microencapsulated, so this study aims to contribute to filling this research gap. Bischofite, a by-product from the non-metallic industry identified as having good potential to be used as inorganic PCM, was microencapsulated by means of a fluidized bed method with acrylic as polymer and chloroform as solvent, after compatibility studies of both several solvents and several polymers. The formation of bischofite and pure MgCl2·6H2O microcapsules was investigated and analyzed. Results showed an efficiency in microencapsulation of 95% could be achieved when using 2 min of fluidization time and 2 kg/h of atomization flow. The final microcapsules had excellent melting temperatures and enthalpy compared to the original PCM, 104.6 ºC and 95 J/g for bischofite, and 95.3 and 118.3 for MgCl2· 6H2OThis project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement N PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES)

Application of Solar Heating on the Electrolyte Conditioning for Electrowinning Process: Thermosolar Plant Performance

2013 ISES Solar World CongressIn this contribution the performance of a thermosolar plant to provide heat to the copper electrowinning (EW) process is analyzed. This plant has a collecting area of 404 m2 with flat plate solar collectors, and generation capacity of 540 MWht/year. It has a thermal storage tank where water can be stored at an average temperature of 95 °C. This allows providing continuously the energy to heat the electrolyte. It was determined the performance of the solar field and global performance of the plant for a working period of 4 months at the northern region conditions from Chile. In addition, the fuel consumption reduction for replacing liquefied gas by thermal solar energy to heat the electrolyte and CO2 emissions reduction were analyzed

Industrial carnallite-waste for thermochemical energy storage application

The key to successful development and implementation of thermochemical storage systems is the identification of high energy density and low-cost storage materials. In this work, an industrial waste based on a double salt hydrate, coming from non-metallic mining was studied for thermochemical storage applications. Initially, chemical characterization was performed and determined that carnallite-waste material consists of 73.54 wt% of KCl·MgCl2·6H2O and impurities such as NaCl (23.04 wt%), KCl (1.76 wt%) and CaSO4 (1.66 wt%). Using thermal analyses methods, the operating conditions such as temperatures and partial pressures, were optimized for seasonal thermochemical storage applications to PHy = 1.3 kPa and ϑHy = 40 °C, and to PDe = 4.0 kPa and ϑDe = 110 °C. Under these conditions, the reaction reversibility over 10 cycles (10 years) was significantly high, with only 8.5% decrease in chemical reversibility. Furthermore, the duration of dehydration and hydration isotherms was optimized to 15 and 360 min, respectively. Finally, 1.129 GJ/m3 energy storage density was calculated after the tenth cycle of hydration/dehydration for this material. Hence 7.1 m3 of carnallite was estimated to meet the demand of 8 GJ of energy for an average household during the six months of cold seasons. These results are comparable and competitive with an energy storage density of materials such as K2CO3 and MgCl2, reported as promising for seasonal thermochemical storage applications. It should be noted that carnallite- waste material has no commercial value so far and its use contributes to developing sustainable low-cost thermochemical energy storage systems