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

Thermal performance evaluation of bischofite at pilot plant scale

The selection of the proper thermal energy storage (TES) material for an application is crucial. On the one hand, these materials should have suitable thermal properties for the operational temperatures range of the systems they are planned to work for, such as thermal stability, high latent heat and high heat capacity. On the other hand, they should be available on the market and at low price. Besides, researchers have to bear in mind the importance of testing TES materials not only at laboratory scale but also at higher scale, since it has been demonstrated that some thermal characteristics are volume-dependant. In the present study, bischofite, a by-product obtained from the non-metallic industry in the North of Chile with desired thermal properties for mid-temperature applications (around 100 C), has been studied. A first analysis was performed in terms of comparing the thermal properties and cost of bischofite with other material previously studied as TES materials in order to evaluate its potential in both latent and sensible phases. Afterwards, a second analysis was experimentally performed in terms of testing bischofite at large-scale (204 kg) in a pilot plant facility. The experimental procedure consisted on several charging processes within two different temperatures ranges: from 50 C to 80 C and from 80 C to 120 C in order to study the behavior of the material in the sensible solid phase and latent phase respectively. The temperature profiles, the power given by the HTF, the energy balance in the storage system and the accumulation energy rate of the bischofite were analyzed. Results of both analysis showed that bischofite has potential as TES material for mid-temperature applications.The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under Grant agreement n PIRSES-GA-2013-610692 (INNOSTORAGE). The work was partially funded by the Spanish government (Project ENE2011-22722). The authors would like to thank the Catalan Government for the quality accreditation given to their research group GREA (2014 SGR 123). The authors would like to acknowledge the collaboration of the company SALMAG. The authors acknowledge to FONDECYT (Grant No 1120422), CONICYT/FONDAP No 15110019, and the Education Ministry of Chile Grant PMI ANT 1201 for the financial support. Laia Miró would like to thank the Spanish Government for her research fellowship (BES-2012-051861). Andrea Gutierrez would like to thank to the Education Ministry of Chile her doctorate scholarship ANT 1106 and CONICYT/PAI NO 7813110010

Lithium in thermal energy storage: A state-of-the-art review

Lithium, mainly used in electrical energy storage, has also been studied in thermal energy storage. It is recognized as a "critical material" and is produced from minerals and from brines. Chile is one of the biggest producers, here from brine and with lower costs than in other countries. With sensible heat storage, in solar power plants lithium is seen as a way to improve the properties of molten salts used today. The low melting point in these ternary salts with lithium, represent a considerable reduction in the maintenance and operational costs associated with current solar technology, demonstrating that the fluids showed, are potential candidates for TES in CSP plants. Many materials have been studied and proposed to be used as PCM. Between the multiple materials studied to be used in PCM, lithium materials and mixtures are listed as potential PCM for building applications and for high temperature applications. In thermochemical energy storage, lithium compounds have been used mainly in chemical heat pumps, following their use in absorption cooling