Compatibility of materials for macroencapsulation of inorganic phase change materials: Experimental corrosion study

Abstract

The potential of the use of salt hydrates MgCl 2 •6H 2 O (bischofite) with typical impurities of the Salar de Atacama as a thermal energy storage material was evaluated with special attention to its corrosion behavior. Bischofite behavior is compared with that of commercial salt MgCl 2 •6H 2 O. The corrosion tests were conducted with metal sheets (copper, aluminum and stainless steel) partially immersed in molten salt hydrates at a temperature of 120°C during 1500 hrs. The results showed minimum corrosion on all the immersed surfaces of all the metals. However, very sever corrosion was observed at the salt/air interface due to a known phenomenon of oxygen enhanced corrosion usually found even with water at ambient temperature. The corrosion products were determined with scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique. For salts hydrates bischofite and MgCl 2 •6H 2 O, the results show the formation of cuprite (Cu 2 O) and hematite (Fe 2 O 3) on copper and stainless steel samples, respectively. For all cases studied in the present work, several chloride compounds were identified as corrosion products.

Development of composition formulations, based on natural bischofite, to protect wood from fire

“…Owing to its unique properties, bischofite is widely used in housing and communal services [12], medicine [11,13], chemical industry [10,14,15], in agriculture [16,17]. Bischofite is also used as a refrigerant and an antifreeze agent, for applying road coatings, as a chemical stabilizer for granulated pavement [18], an anticorrosive agent [19,20], a means to store thermal energy [21][22][23][24][25][26], etc.…”

Macro-Encapsulation of Inorganic Phase-Change Materials (PCM) in Metal Capsules

“…Both metals do not seem to be resistant to corrosion in the present form but there is no detailed information about the applied alloys. Ushak et al [ 3 ] have investigated the corrosion behaviour of stainless steel (316L), aluminium (alloy 1100) and copper (C11000) in contact with MCHH up to 1500 at 120 . In contrast to the studies of El-Sebaii et al [ 5 ] the metal samples have not been completely submerged in the PCM to get information about the behaviour at the liquid-gas interface.…”

“…As drawbacks, non-metallic PCMs have comparatively low thermal conductivities and a considerable volume expansion due to the phase-change [ 1 ]. Furthermore, interactions between the PCM and the TES container have to be considered, especially when combining inorganic PCMs and metallic materials [ 2 , 3 , 4 , 5 ]. Encapsulation has been realised for a lot of different PCMs, application temperatures and capsule materials to overcome the mentioned challenges [ 6 , 7 , 8 ].…”

Comprehensive investigation of butyl stearate as a multifunctional smart concrete additive for energy‐efficient buildings

“…There are studies on corrosion of PCM in contact with metallic containers such as copper, aluminium, carbon steel, and stainless steel . These studies are based on weight loss method .…”

“…There are studies on corrosion of PCM in contact with metallic containers such as copper, aluminium, carbon steel, and stainless steel. [12][13][14][15][16][17] These studies are based on weight loss method. 18 There are also corrosion studies on different admixtures and inhibitors in concrete [19][20][21][22][23][24][25] mortars under wet and dry exposures to chloride solutions, but there are no studies using a combination of electrochemical impedance spectroscopy (EIS), energydispersive X-ray (EDX), and solution assay analysis to particularly determine the corrosive effect of BS in reinforced concrete.…”