Effective Separation of a Water in Oil Emulsion from a Direct Contact Latent Heat Storage System

Abstract

The problem of emulsification between Phase Change Material (PCM) and Heat Transfer Fluid (HTF) in direct contact latent heat storage systems has been reported in various studies. This issue causes the PCM to flow out of the storage tank and crystallize at unwanted locations and thus presents a major limitation for the proper operation of such systems. These anomalies become more pronounced when high HTF flow rates are employed with the aim to achieve fast heat transfer rates. The goal of this paper is to find a method which will enable the fast separation of the formed emulsion and thus the uninterrupted operation of the storage unit. In this study, three separation methods were examined and the use of superhydrophobic filters was chosen as the best candidate for the demulsification of the PCM and HTF mixtures. The filter was produced by processing of a melamine sponge with different superhydrophobic adhesives and was tested with emulsions closely resembling the ones formed in a real direct contact setup. The superhydrophobic filter obtained, was able to separate the emulsions effectively while presenting a very high permeability (up to 1,194,980 kg h−1 m−2 bar−1). This is the first time the use of a superhydrophobic sponge has been investigated in the context of demulsification in direct contact latent heat storage.

Rheological Characterization of Emulsified Bitumen from Industrial Waste

“…Figure 4: Heat change analysis of formulated bitumen emulsions and ATLAS bitumen Additionally, from Figure 4, as the bitumen percentage increases from EMB01 to EMB05, the absolute ΔH value ((|ΔH|) of heat change increases as a higher content of bitumen can withstand higher temperatures. Heat change indicates the energy required for demulsification [19]. The higher the absolute ΔH value ((|ΔH|) of heat change from EMB01 to EMB05, the higher the energy required for demulsification.…”

Experimental Investigation on the Droplet Stability of Superhydrophobic Mesh

“…For example, when a large droplet impacts a superhydrophobic mesh array, monodisperse droplets will be generated, which is useful in microfluidic engineering, materials science, and drug production. A superhydrophobic mesh could be an efficient approach to separate oil from water [29][30][31]. It could be used to enhance the water collection rate from the atmosphere and fog via a superhydrophobic mesh [32].…”