Development and Characterization of Composite Desiccant Impregnated with LiCl for Thermoelectric Dehumidifier (TED)

Abstract

Aqueous salt solutions (LiCl) were impregnated into a porous host matrix to create composite desiccant materials (silica gel). The authors of this paper fabricated and analyzed composite desiccant-coated aluminum sheets (DCAS) with varying LiCl mass concentrations. Nitrogen sorption results revealed that the Brunauer–Emmett–Teller (BET) surface area and pore volume of the composite desiccant-coated aluminum sheets decreased. Furthermore, composite DCAS had lower nitrogen sorption than silica-gel-coated aluminum sheets (SGCAS). According to the results, the composite DCAS had the highest thermal conductivity, measuring 6.1 Wm−1 K−1, doubling that of the SGCAS. For evaluating sorption kinetics, the linear driving force model (LDF) was used, and composite DCAS showed greater dynamic sorption quantities and sorption rate coefficients than SGCAS. Furthermore, three different moisture sorption isotherm models were used to fit the experimental results: the Brunauer–Emmett–Teller (BET) model, the Guggenheim–Anderson–Boer (GAB) model, and the double log polynomial (DLP) model. The DLP model was shown to be the best model for predicting the moisture sorption isotherms of DCAS. Additionally, the composite desiccant-coated heat sink (DCHS) of the thermoelectric dehumidifier (TED) was evaluated and compared to silica gel in terms of dehumidification capacity. According to the findings, the outlet air humidity ratio of the composite DCHS reached a minimum of 10.23 g kg−1, and the dehumidification capacity was 0.117 kg h−1 when the input electrical voltage was kept at 9 V.