Thermal properties of biomass-based form-stable phase change material for latent heat thermal energy storage

Considering platane wood as a kind of natural biomass building material, it features a structure with abundant pores and lightweight, which can be used as a supporting material to prevent the liquid leakage of phase change materials (PCMs). In this work, the lignin of the platane wood is removed, and then, a series of the form-stable PCMs (FSPCMs) are prepared by the vacuum impregnation method, for which implemented the delignified wood (DW) as a supporting material and four kinds of fatty acid (FA) as PCMs. The microstructure and thermophysical characteristics of the FSPCMs are investigated. Furthermore, the results show that DW preserves the inherent porous structure of the platane wood, and the specific surface area and total pore volume of DW are greater than those of the platane wood. Thus, the DW adsorbs more PCMs than platane wood by the physical connection. The maximum impregnation rate of FA in the DW is as high as 76 wt%. There is a little variation in the phase change temperature of DW/FA FSPCMs compared with that of the FA, while the latent heat of DW/FA FSPCMs is almost consistent with the content of FA in the composite. Thermogravimetric analysis results show that DW/FA FSPCMs present good thermal stability. Moreover, DW/FA FSPCMs have good thermal reliability after 500 thermal cycles. Therefore, the prepared DW/FA FSPCMs show a potential application prospect in the thermal energy storage system.