Resource utilization of spent coffee grounds into eco-friendly phase change composite for thermal energy storage applications


Gasimova G., Kuzu İ., Alhas A. G., Tunçel E., COŞKUNER FİLİZ B.

Environmental Science and Pollution Research, 2026 (Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s11356-026-37428-1
  • Dergi Adı: Environmental Science and Pollution Research
  • Derginin Tarandığı İndeksler: Scopus, IBZ Online, ABI/INFORM, BIOSIS, Compendex, Environment Index, Geobase, MEDLINE
  • Anahtar Kelimeler: Eco-friendly composite, Phase change material, Spent coffee grounds, Thermal energy storage, Waste valorization
  • Yıldız Teknik Üniversitesi Adresli: Evet

Özet

Thermal energy storage systems have gained increasing attention in recent years as effective solutions for improving energy efficiency and promoting sustainability. In this study, an eco-friendly phase change material (PCM) composite was developed by upcycling spent coffee grounds (SCG) into a value-added thermal energy storage material. SCG were employed as a natural supporting matrix, while a eutectic mixture of lauric acid (LA) and stearic acid (SA) with a mass ratio of 70:30 served as latent heat storage component. The composite was prepared by using a vacuum impregnation method. To determine the optimal PCM loading, the LA–SA content was varied between 10 and 70 wt%, and a maximum stable loading of 30 wt% was identified based on leakage performance. The leakage behavior, morphological structure, chemical composition, and thermal properties of composites were systematically investigated by leakage tests, FTIR, XRD, DTA/TG, and DSC analyses. 5%CuO@e-PCMC coded composite showed an effective heat storage efficiency (E), relative thermal storage efficiency (μ), and enthalpy efficiency (λ) as 9%, 80%, and 0.1, respectively. Thermal analysis tests confirmed that the composite structure remained stable without significant degradation over repeated phase change cycles. The results demonstrated that the developed SCG-based PCM composite was a cost-effective and an environmentally friendly candidate for low-temperature thermal energy storage applications, particularly in 33–36 °C range, making it well suited for textile and thermal comfort applications. The ability of SCG to stably accommodate up to 30 wt% of the LA–SA eutectic mixture highlighted their potential as a sustainable and natural alternative supporting material for thermal energy storage and thermal management systems.