Thermochemical transformation of biowaste for encapsulation technology and enabling a circular economy

Background: Global warming, resource limitations, and rapid industrialization necessitate the development of renewable energy infrastructure. Upcycling waste biomass into high-value materials has also been pursued as a global agenda for environmental waste management and energy applications. Thermal energy storage based on phase-change materials (PCMs) possesses high energy storage capacity and contributes to reducing greenhouse gas emissions. However, the leakage of PCMs restricts their applications. This can be overcome by encapsulating PCMs in value-added materials with high energy efficiency, carbon neutrality, and which promotes circular economy. Scope and approach: This review systematically discusses the thermochemical conversion of biowaste into useable products and its application in encapsulation technologies. This study focused on the development of phasechange composites using biowaste-derived carbon and PCMs for high thermal-energy storage and help to reach the UN's Sustainable Development Goals (SDGs). Key findings and conclusions: Phase-change composites show high-energy storage capacity, and it is essential to prepare high-quality carbonaceous materials with large surface areas and morphologies. The encapsulation of PCMs and carbon materials upgraded the thermal and physicochemical properties but inescapably reduced the total thermal energy storage density of the composite. They are practically viable for ensuring a continuous energy supply, indoor temperature control, and environmental remediation.