Sustainable Insulation Materials: Design and Performance Evaluation of Periwinkle Shell–Clay Composites in Improved

Recent improved biomass cookstoves have shown superior efficiency compared to conventional three-stone models, driving research interest in enhancing their thermal performance through material optimization. This study investigates the use of a 75:25 blend of clay and periwinkle shell as an alternative insulating material in the design and construction of an improved biomass stove. Key performance evaluation parameters: heat transfer efficiency, specific fuel consumption, wood consumption rate, boiling time, and firepower were evaluated using the University of California, Berkeley (UCB)/Shell Foundation Water Boiling Test (WBT) 4.1.2, in compliance with ISO/IWA/VITA standards. The results revealed significant improvements, showing a mean thermal efficiency of 33.5%, compared to 16% for traditional stoves, representing a 36.84% improvement. The average time to boil 5 litres of water was 24 minutes, with a mean wood consumption rate of 8.63 g/min and firepower ranging from 2.1 to 3.0 kW. The addition of a secondary air inlet in the combustion chamber enhanced combustion, heat retention, and firepower, confirming the stove’s suitability for domestic use. Future research should explore different mixing ratios of insulating materials to further optimize stove performance.