Production and experimental characterization of homogeneous and composite briquettes from fruit processing waste

Abstract

Growth in agricultural produce processing continues to drive up energy consumption and contributes significantly to climate change. Fruits, in particular, are processed to enhance their market value and extend their shelf life; however, fruit processing generates substantial amounts of organic waste, creating a waste management challenge despite its potential as a renewable energy resource. This study focused on converting orange, mango, and jackfruit waste into briquettes using cassava starch, cornstarch, and clay as binders, all locally available. A manual lever press was employed for compaction to produce both homogeneous and composite briquettes. The briquettes were then evaluated for their physical, chemical, mechanical, and thermal properties at varying binder concentrations. Moisture content, volatile matter, fixed carbon, and ash content were analyzed using thermogravimetric analysis. Calorific values were determined using bomb calorimetry. Mechanical strength was assessed using compressive strength and drop strength tests, while thermal performance was evaluated through water boiling tests and burning rate measurements. Fixed carbon ranged from 22.87% to 62.06%, ash content from 6.55% to 57.20%, volatile matter from 15.71% to 39.41%, and moisture content from 4.21% to 13.66%. Calorific values ranged from 17.55 to 32.24 MJ/kg. Compressive strength varied from 0.125 to 0.471 N/mm², bulk density from 413.21 to 580.1 kg/m³, and drop strength from 27.74% to 88.84%. The study confirms that jackfruit, orange, and mango waste are viable biomass feedstock for briquette production. Among the binders tested, cassava starch consistently yielded briquettes with superior mechanical and thermal properties, making it the binder of choice for optimizing performance in small-scale briquette production systems.