Biochar development from thermal TGA studies of individual food waste vegetables and their blended systems

Abstract

Abstract The amount of food waste that is generated all over the world is enormous. As food wastes are rich in nutrients and organics, they serve as a potential source for the generation of many value-added commodities and energy. In most countries, food wastes are predominately dumped in open lands or incinerated, along with other combustible materials such as municipal solid wastes, for the possible extraction of energy. However, these two modes of food wastes disposal are encountering more and more environmental, technical, and economical challenges. More recently, it has been realized that food wastes can be transformed into energy and value-added products, such as horticultural biochars, using thermochemical technologies such as pyrolysis and gasification. In the current research work, three selected food items, carrots, cucumbers, and tomatoes, have been studied using thermogravimetric analysis. The biochar analysis involves one single food item (carrot), one binary mixture (carrot + cucumber), and one ternary blend of carrot, cucumber, and tomato. Two heating rates were used in order to perform kinetic modeling studies using the Arrhenius and Coats-Redfern models. Since the production of the pyrolysis gases—for energy and chemicals production—is of major economic significance regarding the overall process viability, the TGA syngas for a single component, binary component and tertiary component systems were analyzed by TGA coupled mass spectrometry. The results of the gas analysis indicate an increase in hydrogen generation due to blending the food wastes.