Thermogravimetric Analysis of Individual Food Waste Items and their Blends for Biochar Production

Abstract

Food waste is generated in enormous quantities globally. Due to its organic- and nutrient-rich composition, food waste is a potential feedstock for the production of energy and value-added products. In many countries, food wastes are currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy, but these two approaches are facing more and more economic and environmental pressures. Moreover, food waste can be converted into energy using waste to energy technologies. The use of thermochemical technologies has become an acceptable practice that is undergoing widespread research. The ultimate goal of the current research work is to produce value-added biochar products from food waste, hence providing an option to tackle the previously addressed problems of effective waste management. Prior to the production of biochars, three selected food items are studied under Thermogravimetric analysis (TGA). The analysis involves the single food items, a binary mixture, and a blend of the three. The studied food wastes are tomatoes, cucumbers, and carrots. Moreover, TGA revolves around measuring the weight of sample continuously in a controlled temperature program. This, in turn, allows the physical and chemical properties of the sample to be obtained based on the variation of sample weight with respect to time and temperature using the DTG curve resulting from a differential TGA curve. The TGA technique can be helpful in determining the proximate analysis of food waste and to find out the thermal characteristics like ignition, burnout temperature and chemical kinetics of food waste by using the pyrolysis process. The results of TGA are of key importance as they suggest the thermal degradation patterns of food waste, and bio-char under air or an inert environment for succeeding kinetic studies. The configurations explain the response of heating rate, food waste properties, stability and compatibility of food waste to different processes. Furthermore, the results of the different experimental runs and TGA modelling are presented, analyzed and discussed. Very little information is available on the pyrolysis and understanding of individual food waste components.