Food waste to biochars through pyrolysis: A review

Waste generated from anthropogenic activities contributes toward stresses on our natural systems through impacts associated with both production and disposal. Sustainable waste management necessitates that industries shift from the current linear model to a circular based economy, utilizing wastes as raw materials for the production of new products, eg. fuels and chemicals. Biomass and associated waste materials can be converted into value-added products using thermochemical processes. The pyrolysis process is a convenient thermochemical method, whereby biomass is efficiently converted into biofuels, biochars and BBQ briquettes; and further processing yields additional value added products, such as activated carbons, carbon black and printing ink. This paper reviews current development work and evaluates potential opportunities for food waste pyrolysis focusing on the conversion of food waste to biochar products. Overall, it was found that the constituents of the food waste together with the process conditions play a major role in the yield and composition of the produced chars. Moreover, more research work needs to be conducted on food waste to biochar and on mixed food blends in particular.