Chapter 1 - Introduction

Abstract

Food waste is a major global problem that has far-reaching implications related to energy, water and land use, greenhouse gas emissions and economic losses. The origins of food waste can be attributed, at least in part, to changing perceptions of the societal value of food, and now losses of edible food materials are observed across the entire farm-to-fork spectrum, from agriculture to food processing, distribution, and consumption. Although most waste occurs at consumer-facing businesses and households, at these stages the waste materials are relatively heterogeneous and dispersed, and thus difficult to divert to productive use. Widely promoted food recovery hierarchies place the highest value on providing excess food for human or animal consumption, but a relatively small fraction of the total waste volume is suitable for these uses. Waste-to-energy conversion methods, including anaerobic digestion, fermentation, transesterification, bioelectrochemical systems, gasification and pyrolysis, and hydrothermal liquefaction, may provide viable alternatives, but their environmental and economic performance must be rigorously evaluated at a system level. The optimal pathway is also dependent on the existing policy and regulatory framework, as well as factors that influence system deployment, such as waste feedstock transport and energy distribution logistics.