Food Waste to Bioenergy

Abstract

Bioenergy is a renewable energy that can be generated from feedstock of biological origin. The use of bioenergy is key to mitigate the problem of excessive greenhouse gas (GHG) emission, to minimize the use fossil fuels and to provide national energy security. Bioenergy will be the significant source of renewable energy for the next several decades until the solar or wind power becomes an economically attractive for large-scale production (Nallathambi Gunaseelan, 1997). Food wastes include food preparation waste, leftover/residual foods from households and commercial establishments such as restaurants and market, institutional sources like school cafeterias, and industrial sources like food processing factories and factory lunchrooms, etc. Food waste is a highly biodegradable organic fraction of municipal solid waste (OFMSW) and is the major source of odor emanation, leachate, toxic gas emission and groundwater contamination (Kim et al., 2004). In light of rapidly rising costs associated with energy supply and waste disposal, and increasing public concern with environmental quality, successful application of anaerobic digestion (AD) technology could provide an economical and an environmentally friendly means for bioenergy recovery from food wastes with simultaneous remediation of wastes. Thermochemical conversion technologies, such as combustion and gasification are not suitable due to relatively high moisture content of food waste (Cecchi et al., 1992; Edelmann et al., 2000). A high-solid digestion known as dry-digestion is discussed in Chapter 4. This chapter discusses the biochemical principle of AD and key affecting factors in AD design and operation, especially food wastes. Different AD processes and the current technology available are outlined. Some experience with advanced digestion processes in the US, Europe, Singapore and Korea are also shared. Future research direction is also outlined.