Restaurant waste treatment and management

Restaurant waste is composed of solid and liquid waste. The solid waste stream includes food waste, plastics, paper and paperboard, while the liquid waste stream includes fats, oils, and grease (FOG). In the United States, in 2012, 36 million tons of food waste was generated and only 1.7 million tons were recycled. Approximately 20% of the prepared food in the United States ends up as waste. Of the total waste stream from restaurants, over 50% is food waste. This chapter discusses how restaurant waste can be reduced or recycled. Solid restaurant waste can be reduced through food recovery techniques such as food source recovery, food donation, food scraps for animal food, and food scraps for industrial uses. Food waste from restaurant can be used to produce methane from anaerobic digestion (two-stage and 184single high-rate digesters including egg-shape digesters), synthetic gas (syngas) from biomass gasification (fixed bed, fluidized bed, and plasma processes), and hydrogen by fermentation (biohydrogen production). Another industrial use of food waste is the production of compost through windrows or forced air composting processes. Restaurant and hotels generate over 3 billion gallons of waste cooking oil per year. Ideally, the waste oil can be collected and converted to biodiesel fuel by transesterification process. Some restaurant wastes from cruise ships can also be recycled for reuse. The current restaurant waste treatment and management practice on board modern cruise ships is introduced in this chapter.