Contents:
2. Energy Recovery
2.1 Anaerobic Digestion
2.2 Refuse Derived Fuel (RDF)
2.3 Waste-to-Energy (WTE)
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| Spittelau Waste-to-Energy Plant, Source: josylein |
2. Energy Recovery
Energy requirements of a community can be satiated to some extent by energy recovery from wastes as a better alternative to landfilling. Energy recovery is a method of recovering the chemical energy in MSW. Chemical energy stored in wastes is a fraction of input energy expended in making those materials. Due to the difference in resources (materials/energy) that can be recovered, energy recovery falls below material recovery on the hierarchy of waste management.
2.1 Energy and Material Recovery: Anaerobic Digestion (AD)
Other names: Anaerobic Composting, Biogas, Biomethanation
The USEPA defines Anaerobic Digestion (AD) as a process where microorganisms break down organic materials, such as food scraps, manure and sewage sludge, in the absence of oxygen. In the context of SWM, anaerobic digestion (also called Anaerobic Composting or Biomethanation) is a method to treat source separated organic waste to recover energy in the form of biogas, and compost in the form of a liquid residual. Biogas consists of methane and carbon dioxide and can be used as fuel or, by using a generator it can be converted to electricity on-site. The liquid slurry can be used as organic fertilizer. The ability to recover energy and compost from organics puts AD above aerobic composting on the hierarchy of waste management.
