Life cycle environmental assessment of thermal waste-to-energy technologies and energy–environment–economy model development
Résumé
Stimulated by dwindling reserves of fossil fuels and sustainable energy production, Waste-to-energy (WtE) has started playing an increasingly important role in the recovery of energy from municipal solid waste (MSW). A number of WtE technologies, such as pyrolysis, gasification, and incineration, are being developed. However, selecting a more environmentally sustainable option is still made difficult, and comprehensive comparisons of the existing WtE technologies are fairly rare. In this chapter, the development of different WtE technologies, in particular for pyrolysis and gasification, is introduced. This is followed by a life cycle assessment assessing the environmental sustainability of different WtE technologies. First, seven potential WtE systems involving thermal conversion (pyrolysis, gasification, incineration) and energy utilization (steam cycle, gas turbine/combined cycle, internal combustion engine) are modeled as a theoretical analysis. The results are then compared with four types of commercial plants (incineration, pyrolysis, gasification, gasification-melting) as a case study. The establishment of a life cycle Energy–Environment–Economy model is discussed, as well as a case study comparing landfill (with and without landfill gas recovery) and incineration MSW treatment technologies. Finally, the future prospects for developing WtE technologies are discussed.