Novas tecnologias na produção de eletricidade

New WTE Technologies Turn Trash into Treasure - ASME

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ASME

New WTE Technologies Turn Trash into Treasure
May 2013

Municipal solid waste (MSW) is a vast, renewable resource that contains high amounts of energy—the trick is designing an extraction system that is efficient and cost-effective. This kind of sustainable waste management —typically called waste-to-energy (WTE)—is critical for reducing our dependence on fossil fuels and non-renewable materials and improving our environment.

The standard WTE approach is incineration—after materials are removed that interfere with the combustion process, the remaining MSW is transported to the combustion chamber, where it is burned, creating hot gases. These by-products are collected in the boiler section above the combustion chamber. Here the water is converted to steam, which powers an electric generator. The cooled combustion gases are then passed through pollution control devices before being released to the atmosphere.

Today in the U.S. 87 WTE facilities produce a total annual generation capacity of 2.6 GW of electricity. Most of these aging facilities were built in the mid-1980s and early 1990s. As stricter emissions requirements were enacted that required more expensive pollution control equipment, new WTE projects dropped off. Energy prices and landfill disposal costs also fell in the mid-1990s, making WTE plants even less cost-competitive. Even though WTE facilities, when outfitted with top-notch air pollution control equipment, produced significantly cleaner electricity compared to coal or oil, no new WTE capacity was added in the U.S from the mid-1990s to mid-2000s. WTE simply could not compete against landfills, where Americans continue to send most of their non-recycled waste today.

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