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Waste-to-energy facilities produce clean, renewable energy through the combustion of municipal solid waste in specially designed power plants equipped with the most modern pollution control equipment to clean emissions. Trash volume is reduced by 90% and the remaining residue is regularly tested and consistently meets strict EPA standards allowing reuse or disposal in landfills. There are 89 waste-to-energy plants operating in 27 states managing about 13 percent of America’s trash, or about 95,000 tons each day. Waste-to-energy generates about 2,500 megawatts of electricity to meet the power needs of nearly 2 million homes, and the facilities serve the trash disposal needs of more than 36 million people. The $10 billion waste-to-energy industry employs more than 6,000 American workers with annual wages in excess of $400 million.
Why is waste-to-energy clean?
America’s waste-to-energy facilities meet some of the most stringent environmental standards in the world and employ the most advanced emissions control equipment available. The EPA announced that America’s waste-to-energy plants produce "dramatic decreases" in air emissions, and produce electricity "with less environmental impact than almost any other source of electricity." The "outstanding performance" of pollution control equipment used by the waste-to-energy industry has produced "dramatic decreases" in emissions. EPA data demonstrate that dioxin emissions have decreased by more than 99% in the past ten years, and represent less than one-half of one percent of the national dioxin inventory. Mercury emissions have declined by more than 95% and now represent less than two percent of the nation’s man-made mercury emissions. Additionally, EPA estimates that waste-to-energy technology annually avoids 33 million metric tons of carbon dioxide, a greenhouse gas that would otherwise be released into the atmosphere.
Communities served by these facilities recycle an average of 35% of their trash as compared with the national recycling rate of 30%. Waste-to-energy annually removes for recycling more than 700,000 tons of ferrous metals and more than 3 million tons of glass, metal, plastics, batteries, ash and yard waste at recycling centers located on site.
Why is waste-to-energy renewable?
For more than twenty years, waste-to-energy has been recognized as a source of renewable energy under existing law. Waste-to-energy is a "clean, reliable, renewable source of energy," according to the U.S. EPA. The Federal Power Act, the Public Utility Regulatory Policies Act, the Federal Energy Regulatory Commission’s regulations, and the Biomass Research and Development Act of 2000 all recognize waste-to-energy power as renewable biomass, as do fifteen states that have enacted electric restructuring laws. EPA estimates 75% of trash contains biomass on a Btu-output basis. Turning garbage into energy makes "important contributions to the overall effort to achieve increased renewable energy use and the many associated positive environmental benefits," wrote Department of Energy Assistant Secretary for Energy Efficiency and Renewable Energy, David Garman.
What makes waste-to-energy reliable?
Waste-to-energy plants supply power 365-days-a-year, 24-hours a day. Facilities average greater than 90% availability of installed capacity. Waste-to-energy plants generally operate in or near an urban area, easing transmission to the customer. Waste-to-energy power is sold as "base load" electricity. There is a constant need for trash disposal, and an equally constant need for steady, and reliable energy generation. Waste-to-energy promotes energy diversity while helping cities meet the challenge of trash disposal.
How does waste-to-energy produce clean energy from dirty garbage?
Waste-to-energy facilities achieved compliance in 2000 with new Clean Air Act pollution control standards for municipal waste combustors. More than $1 billion was spent to upgrade waste-to-energy facilities, leading EPA to write that the "upgrading of the emissions control systems of large combustors to exceed the requirements of the Clean Air Act Section 129 standards is an impressive accomplishment." In addition to combustion controls, waste-to-energy facilities employ sophisticated pollution control equipment.
- A "bag house" works like a giant
vacuum cleaner with hundreds of fabric filter bags that
clean the air of soot, smoke and metals.
- A "scrubber" sprays a lime slurry
into the hot exhaust. The lime neutralizes acid gases, just
as a gardener uses lime to neutralize acidic soil. Scrubbing
also can improve the capture of mercury in the exhaust.
- "Selective Non-Catalytic Reduction"
or "SNCR" converts nitrogen oxides – a cause of urban smog –
to harmless nitrogen by spraying ammonia or urea into the
- "Carbon Injection" systems blow charcoal into the exhaust gas to absorb mercury. Carbon injection also controls organic emissions such as dioxins.
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Since the late 1800’s the City/State of Hamburg, Germany has been incinerating its municipal solid waste. This method of dealing with MSW was introduced following a cholera outbreak and the recognition that poor waste management had been a major contributor. Throughout the 20th century the mass burning of refuse increased across Germany and the rest of the world.
As technology improved, the power produced from the mass burning of MSW was captured and used for power and steam. Waste to Energy (WTE) became the common way of referring to this process. Germany has done more than any other country in the world to develop the most modern and sophisticated WTE processes. In fact, no landfilling will be allowed beyond 2020 in Germany and the European Community is expected to enact a similar ban.
Today there are over 90 waste to energy facilities in the United States, although none have been built in the last ten years. The lack of new facilities has primarily been driven by the low cost of oil and coal. It has been cheaper to use these dirtier power producing fuels than to invest in alternative technologies such as WTE. Many cities/counties kept tipping fees to artificially low levels due to existing landfills often belonging to their municipalities. Today, all large WTE facilities built before the 1990’s have all been retrofitted to meet the most stringent air quality standards applied by the EPA. WTE have no soil or groundwater discharges therefore soil or groundwater regulations do not apply. In comparison air quality standards for landfills are much more lenient. Despite best efforts through discharge collection systems and new more robust liner materials "all landfills leak" (EPA) and therefore have soil and groundwater contamination.
Rising oil prices, failing landfills, global warming and poor air quality have all contributed to a resurgence in WTE technology. The most sophisticated WTE systems in the world are from European countries such as Germany, Denmark and The Netherlands. Decades of building and utilizing WTE plants have resulted in the finest and most up to date methods emanating from these countries. The most sophisticated facility to date emerged from Hamburg, Germany in 1999 fueled by the German Green Party demanding that only the highest standards be achieved by this industry. Continuous enhancements keep this facility leader in the WTE/Thermal Recycling industry.
This facility is known as MVR which was commissioned in 1999. It is very unique in the manner the flue-gas-control system operates. Not only are pollutants from the boiler and fly ash removed, it also produces high quality hydrochloric acid in the process.
The result is an incredibly clean Thermal Recycling process.
During the process of turning waste into energy 99% of the MSW is transformed into commercial end products. The products produced through the MVR process include ferrous and non-ferrous metals for recycling, hydrochloric acid @ 30% or higher, gypsum more pure than mined gypsum, mixed salts and bottom ash for numerous construction applications.
Slag (Schlacke) and Metal (Schrott)
processing on site
Bottom Ash Hall (Storage)
Bottom Ash (Close up)
Samples of Bottom Ash by Size (for different applications)
Construction with Bottom Ash (Bearing Layer)
Bottom Ash (Bearing Layer of the Hamburg Fire Brigade School)
Bottom Ash (Bearing Layer of Shopping Mall)
Bottom Ash (450,000 metric tons serve as Bearing Layer for Most Modern Container Terminal in the World - 3 Million TEUs Annually)
Bottom Ash (Container Terminal 2 - Bearing Layer - 3 Million TEU's Annually)
The one percent remaining (boiler and fly ash) is mixed into the concrete used in abandoned salt mines (other applications are possible).
MVR produces significant amounts of steam and electricity for industrial and municipal use.
WRSI is the exclusive representative for the MVR technology in the Americas. There is no technology in the world that offers municipalities the array of benefits that MVR affords.
For additional information please view the Question/Answer section
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Alternative Technologies for Dealing with MSW:
In addition to landfilling and Thermal Recycling and conventional WTE there are two other technologies available for dealing with MSW: Pyrolysis and Gasification. Approximately 200 plants and test facilities have been built in the last twenty years. Very few plants remain in operation today. These technologies have proven uneconomic and undependable in dealing with quantities of any consequence. Industry may find solutions for these technical shortcomings over the next couple of decades, however at this time their commercial use is limited.
Pyrolysis is used for the conversion of MSW biomass into liquids. This process burns wet MSW in an oxygen and water free environment. It generates substantial amounts of condensable hydrocarbons which make operating the plant difficult and inefficient. The solids resulting from the pyrolysis process are highly contaminated and are high in carbon thus making the solids unsuitable for landfilling without further treatment. Additional processing required consumes more energy than the pyrolysis produces, thus negating commercial viability.
The use of the pyrolysis condensate from waste pyrolysis for upgrading and production of special oils etc. was tested in many different ways. All failed because inefficient technical performance could not guarantee the pureness of the product. This resulted in poor economic performance with the outcome that the operational costs were several times higher than the gain.
The use of pyrolysis gas and condensate for thermal use with combustion
needs an additional reactor which adds to the price tag significantly.
Direct combustion is far more efficient than pyrolysis.
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Gasification is a process that uses heat, pressure and steam to convert materials directly into a gas composed primarily of carbon monoxide and hydrogen. Typical raw materials used in gasification are coal, petroleum-based materials and organic materials. The feedstock is prepared and fed, in either dry or slurried form, into a sealed reactor chamber called a gasifier. Most commercial gasification technologies do not use oxygen. All require an energy source to generate heat and begin processing.
Hydrocarbon build up in the flue gas of these plants is a significant technical problem. This has been the main contributor to plant failures. Theoretically the power production of a gasification plant can be higher than that of a combustion plant although this has never been achieved. This process requires heterogeneous waste input which means that a great deal of sorting must be done at the front end. The combined cost of the requirements to operate gasification has made it commercially unviable.
Unless significant higher fees are paid for the treatment of waste such as in Japan ($300 to $1000) neither gasification nor pyrolysis are economically viable.
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Limited technology (landfills)
Today the number one competition to WTE is landfilling. WTE and landfilling compete in different areas and on different levels. One can differentiate between region, governmental regulations, political and public perception, and economic perception all on a local, state and/or nationwide level.
Today’s landfill practices incorporate state of the art landfill technology – however, when compared to WRSI’s thermal recycling technology it is completely outdated.
Environmental activists dislike landfills not only because of the potential for pollution, but because they permanently remove various raw materials from economic use. All of the energy and natural resources that went into the manufacturing process of a disposed of item are "wasted" and not conserved. This is said to contribute to damage of forests, and agricultural areas, including in less-developed countries that derive a majority of their export revenues from raw material.
Methane is 21x more potent than CO2
One million tons of Municipal Solid Waste (MSW) treated in a modern WTE facility and not landfilled will release 500,000 tons less CO2 into the atmosphere.
WTE CH4 and CO2 releases:
Landfill CH4 and CO2 releases:
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