Incineration 216187 224431943 2008-07-08T20:35:47Z Claush66 704524 /* Moving grate */ {{for|other forms of waste plant that produce energy|waste-to-energy}} {{for|the fictional character named Incinerator|Incinerator (Transformers)}} [[Image:District heating plant spittelau ssw crop1.png|thumb|float|right|300px|Spittelau incineration plant in [[Vienna]].]] [[Image:Sopförbränningsanläggningen på Spillepengen, Malmö.jpg|thumb|float|right|300px|SYSAV incineration plant in [[Malmö]], [[Sweden]] capable of handling 25&nbsp;tonnes per hour household waste. To the left of the stack, a new identical oven line is under construction (March 2007).]] '''Incineration''' is a [[list of solid waste treatment technologies|waste treatment technology]] that involves the [[combustion]] of organic materials and/or substances.<ref> Knox, A. (2005) [http://www.oneia.ca/files/EFW%20-%20Knox.pdf Overview of incineration], An Overview of Incineration and EFW Technology as Applied to the Management of Municipal Solid Waste (MSW), University of Western Ontario, Canada</ref> Incineration and other high temperature waste treatment systems are described as "[[thermal treatment]]". Incineration of waste materials converts the waste into [[incinerator bottom ash]], [[flue gas]]es, [[particulate]]s, and [[heat]], which can in turn be used to generate [[electric power]]. The flue gases are cleaned of pollutants before they are dispersed in the [[atmosphere]]. Incineration with energy recovery is one of several [[waste-to-energy]] (WtE) technologies such as [[gasification]], [[Plasma arc gasification]], [[pyrolysis]] and [[anaerobic digestion]]. Incineration may also be implemented without energy and materials recovery. In several countries there are still expert and local community concerns about the environmental impact of incinerators (see [[#The_argument_against_incineration|The argument against incineration]]). In some countries, incinerators built just a few decades ago often did not include a [[material recovery facility|materials separation]] to remove hazardous, [[bulky waste|bulky]] or [[recycleable waste|recyclable]] materials before combustion. These facilities tended to risk the health of the plant workers and the local environment due to inadequate levels of gas cleaning and combustion process control. Most of these facilities did not generate electricity. Incinerators reduce the volume of the original waste by 95-96&nbsp;%, depending upon composition and degree of recovery of materials such as metals from the ash for recycling.<ref name=WtE_DK>[http://www.zmag.dk/showmag.php?mid=wsdps Waste to Energy in Denmark], publication by [[Ramboll]] (2006)</ref> This means that while incineration does not completely replace [[landfill]]ing, it reduces the necessary volume for disposal significantly. Incineration has particularly strong benefits for the treatment of certain [[waste types]] in niche areas such as [[clinical waste]]s and certain [[hazardous waste]]s where pathogens and toxins can be destroyed by high temperatures. Examples include chemical multi-product plants with diverse toxic or very toxic wastewater streams, which cannot be routed to a conventional wastewater treatment plant. Waste combustion is particularly popular in countries such as [[Japan]] where land is a scarce resource. [[Denmark]] and [[Sweden]] have been leaders in using the energy generated from incineration for more than a century, in localised [[combined heat and power]] facilities supporting [[district heating]] schemes.<ref>Kleis, Heron and Dalager, Søren (2004) [http://www.ramboll.dk/docs/eng/Press_Releases/Publications/Waste/100YearsofWasteIncinerationinDenmark.pdf 100 Years of Waste Incineration in Denmark], A historical review of incineration in Denmark</ref> In 2005, waste incineration produced 4.8&nbsp;% of the electricity consumption and 13.7&nbsp;% of the total domestic heat consumption in Denmark.<ref>[http://ens.dk/graphics/Publikationer/Statistik_UK/Energy_statistics_2005/index.htm Danish Energy Statistics 2005] by the Danish Ministry of Energy.</ref> A number of other European Countries rely heavily on incineration for handling municipal waste, in particular [[Luxemburg]], [[The Netherlands]], [[Germany]] and [[France]]. <ref name=WtE_DK>[http://www.zmag.dk/showmag.php?mid=wsdps Waste to Energy in Denmark], publication by [[Ramboll]] (2006)</ref> == Technology == ===Types of incinerators=== An incinerator is a [[furnace]] for burning [[waste]]. Modern incinerators include pollution mitigation equipment such as flue gas cleaning. There are various types of incinerator plant design: moving grate, fixed grate, rotary-kiln, fluidised bed. ====Moving grate==== [[Image:Leitstand 2.jpg|thumb|float|right|400px|Control room of a typical moving grate incinerator overseeing two boiler lines]] The typical incineration plant for [[municipal solid waste]] is a moving grate incinerator. The moving grate enables the movement of waste through the combustion chamber to be optimised to allow a more efficient and complete combustion. A single moving grate boiler can handle up to 35&nbsp;tonnes of waste per hour, and can operate 8,000&nbsp;hours per year with only one scheduled stop for inspection and maintenance of about one months duration<ref>[http://vestforbraending.dk/Om_VF/Tekniske_anlaeg/Anl%E6g_6_oktober_2004.pdf Vestforbrænding anlæg 6 - Danmarks største forbrændingsovn], Brochure (in Danish) on the largest incineration line in Europe, 2004</ref>. Moving grate incinerators are sometimes referred to as Municipal Solid Waste Incinerators (MSWIs). The waste is introduced by a [[Grab (tool)|waste crane]] through the "throat" at one end of the grate, from where it moves down over the descending grate to the ash pit in the other end. Here the ash is removed through a water lock. [[Image:Movinggrate.jpg|thumb|float|right|400px|Municipal solid waste in the furnace of a moving grate incinerator capable of handling 15&nbsp;tons of waste per hour. The holes in the grate elements supplying the primary combustion air are visible.]] Part of the combustion air (primary combustion air) is supplied through the grate from below. This air flow also has the purpose of cooling the grate itself. Cooling is important for the mechanical strength of the grate, and many moving grates are also water cooled internally. Secondary combustion air is supplied into the boiler at high speed through nozzles over the grate. It facilitates complete combustion of the flue gases by introducing [[turbulence]] for better mixing and by ensuring a surplus of oxygen. In multiple/stepped hearth incinerators, the secondary combustion air is introduced in a separate chamber downstream the primary combustion chamber. According to the European [[Waste Incineration Directive]], incineration plants must be designed to ensure that the [[flue gas]]es reach a temperature of at least 850&nbsp;°C for 2&nbsp;seconds in order to ensure proper breakdown of organic [[toxin]]s. In order to comply with this at all times, it is required to install backup auxiliary burners (often fueled by oil), which are fired into the boiler in case the [[heating value]] of the waste becomes too low to reach this temperature alone. The [[flue gas]]es are then cooled in the [[superheater|superheaters]], where the heat is transferred to steam, heating the steam to typically 400&nbsp;°C at a pressure of 40&nbsp;[[bar (unit)|bar]] for the electricity generation in the [[turbine]]. At this point, the flue gas has a temperature of around 200&nbsp;°C, and is passed to the [[#Flue gas cleaning|flue gas cleaning system]]. At least in [[Scandinavia]] scheduled maintenance is always performed during summer, where the demand for [[district heating]] is low. Often incineration plants consist of several separate 'boiler lines' (boilers and flue gas treatment plants), so that waste receival can continue at one boiler line while the others are subject to revision. ====Fixed grate==== The older and simpler kind of incinerator was a brick-lined cell with a fixed metal [[grate]] over a lower ash pit, with one opening in the top or side for loading and another opening in the side for removing incombustible solids called [[Clinker (waste)|clinkers]]. Many small incinerators formerly found in apartment houses have now been replaced by [[compactor|waste compactor]]s. ====Rotary-kiln==== The [[rotary dryer|rotary-kiln]] incinerator<ref>[http://www.hitemptech.com/downloads/HTTSolidWasteRotaryKilnQuotation.pdf Rotary-kiln incinerators] An excellent detailed description of rotary-kiln incinerators</ref> used by municipalities and by large industrial plants. This design of incinerators have 2 chambers a primary chamber and secondary chamber. The primary chamber in a rotary kiln incinerator consist of an inclined refractory lined cylindrical tube. Movement of the cylinder on its axis facilitates movement of waste. In the primary chamber, there is conversion of solid fraction to gases, through volatilization, destructive distillation and partial combustion reactions. The secondary chamber is necessary to complete gas phase combustion reactions The clinkers spill out at the end of the cylinder. A tall [[flue gas stack]], fan, or steam jet supplies the needed [[Flue gas stack#Flue gas stack draft (or draught)|draft]]. Ash drops through the grate, but many particles are carried along with the hot gases. The particles and any combustible gases may be combusted in an "afterburner".<ref>[http://www.crownandersen.com/Rotary.html Photos of rotary-kiln incinerators with afterburners.]</ref> A diagram of a rotary-kiln incinerator can be found [http://www.jeag.com/eng/incin%20plant/rotary/rotary%20func%20principle_big.gif here]. ====Fluidized bed==== A strong airflow is forced through a sandbed. The air seeps through the sand until a point is reached where the sand particles separate to let the air through and mixing and churning occurs, thus a [[fluidised bed]] is created and fuel and waste can now be introduced. The sand with the pre-treated waste and/or fuel is kept suspended on pumped air currents and takes on a fluid-like character. The bed is thereby violently mixed and agitated keeping small inert particles and air in a fluid-like state. This allows all of the mass of waste, fuel and sand to be fully circulated through the furnace. ==== Specialized incineration ==== Furniture factory sawdust incinerators need much attention as these have to handle resin powder and many flammable substances. Controlled combustion, burn back prevention systems are very essential as dust when suspended resembles the fire catch phenomenon of any liquid petroleum gas. ===Use of heat=== The heat produced by an incinerator can be used to generate steam which may then be used to drive a [[turbine]] in order to produce electricity. The typical amount of net energy that can be produced per ton municipal waste is about 0.67&nbsp;MWh of electricity and 2&nbsp;MJ of district heating<ref name=WtE_DK>[http://www.zmag.dk/showmag.php?mid=wsdps Waste to Energy in Denmark], publication by [[Ramboll]] (2006)</ref>. Thus, incinerating about 600&nbsp;tonnes per day of waste will produce about 17&nbsp;[[MW]] of electrical power and 1200&nbsp;MJ district heating each day. ===Pollution=== Incineration has a number of outputs such as the ash and the emission to the atmosphere of [[flue gas]]. Before the [[#Flue gas cleaning|flue gas cleaning system]], the flue gases may contain significant amounts of [[particulate matter]], [[heavy metals]], [[dioxins]], [[furans]], [[sulfur dioxide]], and [[hydrochloric acid]]. In a study<ref>[http://www.dswa.com/programs_wastetoenergy4.html Waste-to-Energy Compared to Fossil Fuels for Equal Amounts of Energy] ([[Delaware]] Solid Waste Authority)</ref> from 1994, Delaware Solid Waste Authority found that, for same amount of produced energy, incineration plants emitted fewer particles, hydrocarbons and less SO<sub>2</sub>, HCl, CO and NO<sub>x</sub> than [[coal]]-fired power plants, but more than [[natural gas]] fired power plants. According to [[Germany]]'s Ministry of the Environment, waste incinerators reduce the amount of some atmospheric pollutants by substituting power produced by coal-fired plants with power from waste-fired plants<ref name=waste_incineration_spouting>[http://www.seas.columbia.edu/earth/wtert/sofos/Waste_Incineration_A_Potential_Danger.pdf Waste incineration a potential danger: bidding farewell to dioxin spouting], Report by Germany's Ministry of the Environment</ref>. ===Gaseous emissions=== ==== Dioxin and furans ==== The most publicized concerns from environmentalists about the incineration of municipal solid wastes (MSW) involve the fear that it produces significant amounts of [[dioxin]] and [[furan]] emissions.<ref>{{cite journal|author=Beychok, Milton R. |year=1987 |month=January |title=A data base for dioxin and furan emissions from refuse incinerators |journal=Atmospheric Environment |volume=21 |issue=1 |pages=29–36 |issn=0004-6981 |doi=10.1016/0004-6981(87)90267-8}}</ref> Dioxins and furans are considered by many to be serious health hazards. Older generation incinerators that were not equipped with adequate gas cleaning technologies were indeed significant sources of dioxin emissions. Today, however, due to advances in emission control designs and stringent new governmental regulations, incinerators emit virtually no dioxins. In 2005, The Ministry of the Environment of Germany, where there were 66 incinerators at that time, estimated that "...whereas in 1990 one third of all dioxin emissions in Germany came from incineration plants, for the year 2000 the figure was less than 1&nbsp;%. Chimneys and tiled stoves in private households alone discharge approximately twenty times more dioxin into the environment than incineration plants."<ref name=waste_incineration_spouting>[http://www.seas.columbia.edu/earth/wtert/sofos/Waste_Incineration_A_Potential_Danger.pdf Waste incineration a potential danger: bidding farewell to dioxin spouting], Report by Germany's Ministry of the Environment</ref>. According to the U.S. [[EPA]], incineration plants are no longer significant sources of dioxins and furans. In 1987, before the governmental regulations required the use of emission controls, there was a total of 10,000&nbsp;grams of dioxin emissions from U.S. incinerators. Today, the total emissions from the 87&nbsp;plants are only 10&nbsp;grams yearly, a reduction of 99.9&nbsp;%. Backyard barrel burning of household and [[garden waste]]s, still allowed in some rural areas, generates 580&nbsp;grams of dioxins yearly. Studies conducted by EPA<ref>[http://www.epa.gov/ttn/catc/dir1/barlbrn2.pdf Evaluation of Emissions from the Burning of Household Waste in Barrels], [[EPA]] November 1997</ref> demonstrate that the emissions from just one family using a burn barrel produces more emissions than an incineration plant disposing of 200&nbsp;tonnes of waste per day. Generally the breakdown of dioxin requires exposure of the molecule to a sufficiently high temperature so as to trigger thermal breakdown of the molecular bonds holding it together. When burning of plastics outdoors in a burn barrel or garbage pit such temperatures are not reached, causing high dioxin emissions as mentioned above. While the plastic does burn in an open-air fire, the dioxins remain after combustion and float off into the atmosphere. Modern municipal incinerator designs include a high temperature zone, where the flue gas is ensured to sustain a temperature above 850&nbsp;<sup>o</sup>C for at least 2&nbsp;seconds befores it is cooled down. They are equipped with auxiliary heaters to ensure this at all times. These are often fueled by oil, and normally only active for a very small fraction of the time. A side effect controlling dioxin is the potential for generation of reactive oxides ([[NOx|NO<sub>x</sub>]]) in the flue gas, which must be removed with [[SCR]] or [[SNCR]] (see below). For very small municipal incinerators, the required temperature for thermal breakdown of dioxin may be reached using a high-temperature electrical heating element, plus an SCR stage. ==== CO<sub>2</sub> ==== As for other complete combustion processes, nearly all of the carbon content in the waste is emitted as CO<sub>2</sub> to the atmosphere. [[Municipal solid waste|MSW]] contain approximately the same mass fraction of carbon as CO<sub>2</sub> itself (27%), so incineration of one tonne of MSW produce approximately 1&nbsp;tonne of CO<sub>2</sub>. In the event that the waste was [[landfill]]ed, one tonne of MSW would produce approximately 62&nbsp;m³ [[methane]] via the [[anaerobic]] decomposition of the [[biodegradable waste|biodegradable]] part of the waste. This amount of methane has more than twice the [[global warming potential]] than the one tonne of CO<sub>2</sub>, which would have been produced by incineration. In some countries, large amounts of [[landfill gas]] are collected, but still the global warming potential of the landfill gas emitted to atmosphere in the US in 1999 was approximately 32&nbsp;% higher than the amount of CO<sub>2</sub> that would have been emitted by incineration.<ref name=WMW2003>Themelis, Nickolas J. [http://www.seas.columbia.edu/earth/papers/global_waste_to_energy.html An overview of the global waste-to-energy industry], Waste Management World 2003</ref> In addition, nearly all biodegradable waste has biological origin. This material has been formed by plants using atmospheric CO<sub>2</sub> typically within the last growing season. If these plants are regrown the CO<sub>2</sub> emitted from their combustion will be taken out from the atmosphere once more. Such considerations are the main reason why several countries administrate incineration of the biodegradable part of waste as [[renewable energy]]<ref>[http://www.r-p-a.org.uk/portal_group_view.fcm?groupid=4 Energy From Waste], from the homepage of the UK Renewable Energy Association</ref>. The rest - mainly plastics and other oil and gas derived products - is generally treated as [[Non-renewable resources|non-renewables]]. Different results for the CO<sub>2</sub> footprint of incineration can be reached with different assumptions. Local conditions (such as limited local district heating demand, no fossil fuel generated electricity to replace or high levels of aluminum in the waste stream) can decrease the CO<sub>2</sub> benefits of incineration. The methology and other assumptions may also influence the results significantly. For example the methane emissions from landfills occurring at a later date may be neglected or given less weight, or biodegradable waste may not be considered CO<sub>2</sub> neutral. A recent study by Eunomia Research and Consulting on potential waste treatment technologies in [[London]] demonstrated that by applying several of these (according to the authors) unusual assumptions the average existing incineration plants performed poorly for CO<sub>2</sub> balance compared to the theoretical potential of other emerging waste treatment technologies.<ref>D. Hogg, ''et al'' (2008) [http://www.london.gov.uk/mayor/environment/waste/docs/greenhousegas/greenhousegasbalances.pdf Greenhouse Gas Balances of Waste Management Scenarios], Report for the Greater London Authority, Eunomia</ref>. ==== Other emissions ==== Other gaseous toxins in the flue gas from incinerator furnaces include [[sulfur dioxide]], [[hydrochloric acid]], [[heavy metals]] and [[fine particles]]. The [[steam]] content in the flue may produce visible fume from the stack, which can be perceived as a [[visual pollution]]. It may be avoided by decreasing the steam content by flue gas condensation, or by increasing the flue gas exit temperature well above its dew point. Flue gas condensation allows the latent heat of vaporization of the water to be recovered, subsequently increasing the thermal efficiency of the plant. ==== Flue gas cleaning ==== The quantity of pollutants in the flue gas from incineration plants is reduced by several processes. Particulate is collected by [[Dust collector|particle filtration]], most often [[electrostatic precipitator]]s (ESP) and/or [[Dust collector#Fabric Collectors|baghouse filters]]. The latter are generally very efficient for collecting [[fine particles]]. In an investigation by the [[Ministry of the Environment of Denmark]] in 2006, the average particulate emissions per energy content of incinerated waste from 16 Danish incinerators were below 2.02&nbsp;g/GJ (grams per energy content of the incinerated waste). Detailed measurements of fine particles with sizes below 2.5&nbsp;[[micrometres]] ([[PM2.5|PM<sub>2.5</sub>]]) were performed on three of the incinerators: One incinerator equipped with an ESP for particle filtration emitted 5.3&nbsp;g/GJ fine particles, while two incinerators equipped with baghouse filters emitted 0.002 and 0.013&nbsp;g/GJ PM<sub>2.5</sub>.<ref name=dmu2006>[http://www2.dmu.dk/1_viden/2_Publikationer/3_fagrapporter/rapporter/FR442.pdf Emissionsfaktorer og emissionsopgørelse for decentral kraftvarme], Kortlægning af emissioner fra decentrale kraftvarmeværker, [[Ministry of the Environment of Denmark]] 2006 (in Danish)</ref> Acid gas [[wet scrubber|scrubber]]s are used to remove [[hydrochloric acid]], [[nitric acid]], [[hydrofluoric acid]], [[mercury (element)|mercury]], [[lead]] and other [[heavy metal]]s. Basic scrubbers remove [[sulfur dioxide]], forming [[gypsum]] by reaction with [[Calcium oxide|lime]].<ref>[http://www.sysav.se/upload/ovrigt/AKV%20stor%20sv.pdf Kraftvärmeverket, avfall blir el och värme], brochure on the SYSAV incinerator in [[Malmö]], Sweden (in Swedish)</ref> Waste water from scrubbers must subsequently pass through a waste water treatment plant. Sulfur dioxide may also be removed by dry [[Flue gas desulfurization|desulfurisation]] by injection [[limestone]] [[slurry]] into the flue gas before the particle filtration. [[NOx|NO<sub>x</sub>]] is either reduced by catalytic reduction with ammonia in a [[catalytic converter]] ([[selective catalytic reduction]], SCR) or by a high temperature reaction with ammonia in the furnace ([[selective non-catalytic reduction]], SNCR). Heavy metals are often [[adsorb]]ed on injected [[active carbon]] powder, which is collected by the particle filtration. ===Solid outputs=== Incineration produces [[fly ash]] and [[bottom ash]] just as is the case when coal is combusted. The total amount of ash produced by municipal solid waste incineration ranges from 4-10&nbsp;% by volume and 15-20&nbsp;% by weight of the original quantity of waste<ref name=WtE_DK>[http://www.zmag.dk/showmag.php?mid=wsdps Waste to Energy in Denmark], publication by [[Ramboll]] (2006)</ref><ref name=wte.org_less_environmental>[http://www.wte.org/environment/ Waste-to-Energy: Less Environmental Impact than Almost Any Other Source of Electricity], Integrated Waste Services Association homepage</ref>, and the fly ash amounts to about 10-20&nbsp;% of the total ash{{Fact|date=October 2007}}. The fly ash, by far, constitutes more of a potential health hazard than does the bottom ash because the fly ash often contain high concentrations of heavy metals such as [[lead]], [[cadmium]], [[copper]] and [[zinc]] as well as small amounts of dioxins and furans<ref>[http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27620.pdf Behaviour of metals in MSW fly ash during roasting with chlorinating agents], PhD Thesis by Chan, C.C., Chemical Engineering Department at University of Toronto, 1997.</ref>. The bottom ash seldom contain significant levels of heavy metals. While fly ash is always regarded as hazardous waste, bottom ash is generally considered safe for regular landfill after a certain level of testing defined by the local legislation. Ash, which is considered hazardous, may generally only be disposed of in landfills which are carefully designed to prevent pollutants in the ash from [[leaching]] into underground [[aquifers]] - or after chemical treatment to reduce its leaching characteristics<ref name=BREWEB_2003>[http://www.breweb.org.uk/pdf/IBA_risk_assessment.pdf Environmental and Health Risks Associated with the Use of Processed Incinerator Bottom Ash in Road Construction], Report AEAT/ENV/R/0716 by BREWEB October 2003</ref>. In testing over the past decade, no ash from an incineration plant in the USA has ever been determined to be a [[hazardous waste]]{{Fact|date=August 2007}}. At present although some historic samples tested by the incinerator operators' group would meet the being ecotoxic criteria at present the EA say "we have agreed" to regard incinerator bottom ash as "non-hazardous" until the testing programme is complete{{Fact|date=August 2007}}. ===Other pollution issues=== [[Odor]] pollution can be a problem with old-style incinerators, but odors and dust are extremely well controlled in newer incineration plants. They receive and store the waste in an enclosed area with a negative pressure with the airflow being routed through the boiler which prevents unpleasant odors from escaping into the atmosphere. However, not all plants are implemented this way, resulting in inconveniences in the locality. An issue that affects community relationships is the increased road traffic of [[waste collection vehicle]]s to transport municipal waste to the incinerator. Due to this reason, most incinerators are located in industrial areas. ==The debate over incineration== Use of incinerators for [[waste management]] is controversial. The debate over incinerators typically involves business interests (representing both waste generators and incinerator firms), government regulators, environmental activists and local citizens who must weigh the economic appeal of local industrial activity with their concerns over health and environmental risk. People and organizations professionally involved in this issue include the [[United States Environmental Protection Agency|U.S. Environmental Protection Agency]] and a great many local and national air quality regulatory agencies worldwide. ===The argument for incineration=== *The concerns over the health effects of [[dioxin]] and [[furan]] emissions have been significantly lessened by advances in emission control designs and very stringent new governmental regulations that have resulted in large reductions in the amount of dioxins and furans emissions.<ref name=waste_incineration_spouting>[http://www.seas.columbia.edu/earth/wtert/sofos/Waste_Incineration_A_Potential_Danger.pdf Waste incineration a potential danger: bidding farewell to dioxin spouting], Report by Germany's Ministry of the Environment</ref> *Incineration plants generate electricity and heat that can substitute power plants powered by other fuels at the regional electric and [[district heating]] grid, and steam supply for industrial customers. *The bottom ash residue remaining after combustion has been shown to be a non-hazardous solid waste that can be safely landfilled or recycled as construction aggregate.<ref name=BREWEB_2003>[http://www.breweb.org.uk/pdf/IBA_risk_assessment.pdf Environmental and Health Risks Associated with the Use of Processed Incinerator Bottom Ash in Road Construction], Report AEAT/ENV/R/0716 by BREWEB October 2003</ref> *In densely populated areas, finding space for additional landfills is becoming increasingly difficult{{Fact|date=August 2007}}. *[[Fine particles]] can be efficiently removed from the flue gases with [[Dust collector#Fabric Collectors|baghouse filters]]. Even though approximately 40&nbsp;% of the incinerated waste in Denmark was incinerated at plants with no baghouse filters, estimates based on measurements by the Danish Environmental Research Institute showed that incinerators were only responsible for approximately 0.3&nbsp;% of the total domestic emissions of [[particulate]] smaller than 2.5&nbsp;[[micrometre]]s ([[PM2.5|PM<sub>2.5</sub>]]) to the atmosphere in 2006<!-- Actually the 0.3% includes a few other cogeneration plant types -->.<ref name=dmu2006>[http://www2.dmu.dk/1_viden/2_Publikationer/3_fagrapporter/rapporter/FR442.pdf Emissionsfaktorer og emissionsopgørelse for decentral kraftvarme], Kortlægning af emissioner fra decentrale kraftvarmeværker, [[Ministry of the Environment of Denmark]] 2006 (in Danish)</ref> *Incineration of municipal solid waste avoids the release of [[methane]]. Every ton of MSW incinerated, prevents about one ton of carbon dioxide equivalents from being released to the atmosphere.<ref name=WMW2003>Themelis, Nickolas J. [http://www.seas.columbia.edu/earth/papers/global_waste_to_energy.html An overview of the global waste-to-energy industry], Waste Management World 2003</ref> *Incineration of [[medical waste]] and [[sewage sludge]] produces an end product ash that is sterile and non-hazardous{{Fact|date=August 2007}}. ===The argument against incineration=== [[Image:Kwai Chung Incineration Plant.jpg|thumb|float|right|300px|Decomissioned [[Kwai Chung Incineration Plant]] from 1978]] *The highly toxic [[fly ash]] must be safely disposed of. This usually involves additional waste miles and the need for specialist toxic waste landfill elsewhere, sometimes with concerns for local residents. This has been the case in Bishops Cleeve, Gloucestershire, UK.<ref>[http://www.elc.org.uk/papers/2005vansteenis.doc]</ref> <ref>[http://www.grundon.com/PDFs/leaflets/technical/Haz_Landfill_Flyer_Mar_2004.pdf]</ref> *There are still concerns by many about the health effects of [[dioxin]] and [[furan]] emissions into the atmosphere from old incinerators; especially during start up and shut down events, or where filter bypass events are required. *Incinerators emit varying levels of heavy metals such as [[vanadium]], [[manganese]], [[chromium]], [[nickel]], [[arsenic]], [[mercury (element)|mercury]], [[lead]], and [[cadmium]], which can be toxic at very minute levels. *Incinerator Bottom Ash (IBA) has high levels of heavy metals with ecotoxicity concerns if not reused properly. Some people have the opinion that IBA reuse is still in its infancy and is still not considered to be a mature or desirable product, despite additional engineering treatments.{{Fact|date=March 2008}} *Alternative technologies are available or in development such as [[Mechanical Biological Treatment]], [[Anaerobic Digestion]] (MBT/AD), [[Autoclaving]] or [[Mechanical Heat Treatment]] (MHT) using steam or [[Plasma arc gasification]] [[PGP]], or combinations. *Building and operating an incinerator requires long contract periods to recover initial investment costs, causing a long term lock-in. Incinerator lifetimes normally range from 25-30 years. *Incinerators produce [[fine particles]] and [[ultra fine particles]] in the furnace. Even with modern particle filtering of the flue gases, approximately 1/500 of these (by mass) are emitted to the atmosphere. Most of the filtration in baghouse filters occur in the filter cake formed on the surface, and not in the bag material itself. As an example, the baghouse filter material in an incineration plant planned for erection in the UK, are only specified to capture 10-30 &nbsp;% (in weight) [[particulate]] smaller than 2.5&nbsp;[[micrometre]]s ([[PM2.5|PM<sub>2.5</sub>]])(such as PM2, PM1 and UFP size), and 60-65&nbsp;% (in weight) [[particulate]] of equactly 2.5&nbsp;[[micrometre]]s ([[PM2.5|PM<sub>2.5</sub>]]) size. <ref>[http://www.environment-agency.gov.uk/commondata/acrobat/decision_document_1437658.pdf Determination of an Application for a PPC Permit under the Pollution Prevention and Control], IPPC public registers, November 6. 2006</ref> and PM<sub>2.5</sub> emissions from local incinerators to be a significant PM<sub>2.5</sub> source here.<ref>[http://www.ukhr.org/mapa4.pdf Map of infantility cases in UK by UK Health Research]</ref><ref>[http://www.noharm.org/details.cfm?ID=1963&type=document]</ref><ref>[http://news.bbc.co.uk/2/hi/uk_news/england/cornwall/6668445.stm Incinerator raises fertility fear] BBC News May 18. 2007</ref> PM<sub>2.5</sub> is not separately regulated in the European [[Waste Incineration Directive]], even though they are repeated correlated spatially to infant mortality in the UK (M.Ryan's ONS data based maps around the EfW/CHP waste incinerators at Edmonton, Coventry, Chineham, Kirklees and Sheffield) <ref>[http://www.ukhr.org/incineration/coventrymap.pdf. </ref><ref>[http://www.mole-valley.gov.uk/index.cfm?Articleid=3585]</ref><ref>http://www.suffolktogether.com/Wesaynotoincinerators/198/Home.html]</ref> Under WID there is no requirement to monitor stack top or downwind incinerator PM2.5 levels. <ref>[http://www.countrydoctor.co.uk/precis/precis%20-%20Incinerators%20-%20WMDs.htm Incinerators - Weapons of Mass Destruction], Country Doctor Magazine January 31. 2005, by Dick van Steenis</ref> Several European doctors associations (including cross discipline experts such as physicans, environmental chemists and toxicologists) in June 2008 representing over 33,000 doctors wrote a keynote statement directly to the European Parliament citing widespread concerns on incinerator particle emissions and the absence of specific fine and ultrafine particle size monitoring or in depth industry/ government epidemilogical studies of these minute and invisible incinerator particle size emissions. <ref>[http://www.noharm.org/details.cfm?ID=1963&type=document]</ref><ref>[http://www.countrydoctor.co.uk/precis/precis%20-%20Incinerator%20deaths%20and%20morbidity.htm]</ref> *Local communities are often opposed to the idea of locating incinerators in their vicinity. (The [[NIMBY|Not In My Back Yard]] phenomenon). Studies in [[Andover, Massachusetts]] strongly correlated 10&nbsp;% property devaluations with close incinerator proximity <ref>[http://es.epa.gov/ncer/publications/workshop/pdf/EE-0428-01.pdf Economic Analysis and Land Use Policy], Session of Workshop sponsored by [[EPA]] and [[NCERQA]], Washington 1999</ref>. *Prevention, [[waste minimisation]], [[reuse]] and [[recycling]] of waste should all be preferred to incineration according to the [[waste hierarchy]]. Supporters of [[zero waste]] consider incinerators and other waste treatment technologies as barriers to [[recycling]] and separation beyond particular levels, and that waste resources are sacrificed for energy producion.<ref>[http://www.recycle.ab.ca/2006Proceedings/PaulConnett_Zero_waste.pdf Zero Waste: A Global Perspective] Presentation by Dr Paul Connett, St Lawrence University</ref><ref>[http://www.youtube.com/watch?v=XB5iOtxlpCs Energy from Waste: The Myths Debunked], Press Conference by opposers to incineration in [[Ontario]], [[USA]]</ref><ref>[http://www.foe.co.uk/resource/briefings/main_uk_directives.pdf On the Main EU Directives on Waste], Briefing document by [[Friends of the Earth]]</ref> *A recent Eunomia report found that under some circumstances and assumptions, are less energy efficient than other emerging [[EfW]] and [[CHP]] technology combinations for treating residual mixed waste.<ref>D. Hogg, ''et al'' (2008) [http://www.london.gov.uk/mayor/environment/waste/docs/greenhousegas/greenhousegasbalances.pdf Greenhouse Gas Balances of Waste Management Scenarios], Report for the Greater London Authority, Eunomia</ref> *Some incinerators are architecturally monstrous and ugly. In many countries they require a visually intrusive chimney stack. == Trends in incinerator use == The history of [[municipal solid waste]] (MSW) incineration is linked intimately to the history of [[landfill]]s and other [[list of waste treatment technologies|waste treatment technology]]. The merits of incineration are inevitably judged in relation to the alternatives available. Since the 1970s, recycling and other prevention measures have changed the context for such judgements. Since the 1990s alternative waste treatment technologies have been maturing and becoming viable. Incineration is a key process in the treatment of hazardous wastes and clinical wastes. It is often imperative that medical waste be subjected to the high temperatures of incineration to destroy [[pathogen]]s and [[toxic]] contamination it contains. ===Incineration in North America=== The first full-scale waste-to-energy facility in the U.S. was the Arnold O. Chantland Resource Recovery Plant, built in 1975 located in [[Ames, Iowa]]. This plant is still in operation and produces [[refuse-derived fuel]] that is sent to local power plants for fuel.<ref>[http://www.cityofames.org/worksweb/resourcerecovery/default.htm Arnold O. Chantland Resource Recovery Plant], Ames City Government Homepage</ref> The first commercially-successful incineration plant in the U.S. was built in [[Saugus, Massachusetts]] in October 1975 by Wheelabrator Technologies, and is still in operation today.<ref name=wte.org_less_environmental>[http://www.wte.org/environment/ Waste-to-Energy: Less Environmental Impact than Almost Any Other Source of Electricity], Integrated Waste Services Association homepage</ref> Several older generation incinerators have been closed; of the 186 MSW incinerators in 1990, only 89 remained by 2007, and of the 6200 medical waste incinerators in 1988, only 115 remained in 2003.<ref>[http://www.no-burn.org/resources/library/wiadt.pdf Waste Incineration: A Dying Technology]</ref> Between 1996 and 2007, no new incinerators were built. The main reasons for lack of activity have been: *Economics. With the increase in the number of large inexpensive regional landfills and, up until recently, the relatively low price of electricity, incinerators were not able to compete for the 'fuel', i.e., waste. By contrast, a number of Canadian cities are working toward installation of incinerators. *Tax Policies. Tax credits for plants producing electricity from waste were rescinded in the 1990s. In Europe, some of the electricity generated from waste is deemed to be from a 'Renewable Energy Source (RES)'. A new law granting tax credits for such plants was implemented in the U.S. in 2004.{{Fact|date=December 2007}} Despite these problems, there has been renewed interest in waste-to-energy in the U.S., Canada, and the UK. Projects to add capacity to existing plants are underway, and municipalities are once again evaluating the option of building incinerators rather than continue landfilling municipal wastes. ===Incineration in Europe=== In Europe, with the ban on landfilling untreated waste, scores of incinerators have been built in the last decade, with more under construction. Recently, a number of municipal governments have begun the process of contracting for the construction and operation of incinerators. In Europe, some of the electricity generated from waste is deemed to be from a 'Renewable Energy Source (RES)' and is thus eligible for tax credits if privately operated. ===Incineration in the United Kingdom=== The technology employed in the UK waste management industry has been greatly lagging behind that of Europe due to the wide availablility of landfills. The [[Landfill Directive]] set down by the [[European Union]] led to the Government of the [[United Kingdom]] imposing [[waste legislation]] including the [[landfill tax]] and [[Landfill Allowance Trading Scheme]]. This legislation is designed to reduce the release of greenhouse gases produced by landfills through the use of alternative methods of waste treatment. It is the UK Government's position that incineration will play an increasingly large role in the treatment of municipal waste and supply of energy in the UK. ===Small incinerator units=== [[Image:Incinerator mobile.jpg|thumb|275px|An example of a low capacity, mobile incinerator.]]Small scale incinerators exist for special purposes. For example, the small scale <ref>[http://www.create.org.in/Medical_waste_disposal_unit.htm Waste Disposal Unit] from the homepage of the Indian Centre for Renewable Energy, Appropriate Technology and Environment</ref> incinerators are aimed for [[hygiene|hygienically]] safe destruction of medical waste in [[developing countries]]. Simple, mobile incinerators are becoming more widely used in developing countries where the threat of avian influenza is high{{Fact|date=August 2007}}. Small incinerators can be quickly deployed to remote areas where an outbreak has occurred to dispose of infected animals quickly and without the risk of cross contamination{{Fact|date=August 2007}}. ==Incinerators== *[[Allington Quarry Waste Management Facility|Allington Incinerator]] *[[Isle of Man Incinerator]] *[[Kirklees Incinerator]] *[[List of incinerators in the UK]] *[[SELCHP]] *[[Sheffield Incinerator]] == See also == {{Portal|Sustainable development|Sustainable development.svg}} *[[Cremation]] *[[Gasification]] *[[Incinerating toilet]] *[[Incinerator (Transformers)]] *[[Plasma arc waste disposal|Plasma Gasification]] *[[List of solid waste treatment technologies]] *[[Mobile incinerator]] *[[Pyrolysis]] *[[Thermal treatment]] *[[Waste Incineration Directive]] *[[Waste management]] *[[Waste-to-energy]] ==References== {{reflist}} Brunner, C. R., INCINERATION SYSTEMS HANDBOOK, Incinerator Consultants Incorporated, Ashburn, VA, 2004. ==External links== {{commonscat|Incineration}}{{Wiktionary}} '''Anti-incineration groups''' : [http://onondagapollution.com/ Anti-incineration Organization based in Syracuse,NY] '''Burn barrels''' : [http://www.burnbarrel.org/ Burn Barrel Organization] : [http://www.epa.state.il.us/community-relations/fact-sheets/burn-barrels/ EPA Fact Sheet] : [http://www.mindfully.org/Air/Ban-Burn-Barrels.htm Emissions Information] '''EU information''' : [http://europa.eu/scadplus/leg/en/lvb/l28072.htm EU Directive on waste incineration] : [http://eippcb.jrc.es/pages/Fmembers.htm BREF Drafts & Papers] '''[[International Solid Waste Association]] position''' : [http://www.iswa.org/c/portal/layout?p_l_id=PUB.1.31 position papers] '''Overviews''' : [http://www.pollutionissues.com/Ho-Li/Incineration.html Incineration article] : [http://www.haat-india.com/faqs.htm FAQ's on incineration] '''Tutorial''' : [http://www.sysav.se/upload/flash/sysav.swf Flash presentation of SYSAV], a large incineration plant in [[Malmö]], [[Sweden]]. : [http://www.rpi.edu/dept/chem-eng/Biotech-Environ/incinerator.html Incineration Tutorial] from Rensaleer Polytechnic Institute {{Waste}} [[Category:Incineration| ]] [[Category:Chemical engineering]] [[Category:Thermal treatment]] [[Category:Waste management]] [[Category:Waste treatment technology]] {{Link FA|it}} [[zh-min-nan:Hûn-hoà-lô͘]] [[da:Affaldsforbrænding]] [[de:Müllverbrennung]] [[es:Incineración]] [[fr:Incinération]] [[it:Inceneritore]] [[ja:焼却炉]] [[oc:Incineracion]] [[pt:Incinerador]] [[fi:jätteenpoltto]]