Misplaced Pages

#231768

94-571: The Hindmarsh Incinerator is a decommissioned incinerator located in the Adelaide suburb of Brompton in South Australia , Australia. Designed by Walter Burley Griffin , the architect and designer of Canberra , the incinerator was built in 1935 by the Reverberatory Incinerator and Engineering Co. Pty Ltd. as a means of disposing of household refuse. The incinerator was listed on

188-453: A gas or steam turbine -powered generator. The resulting low-temperature waste heat is then used for water or space heating. At smaller scales (typically below 1 MW), a gas engine or diesel engine may be used. Cogeneration is also common with geothermal power plants as they often produce relatively low grade heat . Binary cycles may be necessary to reach acceptable thermal efficiency for electricity generation at all. Cogeneration

282-510: A paper mill may have extraction pressures of 160 and 60 psi (1.10 and 0.41 MPa). A typical back pressure may be 60 psi (0.41 MPa). In practice these pressures are custom designed for each facility. Conversely, simply generating process steam for industrial purposes instead of high enough pressure to generate power at the top end also has an opportunity cost (See: Steam supply and exhaust conditions ). The capital and operating cost of high-pressure boilers, turbines, and generators

376-753: A reciprocating engine or Stirling engine . The heat is removed from the exhaust and radiator. The systems are popular in small sizes because small gas and diesel engines are less expensive than small gas- or oil-fired steam-electric plants. Some cogeneration plants are fired by biomass , or industrial and municipal solid waste (see incineration ). Some CHP plants use waste gas as the fuel for electricity and heat generation. Waste gases can be gas from animal waste , landfill gas , gas from coal mines , sewage gas , and combustible industrial waste gas. Some cogeneration plants combine gas and solar photovoltaic generation to further improve technical and environmental performance. Such hybrid systems can be scaled down to

470-464: A turbine in order to produce electricity. The typical amount of net energy that can be produced per tonne municipal waste is about 2/3 MWh of electricity and 2 MWh of district heating. Thus, incinerating about 600 metric tons (660 short tons) per day of waste will produce about 400 MWh of electrical energy per day (17  MW of electrical power continuously for 24 hours) and 1200 MWh of district heating energy each day. Incineration has

564-399: A waste heat recovery boiler feeds an electrical plant. Bottoming cycle plants are only used in industrial processes that require very high temperatures such as furnaces for glass and metal manufacturing, so they are less common. Large cogeneration systems provide heating water and power for an industrial site or an entire town. Common CHP plant types are: Smaller cogeneration units may use

658-698: A built-in compressor before delivery to the incinerator. Alternatively, at landfills, the volume of the uncompressed garbage can be reduced by approximately 70% by using a stationary steel compressor, albeit with a significant energy cost. In many countries, simpler waste compaction is a common practice for compaction at landfills. Incineration has particularly strong benefits for the treatment of certain waste types in niche areas such as clinical wastes and certain hazardous wastes 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

752-516: A comparatively simple wire, and over much longer distances for the same energy loss. A car engine becomes a CHP plant in winter when the reject heat is useful for warming the interior of the vehicle. The example illustrates the point that deployment of CHP depends on heat uses in the vicinity of the heat engine. Thermally enhanced oil recovery (TEOR) plants often produce a substantial amount of excess electricity. After generating electricity, these plants pump leftover steam into heavy oil wells so that

846-432: A conventional steam powerplant, whose condensate was then used for space heat. A more modern system might use a gas turbine powered by natural gas , whose exhaust powers a steam plant, whose condensate provides heat. Cogeneration plants based on a combined cycle power unit can have thermal efficiencies above 80%. The viability of CHP (sometimes termed utilisation factor), especially in smaller CHP installations, depends on

940-476: A conventional wastewater treatment plant. Waste combustion is particularly popular in countries such as Japan, Singapore and the Netherlands, where land is a scarce resource. Denmark and Sweden have been leaders by using the energy generated from incineration for more than a century, in localised combined heat and power facilities supporting district heating schemes. In 2005, waste incineration produced 4.8% of

1034-425: A cost-effective steam engine MicroCHP prototype in 2017 which has the potential to be commercially competitive in the following decades. Quite recently, in some private homes, fuel cell micro-CHP plants can now be found, which can operate on hydrogen, or other fuels as natural gas or LPG. When running on natural gas, it relies on steam reforming of natural gas to convert the natural gas to hydrogen prior to use in

SECTION 10

#1732917465232

1128-479: A daily capacity of less than 250 tons) processed only 9% of the total waste combusted, these produced 83% of the dioxins and furans emitted by municipal waste combustion. The breakdown of dioxin requires exposure of the molecular ring to a sufficiently high temperature so as to trigger thermal breakdown of the strong molecular bonds holding it together. Small pieces of fly ash may be somewhat thick, and too brief an exposure to high temperature may only degrade dioxin on

1222-499: A fluid-like state. This allows all of the mass of waste, fuel and sand to be fully circulated through the furnace. 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 essential as dust when suspended resembles the fire catch phenomenon of any liquid petroleum gas. The heat produced by an incinerator can be used to generate steam which may then be used to drive

1316-525: A good baseload of operation, both in terms of an on-site (or near site) electrical demand and heat demand. In practice, an exact match between the heat and electricity needs rarely exists. A CHP plant can either meet the need for heat ( heat driven operation ) or be run as a power plant with some use of its waste heat, the latter being less advantageous in terms of its utilisation factor and thus its overall efficiency. The viability can be greatly increased where opportunities for trigeneration exist. In such cases,

1410-449: A great deal of treatment plant space. A side effect of breaking the strong molecular bonds of dioxin is the potential for breaking the bonds of nitrogen gas ( N 2 ) and oxygen gas ( O 2 ) in the supply air. As the exhaust flow cools, these highly reactive detached atoms spontaneously reform bonds into reactive oxides such as NO x in the flue gas, which can result in smog formation and acid rain if they were released directly into

1504-466: A heat pump of 6. However, for a remotely operated heat pump, losses in the electrical distribution network would need to be considered, of the order of 6%. Because the losses are proportional to the square of the current, during peak periods losses are much higher than this and it is likely that widespread (i.e. citywide application of heat pumps) would cause overloading of the distribution and transmission grids unless they were substantially reinforced. It

1598-471: A higher temperature than the system would produce most electricity at, the lost electrical generation is as if a heat pump were used to provide the same heat by taking electrical power from the generator running at lower output temperature and higher efficiency. Typically for every unit of electrical power lost, then about 6 units of heat are made available at about 90 °C (194 °F). Thus CHP has an effective Coefficient of Performance (COP) compared to

1692-748: A higher temperature where it may be used for process heat, building heat or cooling with an absorption chiller . The majority of this heat is from the latent heat of vaporization when the steam condenses. Thermal efficiency in a cogeneration system is defined as: η t h ≡ W o u t Q i n ≡ Electrical power output + Heat output Total heat input {\displaystyle \eta _{th}\equiv {\frac {W_{out}}{Q_{in}}}\equiv {\frac {\text{Electrical power output + Heat output}}{\text{Total heat input}}}} Where: Heat output may also be used for cooling (for example, in summer), thanks to an absorption chiller. If cooling

1786-449: A later date may be neglected or given less weight, or biodegradable waste may not be considered CO 2 neutral. A study by Eunomia Research and Consulting in 2008 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 2 balance compared to

1880-700: A number of outputs such as the ash and the emission to the atmosphere of flue gas . Before the flue gas cleaning system , if installed, the flue gases may contain particulate matter , heavy metals , dioxins , furans , sulfur dioxide , and hydrochloric acid . If plants have inadequate flue gas cleaning, these outputs may add a significant pollution component to stack emissions. In a study from 1997, Delaware Solid Waste Authority found that, for same amount of produced energy, incineration plants emitted fewer particles, hydrocarbons and less SO 2 , HCl, CO and NO x than coal-fired power plants, but more than natural gas–fired power plants. According to Germany's Ministry of

1974-499: A price of $ 22,600 before installation. For 2013 a state subsidy for 50,000 units is in place. MicroCHP installations use five different technologies: microturbines , internal combustion engines, stirling engines , closed-cycle steam engines , and fuel cells . One author indicated in 2008 that MicroCHP based on Stirling engines is the most cost-effective of the so-called microgeneration technologies in abating carbon emissions. A 2013 UK report from Ecuity Consulting stated that MCHP

SECTION 20

#1732917465232

2068-544: A primary chamber and secondary chamber. The primary chamber in a rotary kiln incinerator consists of an inclined refractory lined cylindrical tube. The inner refractory lining serves as sacrificial layer to protect the kiln structure. This refractory layer needs to be replaced from time to time. 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

2162-514: A process known as 'de novo synthesis' as the emission gases cool is a probable source of the dioxins measured in emission stack tests from plants that have high combustion temperatures held at long residence times. As for other complete combustion processes, nearly all of the carbon content in the waste is emitted as CO 2 to the atmosphere. MSW contains approximately the same mass fraction of carbon as CO 2 itself (27%), so incineration of 1 ton of MSW produces approximately 1 ton of CO 2 . If

2256-449: A single chlorine atom can destroy thousands of ozone molecules. As these molecules are being broken, they are unable to absorb the ultraviolet rays . As a result, the UV radiation is more intense on Earth and there is a worsening of global warming . A heat pump may be compared with a CHP unit as follows. If, to supply thermal energy, the exhaust steam from the turbo-generator must be taken at

2350-553: A single source of combustion. The condensing furnace is a forced-air gas system with a secondary heat exchanger that allows heat to be extracted from combustion products down to the ambient temperature along with recovering heat from the water vapor. The chimney is replaced by a water drain and vent to the side of the building. A plant producing electricity, heat and cold is called a trigeneration or polygeneration plant. Cogeneration systems linked to absorption chillers or adsorption chillers use waste heat for refrigeration . In

2444-426: A source of heat or electricity, such as sugarcane , vegetable oils, wood, organic waste and residues from the food or agricultural industries. Brazil is now considered a world reference in terms of energy generation from biomass. A growing sector in the use of biomass for power generation is the sugar and alcohol sector, which mainly uses sugarcane bagasse as fuel for thermal and electric power generation. In

2538-711: A state agency in advance to check current fire risk and conditions, and to alert officials of the controlled fire that will occur. 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 optimized to allow a more efficient and complete combustion. A single moving grate boiler can handle up to 35 metric tons (39 short tons) of waste per hour, and can operate 8,000 hours per year with only one scheduled stop for inspection and maintenance of about one month's duration. Moving grate incinerators are sometimes referred to as municipal solid waste incinerators (MSWIs). The waste

2632-534: Is a more efficient use of fuel or heat, because otherwise- wasted heat from electricity generation is put to some productive use. Combined heat and power (CHP) plants recover otherwise wasted thermal energy for heating . This is also called combined heat and power district heating. Small CHP plants are an example of decentralized energy . By-product heat at moderate temperatures (100–180 °C (212–356 °F) can also be used in absorption refrigerators for cooling. The supply of high-temperature heat first drives

2726-434: Is also possible to run a heat driven operation combined with a heat pump, where the excess electricity (as heat demand is the defining factor on se ) is used to drive a heat pump. As heat demand increases, more electricity is generated to drive the heat pump, with the waste heat also heating the heating fluid. As the efficiency of heat pumps depends on the difference between hot end and cold end temperature (efficiency rises as

2820-410: Is associated with the latent heat of vaporization of steam that is not recovered when a turbine exhausts its low temperature and pressure steam to a condenser. (Typical steam to condenser would be at a few millimeters absolute pressure and on the order of 5 °C (41 °F) hotter than the cooling water temperature, depending on the condenser capacity.) In cogeneration this steam exits the turbine at

2914-460: Is equivalent to 1.38 ton of CO 2 , which is more than the 1 ton of CO 2 which would have been produced by incineration. In some countries, large amounts of landfill gas are collected. Still the global warming potential of the landfill gas emitted to atmosphere is significant. In the US it was estimated that the global warming potential of the emitted landfill gas in 1999 was approximately 32% higher than

Hindmarsh Incinerator - Misplaced Pages Continue

3008-420: Is introduced by a 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. 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

3102-635: Is less commonly employed in nuclear power plants as NIMBY and safety considerations have often kept them further from population centers than comparable chemical power plants and district heating is less efficient in lower population density areas due to transmission losses. Cogeneration was practiced in some of the earliest installations of electrical generation. Before central stations distributed power, industries generating their own power used exhaust steam for process heating. Large office and apartment buildings, hotels, and stores commonly generated their own power and used waste steam for building heat. Due to

3196-414: 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 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". A strong airflow is forced through a sandbed. The air seeps through

3290-508: Is one of several waste-to-energy technologies such as gasification , pyrolysis and anaerobic digestion . While incineration and gasification technologies are similar in principle, the energy produced from incineration is high-temperature heat whereas combustible gas is often the main energy product from gasification. Incineration and gasification may also be implemented without energy and materials recovery. In several countries, there are still concerns from experts and local communities about

3384-452: Is passed to the flue gas cleaning system . 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 can continue to be received at one boiler line while the others are undergoing maintenance, repair, or upgrading. The older and simpler kind of incinerator

3478-500: Is substantial. This equipment is normally operated continuously , which usually limits self-generated power to large-scale operations. A combined cycle (in which several thermodynamic cycles produce electricity), may also be used to extract heat using a heating system as condenser of the power plant's bottoming cycle . For example, the RU-25 MHD generator in Moscow heated a boiler for

3572-466: Is the most cost-effective method of using gas to generate energy at the domestic level. However, advances in reciprocation engine technology are adding efficiency to CHP plants, particularly in the biogas field. As both MiniCHP and CHP have been shown to reduce emissions they could play a large role in the field of CO 2 reduction from buildings, where more than 14% of emissions can be saved using CHP in buildings. The University of Cambridge reported

3666-621: The United States , Consolidated Edison distributes 66 billion kilograms of 350 °F (177 °C) steam each year through its seven cogeneration plants to 100,000 buildings in Manhattan —the biggest steam district in the United States. The peak delivery is 10 million pounds per hour (or approximately 2.5 GW). Cogeneration is still common in pulp and paper mills , refineries and chemical plants. In this "industrial cogeneration/CHP",

3760-417: The burn pit is one of the simplest and earliest forms of waste disposal, essentially consisting of a mound of combustible materials piled on the open ground and set on fire, leading to pollution. Burn piles can and have spread uncontrolled fires, for example, if the wind blows burning material off the pile into surrounding combustible grasses or onto buildings. As interior structures of the pile are consumed,

3854-451: The gas turbines or reciprocating engines in a CHP plant to heat up water and generate steam . The steam, in turn, drives a steam turbine or is used in industrial processes that require heat. HRSGs used in the CHP industry are distinguished from conventional steam generators by the following main features: Biomass refers to any plant or animal matter in which it is possible to be reused as

Hindmarsh Incinerator - Misplaced Pages Continue

3948-487: The CO 2 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 aluminium in the waste stream) can decrease the CO 2 benefits of incineration. The methodology and other assumptions may also influence the results significantly. For example, the methane emissions from landfills occurring at

4042-507: 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. The most publicized concerns about the incineration of municipal solid wastes (MSW) involve the fear that it produces significant amounts of dioxin and furan emissions. Dioxins and furans are considered by many to be serious health hazards. The EPA announced in 2012 that

4136-544: The US-EPA demonstrated that one family using a burn barrel produced more emissions than an incineration plant disposing of 200 metric tons (220 short tons) of waste per day by 1997 and five times that by 2007 due to increased chemicals in household trash and decreased emission by municipal incinerators using better technology. Most of the improvement in U.S. dioxin emissions has been for large-scale municipal waste incinerators. As of 2000, although small-scale incinerators (those with

4230-500: The United States, private rural household or farm waste incineration of small quantities was typically permitted so long as it is not a nuisance to others, does not pose a risk of fire such as in dry conditions, and the fire does not produce dense, noxious smoke. A handful of states, such as New York, Minnesota, and Wisconsin, have laws or regulations either banning or strictly regulating open burning due to health and nuisance effects. People intending to burn waste may be required to contact

4324-537: The United States, the application of trigeneration in buildings is called building cooling, heating, and power. Heating and cooling output may operate concurrently or alternately depending on need and system construction. Topping cycle plants primarily produce electricity from a steam turbine. Partly expanded steam is then condensed in a heating condensor at a temperature level that is suitable e.g. district heating or water desalination . Bottoming cycle plants produce high temperature heat for industrial processes, then

4418-439: The amount of CO 2 that would have been emitted by incineration. Since this study, the global warming potential estimate for methane has been increased from 21 to 35, which alone would increase this estimate to almost the triple GWP effect compared to incineration of the same waste. In addition, nearly all biodegradable waste has biological origin. This material has been formed by plants using atmospheric CO 2 typically within

4512-735: The base for air intake. Over time, the very high heat of incineration causes the metal to oxidize and rust, and eventually the barrel itself is consumed by the heat and must be replaced. The private burning of dry cellulosic/paper products is generally clean-burning, producing no visible smoke, but plastics in the household waste can cause private burning to create a public nuisance, generating acrid odors and fumes that make eyes burn and water. A two-layered design enables secondary combustion, reducing smoke. Most urban communities ban burn barrels and certain rural communities may have prohibitions on open burning, especially those home to many residents not familiar with this common rural practice. As of 2006 in

4606-435: The boiler in case the heating value of the waste becomes too low to reach this temperature alone. The flue gases are then cooled in the superheaters , where the heat is transferred to steam, heating the steam to typically 400 °C (752 °F) at a pressure of 40 bars (580  psi ) for the electricity generation in the turbine . At this point, the flue gas has a temperature of around 200 °C (392 °F), and

4700-401: The building level and even individual homes. Micro combined heat and power or 'Micro cogeneration" is a so-called distributed energy resource (DER). The installation is usually less than 5  kW e in a house or small business. Instead of burning fuel to merely heat space or water, some of the energy is converted to electricity in addition to heat. This electricity can be used within

4794-416: The burning material inside a metal barrel, with a metal grating over the exhaust. The barrel prevents the spread of burning material in windy conditions, and as the combustibles are reduced they can only settle down into the barrel. The exhaust grating helps to prevent the spread of burning embers. Typically steel 55-US-gallon (210 L) drums are used as burn barrels, with air vent holes cut or drilled around

SECTION 50

#1732917465232

4888-458: The case of dioxins, these substances are considered very toxic and cancerous. In the case of methyl chloride, when this substance is emitted and reaches the stratosphere , it ends up being very harmful for the ozone layer, since chlorine when combined with the ozone molecule generates a catalytic reaction leading to the breakdown of ozone links. After each reaction, chlorine starts a destructive cycle with another ozone molecule. In this way,

4982-582: The controlled combustion of waste accounted for 41.7% of the total dioxin inventory. In 1987, before the governmental regulations required the use of emission controls, there was a total of 8,905.1 grams (314.12 oz) Toxic Equivalence (TEQ) of dioxin emissions from US municipal waste combustors. Today, the total emissions from the plants are 83.8 grams (2.96 oz) TEQ annually, a reduction of 99%. Backyard barrel burning of household and garden wastes , still allowed in some rural areas, generates 580 grams (20 oz) of dioxins annually. Studies conducted by

5076-502: The demand). An example of cogeneration with trigeneration applications in a major city is the New York City steam system . Every heat engine is subject to the theoretical efficiency limits of the Carnot cycle or subset Rankine cycle in the case of steam turbine power plants or Brayton cycle in gas turbine with steam turbine plants. Most of the efficiency loss with steam power generation

5170-414: The difference decreases) it may be worthwhile to combine even relatively low grade waste heat otherwise unsuitable for home heating with heat pumps. For example, a large enough reservoir of cooling water at 15 °C (59 °F) can significantly improve efficiency of heat pumps drawing from such a reservoir compared to air source heat pumps drawing from cold air during a −20 °C (−4 °F) night. In

5264-483: The dioxins remain after combustion and either float off into the atmosphere, or may remain in the ash where it can be leached down into groundwater when rain falls on the ash pile. Fortunately, dioxin and furan compounds bond very strongly to solid surfaces and are not dissolved by water, so leaching processes are limited to the first few millimeters below the ash pile. The gas-phase dioxins can be substantially destroyed using catalysts, some of which can be present as part of

5358-584: The electricity consumption and 13.7% of the total domestic heat consumption in Denmark. A number of other European countries rely heavily on incineration for handling municipal waste, in particular Luxembourg , the Netherlands, Germany, and France. The first UK incinerators for waste disposal were built in Nottingham by Manlove, Alliott & Co. Ltd. in 1874 to a design patented by Alfred Fryer. They were originally known as destructors . The first US incinerator

5452-400: The environmental advantages, cogeneration using sugarcane bagasse presents advantages in terms of efficiency comparing to thermoelectric generation, through the final destination of the energy produced. While in thermoelectric generation, part of the heat produced is lost, in cogeneration this heat has the possibility of being used in the production processes, increasing the overall efficiency of

5546-507: The environmental effect of incinerators (see arguments against incineration ). In some countries , incinerators built just a few decades ago often did not include a materials separation to remove hazardous, bulky or 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

5640-410: The fabric filter bag structure. Modern municipal incinerator designs include a high-temperature zone, where the flue gas is sustained at a temperature above 850 °C (1,560 °F) for at least 2 seconds before it is cooled down. They are equipped with auxiliary heaters to ensure this at all times. These are often fueled by oil or natural gas, and are normally only active for a very small fraction of

5734-496: The form of steam, can be generated at the typically low pressures used in heating, or can be generated at much higher pressure and passed through a turbine first to generate electricity. In the turbine the steam pressure and temperature is lowered as the internal energy of the steam is converted to work. The lower-pressure steam leaving the turbine can then be used for process heat. Steam turbines at thermal power stations are normally designed to be fed high-pressure steam, which exits

SECTION 60

#1732917465232

5828-435: The fuel cell. This hence still emits CO 2 (see reaction) but (temporarily) running on this can be a good solution until the point where the hydrogen is starting to be distributed through the (natural gas) piping system. Another MicroCHP example is a natural gas or propane fueled Electricity Producing Condensing Furnace. It combines the fuel saving technique of cogeneration meaning producing electric power and useful heat from

5922-421: 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

6016-411: The grid. Smaller industrial co-generation units have an output capacity of 5–25 MW and represent a viable off-grid option for a variety of remote applications to reduce carbon emissions. Industrial cogeneration plants normally operate at much lower boiler pressures than utilities. Among the reasons are: A heat recovery steam generator (HRSG) is a steam boiler that uses hot exhaust gases from

6110-406: The heat from the CHP plant is also used as a primary energy source to deliver cooling by means of an absorption chiller . CHP is most efficient when heat can be used on-site or very close to it. Overall efficiency is reduced when the heat must be transported over longer distances. This requires heavily insulated pipes, which are expensive and inefficient; whereas electricity can be transmitted along

6204-444: The heat is typically recovered at higher temperatures (above 100 °C) and used for process steam or drying duties. This is more valuable and flexible than low-grade waste heat, but there is a slight loss of power generation. The increased focus on sustainability has made industrial CHP more attractive, as it substantially reduces carbon footprint compared to generating steam or burning fuel on-site and importing electric power from

6298-400: The high cost of early purchased power, these CHP operations continued for many years after utility electricity became available. Many process industries, such as chemical plants , oil refineries and pulp and paper mills , require large amounts of process heat for such operations as chemical reactors , distillation columns, steam driers and other uses. This heat, which is usually used in

6392-615: The home or business or, if permitted by the grid management, sold back into the electric power grid. Delta-ee consultants stated in 2013 that with 64% of global sales the fuel cell micro-combined heat and power passed the conventional systems in sales in 2012. 20,000 units were sold in Japan in 2012 overall within the Ene Farm project. With a Lifetime of around 60,000 hours. For PEM fuel cell units, which shut down at night, this equates to an estimated lifetime of between ten and fifteen years. For

6486-415: The last growing season. If these plants are regrown the CO 2 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 biodegradable waste as renewable energy . The rest – mainly plastics and other oil and gas derived products – is generally treated as non-renewables . Different results for

6580-407: The local environment. These reactive oxides must be further neutralized with selective catalytic reduction (SCR) or selective non-catalytic reduction (see below). The temperatures needed to break down dioxin are typically not reached when burning plastics outdoors in a burn barrel or garbage pit, causing high dioxin emissions as mentioned above. While plastic does usually burn in an open-air fire,

6674-425: The majority of their electrical power needs in large centralized facilities with capacity for large electrical power output. These plants benefit from economy of scale, but may need to transmit electricity across long distances causing transmission losses. Cogeneration or trigeneration production is subject to limitations in the local demand and thus may sometimes need to reduce (e.g., heat or cooling production to match

6768-427: The molecular breakdown temperature is higher, the exposure time for heating can be shorter, but excessively high temperatures can also cause wear and damage to other parts of the incineration equipment. Likewise the breakdown temperature can be lowered to some degree but then the exhaust gases would require a greater lingering period of perhaps several minutes, which would require large/long treatment chambers that take up

6862-837: The now-defunct Register of the National Estate on 21 March 1978 and on the South Australian Heritage Register on 24 July 1980. It is listed as a nationally significant work of 20th-century architecture by the Australian Institute of Architects . Incinerator Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high-temperature waste treatment systems are described as " thermal treatment ". Incineration of waste materials converts

6956-433: The oil will flow more easily, increasing production. Cogeneration plants are commonly found in district heating systems of cities, central heating systems of larger buildings (e.g. hospitals, hotels, prisons) and are commonly used in the industry in thermal production processes for process water, cooling, steam production or CO 2 fertilization. Trigeneration or combined cooling, heat and power ( CCHP ) refers to

7050-435: The pile can shift and collapse, spreading the burn area. Even in a situation of no wind, small lightweight ignited embers can lift off the pile via convection , and waft through the air into grasses or onto buildings, igniting them. Burn piles often do not result in full combustion of waste and therefore produce particulate pollution. The burn barrel is a somewhat more controlled form of private waste incineration, containing

7144-522: The primary combustion chamber. According to the European Waste Incineration Directive , incineration plants must be designed to ensure that the flue gases reach a temperature of at least 850 °C (1,560 °F) for 2 seconds in order to ensure proper breakdown of toxic organic substances. 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

7238-419: The process. In sugarcane cultivation, is usually used potassium source's containing high concentration of chlorine , such as potassium chloride (KCl). Considering that KCl is applied in huge quantities, sugarcane ends up absorbing high concentrations of chlorine. Due to this absorption, when the sugarcane bagasse is burned in the power cogeneration, dioxins and methyl chloride ends up being emitted. In

7332-512: The safe limit for human oral consumption is 0.7 picograms Toxic Equivalence (TEQ) per kilogram bodyweight per day, which works out to 17 billionths of a gram for a 150 lb person per year. 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

7426-413: The sand until a point is reached where the sand particles separate to let the air through and mixing and churning occurs, thus a fluidized 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

7520-579: The simultaneous generation of electricity and useful heating and cooling from the combustion of a fuel or a solar heat collector. The terms cogeneration and trigeneration can also be applied to the power systems simultaneously generating electricity, heat, and industrial chemicals (e.g., syngas ). Trigeneration differs from cogeneration in that the waste heat is used for both heating and cooling, typically in an absorption refrigerator. Combined cooling, heat, and power systems can attain higher overall efficiencies than cogeneration or traditional power plants. In

7614-416: The solid mass of the original waste by 80–85% and the volume (already compressed somewhat in garbage trucks ) by 95–96%, depending on composition and degree of recovery of materials such as metals from the ash for recycling. This means that while incineration does not completely replace landfilling , it significantly reduces the necessary volume for disposal. Garbage trucks often reduce the volume of waste in

7708-409: The sugarcane industries are able to supply the electric energy demand needed to operate, and generate a surplus that can be commercialized. In comparison with the electric power generation by means of fossil fuel-based thermoelectric plants, such as natural gas , the energy generation using sugarcane bagasse has environmental advantages due to the reduction of CO 2 emissions. In addition to

7802-456: The sugarcane industry, cogeneration is fueled by the bagasse residue of sugar refining, which is burned to produce steam. Some steam can be sent through a turbine that turns a generator, producing electric power. Energy cogeneration in sugarcane industries located in Brazil is a practice that has been growing in last years. With the adoption of energy cogeneration in the sugar and alcohol sector,

7896-434: The summer when there's both demand for air conditioning and warm water, the same water may even serve as both a "dump" for the waste heat rejected by a/c units and as a "source" for heat pumps providing warm water. Those considerations are behind what is sometimes called "cold district heating" using a "heat" source whose temperature is well below those usually employed in district heating. Most industrial countries generate

7990-437: The surface of the ash. For a large volume air chamber, too brief an exposure may also result in only some of the exhaust gases reaching the full breakdown temperature. For this reason there is also a time element to the temperature exposure to ensure heating completely through the thickness of the fly ash and the volume of waste gases. There are trade-offs between increasing either the temperature or exposure time. Generally where

8084-502: The theoretical potential of other emerging waste treatment technologies. Other gaseous emissions in the flue gas from incinerator furnaces include nitrogen oxides , sulfur dioxide , hydrochloric acid , heavy metals , and fine particles . Of the heavy metals, mercury is a major concern due to its toxicity and high volatility, as essentially all mercury in the municipal waste stream may exit in emissions if not removed by emission controls. Combined heat and power Cogeneration

8178-497: The time. Further, most modern incinerators utilize fabric filters (often with Teflon membranes to enhance collection of sub-micron particles) which can capture dioxins present in or on solid particles. For very small municipal incinerators, the required temperature for thermal breakdown of dioxin may be reached using a high-temperature electrical heating element, plus a selective catalytic reduction stage. Although dioxins and furans may be destroyed by combustion, their reformation by

8272-419: The turbine at a condenser operating a few degrees above ambient temperature and at a few millimeters of mercury absolute pressure. (This is called a condensing turbine.) For all practical purposes this steam has negligible useful energy before it is condensed. Steam turbines for cogeneration are designed for extraction of some steam at lower pressures after it has passed through a number of turbine stages, with

8366-557: The un-extracted steam going on through the turbine to a condenser. In this case, the extracted steam causes a mechanical power loss in the downstream stages of the turbine. Or they are designed, with or without extraction, for final exhaust at back pressure (non-condensing). The extracted or exhaust steam is used for process heating. Steam at ordinary process heating conditions still has a considerable amount of enthalpy that could be used for power generation, so cogeneration has an opportunity cost . A typical power generation turbine in

8460-447: The waste into ash , flue gas and heat. The ash is mostly formed by the inorganic constituents of the waste and may take the form of solid lumps or particulates carried by the flue gas. The flue gases must be cleaned of gaseous and particulate pollutants before they are dispersed into the atmosphere . In some cases, the heat that is generated by incineration can be used to generate electric power . Incineration with energy recovery

8554-403: The waste was landfilled without prior stabilization (typically via anaerobic digestion ), 1 ton of MSW would produce approximately 62 cubic metres (2,200 cu ft) methane via the anaerobic decomposition of the biodegradable part of the waste. Since the global warming potential of methane is 34 and the weight of 62 cubic meters of methane at 25 degrees Celsius is 40.7 kg, this

8648-698: The year 2000 the figure was less than 1%. Chimneys and tiled stoves in private households alone discharge approximately 20 times more dioxin into the environment than incineration plants." According to the United States Environmental Protection Agency , the combustion percentages of the total dioxin and furan inventory from all known and estimated sources in the U.S. (not only incineration) for each type of incineration are as follows: 35.1% backyard barrels; 26.6% medical waste; 6.3% municipal wastewater treatment sludge ; 5.9% municipal waste combustion; 2.9% industrial wood combustion. Thus,

8742-445: 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 clinkers . Many small incinerators formerly found in apartment houses have now been replaced by waste compactors . The rotary-kiln incinerator is used by municipalities and by large industrial plants. This design of incinerator has two chambers:

8836-554: Was built in 1885 on Governors Island in New York, NY. The first facility in Austria-Hungary was built in 1905 in Brunn . 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, and fluidised bed. The burn pile or

#231768