How to convert waste into energy
Energy Recovery from the Combustion of Municipal Solid Waste (MSW)
Energy recovery from waste is the conversion of non-recyclable waste materials into usable heat, electricity, or fuel through a variety of processes, including combustion, gasification, pyrolization, anaerobic digestion and landfill gas recovery. This process is often called waste to energy.
On this page:
- Energy Recovery from Combustion
- The Mass Burn Process
- Combustion Technologies
- The History of Energy Recovery from Combustion
- Frequent Questions on Energy Recovery from Combustion
- How much waste does America combust for energy recovery?
- Why are MSW combustion facilities not more common in the United States?
- What is the ash generated by combustion and what happens to it?
- Which regulations apply to energy recovery from waste?
- Does EPA consider burning for energy recovery to be waste minimization?
Energy Recovery from Combustion
Energy recovery from the combustion of municipal solid waste is a key part of the non-hazardous waste management hierarchy, which ranks various management strategies from most to least environmentally preferred. Energy recovery ranks below source reduction and recycling/reuse but above treatment and disposal. Confined and controlled burning, known as combustion, can not only decrease the volume of solid waste destined for landfills, but can also recover energy from the waste burning process. This generates a renewable energy source and reduces carbon emissions by offsetting the need for energy from fossil sources and reduces methane generation from landfills.
The Mass Burn Process
At an MSW combustion facility, MSW is unloaded from collection trucks and placed in a trash storage bunker. An overhead crane sorts the waste and then lifts it into a combustion chamber to be burned. The heat released from burning converts water to steam, which is then sent to a turbine generator to produce electricity.
The remaining ash is collected and taken to a landfill where a high-efficiency baghouse filtering system captures particulates. As the gas stream travels through these filters, more than 99 percent of particulate matter is removed.
Captured fly ash particles fall into hoppers (funnel-shaped receptacles) and are transported by an enclosed conveyor system to the ash discharger. They are then wetted to prevent dust and mixed with the bottom ash from the grate. The facility transports the ash residue to an enclosed building where it is loaded into covered, leak-proof trucks and taken to a landfill designed to protect against groundwater contamination. Ash residue from the furnace can be processed for removal of recyclable scrap metals.
Combustion Technologies
Common technologies for the combustion of MSW include mass burn facilities, modular systems and refuse derived fuel systems.
Mass Burn Facilities
Mass burn facilities are the most common type of combustion facility in the United States. The waste used to fuel the mass burn facility may or may not be sorted before it enters the combustion chamber. Many advanced municipalities separate the waste on the front end to save recyclable products.
Mass burn units burn MSW in a single combustion chamber under conditions of excess air. In combustion systems, excess air promotes mixing and turbulence to ensure that air can reach all parts of the waste. This is necessary because of the inconsistent nature of solid waste. Most mass-burn facilities burn MSW on a sloping, moving grate that vibrates or otherwise moves to agitate the waste and mix it with air.
Modular Systems
Modular Systems burn unprocessed, mixed MSW. They differ from mass burn facilities in that they are much smaller and are portable. They can be moved from site to site.
Refuse Derived Fuel Systems
Refuse derived fuel systems use mechanical methods to shred incoming MSW, separate out non-combustible materials, and produce a combustible mixture that is suitable as a fuel in a dedicated furnace or as a supplemental fuel in a conventional boiler system.
The History of Energy Recovery from Combustion
The first incinerator in the United States was built in 1885 on Governors Island in New York, NY.
By the mid-20th Century hundreds of incinerators were in operation in the United States, but little was known about the environmental impacts of the water discharges and air emissions from these incinerators until the 1960s. When the Clean Air Act (CAA) came into effect in 1970, existing incineration facilities faced new standards that banned the uncontrolled burning of MSW and placed restrictions on particulate emissions. The facilities that did not install the technology needed to meet the CAA requirements closed.
Combustion of MSW grew in the 1980s. By the early 1990s, the United States combusted more than 15 percent of all MSW. The majority of non-hazardous waste incinerators were recovering energy by this time and had installed pollution control equipment. With the newly recognized threats posed by mercury and dioxin emissions, EPA enacted the Maximum Achievable Control Technology (MACT) regulations in the 1990s. As a result, most existing facilities had to be retrofitted with air pollution control systems or shut down
Frequent Questions on Energy Recovery from Combustion
1.
How much waste does America combust for energy recovery?Currently, there are 75 facilities in the United States that recover energy from the combustion of municipal solid waste. These facilities exist in 25 states, mainly in the Northeast. A new facility was built in Palm Beach County, Florida in 2015.
A typical waste to energy plant generates about 550 kilowatt hours (kWh) of energy per ton of waste. At an average price of four cents per kWh, revenues per ton of solid waste are often 20 to 30 dollars. For more information, read Is It Better to Burn or Bury Waste for Clean Energy?
2. Why are MSW combustion facilities not more common in the United States?
According to the Advancing Sustainable Materials Management: Facts and Figures Report, the United States combusted over 34 million tons of MSW with energy recovery in 2017.
MSW combustion accounts for a small portion of American waste management for multiple reasons. Generally speaking, regions of the world where populations are dense and land is limited (e.
g. many European countries, Japan), have greater adoption of combustion with energy recovery due to space constraints. As the United States encompasses a large amount of land, space limitations have not been as important a factor in the adoption of combustion with energy recovery. Landfilling in the United States is often considered a more viable option, especially in the short term, due to the low economic cost of building an MSW landfill verses an MSW combustion facility.
Another factor in the slow growth rate of MSW combustion in the United States is public opposition to the facilities. These facilities have not always had air emission control equipment, thus gaining a reputation as high polluting. In addition, many communities do not want the increased traffic from trucks or to be adjacent to any facility handling municipal waste.
Additionally, the upfront money needed to build an MSW combustion facility can be significant and economic benefits may take several years to be fully realized.
A new plant typically requires at least 100 million dollars to finance the construction; larger plants may require double to triple that amount. MSW Combustion facilities typically collect a tipping fee from the independent contractors that drop the waste off on a daily basis to recover costs. The facilities also receive income from utilities after the electricity generated from the waste is sold to the grid. A possible third stream of revenue for the facilities comes from the sale of both ferrous (iron) and non-ferrous scrap metal collected from the post-combusted ash stream.
3. What is the ash generated by combustion and what happens to it?
The amount of ash generated ranges from 15-25 percent (by weight) and from 5-15 percent (by volume) of the MSW processed. Generally, MSW combustion residues consist of two types of material: fly ash and bottom ash. Fly ash refers to the fine particles that are removed from the flue gas and includes residues from other air pollution control devices, such as scrubbers.
Fly ash typically amounts to 10-20 percent by weight of the total ash. The rest of the MSW combustion ash is called bottom ash (80-90 percent by weight). The main chemical components of bottom ash are silica (sand and quartz), calcium, iron oxide, and aluminum oxide. Bottom ash usually has a moisture content of 22-62 percent by dry weight. The chemical composition of the ash varies depending on the original MSW feedstock and the combustion process. The ash that remains from the MSW combustion process is sent to landfills. Visit EPA's Landfill Methane Outreach Program for additional information on how facilities recover energy from landfills.
4. Which regulations apply to energy recovery from waste?
Energy recovery from waste is important in the development of sustainable energy policies. EPA continues to develop regulations that encourage energy recovery from hazardous materials or materials that might otherwise be disposed of as solid waste.
Identification of Non-Hazardous Materials that are Solid Waste
The 2011 non-hazardous secondary material (NHSM) final rule under the Resource Conservation and Recovery Act (RCRA) identifies which non-hazardous secondary materials are, or are not, solid wastes when burned in combustion units.
This determines which Clean Air Act emission standards a combustion unit is required to meet.
Gasification
Gasification is a process that converts any material containing carbon—such as coal, petroleum or biomass—into synthesis gas (syngas) composed of hydrogen and carbon monoxide. The syngas can then be burned to produce electricity or further processed to produce vehicle fuel. As part of EPA’s effort to promote flexible, innovative ways to convert waste to energy, EPA finalized an exclusion to RCRA’s regulation for oil-bearing hazardous waste generated at a petroleum refinery in January 2008. This exclusion ensures that the gasification of these materials will have the same regulatory status (i.e., excluded) as other oil-bearing hazardous waste reinserted into the petroleum refining process.
5. Does EPA consider burning for energy recovery to be waste minimization?
Waste minimization, the term employed in the RCRA statute, is defined to include both source reduction and certain types of environmentally sound recycling.
EPA's highest priority is to achieve reductions through source reduction. However, if this is not achievable, then environmentally sound recycling is also an Agency priority.
Recycling activities closely resembling conventional waste treatment activities (such as burning for energy recovery) do not constitute waste minimization. Also, treatment for the purposes of destruction or disposal is not part of waste minimization, but is, rather, an activity that occurs after the opportunities for waste minimization have been pursued.
Turning waste into clean fuels
Credit: JWest DesignAn MIT researcher and his colleagues have developed a system that can make liquid fuels from an abundant, familiar, and troublesome source: trash.
The system can convert municipal and nonhazardous industrial waste into valuable products including ethanol, methanol, and synthetic diesel at an affordable cost, in part because the starting materials come at a negative cost: people pay to have them taken away.
“In the ideal case, if we processed all U.S. municipal and industrial waste this way, we could produce up to 50 billion gallons of alcohol fuel, which is equivalent in energy to around a fifth of the gasoline used in this country,” says Daniel R. Cohn, senior research scientist at the MIT Plasma Science and Fusion Center and the MIT Energy Initiative. “At the same time, we’d reduce the amount of material in landfills, which are now a major source of methane, a very potent greenhouse gas.”
The work is a striking demonstration of how basic research on a long-term technology—nuclear fusion—can lead to commercial products with significant near-term impacts, in this case, protecting the environment and reducing U.S. dependence on foreign oil.
Thinking outside the box
In the late 1980s, Cohn and his collaborators were working to understand the behavior of plasmas, ionized gases that play a key role in fusion energy devices. The goal of fusion research is to harness the same energy—nuclear fusion—that powers the sun to serve as a sustainable power source on Earth, and a key challenge is finding a way to contain the hot, dense plasma long enough for fusion reactions to occur.
Plasmas also form at lower temperatures, for example, when lightning cuts through the air, breaking apart molecules in its path into a mixture of free electrons and positive ions. Sometimes called the fourth state of matter, plasmas have characteristics that are not seen in ordinary gases, and they have become a valuable tool in materials processing.
Recognizing that practical fusion energy was still well in the future, the research team began to think about nearer-term applications for plasma technology. “We decided that the environmental area was in need of new approaches and that plasma technology could make a real difference,” says Cohn. “In particular, it seemed well suited to waste disposal because it can simply disintegrate or vaporize even the nastiest of materials.”
Their first target for destruction was “mixed waste,” a combination of chemical and nuclear waste that the U.S. Department of Energy (DOE) must dispose of. Taking advantage of the huge space and high power supply available at the MIT Plasma Science and Fusion Center, Cohn and his collaborators—including a group from the Battelle Pacific Northwest National Laboratory (PNNL) led by Jeffrey Surma—designed and built a largescale plasma furnace in that MIT facility.
They then demonstrated its ability to deal with simulated waste, specifically, hazardous chemicals mixed with dirt and metals (which stood in for the radioactive component in nuclear waste). Later PNNL tests in an actual radioactive environment were successful. Those tests were carried out at the PNNL facility in Richland, Washington, near the DOE Hanford site.
Cohn and his colleagues next thought about using plasma technology for a wider range of waste materials and finding ways to make it more effective. They came up with the idea of adding a second stage to the plasma furnace. This second stage—a “joule-heated melter”—is a technology that had been developed at PNNL and used by DOE to isolate the most hazardous radioactive components of nuclear waste. Key to the melter is a molten glass bath, kept hot by a current passing between two submerged electrodes. Inorganic material from the hazardous waste is incorporated into the glass bath. When the glass is removed and cooled, it traps the waste within its solid matrix.
In 1995, Cohn, Surma, and two other partners founded a company called InEnTec to commercialize the two-stage device, the Plasma-Enhanced Melter, or PEM. Small demonstration and commercial units were installed in the United States, Japan, and Taiwan. These units achieved a high degree of waste destruction, converting the waste into a valuable hydrogen-rich gas while surpassing environmental regulatory requirements.
In fall 2008, InEnTec and Dow Corning Corporation announced an agreement under which a larger PEM unit would be built at the Dow Corning facility in Midland, Michigan. The unit would process chemical hazardous waste and produce valuable products that could be reused within the plant. “None of this chemical waste needs to be shipped out of the plant,” says Cohn. “The concept is a sustainable process whereby the chemical industry uses the waste it produces.”
The Dow Corning unit is now being constructed and will be operated by InEnTec Chemical, a joint venture between InEnTec and Lakeside Energy LLC.
It is the first in a series of units that InEnTec plans to build for the chemical industry using a project financing fund of up to $150 million provided by Lakeside Energy.
Converting trash to liquid fuels for cars and trucks
About two years ago, InEnTec began to set its sights on municipal waste, a feedstock with several advantages. It is available in huge quantities just about everywhere; people pay to have it taken away; and—best of all—it is rich in biomaterials, so it should be ideal for producing fuels, in particular, liquid fuels needed for transportation.
Cohn notes that turning garbage into energy is not a new idea. “But present technology involves incineration, which burns the waste, generates hard-tohandle toxic pollutants such as dioxin, produces potentially hazardous ash—and in the end generates heat, which is then used to raise steam to run a power-generating turbine,” he says. “Our system uses plasma-enhanced gasification, which converts the waste directly into clean fuel and essentially eliminates the production of dioxin and ash. ” Added environmental benefits come from diverting material from landfills, which can contaminate soil and groundwater and—as materials decompose—generate huge amounts of methane, a greenhouse gas that is 20 times more potent than carbon dioxide.
To optimize their system for destroying municipal waste, engineers at InEnTec added one more stage to their setup: a conventional gasifier that acts as a preprocessor. This simple, inexpensive technology handles the abundant easy-to-treat part of the waste, leaving just the difficult-to-treat parts to move on to the next stages.
InEnTec’s demonstration unit for converting up to 25 tons per day of municipal waste into syngas. The unit is located in Richland, Washington. Shredded waste is transported to the top through the diagonal white pipe at the upper left and is then processed in the various stages of the unit. Photo: InEnTec
The figure above shows the threestage system. Trash is shredded into pieces about six inches long and dumped into the gasifier at the top.
There, the material is heated and mixed with just enough oxygen to cause chemical reactions but not enough to burn the waste as in an incinerator. Much of the organic content (waste made of hydrogen and carbon) reacts to produce a combination of hydrogen and carbon monoxide called synthesis gas, or syngas. The syngas is sent to a catalytic system that converts it to ethanol and methanol or other liquid fuels or chemicals.
The inorganic material and remaining organics—now in the form of char— enter the second stage, the plasma furnace, where they are subjected to the electric arc that turns them into high-temperature plasmas. The remaining organics are converted to syngas, which is sent to the catalysts.
The inorganic waste drops into the molten glass bath in the joule-heated melter. When the glass is removed and cooled, it traps the inorganics, forming a material that can be safely landfilled (without decomposing or leaching) or used as construction material or sandblasting grit.
Metals in the molten mix that are not incorporated into the glass separate from the bath and drop to the bottom, where they are removed and—depending on their composition—are recycled or safely discarded.
InEnTec has built a demonstration unit—one-fifth commercial scale—of the waste conversion system that uses municipal waste diverted from a landfill in Richland, Washington (see the photo at the left). The unit has processed 12 tons per day of Richland’s municipal waste, with a goal of 25 tons per day.
Cohn believes that their “plasma-melter gasification system” could provide the first significant non-corn-based renewable fuel replacement for liquid fuels. “Because it uses known technologies, it’s likely to come ahead of cellulosic ethanol, which requires more biochemistry research to develop an economically viable process,” he says. And the price is right. Given the negative cost of the feedstock, the system should produce alcohol fuels for less than $1.00 per gallon, which translates into the energy equivalent of less than $2.
00 per gallon of gasoline.
Finally, the quantities involved are substantial, potentially replacing up to 20% of all the gasoline used in the United States. “That’s a lot of fuel that doesn’t come from food or from oil—and it’s a lot of money that doesn’t go overseas,” says Cohn. “It looks like the MIT fusion program has spun off one of the most promising near-term technologies for replacing gasoline and reducing greenhouse gas emissions at the same time.”
This article appears in the Spring 2009 issue of Energy Futures.
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how to turn waste into energy
By tradition, on World Environment Day, which is celebrated annually on June 5, we talk about projects in the field of ecology.
The central theme of the national project "Ecology" is the solution to the problem of waste disposal.
Rostec, represented by its subsidiary RT-Invest, is actively participating in this global reform of the waste management system. The company acts as an operator in two most important projects at once - the construction of special waste processing complexes (KPO) and the construction of waste energy recycling plants.
Rostec commissioned the first innovative KPO in October last year. Very soon, the third such complex will open in Kashira near Moscow. Modern KPO can give a “second life” to approximately 50% of waste, and what cannot be recycled will become fuel for the plants of the Energy from Waste project. At the moment, RT-Invest is building several such plants, and as the company assures, even the situation with COVID-19 will not affect the timing of the commissioning of facilities..
About how new technologies allow solving the problem of landfills and landfills without harming the environment - in our material.
"Ecology" of the national scale
The national project "Ecology", along with other 11 national projects, was approved by Vladimir Putin's decree in May 2018. Its goal is to improve the ecological situation in Russia and create comfortable living conditions in the country. The work is carried out in five areas: waste, water, air, nature and animals, the best available technologies.
The problem of waste disposal has become one of the central topics of the national project. According to the Presidential Council for the Development of Civil Society and Human Rights, there are about 15,000 official landfills in our country alone, covering a total area of 4 million hectares. This is comparable to the territory of an entire country, for example, Switzerland.
Approximately 70 million tons of municipal solid waste (MSW) is generated in Russia every year. Almost all of this is taken to landfills, authorized and unauthorized dumps, buried in the ground in the most primitive way.
Growing mountains of garbage annually "conquer" new lands.
The program "Integrated System for the Management of Solid Municipal Waste" of the national project "Ecology" includes, among other things, the following targets: by 2024, the share of processed waste should increase from 12% to 60%, recycled - from 7% to 36%, and it is also planned to introduce waste treatment facilities with a total capacity of 37.1 million tons were put into operation.
"Smart" sorting: how to extract useful things from garbage
The creation of modern KPO, where the maximum possible amount of useful fractions is extracted from garbage, is one of the most important stages of the waste disposal system. To date, RT-Invest has already launched two such waste processing complexes - in the Kolomna and Sergiev Posad urban districts. A third one will open soon - in Kashira near Moscow. The fourth facility will be put into operation at the end of the year in the Mozhaisk city district.
Innovative KPO can efficiently recycle approximately 50% of the total waste. Moreover, the process of waste sorting at such complexes is almost completely automated, as local employees say: “Robots work hard here.” The personnel works only at the control section for the selection of large fractions, in order to prevent them from falling onto the sorting belts. Further, the "smart" technology itself selects useful fractions from the flow and turns them into briquettes. It should be noted that the share of localized equipment at KPO RT-Invest already exceeds 70%.
At the very beginning of its "transformation" recyclables pass through the "drum screen" - a giant sieve. It helps to separate waste into fractions of various sizes: large (more than 30 cm), medium (from 7 cm) and small (less than 7 cm).
Small garbage, along with organic waste, is sent to the composting shop. Here, too, everything is automated: once every three days, machines stir up the so-called heaps with organic matter, for the processing of which thermophilic bacteria are added.
This speeds up the decomposition process - if under normal conditions it takes an average of 2-3 months, then here the period is reduced to two weeks. As a result, technical soil is obtained, which is suitable for filling and reclamation of landfills, as well as filling roads.
Inorganic debris, having passed the "drum screen", moves its own way - through various separators. First, the optical separator separates all polymers, that is, plastic, which are sent for additional sorting. The magnetic separator removes ferrous metals from the flow. There is also a device for the selection of non-ferrous metals. All these high-precision assemblers leave almost no chance for recycled materials to slip past. Each fraction is collected on its own conveyor belt, and then pressed into briquettes weighing from 200 kg to 1 ton.
Burning tails: waste as a source of energy
Thanks to this well-coordinated work of KPO, the amount of incoming waste is reduced by about half.
The output is only what cannot be recycled, or the so-called "tails". It is they who will be sent for thermal processing, that is, to factories. And this is not about classic incinerators, but a completely new approach to waste recycling. It is based on the fact that garbage can become a renewable energy source. Today there is even a special term Waste-to-Energy (WtE). It is precisely such modern waste disposal enterprises that RT-Invest is building, which is why this project received the same name - Energy from Waste.
To date, the company is already building four pilot plants in the Moscow region (in the Voskresensk, Naro-Fominsk, Solnechnogorsk and Bogorodsk districts), as well as in the Republic of Tatarstan. Closest to the opening of the plant in the Voskresensky district - now it is being installed large-sized boiler equipment. In Naro-Fominsk, work has already begun, in the Solnechnogorsk and Bogorodsk districts, a procedure is underway to select a general contractor and conclude an agreement.
In Tatarstan, the preparatory stage of construction work has also begun. According to RT-Invest, despite the restrictions due to the coronavirus pandemic, in general, everything is going according to plan. The plants should be commissioned by the end of 2022.
Infographic: Energy from Waste Project
But the pilot construction of several plants will not complete the Energy from Waste project. At least 25 more such waste-to-energy enterprises will appear in Russia. The corresponding agreement was recently concluded by the state corporations Rostec, Rosatom and VEB.RF. According to preliminary estimates, this will prevent the emergence of more than 80 new landfills, close 25 existing ones and save about 60,000 hectares of land.
Of course, waste disposal is the main goal of such a modern plant, and electricity is a by-product, but at the same time very tangible economically. One plant can generate electricity that is enough for the operation of the enterprise itself, and in addition to this, the network can receive additional millions of kilowatts per year.
For example, one ton of waste provides 690 kWh of "green" electricity. Thus, only the first five pilot plants in total can produce up to 2.2 billion kWh of electricity per year.
Ultra-modern enterprise, not a "kerosene"
The project to create new plants "Energy from Waste" has already received positive conclusions from the state environmental review, however, remains under the close attention of environmentalists.
The main myths about the dangers of incineration relate to old-generation plants, where the incineration temperature does not exceed 800 degrees. The new factories are not "kerosene stoves" that have a detrimental effect on the environment, but ultra-modern enterprises with advanced technologies. Here, the combustion temperature reaches 1260 °C, which ensures the complete decomposition of hazardous substances. At the same time, a perfect filtration system is used - emissions from such a plant are less than from cars passing along any federal highway.
As a result, after the waste is thermally destroyed at very high temperatures, and kilowatts of electricity have replenished the network, slag and ash remain. Slag is the fourth hazard class of waste, that is, it is practically harmless. It, after choosing the metals contained in it, is used, for example, in road construction. So, in Japan, with its help, islands are poured into the ocean (which says a lot, given the responsible attitude of the Japanese to the environment).
Ash belongs to the third class of waste hazard. It is formed on filters that are installed to clean combustion flue gases. Fly ash will only make up about 3% of the total recycled waste, yet various uses are being considered. For example, there is a British technology called Carbon8 that successfully converts ash into various blocks, borders, tiles and even into cement.
Today, more than 1,500 plants for recycling waste into electricity operate in different countries of the world.
Currently, Waste-to-Energy plants are being built in Switzerland, Great Britain, Finland, Serbia, Singapore, UAE, Turkey, Australia, Mexico, Malta, Sri Lanka and other countries. More than 30 similar enterprises are now being built in the European Union alone.
Photo: Official website of the Amager Bakke incinerator in Copenhagen
The safety of this technology is only evidenced by the fact that in many European countries such enterprises are located right within the city, as, for example, in Paris. They are also in Vienna, Copenhagen, Amsterdam, London and other cities. About 200 of the European plants were built using the technologies of the Swiss-Japanese company Hitachi Zosen Inova, the world leader in the field of thermal waste processing. Worldwide, this company has built more than 600 such facilities on a turnkey basis. Hitachi Zosen Inova is the technical partner of RT-Invest.
According to RT-Invest, the transition to a new waste management system requires information transparency.
Mistrust in the construction of new plants and in the industry as a whole is often caused by a lack of information, and the company plans to correct this state of affairs. In particular, monitoring data on the composition of substances at the outlet of the pipe of each plant will be available online for everyone. Well, in the future, everyone will be able, so to speak, to see everything with their own eyes - factories can become not just part of the ecological infrastructure, but also objects of industrial tourism.
Energy from waste: the latest technology against waste
By the end of 2022, it is planned to build four facilities for the thermal processing of waste into electricity in the Moscow Region, and one more should appear in Kazan. Modern waste incineration plants will be built as part of the Energy from Waste project, which is being implemented by RT-Invest of the Rostec State Corporation. The new technology will make it possible to solve the problem of landfills and landfills forever without harming the environment.
Waste incineration plant as a source of energy
One of the main principles underlying the new generation waste incineration plant is environmental friendliness and safety. The plants of the project “Energy from Waste” perform an important task - the involvement in the secondary circulation of waste that is not suitable for classical processing. All this will lead to a reduction in the volume of waste disposal, which will avoid the damage caused to the environment by landfills and landfills.
Only Moscow and the Moscow region annually produce 11 million tons of waste, and at the same time, 95% of this volume ends up in landfills. It is not even worth mentioning how much waste disposal has a detrimental effect on nature and public sentiment.
In addition, landfills and landfills occupy vast territories: only in the Moscow region 100 hectares are required annually. According to experts, the situation in Moscow and the Moscow region is the most serious - in a few years there will be no place for landfills at all.
Andrey Shipelov, CEO of RT-Invest, noted that with the help of this project, Russia can save 500 hectares of land by preventing the creation of a "dirty" landfill.
The waste incineration plant of the Energy from Waste project differs from the classic incinerators not only in its environmental friendliness, but also in the very approach to waste processing. Waste is considered a renewable energy source that can be compared to solar or wind energy.
Infographic: Energy from Waste Project
For example, one such plant in the Moscow region will process about 700,000 tons of waste and supply 485 million kWh of electricity per year to the grid. This can provide electricity to about 250 thousand inhabitants or a city with a population of about 100 thousand people.
RT-Invest is building new plants using the technology of the Japanese-Swiss company Hitachi Zosen Inova (HZI), the world leader in the waste-to-energy industry. At the same time, the production of a significant part of the equipment of the plants will be localized in Russia.
Hitachi Zosen Inova has already built more than 500 such plants in major cities, including Japan and Switzerland itself.
How it works: the incinerator in action
The plants receive only the waste that remains after sorting and is unsuitable for recycling. Garbage trucks entering the territory of the plant undergo mandatory radiation control, weighing and accounting procedures, after which the waste is unloaded into a receiving bunker. Here, waste can accumulate up to two weeks, and then enter the boiler, which is designed for 7 thousand tons of waste and is a 7-story structure. There are three of them at the plant, and each of them has two zones.
In the first, the waste is thermally processed at a temperature of 1260 °C. Such critical temperatures burn absolutely everything, even toxic dioxins. In this zone of extreme high-temperature combustion, all harmful elements disappear.
The second zone is the afterburner for gas emissions.
Flue gases from the combustion process enter here. Even if we assume that some harmful substances have passed the first zone, then during the secondary afterburning, where the temperature exceeds 850 ° C, they will definitely be destroyed. In addition, a special carbamide solution is injected into the afterburner chamber to completely remove organic compounds and neutralize flue gases.
Infographic: Energy from Waste Project
The flue gases and slag then enter the reactor. There, activated carbon and ammonia are processed, chemical elements are added for additional neutralization.
Already purified flue gases exit the reactor, they enter bag filters, where very thin tubes select any fraction, up to microparticles, which simply hover in the air. According to experts, if we take measurements of the air in the city and the air after the bag filter, then it is much cleaner at the plant.
So, a ton of garbage 15 minutes after entering the boiler turns into steam.
This steam is sent to a turbine generator to produce electricity. At the same time, only 5-10% of the energy produced is spent on the plant's own needs, the rest goes to the grid.
Zero waste: slag and ash handling
After incineration, the waste is reduced by 90% in volume. Ash and slag remain after thermal processing of waste.
Slag is the fifth hazard class of waste; unsorted waste has the same hazard class. It can be immediately used for backfilling roads. Ferrous and non-ferrous metals are preliminarily selected from the slag, which are subsequently sent for processing.
Energy from Waste Project
Fly ash makes up approximately 3-5% of recycled waste and belongs to a higher, third, hazard class. Therefore, RT-Invest plans to build a plant in the Moscow region to process such ash into building material using Carbon8 technology. This technology has been recognized by the UN and has been awarded an award for its contribution to the EU's circular economy.
