Equipment and technology for waste incineration. Burning waste is incompatible with the concept of sustainable development. Thermal methods of waste processing

Waste incineration- an old tradition. Since ancient times, people have put into the oven what was not useful for feeding livestock or fertilizing the land. Residents of Austria, still in early XIX centuries, they learned to burn garbage, because they had to pay a tax, the size of which was proportional to the volume of garbage removed.

In most European private houses in the 20th century, waste incinerators were installed. But, despite the effective reduction of waste, the method turned out to be unsafe - leaks of harmful gases occurred quite often.

England was the first to burn waste in factories in 1870. The workers simply threw it into the stove and scooped out the ashes.

In 1893, near Paris, the first waste incineration plant was built, which caused disapproval from agronomists - why destroy organic waste if it can be used beneficially, as fertilizer. At first their opinion was listened to, but in 1906 organic waste was again allowed to be destroyed if there was no buyer for it.

At first, traditional fuels such as coal or fuel oil were added to the garbage. Over time, the equipment was improved. In 1930, a stove with a grill appeared, which significantly increased efficiency (up to 90% of the mass was burned) and facilitated human labor.

Garbage can be turned into fuel. Similar to low-grade coal. But only if they are removed when wet. organic waste, iron, glass.

The incinerator will, among other things, need filters to clean the smoke before releasing it into the atmosphere. Because it contains harmful gases and particles called “fly ash” (particles ranging in size from fractions of a micron to 0.14 mm). It is also necessary to filter out volatile compounds of heavy metals and gaseous hydrochloric acid.

The solid residues remaining after purification (35–50 kilograms of toxic substances per ton of waste burned) are chemically stabilized or compressed, and then sent to specialized storage facilities as “hazard class 1 waste.”

When burned, slag remains. They can be useful in steelmaking, for producing aluminum wires, and after sifting, for laying underlying soil when laying roads designed for light loads, such as pedestrian and parking lots. True, the use of such slags is subject to strict regulations, because they may contain toxic inclusions and residues of flammable substances.

The technology of thermal treatment and waste disposal is used primarily by developed countries. For example, Japan, Belgium, Germany, France, the Netherlands, Switzerland, Sweden, Austria, Denmark. The number of factories is not increasing, but their size is increasing.

Disadvantages of combustion technology

• Harmful chemical compounds and microparticles hazardous to health and environment, too small to clean the filters.
• Furnaces require a constant load, so there is a high probability of burning raw materials that could be recycled.

The EEC Council at one time issued a dozen directives regulating waste management, including: limits on emissions of harmful substances into the atmosphere, availability of permits for enterprises, operating conditions, control and measurement of substances.

The Waste Directive of July 15, 1975 stipulates that waste must be disposed of without harming human health or harming the environment. The June 1989 directive dealt specifically with air pollution from waste burning.

In 2000, the European Union issued even stricter regulations on waste incineration. Article 6 is not much different from the conditions of operation of recycling enterprises described in the 1989 directive:

Gases released during combustion must be heated for at least 2 seconds, at a temperature of at least 850 °C. If burned hazardous waste containing more than 1% halogenated organic compounds (eg chlorine), the temperature should be 1100 °C minimum. If the temperature will drop, the burners should turn on automatically.

If emission limits are exceeded, under no circumstances should waste combustion be continued for more than four hours of continuous operation. During the year, they should accumulate no more than 60 hours.

Factories had to take this newer regulation into account and acquire new smoke cleaning equipment, the cost of which accounts for up to two-thirds of all costs.

In Art. 6 (clause 1) stipulates the need to heat the smoke for 2 seconds at a temperature of 850 °C to destroy dioxins and furans - a total of about 20 compounds of varying degrees of toxicity. Also, surviving dioxins are absorbed by activated carbon or decomposed through catalysts. Despite precautions, poisoning of livestock, people and the environment still occurs. Thus, in Savoie, poisoning by dioxins contained in the fumes of a waste incineration plant led to the slaughter of 7,000 head of livestock in 2001.

Explosion at the chemical plant of the Swiss pharmaceutical company Hoffmann-La Roche in Seveso (Italy) in 1976.

After an explosion at a chemical plant in the city of Seveso in Italy, a cloud with a high concentration of dioxin spread over an area of ​​16 square kilometers and caused mass poisoning of people and domestic animals. In fact, dioxin emissions at the plant are controlled (except for emergency situations). More powerful sources are burning landfills, bonfires in which garbage and plant waste are burned, including in garden plots. Their combustion temperature is relatively low - up to 600°C. This mode produces tens of times more dioxins and furans than in waste incineration plants, which use a high-temperature process (about 1000°C). If the technology is followed, the volume of harmful emissions will be close to the prescribed European standards.

In France, in 2007, the Isseana plant was built to heat 79,000 homes and produce electricity for 50,000 apartments. Listening to environmentalists, the administration deliberately lowered production standards to encourage the inhabitants of Ile-de-France to reduce the volume of waste, resorting to more complete pre-sorting in order to increase the volume of recyclable raw materials. The sorting shop also contributes to this.

Waste incineration plants were renamed “enterprises for the use of waste as energy raw materials.” Simply destroying waste by burning is ineffective and unprofitable; it is necessary to first sort the waste and reuse it. And burn the remains using the resulting heat. At the government level, in Germany, in the Netherlands, in the Scandinavian countries, they decided to reduce the volume of waste through sorting, processing and recycling.

Report by Doctor of Technical Sciences Igor Mikhailovich Mazurin (NRU MPEI) and environmental engineer Vera Vladimirovna Ponurovskaya (NRU MPEI) at the XXV meeting of the All-Russian Interdisciplinary Seminar-Conference of the Geological Faculty of Moscow State University “Planet Earth System” on January 31, 2017.

Today, more than 31 billion tons of unrecycled waste have accumulated in Russia, and their amount annually increases by more than 60 million tons per year. However, main problem is not constant increase the amount of garbage, but rather the inability to manage it. The diagram below clearly shows that Russia is the world leader in waste deposition.

There are no factories in Russia that carry out the full cycle of waste processing. Most domestic industries are still limited to the purchase of industrial presses necessary for compacting waste for its further placement at a landfill.

There are four official waste landfills in Moscow: “Salaryevo”, “Rakitki”, “Sosenki” and “Malinki”, their capacity is almost exhausted. During the first week of the All-Russian project popular front(ONF) " spring-cleaning“On the “Interactive Map of Landfills,” 21 illegal landfills were noted in Moscow and the Moscow region alone. In total, according to unofficial data, there are more than 20 thousand such landfills in Russia.

How are they going to solve this problem in the Year of Ecology? Just before the New Year, the Government approved the passport of the priority project “Clean Country”.

From January 2017 to 2025, it is planned to build five environmentally friendly waste incineration plants with thermal treatment of municipal solid waste in the country: four in the Moscow region and one in Kazan. The regions where the project began to be implemented were not chosen by chance - Tatarstan and Moscow and the Moscow region cannot cope with the volume of solid municipal waste that is generated on their territory. At the same time, these plants will be built using foreign technologies included in the BAT reference book for waste management.

In the process of working on the reference book of the best available technologies, the European technical reference books BREF, directives of the Council of Europe in the field of waste management and other foreign sources containing information on the mechanisms for applying the principle of the best available technologies were translated and abstracted.

The BAT guide for waste management is compiled in 3 parts. Parts 1 and 2 are devoted to BAT for waste management by various methods, with the exception of special combustion technologies; Part 3 presents BAT for waste incineration. BAT for waste management and BAT for waste incineration are compiled on the basis of separate European reference books, that is, a structure similar to that prevailing in the EU countries has been adopted. The authors of the directory assure that the organizational, technical, environmental and economic information contained in the directory is adapted for use in Russian Federation. Several questions arise here:

1. How is the above information adapted to Russian realities?

2. Why is not a single domestic technology included in the directory, either for waste processing using various methods, or for thermal processing?

3. And finally, why did the priority project include only technologies related to waste incineration?
There are no answers to these questions.

But first of all, it is necessary to understand whether the construction of waste incineration plants complies with Russian environmental legislation. According to Article 1 of Federal Law No. 89 “On production and consumption waste” The purpose of waste disposal is to “reduce negative impact waste on human health and the environment."

Foreign studies of the health of people living near incinerators note more frequent cases of sarcoma, lymphoma, lung cancer, liver cancer, congenital deformities, and allergic diseases.

Plant employees and residents of nearby dachas will inevitably find themselves in the dirtiest 1-kilometer zone, where the risk of cancer is high for everyone. There are many villages in the 5-kilometer zone, where the risk of cancer in children doubles. More than half a million people live within the 24-kilometer pollution zone (the distance over which dioxins generated by burning waste can spread).

When 1 kilogram of polyvinyl chloride, from which many types of linoleum, window frames and electrical equipment are made, is burned at an incineration plant, up to 50 micrograms of dioxins are formed. This amount is enough to develop cancerous tumors in 50,000 laboratory animals.

Burning garbage

Dioxins are global ecotoxicants with powerful mutagenic, immunosuppressant, carcinogenic, teratogenic and embryotoxic effects. They are weakly broken down and accumulate both in the human body and in the biosphere of the planet, including air, water, and food. The reason for the toxicity of dioxins lies in the ability of these substances to precisely fit into the receptors of living organisms and suppress or alter their vital functions.

Dioxins, suppressing the immune system and intensely affecting the processes of cell division and specialization, provoke the development of cancer. Dioxins also interfere with the complex functioning of the endocrine glands. They interfere with reproductive function, sharply slowing down puberty and often leading to female and male infertility. They cause profound disturbances in almost all metabolic processes, suppress and disrupt the functioning of the immune system, leading to the state of so-called “chemical AIDS”. Recent studies have confirmed that dioxins cause deformities and developmental problems in children.

Dioxins enter the human body in several ways: 90 percent - with water and food through gastrointestinal tract, the remaining 10 percent comes with air and dust through the lungs and skin. These substances circulate in the blood, deposited in adipose tissue and lipids of all cells of the body without exception. They are transmitted through the placenta and breast milk to the fetus and child.

Currently, there are 7 waste incineration plants operating in Russia. They burn waste at temperatures up to 850 degrees Celsius. At this temperature, the maximum amount of dioxins is formed, since effective destruction of dioxins is possible only at temperatures above 1200 degrees.

How are they going to control such a dangerous pollutant as dioxins? According to the same BAT reference book - once a year. Such rare control is not surprising if we remember the fact that in Russia there are only 3 laboratories capable of dioxin analysis: in Moscow, Ufa and Obninsk.

Tab. 1. Frequency of monitoring marker pollutants in emissions in atmospheric air

Once a year they also plan to monitor cadmium, thallium, mercury and its compounds. Meanwhile, New York's Department of Environmental Conservation has found that state-owned waste incinerators emit up to 14 times more mercury per unit of energy than coal-fired power plants. In 2009, in New York City, waste incinerators released a total of 36% more mercury than coal plants.

Let us recall what the concept of "environmental crime" is absent in our legislation, and pollution is often considered to be the excess of a harmful component above the background.

At the same time, there are no archival data from state monitoring of most of the territory of our country, and it is almost impossible to prove the damage caused by the OS (especially cumulative damage).

As for less serious pollutants than mercury and dioxins, the concentrations of their emissions into the air from waste incineration plants exceed the maximum permissible concentrations of the same substances often by three orders of magnitude.

Tab. 2. Current air emissions levels

In addition, the Russian Ministry of Natural Resources is still planning to ban the burning of unsorted recyclable waste. And before this ban, waste incineration plants will burn everything.

Why Russia did not borrow world experience in this aspect remains unclear. In Europe, where there are also waste incineration plants, separate collection:

— fluorescent lamps containing mercury;

— radio electronics elements: batteries, accumulators, microcircuits containing heavy metals;

- plastic;

- chemically aggressive components.

Besides, EU Directive on waste requires separate collection of at least four fractions of solid municipal waste: glass, paper, metal and plastic. At the same time, various national legislations may require the population to carry out even more careful sorting of waste.

The EU has also adopted separate directives regulating the handling of special types waste - packaging, used oils, waste from treatment plants, disused batteries vehicles, electronic waste.

In Russia there is no regulatory framework waste sorting will lead to the fact that it will be almost impossible to select a sorbent for harmful emissions, because it will be impossible to predict the composition of active radicals that will produce waste during oxidation. It will also be impossible to predict the substances that will be obtained during the recombination of the resulting radicals. With this approach, we can end up with even more toxic substances than those we planned to burn.

I would also like to draw attention to ultra-small particles that even a properly selected filter cannot retain.

Ultra-fine particles are particles generated from the combustion of materials (including polychlorinated biphenyls, dioxins and furans). These particles can be deadly, causing cancer, heart attacks, strokes, asthma and lung diseases. It is estimated that airborne particulate matter is responsible for the deaths of more than 2 million people worldwide each year.

We should also not forget that filter units and elements for them usually account for about 2/3 of the cost of the entire waste incineration plant project. In Russian reality, expensive filters can be installed, but then turned off. Fines for such a violation are insignificant, and Rosprirodnadzor specialists must warn about the upcoming inspection three days in advance.

Let us recall that Rosprirodnadzor already had complaints against the gas treatment plants of the waste incineration plant. Thus, during an inspection in 2009 of MSZ No. 2 in Moscow, claims were made regarding the quality of work and maintenance of gas treatment units (GPU):

“In 2007, there was no assessment of the efficiency of the state educational institution at all. Technical inspections of gas treatment plants are not carried out,” “the actual efficiency of gas treatment plants for substances: dioxins and furans is lower than the design efficiency stated in the passports of gas treatment plants.”

For some reason, wastewater from waste incineration plants is also passed over in complete silence.

Tab. 3. Current levels of wastewater discharges from wet gas cleaning systems

It is clear that these discharge levels are not intended for discharge into a body of water, which means that expensive and multi-stage wastewater treatment systems from waste incineration plants are required.

Thus, it can be seen that waste incineration plants harm the environment and do not satisfy the main purpose of the Law “On Industrial and Consumption Waste”.

In addition to the main goal, the law also stipulates main criterion for waste disposal. This main criterion is reduction of waste mass.

The construction of a waste incineration plant in Kazan is planned under the slogan “Zero Disposal”. The ash remaining after burning waste (which is 20-30% of the waste mass) is planned to be used in road construction.

However, in fact, ash is very toxic (hazard class III), so its scope useful application very limited. In addition, there is no provision for radiological control of incineration waste ash, although, as is known, during combustion there is an increase in radioactivity by approximately 10 times.

Due to its chemical instability, ash is of limited use as a filler in the construction of roads and low-impact reinforced concrete products (curb stones), that is, where its stabilization is ensured by adding it to hardening mixtures. In addition, according to recent studies, the addition of waste incineration ash to cement mixtures worsens the strength of cement, although it leads to stabilization of the metals contained in it. In many cases, ash is buried as toxic waste at specially equipped sites.

To ensure environmental safety and the possibility of widespread use of ash in construction, its special processing is required. The main technology for neutralizing ash is its remelting using various heat supply schemes (electric arc, plasma, etc.). This approach to the problem seems unjustified both for technological (multi-stage waste disposal process) and economic reasons (additional capital and energy costs).

Of course, in Russia there are also domestic technologies (for example, waste disposal in molten slag in Vanyukov furnaces) that make it possible to obtain potentially environmentally friendly slags for the production of a wide range of building materials.

But, we repeat, not a single domestic technology was included in the BAT reference book.

In addition, according to various estimates, 1 ton of waste, when burned, produces 4-5 tons of combustion products and 2.5 m3 of wastewater. We discussed their danger to humans and the environment in detail above.

It is also worth mentioning that lobbyists for waste incineration plants stubbornly remain silent about future fate sorbents that should capture harmful emissions. On average, any sorbent is designed for approximately 10 thousand cycles. This is about a year of operation, a little more or a little less. And then the sorbents must either be disposed of or regenerated, removing toxic components from them. Nothing is known either about regeneration or disposal of sorbents. Let us remind you that since the technology is foreign, then, accordingly, the components of these factories and service are foreign, that is, we inevitably fall into technological dependence.

Thus, it becomes obvious that the principle of “zero disposal” is practically impossible, and waste incineration plants do not reduce, but increase the mass of waste, that is, they do not meet the main criterion for their disposal.

Factories of the Swiss-Japanese company Hitachi Zosen, which has built more than 500 factories around the world, will be built in the Moscow region and Kazan. Below we will briefly look at how things are going in these countries regarding waste disposal.

In Switzerland, slag from MSZ is not used for road surfaces(as is proposed in Russia), but are buried or used in the reclamation of landfills. Filters from MSZ are generally exported for disposal in Germany. Let us repeat that the fate of Russian filters is stubbornly passed over in silence.

It has been held in Japan for a long time deep processing recyclable materials. In Yokohama Prefecture, residents sort their garbage into 10 categories. And the town of Kamikatsu, in Shikoku, until recently there were 34 such names, this number is planned to increase to 44 in the next couple of years.

Sorting waste is not necessarily more expensive than burning it, they believe in Japan. And in some places they are already reducing the number of waste incineration plants. In Kamikatsu, the amount of waste burned has been halved over the past four years.

Finally, consider the Japanese dynamics. In 2001, 42 million tons were burned, 3 million tons were buried, and 7 million tons of waste were processed per year. In 2008, only 36 million tons were burned, 0.75 million tons were buried, 10 million tons were processed, and it is easy to notice that total waste generated decreased by 12% - the result of targeted, systemic efforts of municipalities and civil initiative groups.

As for other countries, in the USA, for example, out of 150 incinerators in the USA today, about 70 remain, and over the past 8 years not a single new waste incineration plant has been built at all. In the UK in 2009, the advertising standards agency banned waste company SITA Cornwall from distributing brochures for promoting incineration and, among other things, made claims for unsubstantiated claims that the UK Health Protection Agency allegedly stated that modern incinerators were safe.

It should be noted that in Russia the public is categorically against waste incineration plants. Thus, Greenpeace Russia, the Separate Collection movement and ECA united into the Alliance Against Incineration and for Waste Recycling to inform the Russian population about the dangers posed by the use of waste incineration technologies.

The Alliance has prepared and published a memorandum in which you can familiarize yourself in detail with the position of public organizations on the issue of waste management. The document emphasizes that plans for the construction of waste incineration plants contradict current legislation and the main directions public policy in the field of waste management in the Russian Federation. An environmentally friendly and cost-effective alternative that meets the objectives sustainable development countries are reducing consumption and reuse, as well as separate collection and recycling of waste.

The Alliance notes that there is competition for waste between the incineration and recycling industries. Therefore, by supporting primarily the construction of waste incineration plants (WIP), the Russian government is blocking the development of the industry recycling, since the best-burning waste - plastic and waste paper - are also the most in demand on the recyclables market.

The memorandum notes the danger of attempts to declare energy from waste incineration renewable and introduce a “green” tariff on it, which will oblige participants in the wholesale electricity market to purchase energy from MSZ. The difference in tariffs will be passed on to consumers, or will be compensated through subsidies from the budget, which could be directed, among other things, to the development of the recycling industry.

So, waste incineration plants not only destroy useful components contained in waste, but are also an extremely dangerous industry for humans and the environment.

Igor Mazurin, Vera Ponurovskaya

Along with the maximum use of their energy potential, a necessary requirement is the environmental safety of the process.

The Moscow Waste Incineration Plant (MSZ No. 2), in accordance with the Moscow Sanitary Cleanup Program, set out in Moscow Government Decrees No. 239 of May 5, 1992 and No. 941 of October 18, 1994, in the period from 1995 to 2000 was reconstructed The reconstruction was carried out in order to increase productivity and ensure environmental safety. The main technological equipment for the reconstruction of MSZ No. 2 was supplied by the French company CNIM in accordance with the contract. The scope of supply included three technological lines, consisting of waste incineration boilers, a complete gas purification system, a process monitoring and control system, as well as a continuous environmental monitoring system. Increasing the number of technological lines from two to three while maintaining their unit productivity (8.3 tons of solid waste per hour) made it possible to ensure reliable and stable operation of the plant and increase its productivity to 150 thousand tons of solid waste per year.

The multi-stage gas purification system installed after reconstruction fully meets the requirements of European and Russian standards and can significantly reduce emissions of harmful substances. Moreover, it should be noted that after the introduction of domestic cleaning technology, the plant obtained the best results in the world for the content of nitrogen oxides in flue gases.

Control and management of the technological process, starting with waste disposal, flue gas purification and ending with environmental monitoring, are automated. Thus, the likelihood of operator error is practically reduced to zero. Thanks to the utilization of the generated steam, the plant's needs for thermal and electrical energy are fully met, and the excess generated electricity is transferred to the city electrical networks.

The reconstruction of the plant made it possible to almost completely solve the problem of recycling solid waste generated in the North-Eastern Administrative District of Moscow, reduce the volume of disposal of this waste at landfills, as well as the number of garbage trucks transporting it and the fuel consumption they consume, and as a result improve the environmental situation in Moscow.

Garbage trucks transporting solid waste to MSZ No. 2 are weighed on scales upon arrival at the plant and checked for the absence (presence) of radiation. Solid waste is unloaded into a storage bunker with a volume of 39 thousand m3, located in the receiving department of the plant. Then, using two overhead grab cranes, the waste is distributed over the storage hopper, mixed, large items are removed from it, and also loaded into the receiving funnels of the boilers. After loading solid waste into the boiler funnel, the feeder delivers it to the grate. Through the gaps between the grates, primary air heated to a temperature of 170 ° C enters, which is necessary both for the combustion of solid waste and for cooling the grates.

The slag formed as a result of the combustion of solid waste on a grate is fed on a belt conveyor to a storage hopper. Along the way, ferrous metal is separated from the slag, which is then recycled. And a lot of such metal is produced - about 1.5 thousand tons per year! From the storage bunker, slag, in accordance with the permission of the Main Directorate of Natural Resources of the Ministry of Natural Resources for Moscow, is taken to the solid waste disposal site owned by the State Unitary Enterprise "Ekotekhprom".

Currently, the plant is completing the construction of a workshop for processing ash and slag waste using domestic technology. After the launch of this workshop, the technology for neutralizing solid waste will become waste-free.

As a result of recycling the heat of flue gases generated during the combustion of solid waste, superheated steam is obtained from one boiler with the following characteristics: pressure - 15 atm, t - 240 °C, volume - 15 t/h, which is sent to turboelectric generators. There are only three of them at the plant, each with a capacity of 1.2 MW. A third of the generated electrical energy goes to the plant’s own needs, and the rest is transferred to the Mosenergo network. Steam with a pressure of 6 atm is sent to the needs of the plant, the rest of the steam is sent to aerocondensers, where it is condensed and also used in the production cycle of the plant.

As is known, the combustion of solid waste produces a number of harmful substances: nitrogen oxides (N 0 x), sulfur oxides (S 0 x), carbon oxides (CO), hydrogen chlorides and fluorides (HCI, HF), dioxins and furans. Therefore, the composition technological equipment waste incineration plants must include dust and gas collection systems that ensure a reduction in the content of harmful substances in flue gases to the required standards. MSZ No. 2 is the first enterprise in Russia where there is multi-stage system gas purification, meeting the requirements of European standards for emissions of harmful substances from flue gases adopted for solid waste combustion plants.

In addition to heat recovery, the waste incineration boiler performs the functions of the first stage of flue gas purification. It is known that the concentration of dioxins and furans formed during the combustion of solid waste is significantly reduced if the flue gases are in an area with a temperature > 850 °C for at least 2 seconds. For these purposes, in the semi-radiation part of the boiler, by optimizing the combustion mode of solid waste, a temperature of 850-950 "C is maintained and the required residence time of the flue gases is ensured. Technological equipment for cleaning flue gases in the plant's incineration boilers (with the exception of M0 x) was supplied complete with main equipment by the French company CNIM... To purify gases from M0 x, domestic technology is used, developed and patented by the I.M. Gubkin Russian State University of Oil and Gas.

MSZ No. 2 is located within the city, in a residential area, therefore the Department of Natural Resources and Environmental Protection of the Moscow Government has set an emission limit corresponding to the concentration of M0 x in flue gases - 50-70 mg/m³. And this is significantly below European standards.

As shown by the results of research and industrial implementation of non-catalytic reduction of NO (CHKB) processes carried out at the Russian State University of Oil and Gas named after. THEM. Gubkin, in waste incineration boilers, when using this cleaning method, it is possible to reduce the NO content to 70-90%. The SNCR process occurs at a temperature of 900-1,000 °C, does not require the use of a catalyst, and does not depend on the content of sulfur oxides and the degree of dust content of gases. To achieve the maximum degree of N0 reduction, at least 0.5 s is required. Various amine-containing compounds, such as ammonia or urea, can be used as a nitrogen oxide reducer.

Environmentally friendly urea was chosen for the purification process scheme for MSZ No. 2 of the State Unitary Enterprise "Ekotekhprom". The reduction of NO in this case occurs in accordance with the reaction equation: 4 NO + 2 CO (NH²)² + 0² = 4 N² + 2С0² + 4Н² 0.

Solid urea from the storage facility is supplied using a screw feeder into a container for preparing a solution, where chemically purified water is simultaneously supplied. The prepared 40% urea solution is automatically pumped into working containers by a signal from the level gauge sensor, then supplied by dosing pumps to mixers, where it is mixed with steam. The resulting reducing mixture is introduced through a special distribution system into the design zone of the combustion chamber of waste incineration boilers. It should be said that the process of NO reduction with urea in the case of excessive consumption of the reducing agent, ineffective mixing with flue gases, or a decrease in the temperature in the reducing agent input zone below optimal values ​​may be accompanied by the leakage of unreacted ammonia (NH³).

The NH³ content in purified gases is regulated and, in accordance with international standards, should not exceed 10 mg/Nm³. To monitor the content of N0 and МН³ in flue gases, automatic gas analyzers GM 31 from Sick Maihak GmbH (Germany) are used. These devices are based on the optoelectronic measurement principle, which allows simultaneous determination of the content of each component in real time directly in the gas flow. Monitoring and regulation of the process of cleaning flue gases from nitrogen oxides is carried out using an automated control system

The cleaning system operates on domestic equipment; granulated urea is used as a reducing agent (GOST 2081-92).

At a temperature of about 850 °C, the degree of purification is about 60%; with an increase in temperature to 900 °C, it increases to 70% and reaches maximum values ​​at 80-85% at a temperature of 970-990 °C. The concentration of ammonia in purified gases at temperatures above 900 °C, characteristic of the normal operation of waste incineration boilers, does not exceed 10 mg/nm³ and is, as a rule, 3-5 mg/nm³.

Experience in operating the cleaning system has shown that it fully copes with the task and ensures that the NO concentration in flue gases is maintained at a level of 60-90 mg/nm³ (for comparison: European standards for the content of nitrogen oxides in flue gases of waste incineration boilers are 200 mg/nm³) .

The introduction of domestic treatment technology at MSZ No. 2 made it possible to save about $3.5 million by replacing imported technology.

Flue gases are purified from other pollutants as follows. Due to the alternating change in the direction of movement of flue gases in the boiler by 180° (down - up), fly ash is partially released, which enters the ash removal system. From the boiler, flue gases are sent to the next gas purification stage - into a reactor designed to purify gases from acidic components: S0², HCI, HF. As the flue gases move towards the reactor, finely dispersed activated carbon is introduced into them to bind dioxins, furans and heavy metal salts. In the reactor, as a result of the interaction of lime milk with acidic components, the process of their neutralization occurs.

After the reactor, flue gases enter a “pulse-jet” type bag filter, where fly ash, dust and gas purification products (calcium salts formed when flue gases come into contact with lime milk), as well as activated carbon with components adsorbed on it, are captured. . Less than 10 mg/Nm³ of dust remains in the flue gases after the bag filter.

After cleaning in a bag filter, the flue gases are removed through a 100 m high chimney. A gas analyzer is installed in this chimney, designed for continuous monitoring of the content of harmful substances in the flue gases (HCI, CO, 0², dust, S0²). The content of dioxins and HF is periodically measured by the center analytical control Department of Natural Resources and Environmental Protection of the Moscow Government. The content of HCI at the exit from the chimney is less than 10 mg/nm³, dioxins and HF - no more than 0.1 ng/nm³ and 1 mg/nm³, respectively, and also does not exceed European standards.

Thus, the organization of the combustion process of solid waste and the solution of environmental safety issues at MSZ No. 2 made it possible to meet the most stringent requirements for emissions of pollutants into the atmosphere.

Combustion and pyrolysis of municipal solid waste

Experience shows that for major cities with a population of more than 0.5 million inhabitants, it is most advisable to use thermal methods of solid waste disposal.

Thermal methods of processing and disposal of solid waste can be divided into three methods:

-layer combustion of initial (unprepared) waste in waste incineration boilers (MSCs);

-layer or chamber combustion of specially prepared waste (freed from ballast fractions) in power boilers together with natural fuel or in cement kilns;

-pyrolysis of waste, with or without preliminary preparation.

Despite the heterogeneity of the composition of municipal solid waste, it can be considered as a low-grade fuel (a ton of waste produces 1,000-1,200 kcal of heat when burned). Thermal processing of solid waste not only neutralizes it, but also allows you to obtain thermal and electrical energy, as well as extract the ferrous scrap metal contained in them. When incinerating waste, the process can be fully automated, therefore, the maintenance staff can be sharply reduced, reducing their responsibilities to purely management functions. This is especially important when you consider that staff must deal with unsanitary material such as solid waste.

Layered combustion of solid waste in boilers. With this method of neutralization, all waste entering the plant is burned without any preliminary preparation or processing. The method of layered combustion of initial waste is the most common and studied. However, during combustion, a large amount of pollutants is released, so all modern waste incineration plants are equipped with highly efficient devices for capturing solid and gaseous pollutants, their cost reaches 30% cap. costs for the construction of the incinerator plant.

The first waste incineration plant with a total capacity of 9 t/h was put into operation in Moscow in 1972. It was intended to burn residues after composting at a waste treatment plant. The incineration shop was located in the same building with the rest of the plant's shops, which was closed in 1985 due to the imperfection of the technological process and the resulting compost, as well as the lack of a consumer for this product.

The first domestic waste incineration plant was built in Moscow (special plant No. 2). The plant's operating hours are 24 hours a day, seven days a week. The heat obtained from waste combustion is used in the city's heating system.

In 1973, the company ČKD-Dukla (CSFR) acquired a license from the Deutsche Babcock company (Germany) to produce MSCs with a roll grate. Due to foreign trade relations, boilers produced by this enterprise were purchased for a number of cities in our country.

In 1984, the largest domestic waste incinerator was put into operation in Moscow. plant No. 3. The productivity of each of its four units is 12.5 tons of incinerated waste per hour. Distinctive feature unit - an afterburning drum installed behind a cascade of inclined-pushing grates.

The operating experience of domestic plants has made it possible to identify a number of shortcomings that affect the reliability of the main process equipment and the state of the environment. To eliminate the detected deficiencies it is necessary:

-ensure separate collection of ash and slag;

-provide for the installation of backup conveyors for the removal of ash and slag waste;

-increase the degree of extraction of scrap ferrous metals from slag;

- ensure cleaning of the recovered scrap metal from ash and slag contamination;

-provide optional equipment for packaging recovered scrap ferrous metals;

-develop, manufacture and install technological line for preparing slag for recycling;

Installations or plants for processing municipal solid waste by pyrolysis operate in Denmark, the USA, Germany, Japan and other countries.

Activation scientific research and practical developments in this area began in the 70s of the twentieth century, during the period of the “oil boom”. Since that time, the production of energy and heat from plastic, rubber and other combustible waste by pyrolysis began to be considered as one of the sources of energy resources. Especially great importance given to this process in Japan.

High temperature pyrolysis. This method of solid waste disposal is essentially nothing more than gasification of garbage. The technological scheme of this method involves the production of secondary synthesis gas from the biological component (biomass) of waste in order to use it to produce steam, hot water, electricity. An integral part of the high-temperature pyrolysis process are solid products in the form of slag, i.e., non-pyrolyzable residues. The technological chain of this disposal method consists of four successive stages:

1. selection of large-sized objects, non-ferrous and ferrous metals from garbage using an electromagnet and by induction separation;

2. processing of prepared waste in a gasifier to produce synthesis gas and by-product chemical compounds - chlorine, nitrogen, fluorine, as well as slag from melting metals, glass, ceramics;

3. purification of synthesis gas in order to increase its environmental properties and energy intensity, cooling and entering it into a scrubber for cleaning with an alkaline solution from pollutants of chlorine, fluorine, sulfur, cyanide compounds;

4. combustion of purified synthesis gas in waste heat boilers to produce steam, hot water or electricity.

When processing, for example, wood chips, synthesis gas contains (in%): moisture - 33.0; carbon monoxide - 24.2; hydrogen - 19.0; methane - 3.0; carbon dioxide -10.3; nitrogen - 43.4, as well as 35-45 g/nm of tar.

From 1 ton of solid waste, consisting of 73% solid waste, 7% rubber waste (mainly car tires) and 20% coal, 40 kg of tar used in the boiler room and m3 of wet gas are obtained. Volume fraction components of dry gas are as follows (in%): hydrogen - 20, methane - 2, carbon monoxide - 20, carbon dioxide - 8, oxygen - 1, nitrogen - 50. The lower calorific value is 5.4-6.3 MJ/m3. The slag produced is 200 kg/t.

Director of Paritet LLC Gmyzin Oleg Gennadievich 8 9039134717, 8 9618915050
a unique product in the field of environmental protection. Waste incinerator "Ecofan 800"(standard 800 kW thermal power output)

The installation is designed for burning municipal solid waste (MSW), medical waste, combustible industrial waste, livestock waste, greenhouse farms, liquid dense hydrocarbon masses, for example oil sludge, car tires. Allows you to reduce the size of landfills.

The process is accompanied by the production of heat for heating industrial and commercial facilities, as well as providing hot water supply (DHW).So we win twice:Using an extremely simple, cheap and reliable technological cycle waste incineration.We get the opportunity to use the heat of the water circuit for heating rooms and hot water.

The principle of combustion of solid waste in the installation is based on a completely new, unique, innovative technology. This is a thermochemical reaction in the boiler itself and a catalytic reaction of the exhaust gases. In the process of these reactions, we obtain high thermal power of the installation, 2 times more than with conventional combustion, and clean waste gases at its output. These gases consist of a mixture of carbon dioxide (CO2) and water vapor (H2O).

Why the unique Ecofan 800 Waste Incinerator?Because:Existing analogues require additional costs for the disposal of garbage and production waste in the form of:Requires afterburning of waste gases with natural gas 0.1-0.2 m3/h (per 50 kg of waste) or diesel fuel at the rate of 0.12-0.17 l/kg of waste;Requires electricity consumption in excess of 14 kW/h;Requires the use of adsorbents and filter elements (consumables);Require the use of chemical components and additives that require precise dosage and adherence to a clear technological cycle;They require the use of computer systems for controlling technological processes, which are expensive both to purchase and to maintain;

The listed factors affect the reliability and fault tolerance of processing plants in general, and increase the dependence of the cycle on the human factor. These factors together significantly increase the costs of operation and maintenance of installations, which leads to a significant increase in the cost of the waste disposal process, and often reduces the entire project to unprofitability.

The Ecofan 800 waste incinerator is free of these disadvantages; it uses a new principle of waste combustion. This is a thermochemical and catalytic reaction of neutralization of waste gases inside the furnace (dioxins, pyrene), and with it the generation of a large amount of thermal energy, and its use for the needs of the enterprise!At the exit we get a gas flow,

The tasks that we set for ourselves when working on this project are:Environmental friendliness (Environmental safety);Thermal efficiency;Reliable operation, long service life;

1. Environmental SafetyWhen burning MSW (municipal solid waste), various oils (hydrocarbons), dioxins and pyrene can be formed. These substances are very dangerous; they can accumulate (accumulate) in the human body and affect the development of the body, causing various pathologies and diseases. Therefore, the main emphasis when creating the installation was the principle of environmental safety. Emission of harmful substances from the installation"Ecofan 800"into the atmosphere significantly below the maximum permissible concentration.

The installation passed all production cycle tests and exhaust gas measurements:Work on measuring gases emitted into the atmosphere was carried out by the Saratov State University them. N.G. Chernyshevsky under the guidance of Doctor of Chemical Sciences, Professor R. I. Kuzmina.Protocol for the analysis of industrial emissions into the atmosphere No. 197 October 23, 2013 Branch of TsLATI in the Saratov region.Environmental certificate of conformity No. 00002161 was issued by the Ministry of Natural Resources and Ecology of the Russian Federation.

2. Thermal efficiencyWhen burning industrial waste and solid waste in a complex"Ecofan 800", both in the combustion chamber and in the thermochemical chamber there is a large release of heat, which we select with a water circuit and can use for heating premises and buildings, and for hot water supply. When burning solid waste, we receive heat in the combustion chamber of the order of 2000 kcal/kg of fuel, and then during the oxidation process of the gas flow in the thermochemical chamber another about 2000 kcal. In terms of heat efficiency, this is comparable to burning an equivalent amount of medium-quality coal.This installation in standard produces an average of 800 kW/h of heat, which makes it possible to heat about 5000-7000 m2 of space, with electricity costs in operating mode ranging from 2 to 4 kW. Electricity costs are about 150 rubles per day with intensive waste burning.

Using our combustion technology, waste becomes highly efficient fuel, cheap fuel and allows the owner of the installation to generate profit.

3. Profitability and self-sufficiency. Expenses: When servicing the installation around the clock, 4 people are required, i.e. staff salary is on average 1000 rubles. for each + electricity costs 150 rubles. per day. Total 4150 rubles per day.

Profit: - from the disposal of solid waste on average at the rate of 500 rubles per 1 ton (this is how landfills accept it)how much waste we can dispose of, with an average combustion of 500 kg/hour with a standard installation: 0.5t*24h=12t per day. This is 3 Kamaz vehicles per day. Total we have 6000 rubles per day

And if you burn hazardous waste, sleepers, medical waste, oil sludge, then the level of profit increases many times over.

Installation "Ecofan" can be supplied in an extended configuration with a thermal equivalent power of up to 5 MW. With a garbage loading chamber of up to 7 cubic meters. and the average combustion rate of solid waste is up to 2500 kg/hour. The use of such modular installations will solve many issues regarding heat supply to enterprises, residential areas, and issues with waste disposal

Today, the approximate cost for the city to transport waste to a landfill is 5 million rubles per day. This is based on export to Tomsk 4000 tons of garbage per day. 1 ton of garbage costs, according to our calculations, 1,250 rubles (500 rubles / ton - garbage reception at the landfill, 1,000 rubles per vehicle / hour for 1 Kamaz with a capacity of 4 tons). The installation allows you to burn from 200 to 800 kg of solid waste per hour, depending on the combustion mode and composition of solid waste. It is easy to calculate how much waste we can recycle with an average combustion of 500 kg/hour using a standard installation: 0.5t*24h=12t per day. This is 3 Kamaz vehicles per day.

Applying 3 settings "Ecofan" at 5 MW will allow to receive up to 30 - 40 Kamaz vehicles per day, working on average 140 tons of garbage per day. This is 50,400 tons per year. For comparison, a waste incineration plant in Moscow burns 150,000 tons per year, with a processing cost of 2,148 rubles/t. Here we will be paid for recycling and heating, hence the profit.

Design and principle of operation of the Ecofan 800 complex. The solid waste destruction complex is an all-welded metal structure assembled from several components that are extremely simple, cheap and reliable, which allows for a stable and sustainable technological cycle. The guaranteed service life of the installation is 10 years. It can serve for 20 years. It does not require regular replacement of the furnace wall coating due to the presence of a cooling circuit. The catalyst is changed once every 5-10 years. The oven is two or multi-chamber, which allows you to organize a continuous working cycle.

1) The combustion chamber The first stage of combustion of solid waste and neutralization of harmful substances.It is a cylindrical combustion chamber, partitioned inside with a slotted grill along the longitudinal axis into two equal compartments. This allows for a continuous combustion process throughout the entire working period and ensures cleaner combustion of waste due to preheating of solid waste from the half of the chamber where combustion is already taking place, so ignition is carried out first in one half of the chamber, then the second half of the chamber is loaded and the resulting heat dries the waste in the second half, “squeezes” out of it all the substances that evaporate to a temperature of 340 0 C, this makes it possible to destroy up to 75-80% of all components contained in organic substances that “organize” dirty emissions into the atmosphere, after which they spontaneously combust. Those. We perform “open” pyrolysis of newly loaded waste, using the temperature already obtained in the combustion chamber from the already burning waste. This design of the combustion chamber allows it to be freed from accumulated ash and loaded without stopping the operation of the apparatus. In addition, the combustion chamber grate system also contributes to the cleanliness and completeness of waste combustion. It consists of hollow pipes through which atmospheric air is supplied. The intensity of its supply is regulated using a frequency converter that controls the speed of the electric motor. The integrated air supply system allows for very precise adjustment of oxygen depending on the phase of waste combustion, which in turn contributes to a high degree of cleanliness of waste combustion. The remaining ash after combustion of solid waste is 1% - 3%. Atmospheric air, passing through hot layers of carbon formed as a result of combustion, synthesizes generator gas and methane gas in small volumes. The combustion of these gases allows the temperature in the combustion chamber to rise above 1200 0 C, and at such temperatures dioxins and pyrene burn, this allows us to organize, even at the initial stage of waste destruction - incineration, the first protective barrier to the path of harmful substances (dioxins, pyrene) before their release into the atmosphere.

2) Thermochemical chamber The second stage of neutralization of harmful substances.Designed to neutralize waste gases by carrying out thermochemical reactions. It is a vertically located all-metal cylinder, connected to the combustion chamber by welding. Atmospheric air is forced into the column into the system to carry out thermochemical reactions. As a result of this process, it is neutralized a large assortment harmful gases and suspended solids released into the atmosphere. In the process of ongoing thermochemical reactions, a large amount of heat is generated that can be used, which is what we do, using water as a coolant, which can be used to heat industrial and social facilities or hot water supply.

3) Flue gas separation system The third stage of neutralization of harmful substances in exhaust gases.Exhaust gases are separatedbattery of multicyclones.In it there is a sedimentation of hot solid particles of soot, which are the purest carbon, and mineral coking residues. The degree of gas purification in such a system reaches 99.5 - 99.8%. Purification of exhaust gases from solid impurities allows you to rid the gas flow of dioxides and pyrene. The resulting solid sediment has a very high degree of carbon purity and can subsequently be used as raw material for sale -a decorative additive in finishing building mixtures, in concrete for jointing, in the paint and varnish, perfume industries and in the production of rubber, or as a high-calorie fuel, from which even coal-water fuel (CWF) can be produced.It can also be used to apply it to the soil as a fertilizer, since all plants consist of at least 50% carbon.

4) Catalyst The fourth stage of neutralization of harmful substances in exhaust gases.The catalyst has a specially treated ceramic base with a porous highly developed surface, impregnated with a special catalytic composition. The catalyst composition is based on available cheap metals. This made it possible to eliminate precious materials such as gold, platinum and iridium in the production of catalysts. The catalyst is located in a metal cartridge on metal substrates. Their vertical arrangement forms cellular labyrinths, passing through which hot gas flows acquire turbulent movement, and the large length of the channels, labyrinths of the catalyst, allows all redox reactions of gases passing through it to be completed to the end and obtain a high-quality purified gas flow before releasing it into the environment Wednesday.

CONCLUSION

Incinerators of this type will help solve the global problem of recycling solid waste, industrial combustible waste, and car tires. Using the allocated heat for your own needs, the needs of the enterprise, and the needs of the population.When burning solid waste, we get a gas flow at the outlet,containing carbon dioxide and water vapor- the end products of the decomposition of any organic matter.