Processing of solid household waste to generate heat and electricity. Obtaining alternative energy from waste Energy from waste

Alexey Stepanov, Head of the Sveza Novator company, Novator village (Velikoustyug district, Vologda region)

• How can an enterprise generate 70% of its own electricity from waste?

Today it is more profitable to produce electricity from waste. For every cubic meter of finished plywood there is a cubic meter of waste. In Soviet times, waste could be buried. Due to stricter environmental regulations, recycling is now expensive.

Companies collect vast amounts of customer data, which ultimately turns out to be useless. The information is scattered, often outdated or distorted - on this basis it is impossible to make a unique selling proposition to the buyer and predict sales. Our article describes tools for collecting and analyzing information, the use of which:

• optimizes the company's marketing expenses;
• will help build a sales strategy;
• will reduce customer churn due to improved service quality.

For many years, our plant has been generating electricity from waste, which it uses in production. The plant operates around the clock and produces 500 cubic meters of waste (bark, wood chips, pencil and grinding dust). This is what we do with waste.

1. Burn the bark and wood chips. When waste is burned, thermal energy is generated. We use it for drying veneer and gluing plywood. We use thermal oil and power plants. The former heat the coolant, the latter heat the water, producing steam. 21% of waste is used for drying veneer, and 7% for gluing plywood. We also use waste to generate electricity at our own thermal power plant. The fuel is fed into the boiler room, which produces steam. Steam enters the hall through pipes, where there are two turbines from the Kaluga plant, each producing 1.5 MW. The turbines are spun by steam. Each of them is connected to a generator that produces electricity. A quarter of the bark and wood chips are used for the process.

2. We sell a pencil. The pencil is the remainder of the block (in professional language it is called churak). When peeling, the block rotates around its axis. The peeling knife moves perpendicular to the axis of rotation of the block, uniformly removing a strip of wood 1.6 mm thick. The churak is “unwound” to a cylinder 50 mm thick - a pencil is obtained, which accounts for 13% of waste. We sell it retail to factory workers and local residents: the pencil is turned into firewood. Local businessmen use the pencil in the production of coal. A cubic meter of pencil costs 200 rubles.

3. We make a new product from grinding dust (waste share - 3%). Previously, we burned the dust, but then we found a profitable recycling option. Together with my partner, we make fuel briquettes from dust. One briquette contains 3 kg of firewood. When they are burned, almost no ash is produced (the percentage of ash from dust is low, since the dust is produced by sanding the face of the plywood, where there are no bark particles).

• Industrial waste: 9 ideas on how to make money from it

Organization of collection, storage and redistribution of waste

We deliver waste to the warehouse using conveyors. There is no manual labor: the process is regulated by operators at the control panel, and tractor-loaders operate. Along the way, the waste is loaded into the ovens of the drying and gluing areas. The furnace loading device is open until the container is full, then the operator closes the valve by pressing a button. If the valve is closed, the waste travels further along the conveyor to the warehouse. At the warehouse, waste is poured off the belt, some of it is distributed into piles by front loaders, and some is leveled. There is a road around and among the piles of waste; it is needed for travel and fire-fighting purposes.

Waste is transported from the warehouse to the power plant by conveyors. A front-end loader scoops up 10 cubic meters with a bucket, brings it to the desired belt (a movable floor that delivers waste to a scraper conveyor) and dumps it out. The waste is transported along a conveyor to the furnace of the power plant.

Eventually

We generate 70–80% of our electricity from industrial waste. On repair days, when the machines (60% of the fleet) are resting, we make do with our own resources. Only once, during severe frosts, we did not have enough waste to generate electricity, then we took free wood chips from a nearby sawmill. The plans are to increase the number of turbines in order to completely eliminate purchased energy.

• How to create a waste-free production to maximize profits

GC "EKONATSPROEKT" is the official representative of a large German industrial manufacturer of equipment in the field of energy generation and power plant technology - Oschatz. One of the areas of our work is the promotion of environmentally friendly technologies for the generation of thermal and electrical energy from industrial and consumption waste. For additional information, we invite you to read our brochure “Energy Generation from Waste”.

Of the various methods for processing solid waste, the most mature and frequently used is thermal processing. The possibility of using this method is based on the morphological composition of the waste, which contains up to 70% flammable components.

The main advantages of thermal processing are:

• reduction in waste volume by more than 10 times;
• effective disposal of waste under the influence of high temperatures (from 850 to 1250°C);
• associated use of waste energy potential.

CHP plant using fuel from waste, Hagenow (Germany) was put into operation in 2009.

Mixed municipal waste contains significant amounts of moisture and unwanted components such as metals, chlorinated plastics, etc. For the safe thermal processing of such waste and improving its thermal characteristics, it is planned to prepare the waste into an alternative RDF fuel.

Alternative fuel - RDF.

RDF (from the English RefuseDerivedFuel) is a dehydrated and crushed mixture of calorific waste fractions, with a calorific value of up to 18,000 KJ/kg, a new alternative source of energy. Widely used as a fuel in the cement and power generation industries in developed countries.

Today, different technologies are used for thermal waste processing. However, the technology of combustion on a grate is most widespread in Europe. This technology has proven itself to be the best for burning residues after waste sorting, it is universal and the least demanding on fuel quality. The technology is described in detail in the BAT document “Integrating Pollution Prevention and Abatement - A Guide to Best Available Waste Incineration Technologies” from the European Union.

Description of technology

Schematic diagram of the technology for thermal processing of waste in a furnace with a grate:

Mixed waste or RDF enters the receiving department, where it undergoes primary control, then enters the storage hopper. From the bunker, fuel (waste) is dosed into a layer combustion furnace with a grate, where it burns at a temperature of 850 - 1000°C (depending on the properties of the waste). Burnt residues in the form of ash and slag are removed for further disposal. The resulting hot gases heat the walls of the recovery boiler and the superheater system, which convert the heat into water vapor, then the energy of the water vapor is converted into electrical energy or used in the form of heat. The exhaust gases are cooled and react with lime milk, urea and activated carbon, while nitrogen and sulfur oxides, as well as dioxins and heavy metals are neutralized in the gas flow. Next, particles of ash and reagents are captured by a system of bag filters and removed for disposal. Thus, the outlet gases contain harmful impurities within the limits of environmental and sanitary standards, for example, thermal recycling plants located in densely populated European cities.

Grate for layer combustion

The branded Oschatz grate is a further development of DanishEnergySystems horizontal grate technology, which has been in operation for several decades. The Oshatz grid provides such features of waste fuel as: lower heating value (LCC), high ash content and moisture content.

Schematic diagram of the Oschatz layer combustion furnace.

Lattice configuration and functionality. To control the combustion process, the grate is divided into several sections. The speed and stroke length of the grate bars can be adjusted individually. Likewise, the grille is divided into several air zones to adapt the primary air to the combustion characteristics of the fuel. Fuel is supplied to the grate continuously using a custom-designed feeder. The grate bars, mounted in series on the grate, are made of special heat- and wear-resistant alloy steel with a high content of chromium, silicon and nickel. Primary air is supplied to the grille from below along with flue gas recirculation. Secondary air is supplied to the space above the stove grate and provides the necessary oxygen for optimal afterburning of the fuel.

For layer combustion of waste, RDF or biomass, a waste heat boiler with a steam superheater system is located behind the furnace, followed by a system for neutralizing harmful impurities, dust and gas purification systems, as well as a thermal and electrical energy generator unit. EKONATSPROEKT supplies conceptual water tube boilers designed by Oschatz using the latest modern advances in vertical, horizontal or combined layouts.

We supply both individual units and the development and construction of entire turnkey plants.

To receive a product catalog and additional information, please call:

Generating electricity from waste is one of the ways to protect the environment.

Next, we will look at different ways to obtain energy from waste. As already noted, waste recycling is one of the ways to protect the environment. When carrying out the recycling process, you can not only save in the consumption of many natural resources, but also reduce the level of pollution of water, air and soil. Today, countries' environmental protection programs include issues of generating fuel from waste. Today we want to look at this issue.

As it was said, "The road of civilization is paved with mountains of garbage" . If the waste is recycled, it can be reused, but if it remains untouched and buried, it will remain an environmental pollutant. According to research by the World Health Organization (WHO), ignoring waste collection and disposal can cause at least 32 environmental problems. This is why recycling is being taken seriously by many countries today. One of the newest ways to reduce the negative impact that landfills have on the environment is to recycle waste into fuel. Garbage-to-fuel conversion is a process in which useless waste is converted into virtually free thermal energy that can be used in the form of electricity or heat. This practice has been carried out traditionally since ancient times in many countries around the world. For example, 400 years ago in Iran, the Iranian scientist Sheikh Bahai created a bathhouse, the energy supply of which was provided by gas emitted from wastewater. In India also, some people collected animal waste in closed containers and burned it for 9 months. This process is used in modern technology in various cities around the world. Particular attention is paid to the use of gas obtained from waste disposal centers in some cities around the world.

Methane, which makes up about 55% of all gas emitted from landfills, is a greenhouse gas that has the same greenhouse gas potential as carbon dioxide or even greater, so that atmospheric methane concentrations would increase by 0.6 percent per year. The concentration of other greenhouse gases in the atmosphere, including carbon dioxide, increases by only 0.4%. Methane, if not properly controlled, can lead to groundwater contamination. Thus, recovery and proper use of methane can play a significant role in protecting the environment.

Each ton of raw solid waste can produce between 5 and 20 cubic meters of gas per year, and increasing this amount is possible through proper resource development and management. Some ordinary people believe that since this gas is produced from waste, it is dangerous and polluting, and its combustion is unreliable. However, scientists believe that it is just the opposite, and that the gas produced from a landfill is less polluting, and since the flame temperature is low, the amount of pollution will be 60% less than when burning natural gas. Therefore, according to environmentalists, curbing gas from garbage is imperative. In recent years, as energy prices have risen, this type of fuel has received greater attention. According to statistics, there are now hundreds of landfills in the world where emitted gas is used to generate electricity and even sell it to other buyers.

Collecting this type of gas in the center of the landfill is quite easy. To do this, you need to dig vertical wells around the landfill. These wells are connected through a network of pipes designed to collect gas. Of course, in order to increase the performance of the system, layers of crushed stone, concrete and sand can be placed in their path. In addition, all these wells are connected to the central reservoir. The manifold can be connected to a compressor or blower. For approximately every 0.4 hectare of landfill area, a gas collection well is required. Ultimately, it is possible to inject gas into a flare or allocate it to any other consumption, or even purify it and improve its quality. Thus, with the joint production of thermal and electrical energy, a sharp reduction in carbon dioxide emissions and an increase in fuel efficiency can be observed. The high overall efficiency of this technology compared to the production of electrical and thermal energy using traditional methods has contributed to the fact that this type of technology has been highly valued in recent years in Europe. Europe's largest biogas plant is located in the Austrian capital of Vienna, using gas extracted from a landfill to produce 8 MW of electricity. The launch of congeneration plants is expanding at lightning speed across the European Union as private and public sectors have embraced congeneration technology as a cost-effective energy source with a variety of capabilities.

One of the successful projects carried out in this area is carried out in the Canadian city of Edmonton. An Edmonton electricity utility has managed to use methane from the Clover Bar landfill to launch a large power plant. The launch of this project in 1992 contributed to the reduction of atmospheric carbon dioxide emissions by about 662 thousand tons. In 1996 alone, this project contributed to the reduction of greenhouse gas emissions by 182 thousand tons, and between 1992 and 1996, about 208 gigawatt-hours of electricity were generated. Even the gas produced by this method was sold at a lower price than natural gas, so it turned out to be more economical. In Asia, the capital of South Korea, Seoul, is one of the cities that partially provides thermal energy from waste incineration. A lot of waste is thrown away in this city. Based on published reports, Seoul has used 730,000 tons of its 1.1 million tons of flammable municipal waste as fuel for energy production in recent years. It is said that this is equivalent to the annual heating needs of 190 thousand urban households. South Korea plans to meet more than 10% of its energy needs from renewable sources and by 2030 become one of the top five countries in the world with "green economy" .

In addition to generating energy from waste, another way to utilize waste is to convert it into compost fertilizer. Composting is a method of neutralizing household, agricultural and some industrial solid waste, based on the decomposition of organic substances by aerobic microorganisms. The resulting compost is similar to humus and is used as fertilizer. This is perhaps the oldest method of disposal. The composting process is very simple, done by experienced professionals either in the farmers' own homes or lands, or industrially. These fertilizers are considered one of the best fertilizers for agricultural purposes and can also be useful for growing flowers. The result of the presence of magnesium and phosphate in fertilizers will be the formation of alluvium and the rapid absorption of nutrients in the soil. Compost is also considered a natural pesticide for the soil. Using compost you can save 70% in the consumption of chemical fertilizers. Each person living in the city throws away more than half a kilogram of garbage a day, one third of which is convertible into compost. If we assume that the city has a population of 30 million people, then the city produces 15 million kg of waste daily, 5 million of which can be converted into compost.

Thus, modern man, after the bitter experience of the last century, decided that he must appreciate God’s blessings and take up environmental protection, since the existence of the future human generation and the world depends precisely on his current efforts.

Ministry of Education and Science of the Russian Federation

Federal State Budgetary Educational Institution

higher professional education

"Russian State University

Oil and Gas named after I.M. Gubkin"

Department of Industrial Ecology

Specialty: 241000

Grade _____________ (_____)

Date ________________

____________________________

teacher's signature

Coursework in the discipline

“Modern problems of chemical oil and gas technologies”

On the topic: “Recycling of municipal solid waste for the generation of thermal and electrical energy”

Student: Aurorv V.B.

Group:

Moscow 2015

Introduction

Human life is associated with the emergence of a huge amount of various waste. The sharp increase in consumption in recent decades has led to a significant increase in the volume of household waste generated.

Waste, when disposed of uncontrolledly, clogs and litters the natural landscape around us and is a source of harmful chemical, biological and biochemical substances entering the natural environment. This poses a certain threat to the health and life of the population.

Solving the problem of waste recycling has become of paramount importance in recent years.

In conditions of constant deterioration of the environmental situation, there is an increasing need to ensure the maximum possible safety of technological processes and safe disposal of waste.

1. Basic definitions of solid waste

1.1 Definition, classification, composition of solid waste

Solid household waste (MSW, household garbage) objects or goods that have lost their consumer properties. Solid waste is also divided into waste (biological waste) and household waste itself (non-biological waste of artificial or natural origin), and the latter is often referred to simply as garbage at the household level.

According to its morphological characteristics, solid waste currently consists of the following components:

Biological waste:

• Bones
• Food and vegetable waste (slops, garbage)

Synthetic waste:

• Old tires

Pulp processing:

• Paper newspapers, magazines, packaging materials
• Wood

Petroleum products:

• Plastics
• Textile
• Leather, rubber

Various metals (non-ferrous and ferrous)

Glass

Estimate

The fractional composition of solid waste (the mass content of components passing through sieves with cells of different sizes) affects both the collection and transportation of waste and the technology for their subsequent processing and sorting. The composition of solid waste differs in different countries and cities. It depends on many factors, including the welfare of the population, climate and amenities. The composition of garbage is significantly influenced by the city’s collection system for glass containers, waste paper, etc. It may change depending on the season and weather conditions. Thus, in autumn there is an increase in the amount of food waste, which is associated with a greater consumption of vegetables and fruits in the diet. And in winter and spring, the content of fine screenings (street waste) is reduced. Over time, the composition of solid waste changes somewhat. The share of paper and polymer materials is increasing.

1.2 Quantity of solid waste generation

Municipal solid waste makes up the majority of all consumer waste. Every year the amount of municipal solid waste worldwide increases by 3%. In the CIS countries, 100 million tons of solid household waste are generated per year. And almost half of this volume comes from Russia.

The greatest problem is posed by municipal solid waste - MSW, which accounts for about 8-10% of the total amount of waste generated. This is due to the complex composition of solid waste and distributed sources of its formation.

In Russia, the share of the urban population is 73%, which is slightly lower than the level of European countries. But, despite this, the concentration of solid waste in large Russian cities has now increased sharply, especially in cities with a population of 500 thousand people and above. The volume of waste is increasing, and the territorial possibilities for its disposal and processing are decreasing. Delivery of waste from the places of its generation to disposal points requires more and more time and money.

Currently, in most cases, waste is simply collected for disposal in landfills, which leads to the alienation of vacant areas in suburban areas and limits the use of urban areas for the construction of residential buildings. Also, the joint burial of different types of waste can lead to the formation of hazardous compounds.

According to Rosprirodnadzor, about 35-40 million tons of solid household waste are generated annually in Russia and almost all of this volume is disposed of in solid waste landfills, authorized and unsanctioned landfills, and only 4-5% is involved in recycling. This is primarily due to both the lack of the necessary infrastructure and the lack of processing enterprises themselves, of which there are only about 400 units throughout the country. You should also pay attention to the fact that the number of specially equipped places for waste disposal solid waste landfills in the country as a whole is about one and a half thousand (1399), which is several times less than even the authorized landfills of which there are slightly more than 7 thousand (7153). And the number of unauthorized landfills, which should be regarded as past environmental damage already accumulated over the past decades, as of August of this year exceeds the indicated figure by 2.5 times and amounts to 17.5 thousand. All of these solid waste disposal facilities occupy an area of ​​more than 150.0 thousand hectares.

1.3 Legislation in the field of solid waste

In accordance with the “Fundamentals of state policy in the field of environmental development of the Russian Federation for the period until 2030”, approved by the President of the Russian Federation on April 28, 2012. No. Pr-1102, the main directions of waste management are the prevention and reduction of waste generation, the development of waste disposal infrastructure and the phased introduction of a ban on the disposal of waste that has not been sorted and processed in order to ensure environmental safety during storage and disposal.

One of the main laws is “On industrial and consumer waste” dated June 24, 1998 (with the latest amendments at the beginning of this year), which establishes the basic principles of state policy in the field of waste management (except for radioactive waste), the procedure for determining ownership of them, as well as the basics of environmental control. In addition, this legal act places the organization of activities in the field of waste management within the competence of local governments. This is also indicated by another Federal Law No. 131 “On the general principles of organizing local self-government in the Russian Federation.” Thus, the procedure for collecting solid waste, places for their sorting and disposal, sanitary standards and rules for landscaping are determined by local authorities.

A significant part of the regulatory framework regulating this area consists of laws such as: Federal Law “On Environmental Protection” (dated January 10, 2002), Federal Law “On Atmospheric Air Protection” (dated May 4, 1999), Federal Law “On Sanitary epidemiological well-being of the population" (dated March 30, 1999), Land Code of the Russian Federation and others.

As well as numerous methodological recommendations, SanPiNs, SPs and SNiPs (for example, SP 31-108-2002 “Garbage chutes for residential and public buildings and structures”; SanPiN 2.1.7.1322-03 “Hygienic requirements for the placement and disposal of production and consumption waste” and etc.).

The current situation in the Russian Federation in the field of education, use, neutralization, storage and disposal of waste leads to dangerous environmental pollution, irrational use of natural resources, significant economic damage and poses a real threat to the health of current and future generations of the country.

2. Recycling of solid waste

2.1 Solid waste collection

Sanitary cleaning of residential areas and neighborhoods from solid household waste is a set of measures for their collection, removal, neutralization and disposal.

Clearing residential areas of solid waste consists of various operations. A unified system has not yet emerged, and there is a fairly wide variety of different methods and methods for collecting, removing and neutralizing solid waste.

Basically, two methods of collection are accepted: unitary and separate. With the unitary method, all waste is collected in a single garbage container; with separate waste, solid waste is collected by type of waste (glass, paper, non-ferrous metal, food waste, etc.) into different garbage containers. This scheme requires special vehicles for the removal of collected solid waste, but allows the collection of raw materials for recycling, food waste, and significantly reduces the volume of waste requiring disposal.

Yard collections and containers are installed in microdistricts on special sites, which are placed in utility yards, on the side of the end walls of buildings or between buildings, but with mandatory fencing with green spaces or low walls. Garbage collection sites and pavilions should be located among residential buildings in such a way as to create maximum convenience for residents when using waste bins, ensure convenient passage for vehicles removing waste, eliminate the possibility of soil and air pollution, and ensure compliance with modern aesthetic requirements.

One of the areas of waste management is the separate collection and processing of secondary raw materials into usable products.

The system of separate collection of waste and recyclable materials will solve the problem of waste disposal, attract small businesses to this area of ​​activity and increase the efficiency of sanitary cleaning of the city. This is the most effective solution to the problem of reducing the amount of waste sent to landfill. In order to increase the efficiency of the system for collecting and processing secondary raw materials, work is needed aimed at creating modern processing technologies for the production of competitive products. The system of separate collection and processing must be a well-managed structure, operating on an ongoing basis, using modern methods of regulation and control.

Separating waste into fractions (separate storage) is the most acceptable option for waste disposal. In this case, recycling costs are significantly reduced, and unused residues account for no more than 15% of the total mass (European practice).

Solid waste is removed to a specially equipped site - a solid waste landfill, waste processing or incineration plant. A specialized company specializing in waste collection and transportation must enter into an agreement with all enterprises that dispose, process or bury household waste. Only in this case will its activities be legal.

2.2 Types of processing

Recycling reuse or return into circulation of industrial waste or garbage. The most common are secondary, tertiary, etc. recycling on one scale or another of materials such as glass, paper, aluminum, asphalt, iron, fabrics and various types of plastic. Also, organic agricultural and household waste has been used in agriculture since ancient times.

The main types of waste management include:

Waste storage - maintenance of waste in waste disposal facilities for the purpose of its subsequent disposal, neutralization and use;

Waste disposal - isolation of waste that is not subject to further use in special storage facilities in order to prevent harmful substances from entering the environment;

Waste disposal is the processing of waste, including its incineration and disinfection in specialized installations, in order to prevent the harmful effects of waste on human health and the environment.

Use of waste - use of waste for the production of goods (products), performance of work, provision of services and for generating electricity;

Waste disposal facility is a specially equipped structure designed for waste disposal (landfill, sludge storage, rock dump, etc.).

2.2.1 Waste disposal

The selection of a site for a solid waste landfill is carried out on the basis of the functional zoning of the territory and urban planning decisions; the latter are carried out in accordance with SNiP. Landfills are located outside the residential area and in separate territories, ensuring the size of the sanitary protection zone.

A solid waste disposal site is a complex of environmental structures designed for storing, isolating and neutralizing solid household waste, providing protection from pollution of the atmosphere, soil, surface and groundwater, and preventing the spread of rodents, insects and pathogens. Solid waste storage sites contain waste from residential buildings, public buildings and institutions, trade enterprises, public catering establishments, street, garden and park waste, construction waste and some types of solid industrial waste of III - IV hazard class.

Typically, a landfill is constructed where the base can be clay and heavy loam. If this is not possible, a waterproof base is installed, which leads to significant additional costs. The area of ​​the land plot is selected based on its service life (15-20 years) and, depending on the volume of buried waste, can reach 40-200 hectares. The height of waste storage is 12-60 m.

A landfill for solid household waste generally consists of the following parts:

Access road along which solid waste is transported and empty garbage trucks return;

Economic zone intended for organizing the operation of the landfill;

Solid waste storage area where waste is placed and buried; the storage area is connected to the economic zone by a temporary on-site road;

Power supply line from external electrical networks.

Landfills can be low-load (2-6 t/m²) and high-load (10-20 t/m²). The annual volume of waste received can range from 10 thousand to 3 million m³. The technology for storing solid waste at landfills involves the installation of waterproof screens to protect groundwater and daily external insulation to protect the atmosphere, soil, and adjacent areas. All work on storing, compacting and isolating solid waste at landfills is carried out mechanized.

The organization of work at the landfill is determined by the technological scheme for operating the landfill, developed as part of the project. The main work planning document is the operation schedule drawn up for the year. It is planned monthly: the number of solid waste received, indicating N cards on which waste is stored, development of soil for isolating solid waste. The organization of work at the site must ensure environmental protection, maximum productivity of mechanization equipment and safety precautions.

Post-cultivation use of solid waste landfill territories is possible in various areas - forestry, recreational (ski hills, stadiums, sports grounds), civil engineering, commercial or industrial creation. The nature of such use and the costs of reclamation must be taken into account at the design stage of the landfill.

2.2.2 Waste disposal

Thermal methods.Thermal methods of waste disposal include incineration and pyrolysis.

Incineration is one of the fastest and most radical methods for neutralizing solid household waste. It is carried out in special destructor furnaces at a temperature of 900×1000°C, at which almost all organic solid, liquid and gaseous compounds are destroyed. Waste with humidity up to 60%, ash content up to 60% and content of combustible components (organic substances) more than 20% burns without adding fuel. In addition, due to the significant heat-generating capacity (4 x 8 mJ/kg) of waste during its combustion, energy is generated that can be used in the national economy.

At the same time, during the waste incineration process, there is a need to store solid products of incomplete combustion (slag and ash) and purify emissions into the air. On average, the combustion of 1 ton of solid waste produces almost 300 kg of slag and 6000 m 3 flue gases, from which 30 kg of ash is retained at treatment plants. Slag and ash contain a significant amount of silicon (up to 65%), alkali and alkaline earth metals, aluminum, iron, lead, zinc, etc. In addition, ash may contain dioxins - polychlorinated dibenzodioxins and polychlorinated dibenzofurans. These substances (there can be more than 210 of them, depending on the number of chlorine atoms and their placement in the molecule) have carcinogenic, hepatotoxic, neurotoxic effects, suppress the immune system, are able to pass through the placenta, and accumulate in breast milk. The most toxic and dangerous to human health is 2,3, 7, 8-tetrachlorodibenzodioxine. These substances are also dangerous because of their extreme stability in the environment. Therefore, it is necessary to store ash in the same way as toxic industrial waste, i.e. in special landfills. The slag can be stored in improved landfills or even used, for example, in construction to improve the terrain. The positive thing is that the area for storing slag and ash is 20 times less than for solid waste dumps.

Flue gases generated during waste incineration contain, in addition to ash (2 x 10 g/m3), carbon dioxide CO2 (15%), carbon oxide CO (0.05%), sulfur dioxide (S0 2 ), nitrogen oxides, HCl, HF, as well as polychlorinated dibenzodioxins and dibenzofurans. During the combustion of 1 ton of waste, 5 micrograms of dioxins can be formed, most of which are associated with ash, and a smaller part remains in the flue gases. Dioxins can be contained both in the waste itself and can be formed during the cooling process of flue gases after burning waste. During combustion at a temperature of 1000 °C, the dioxins contained in the waste are destroyed. But when the flue gases are cooled to 250×350 °C, they can be formed from organic carbon and chlorides in the presence of water vapor and copper ions. Therefore, it is mandatory to clean flue gases before releasing them into the atmosphere. To retain ash, electric precipitators and bag filters are used, which make it possible to reduce the concentration of ash in emissions from 2000 x 10,000 to 10 x 50 mg/m 3 . For gas purification, dry and wet methods are used, the efficiency of which is on average almost 70 and 90%, respectively.

Incinerators must be located at least 300 m from residential areas. High-capacity furnaces and associated structures (for loading waste, mixing it, purifying emissions into the atmosphere, etc.) are called waste incineration stations or factories.

Thus, the neutralization of solid household waste at waste incineration plants, subject to compliance with sanitary and hygienic requirements for their equipment and operation, has a hygienic, epidemiological and economic advantage, namely that the neutralization occurs radically and quickly. There is no need to transport waste far outside the city, i.e., transportation costs are reduced, large land plots are not required, and heat, steam and slag can be used. This is the reason for the widespread use of waste incineration in the world.

Pyrolysis. The process of pyrolysis of municipal solid waste is carried out in high-temperature reactors at a temperature of almost 1640 ° C under conditions of oxygen deficiency and does not require preliminary preparation. High temperature ensures the destruction of almost all complex organic substances, converting them into simple flammable (flammable gas, petroleum-like oils) or non-flammable (slag) compounds. During the pyrolysis of municipal solid waste, no emissions are generated into the environment. This method of waste disposal is very promising from a hygienic and economic point of view.

Chemical methods.Chemical methods for neutralizing solid household waste include their hydrolysis in the presence of hydrochloric or sulfuric acid at high temperatures in order to obtain ethyl alcohol, vitamins B, PP, D and other important products. In addition, waste from the hydrolysis plant can be used in the form of biofuels and organic fertilizers. When these fertilizers are applied to the fields of the chernozem zone, the potato yield becomes 2 times greater compared to fields treated with other composts. The hydrolysis method provides a waste-free production technology while complying with sanitary environmental protection requirements.

Mechanical methods. Mechanical methods for neutralizing solid waste include the production of various blocks (large-volume briquettes, building materials) by pressing them and using special binders. Currently, mechanical separation of household waste is one of the main previous operations of complete recycling and actual waste disposal.

2.2.3 Use of waste to obtain recyclable materials

Solid waste should be considered as technogenic formations, which can be characterized as a kind of carriers containing practically free components of various metals and other materials suitable for use in metallurgy, mechanical engineering, the construction industry, the chemical industry, energy, agriculture and forestry, etc. d.

The main directions for using recyclable materials are presented in Table 1.

Table 1. Main directions for using recyclable materials

Type of waste	Products
Waste paper	Paper, cardboard, soft roofing materials, thermal insulation materials, fiber boards, facing tiles
Wood	Chipboard, fibreboard, industrial chips, fuel briquettes, activated carbon, wood-polymer boards
Worn tires	Crumb rubber to replace primary raw materials, roofing materials, technical products, added to asphalt concrete mixtures when laying roads, slabs for speed bumps, rubber mats
Textile	Tow, batting, flooring materials, fibers, recovered wool, heat and sound insulation boards
Polymers	Polymer film, furniture fittings, baseboards, corners, polymer dishes (buckets, canisters, glasses, etc.)
Mercury containing lamps	Mercury concentrate, non-toxic compounds (mercury sudfide) for subsequent disposal
Scrap metal	Non-ferrous metals (aluminum, copper, zinc), ferrous metals (steel, cast iron)

Let's look at some types of processing.

It is advisable to recycle most metals. Unnecessary or damaged items, so-called scrap metal, are handed over to recycling collection points for subsequent melting. Particularly profitable is the processing of non-ferrous metals (copper, aluminum, tin), common technical alloys and some ferrous metals (cast iron).

Steel and aluminum cans are melted down to obtain the corresponding metal. However, smelting aluminum from soft drink cans requires only 5% of the energy required to make the same amount of aluminum from ore, and is one of the most profitable types of recycling.

Processors, microcircuits and other radio components are recycled; precious metals are extracted from them (the main target component is gold). Radio components are first sorted by size, then crushed and immersed in aqua regia, as a result of which all metals go into solution. Gold is precipitated from solution by certain displacers and reducers, and other metals by separation. Sometimes, after crushing, radio components are annealed.

Paper waste of various types has been used for many decades along with conventional cellulose to make pulp, the raw material for paper. Mixed or low-quality paper waste can be used to make toilet paper, wrapping paper and cardboard. Unfortunately, in Russia only on a small scale there is a technology for producing high-quality paper from high-quality waste (printing house scraps, used paper for copiers and laser printers, etc.). Paper waste can also be used in construction to produce insulation materials and in agriculture instead of straw on farms.

Plastic recycling can be considered using PET as an example.

Existing methods for recycling polyethylene terephthalate (PET) waste can be divided into two main groups: mechanical and physicochemical.

The main mechanical method for processing PET waste is grinding, which involves substandard tape, injection molding waste, partially drawn or undrawn fibers. This processing makes it possible to obtain powdered materials and crumbs for subsequent injection molding. It is characteristic that during grinding the physicochemical properties of the polymer practically do not change. When processed mechanically, PET containers are obtained into flakes, the quality of which is determined by the degree of contamination of the material with organic particles and the content of other polymers (polypropylene, polyvinyl chloride) and paper from labels.

Physico-chemical methods for processing PET waste can be classified as follows:

• destruction of waste in order to obtain monomers or oligomers suitable for producing fiber and film;
• re-melting of waste to produce granulate, agglomerate and products by extrusion or injection molding;
• reprecipitation from solutions to obtain powders for coating; obtaining composite materials;
• chemical modification to produce materials with new properties.

Each of the proposed technologies has its own advantages. But not all of the described methods for processing PET are applicable to food packaging waste. Many of them allow the processing of only uncontaminated technological waste, leaving unaffected food containers, which, as a rule, are heavily contaminated with protein and mineral impurities, the removal of which is associated with significant costs, which is not always economically feasible when processing on a medium and small scale.

The main problem in recycling recyclables is not the lack of recycling technologies - modern technologies make it possible to recycle up to 70% of the total amount of waste - but the separation of recyclables from the rest of the garbage (and the separation of various components of recyclables). There are many technologies that allow you to separate waste and recyclables. The most expensive and complex of them is the extraction of recyclable materials from the already formed general waste stream at special enterprises.

3. Obtaining thermal and electrical energy from solid waste

Solid household waste is a fuel comparable in calorific value to peat and some brands of brown coal. It is formed where thermal and electrical energy is most in demand, i.e. in large cities, and has a guaranteed predictable resumption as long as humanity exists.

Recently, there has been a steady overall increase in energy production from waste, which is predicted to continue, with the share of electricity generation slightly increasing (Fig. 1). Approximate calculations for solid waste with a calorific value of, for example, 10 MJ/kg show that the total specific costs of building a plant with an increase in its capacity from 100 to 300 thousand tons of solid waste per year decrease by approximately 25-35%.

Figure 1. Electricity and heat generation in Europe.

Abroad, revenue from the sale of generated energy primarily depends on the type and quality of energy sold. For example, in Austria, electricity is purchased at a price of 45 euros/MWh if the supply to the consumer is guaranteed, and 25 euros/MWh if the supply of electricity depends on the operating mode of the supplier. Tariffs for the supply of thermal energy are 10 and 6 euros/MWh (11.6 and 7 euros/Gcal), respectively.

Guaranteed supply of thermal and electrical energy from an enterprise that burns solid waste (and thereby increasing the price for its sale) can be ensured, for example, by working together with a city thermal power plant. Specialists of JSC VTI, on instructions from the Moscow Government, have developed technical proposals for the creation of domestic standard complexes for the energy recycling of solid waste. When developing them, we took into account the fact that, as calculations and foreign experience show, the most efficient in terms of energy use of waste is an enterprise with an annual supply of electrical energy of 100 thousand MWh or more (with an installed electrical capacity of more than 15 MW). Such an enterprise can rightfully be considered a thermal power plant using solid waste.

Currently, basic fundamental technical solutions have been developed that make it possible to create a full-scale pilot industrial model of a modern domestic thermal power plant using solid waste with an installed electrical capacity of 24 MW (360-420 thousand tons of solid waste per year), which is a modern enterprise with a completed technological process thermal processing of waste and the traditional steam power cycle for electricity generation. The unit capacity of each of the two technological lines for incinerated waste is approximately 180 thousand tons of solid waste per year.

The thermal power plant uses a thermal circuit with cross connections and a condensing turbine with controlled intermediate steam extraction for district heating. This scheme has the most flexible nature for steam utilization. Depending on the time of year and the demand of energy consumers, thermal power plants can produce from 10 to 25 MWh of electrical energy and from 0.57 to 1.9 Gcal of thermal energy every hour.

3.1 Obtaining thermal energy

The objective of environmentally friendly processing of municipal solid waste is the environmentally friendly combustion of solid waste and other combustible waste with the production of thermal energy, with minimal impact on the environment, with maximum efficiency, minimal labor costs and maximum use of non-combustible solid waste and an ash disposal system.

In the bunker block, solid household and industrial waste is received without sorting, both from special vehicles and from general-purpose freight transport. Large metal inclusions are separated from waste at the receiving stage, and fines are separated from ash after waste incineration. Liquid flammable and liquid water-saturated wastes are taken into separate containers. Then the sorted combustible solid waste is uniformly fed to the combustion unit for combustion. To ensure high neutralization efficiency, the waste incineration process is carried out in two stages:

Ashing in a countercurrent rotary kiln;

Afterburning of flue gases in a vortex afterburner.

Flue gases are cooled in a recovery boiler to produce superheated steam. The generated steam is given to city enterprises and is used for the plant’s own needs as a heating source for absorption heat pumps and reheating the city’s network heating water or heating greenhouses. Then the flue gases enter the smoke purification unit, where wet cleaning of the flue gases from dust and harmful impurities is carried out.

Concentrated effluents from the gas purification system and wastewater from washing process equipment are used to cool the ash with steam discharge to the fire-technical unit. Ash and sludge from the combustion unit and smoke purification unit are used in the ash recovery unit for the production of building materials. From the melted ash, highly volatile components (K, Na, C, Cl, S) and heavy metals (Zn, Cu, Cd, Pb) are removed into the gas purification system. Here, secondary dust with a high content of heavy and non-ferrous metals (including in the form of sludge in the central storage tank) is collected. The mass of the original ash and gases after melting is distributed in the following ratios: slag - 60%, secondary ash from the evaporation of volatile substances and due to mechanical entrainment - 9.0%, flue gases - 29%, metal - 2%. Granulated slag in the form of particles up to several mm in size has high resistance to dissolution in water and weak acids. This slag is suitable for road construction and the production of building materials.

In general, the ash recycling unit as part of the MSZ ensures the processing of up to 90% of the initial mass of ash into environmentally friendly products. The dioxins contained in the original ash are completely absent in the slag obtained after melting.

Figure 2. Block diagram of the ash recovery unit.

The ash recycling unit contains 1 - power supply, 2 - air compressor, 3 - plasmatron, 4 - water pump, 5 - ash hopper with ash supply system, 6 - melting reactor, 7 - melt drainage and slag granulation system, 8 - waste afterburner gases, 9 - receiver for ash residue, 10 - centrifugal bubbling apparatus, 11 - bag filter, 12 - smoke exhauster, 13 pipe.

3.2 Electricity generation

There are several possible schemes for combining MSZ and power equipment to produce various energy resources. Waste incineration plants are constructed as recycling boiler houses (UK) and combined heat and power plants (CHPP):

Boiler house and incineration plant; the final product is thermal energy.

CHP with solid waste combustion; the final product is thermal and electrical energy (or only electricity)

o CHP plants burning solid waste based on CCGT units;

o CHP plants burning solid waste based on gas turbine units;

o CHP-based combined heat and power plants that burn solid waste (or fuel from solid waste) together with fossil fuels.

Management units are equipped with waste heat boilers with steam parameters, usually pressure 1.4-2.4 MPa and temperature up to 250 300 0 C, during layer combustion of fuel on special grates of various systems (including a “fluidized” bed). Sometimes water-heating waste heat boilers are used.

UTPPs are equipped with turbogenerators with turbines for various purposes:

Cogeneration systems for generating electricity with the extraction of low pressure steam and heat both for the MSZ’s own needs and for distribution to external consumers through the electrical and heating networks of cities;

Production with high-pressure steam extractions, providing technological and utility needs of enterprises,

And also purely condensing ones, generating only electricity.

For the greatest clarity of the features of the implementation of each of the combination schemes, we present Russian and foreign experience in the use of the described technologies, as well as promising developments in this area.

At the first stage, solid waste is converted into a gaseous combustible product, gas, and at the second, the resulting gas is burned in a steam or hot water boiler. The total thermal power factor is approximately 95%. Thus, when operating a mini-CHP using waste, it is possible to provide hot water and heating to several large houses. Based on this, the installation should be most rationally located in that area of ​​the city where there are problems with waste transportation and there is a need for additional thermal energy. One of the options is to use the installation as part of the modernization of old coal-fired thermal power plants. Before the waste is burned, it will undergo primary sorting and grinding to the required linear dimensions of the pieces - within 20 by 20 cm.

The proposed technology ensures an acceptable level of dioxin formation. The maximum temperature (1000-1200 degrees) and burning time in the gasification zone guarantee the destruction of dioxins. After the first stage of combustion there are no emissions into the atmosphere, since all the product gas goes to the burner to generate heat. Low linear velocities of the gas flow in the reactor and its filtration through the layer of the initial processed material ensure extremely low removal of dust particles with the product gas. As a result, it becomes possible to significantly reduce capital costs for gas cleaning and energy equipment. Thus, combustion in two stages can dramatically reduce the formation of dioxins and ensure acceptable standards.

As for the resulting ash, a technology is proposed that allows the ash to be processed into a chemically neutral, mechanically quite resistant product that can be used even during construction without any fear. Ceramic balls are obtained from the ash, which have triple physical and chemical protection for the release of heavy metals into the environment. The degree of leaching of heavy metals from such balls is thousands of times less than from the ash itself. This transfers the ash to a safe state, because simply mixing it into cement simply means postponing the negative consequences, since cement blocks are short-lived.

4. Problems of solid waste processing

The problems of solid waste processing lie in many areas.

Today, the main source of compensation for the costs of removal and disposal of solid waste is payments from the population. Moreover, it is quite obvious that the existing tariffs for the disposal of household waste are inadequately low, and they are not even able to cover the costs of waste disposal and removal. The lack of funds for recycling is compensated by subsidies from the state budget, but still, housing and communal services authorities do not have money for the development of a separate collection system, such as has long been used in Europe. In addition, today the tariff for handling solid waste is not differentiated; it does not matter at all whether you collect waste separately or simply dump everything into one common container - you will pay the same for waste disposal.

Another problem of the existing solid waste management system in our country is the rather limited market for secondary raw materials; many waste recyclers face problems in selling raw materials that were obtained from waste.

Currently, there is practically no awareness of the population about the problem of solid waste disposal, and the population of Russia knows nothing about what opportunities the separate collection system offers.

In addition, all waste management methods have their pros and cons.

The oldest and most famous disposal, construction and maintenance of a landfill is much simpler and cheaper than setting up a waste incineration plant (WIP) or a waste processing plant (WRP). This is perhaps the main advantage of storing waste at a landfill. There are quite a lot of disadvantages:

• large areas of land are occupied (in addition to the landfill itself, the surrounding sanitary protection zone should also be taken into account). Nowadays, land near large cities is expensive, and it makes sense to spend it on cleaner purposes; and the construction of a landfill at a great distance is not economically feasible;
• with this method, practically no useful components of the waste are extracted something on which a lot of materials, labor and energy was spent is simply buried in the ground;
• difficulties with land reclamation. Any, even the most highly loaded landfill will sooner or later exhaust its capacity. After this, it should be covered with earth, and trees should be planted on the surface. But this territory will not be suitable for practically any useful applications for a very long time. Anaerobic (that is, without air access) processes occur in the waste layers, and they take a very long time. Thus, not only during operation, but also after its completion, the solid waste landfill occupies significant land areas.

Waste incineration requires significant capital investment. Theoretically, waste can be considered as fuel, and incinerators, accordingly, as heating plants. In practice, things don't work out so well.

Firstly, the calorific value of waste that has not been separated is very low; in other words, it may not burn at all in air (this depends on the content of non-combustible fractions in solid waste and humidity changing due to weather conditions); additional combustion may be required for complete combustion. drying, use of real fuels, use of an oxygen-enriched gas mixture as an oxidizer (instead of air).

Secondly, waste flue gases from MSZ contain a significant amount of harmful impurities, both solid and gaseous or vaporous. For example, modern waste may include a significant amount of chlorine-containing organics, the combustion of which produces a substance such as dioxin, which is classified as a super-ecotoxicant, i.e., a super-toxic substance. In this regard, careful multi-stage purification of exhaust gases is required, as well as the use of particularly high temperatures to prevent incomplete combustion of waste (with complete combustion, less toxic substances are formed).

Finally, incineration still does not eliminate the waste problem: the non-combustible slag remaining in the furnaces and the ash collected in treatment plants constitute up to 10% by volume and 30% by weight of the initial amount of solid waste that “entered” the gates of the MSZ. This slag and ash still needs to go somewhere. Often just to a landfill, although it is possible to use the slag as a filler for cinder blocks, etc.

Thus, the disadvantages of MSZ are the high cost of equipment, the much more complex technology of combustion and gas purification compared to conventional thermal power plants, and poor extraction of useful components. Even taking into account various kinds of tricks (pre-sorting, beneficial use of the generated heat and slag), MSZs are rarely profitable enterprises. Nevertheless, despite all the shortcomings, there are more than a thousand incinerators operating in the world, although recently there has been a tendency to reduce their number.

The main problem with existing methods of recycling recyclables is not the lack of processing technologies, but the separation of recyclables from the rest of the garbage (and the separation of various components of recyclables). There are many technologies that allow you to separate waste and recyclables. All of them are costly and the most expensive and complex of them is the extraction of recyclable materials from the already formed general waste stream at special enterprises.

The main problems associated with the use of solid waste as fuel for energy production for Russia, and for Moscow in particular, are the following:

1. Effective utilization of heat generated by waste combustion, and, above all, the problem associated with the sale of generated energy. The instability of electricity generation due to seasonal and daily fluctuations in the quantity and quality of solid waste, as well as when technological lines are stopped, makes it difficult to sell it to electric networks.

2. The most pressing issue at the moment is the effective conversion of solid waste energy into electrical energy, because the absolute electrical efficiency does not exceed 14-15%, while abroad, newly commissioned installations that burn solid waste have an absolute electrical efficiency of approximately 22%.

6. Prospects for solid waste processing

At the same time, there are two possible directions for modernizing this waste management system:

1) creating conditions to minimize waste generation, i.e. technological modernization of the economy based on the best available technologies;

2) involvement of waste, including volumes accumulated over previous years, into economic use as secondary material and energy resources, i.e. development of the waste recycling industry in Russia.

Use of solid waste, including industrial waste similar to household waste, as fuel using energy when it is converted into electricity and heat; mechanical and chemical purification of gases leaving boilers; introduction of new combustion technologies, including so-called fluidized bed furnaces; beneficial use of a number of waste components, including slag, ash, metals - all of this is of great importance from the point of view of saving fossil fuels, materials, but, mainly, protecting nature, air and water basins in Moscow and the Moscow region through the gradual closure existing landfills and refusal to allocate new land for their organization.

Along with generally accepted (traditional) schemes for incinerating solid waste using thermal and electrical energy in energy supply systems of cities, including Moscow, there is extensive experience in European countries in scheme solutions leading to combined energy supply sources. As part of such sources, along with technological lines for the neutralization of solid waste with energy generation, not only power equipment in the form of steam generators is used, but also gas turbine units (GTU), combined cycle gas units (CCG).

The operating experience of numerous foreign enterprises for thermal processing of solid waste shows that a modern thermal power plant using solid waste is an environmentally friendly enterprise. This is confirmed by the results of studies conducted at Moscow special plants during the period of their launch and subsequent operation. The concentration of regulated substances in the gaseous combustion products of solid waste does not exceed the EU standard values, which ensures the environmentally safe operation of such enterprises. The resulting ash and slag residues can be processed into an inert product for subsequent use, for example, in road construction, on the territory of the thermal power plant itself.

To increase the market for recyclable materials in developed foreign countries, various influence mechanisms are used today - requirements for the mandatory use of recyclable materials when releasing new goods (in percentage) and preferential lending for such industries. Also, the European public procurement system provides benefits for such enterprises and organizations that produce or supply goods and products that are made from recycled materials or using recyclable materials.

The prospects for the use of municipal solid waste as secondary energy resources in the Russian Federation are associated with the adoption of legislative documents aimed at significantly reducing landfill disposal, at least for large cities, and increasing the interest of energy companies in the development of renewable energy sources, as well as the active introduction of new technologies in the field of processing.

Conclusion

The process of recycling solid household waste must be selected in each individual case, taking into account all the characteristics of the waste, the area, and its quantity.

The complexity of solving problems of household waste disposal is explained by the need to use complex, capital-intensive equipment and the lack of economic justification for each specific solution.

Summarizing everything written above, we can confidently say that despite the existing technologies for the rational use of waste, the main reason for the ineffective work on solid waste disposal is that the problems of environmental protection, resource use and the continuous development of the waste disposal system are still not a priority for governing bodies in our country.

We can only hope that in the near future the government will take the steps necessary to create a new, more environmentally friendly and efficient solid waste management system.

Bibliography

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Not only rats and cats, homeless people and tireless seekers of various valuables have long been rummaging through the garbage. Scientists and engineers are increasingly involved in this. But what are they trying to find in it? Of course energy. After all, trash can be useful.

Energy potential

Garbage as a renewable and virtually inexhaustible source of energy? Why not. Remember good old Dr. Emmett Brown from the Back to the Future film trilogy? Finding himself in this very future, the pundit modified his time machine, equipping it with a “home nuclear reactor” that produces electricity from food waste. Meanwhile, the year 2015 indicated in the film is no longer a distant fantastic future, but the real past, albeit recent. And if it has not yet come to the point of using nuclear reactors in everyday life (although developments are being carried out tirelessly), then the production of energy from waste has become quite commonplace.

Natural resources for energy production on Earth are becoming less and less, and all kinds of garbage are becoming more and more, and sometimes there is simply nowhere to put it. Yes, rich developed countries (especially those where landfilling of waste is legally prohibited) can afford to fuse waste in third world countries for a fee, but this is a ticking time bomb, since these states do not have the proper processing capabilities and technologies, and a special desire to do this too. And there is one planet for everyone.

What follows follows from the well-known fundamental law of nature: energy does not disappear anywhere, but is preserved in one form or another - the only question is how to effectively and harmlessly extract and transform it. And if so, then it is no good to squander or stupidly destroy valuable raw materials, which for the most part is garbage - it is better to profitably use its fairly high energy potential. A good example is the recycling of used car tires. There are a lot of them and they are very bulky, but at the same time they represent valuable recyclable materials. If you simply burn a ton of tires, about 300 kg of soot and almost half a ton of toxic gases will be released into the atmosphere. If we subject them to processing through low-temperature pyrolysis (up to 500 ° C), then the output will be synthetic oil, carbon black and flammable gas.

Many people, organizations and enterprises in many countries have devoted themselves to solving the problems of “energy development” of waste deposits, and all this has already given rise to a whole complex of research, technologies, systems, programs and activities under the general name Waste-to-Energy (WEA) or Energy -from-Waste - “Garbage into energy”, or “Energy from waste”.

Kilotons to kilowatts!

For almost a century and a half, an alternative to waste disposal at landfills, such as incineration, has existed and continues to develop widely: the first waste incineration plant was built in Nottingham, British, back in 1874. But why just burn (poisoning the atmosphere) if you can use the energy of the heat generated for good? As a textbook example of such “waste” energy, the environmentally friendly Spittelau incineration plant in the 9th district of Vienna (one of the central ones, where Mozart and Schubert, Beethoven and Freud lived at different times) is most often cited.

A masterpiece of industrial design, this plant is one of the attractions of the Austrian capital, along with its opera house, cathedral or imperial palaces, and at the same time, by processing 250 thousand tons of city waste annually, it produces thermal energy that has been used to heat more than 100 thousand houses for a good quarter of a century in several areas of Vienna at once. Today, the Austrian experience is becoming more widespread, and municipal solid waste (MSW) is playing an increasingly important role in the fuel and heat supply of developed countries. Thus, in Holland, which processes 100% of its waste, there are 11 “garbage” thermal power plants.

The next logical step is to convert, if necessary, thermal energy into more “appliable” and “all-season” electrical energy. And now 130 factories in France, which is recognized as the European leader in the production of energy from municipal waste, annually generate almost 10 million Gcal of thermal energy and more than 3 billion kWh of electricity. In total, there are about 500 enterprises producing energy from waste in Europe, and the same number in China alone, and in Japan, for which both waste and fuel problems are especially relevant for obvious reasons, there are almost 2 thousand of them. At the same time, calculations by experts show that direct combustion technologies make it possible to obtain the same amount of thermal energy from 1 ton of solid waste as by burning 250 kg of fuel oil or 200 liters of diesel fuel.

And in Russia we process

Not so long ago, the Moscow government - Russia's largest "supplier" of solid waste - abandoned (largely under the influence of protests from local residents and environmentalists) the idea of ​​​​building waste incineration plants, preferring instead enterprises using hydroseparation technology, which is much cheaper and allows for separation waste into fractions (paper, metal, glass, plastic, etc.), and then process them into recyclable materials, fertilizers and energy. By the way, the composition of solid waste in Russia is as follows: paper and cardboard - 35%, food waste - 41%, plastics - 3%, glass - 8%, metals - 4%, textiles and other - 9%.

Now, after harsh presidential criticism of the giant Balashikha landfill, which has long been boring to local residents and has now gained all-Russian “fame,” the topic of constructing waste incineration plants has again become relevant. In connection with the liquidation of this and the upcoming closure of a number of landfills near Moscow, a decision was made to build a network of factories of a fundamentally new generation in the region, using WPC plasma gasification technology - one of the most advanced and environmentally friendly today.

Each such plant is capable of processing 1,500 tons of unsorted waste per day (500,000 tons per year). The plasma gasification unit operates at temperatures above 5,500 °C, ensuring almost complete conversion of feedstock into the purest synthetic gas and 80% energy recovery.

The final product of the process can be different - the same electricity (50 MWh), steam or liquid fuel. Inorganic substances are removed as an inert slag, which is cooled and converted into a non-hazardous, non-leachable product, after which it can be sold as building material filler.

Finally, the emission of greenhouse gases into the atmosphere is radically reduced.

Pyrolysis, hydropyrolysis, “stoker”, depolymerization, direct smelting, gasification, esterification, anaerobic digestion, fluidized bed and fluidization process are all names of technologies and their varieties from the oldest to the most modern, reflecting the variety of approaches in the search for the fastest, an effective and harmless way to recover energy through waste recycling. Without going into details, we note that each technology has its pros and cons, its supporters and opponents. But, one way or another, the trend is already evident and progress, as they say, cannot be stopped. Once upon a time, nuclear energy seemed something unrealistic, but why is “garbage” worse? On the contrary, it’s even immeasurably safer!

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