Wasteless production. Wasteless production: examples of creation. Waste-free and low-waste production What is the meaning of waste-free production technology
WASTE-FREE PRODUCTIONS in chem. technologies (non-waste technology) are carried out according to the optimum. technol. schemes (see Optimization) with closed (recirculating) material and energy. streams, do not have wastewater (non-drainage production), gas emissions into the atmosphere and solid waste (non-dumping production). The term "non-waste production" is conditional, because in real conditions due to the imperfection of modern. technology, it is impossible to completely eliminate all waste and the impact of production on the environment. In non-waste production, nature is most rationally used. and secondary raw materials and energy with a minimum. damage to the environment.
In the concept of non-waste production, it means. contributions were made by Soviet scientists (A. E. Fersman, N. N. Semenov, I. V. Petryanov-Sokolov, B. N. Laskorin, and others). By analogy with nature. ecological non-waste production systems are based on the technogenic cycle of matter and energy. The need to create non-waste industries arose in the 50s. 20th century due to the depletion of the world's natural resources. resources and pollution of the biosphere as a result of rapid development, along with the chemicalization of the village. x-va and the growth of transport, the leading branches of energy and the manufacturing industry (oil refining, chemical industry, nuclear power, non-ferrous metallurgy, etc.).
According to the ideas of D. I. Mendeleev (1885), the measure of the perfection of production is the amount of waste. With the development of science and technology, each production is increasingly approaching waste-free. At this stage, non-waste industries include, in essence, low-waste production, in which only a small part of the raw material is converted. into waste. The latter are buried, rendered harmless or sent for long periods of time. storage for the purpose of their disposal in the future. In low-waste production, emissions of harmful substances do not exceed the MPC, as well as the level at which irreversible environmental changes are prevented (see Nature Protection).
Main directions of creation of low-waste products in a separate enterprise or in general prom. region: environmentally friendly preparation and complex processing of raw materials in combination with the purification of harmful emissions, waste disposal, optim. the use of energy, water and gas circulation cycles; the use of the so-called. short (low-stage) technol. schemes with max. extraction of target and by-products at each stage; periodic replacement. processes continuous using avtomatizir. their control systems and more advanced equipment; wide involvement in the production of secondary resources.
The development of chemical, oil refining, petrochemical. and a number of other branches of industry is associated with the development of the so-called. energy technol. schemes - systems of large unit power. The latter along with max. using raw materials and energy provide highly efficient treatment of wastewater and gas emissions into the atmosphere through the use of anhydrous technol. processes, water and gas circulation (including air circulation) cycles, to-rye environmentally and economically more expedient than acc. direct-flow water supply and gas purification to sanitary standards.
Optimal the use of raw materials is achieved by their complex processing. Examples: chem. processing of solid fuels (see Coke Chemistry), oil (see Oil refining), apatite-nepheline, phosphorite-apatite, polymetallic. ores, etc. For example, in the complex processing of apatite-nepheline ores, in addition to phosphates, other valuable products are also obtained. Thus, in the USSR, for the first time in the world, a technology for processing nephelines, a waste from apatite enrichment, was developed and implemented. As a result, 0.2-0.3 tons of K 2 CO 3 , 0.60-0.75 tons of Na 2 CO 3 and 9-10 tons of cement are obtained per 1 ton of alumina. This technology, combined with a closed water cycle and efficient gas cleaning of sintering and cement production furnaces, provides a minimum. amount of waste. The progressive method of nitric acid decomposition of phosphorites and apatites in the production of complex fertilizers (eg, nitroammophoska) eliminates the formation of phosphogypsum - a large-tonnage waste product of these fertilizers using the sulfuric acid method. Along with nitrogen-phosphorus or nitrogen-phosphorus-potassium fertilizers, SrCO 3 , CaCO 3 , CaF 2 , NH 4 NO 3 , REE oxides, and other important products are obtained.
Optimal the use of energy resources is achieved by their rational use for technol. needs for various stages of production, as well as the utilization of low-potential heat (50-150 ° C) to ensure comfortable conditions labor in the industry. and non-production. premises, for municipal hot water supply, heating, ventilation, air conditioning, heating of greenhouses, reservoirs, etc. max. effective in chem. prom-sti energy resources are used in modern. energy technol. schemes for the production of NH 3, weak HNO 3 and urea.
A progressive form of organization of non-waste production is a combination of different technologies. schemes. For chem. prom-sti is especially characteristic of the use of waste DOS. production as a raw material for newly organized subordinate productions. So, the production of NH 3 is combined, using its waste - CO 2, with the production of carbamide in one chemical. enterprise. Dr. a typical example is the combination of chem. enterprises for the production of H 2 SO 4 with metallurgical, on the waste to-rogo (flotation pyrite and flue gases containing SO 2) it is based. An important role in the recycling of solid secondary raw materials belongs to the industry builds. materials. For example, blast-furnace slags (almost completely) and phosphogypsum are used for the production of cement, slag crystals, miners. cotton wool, slag pumice, gypsum binders, etc.
The creation of non-waste industries is especially effective on the basis of fundamentally new technologies. processes. An example is a coke-free, domainless method for producing steel, with a Krom of technol. schemes excluded stages, in max. degrees influencing environmental pollution: domain redistribution. production of coke and agglomerate. This technology provides reduction of emissions of SO 2, dust and other harmful substances into the atmosphere, allows three times to reduce water consumption and almost completely utilize all solid waste.
Also promising is the use, for example, in hydrometallurgy of sorption, sorption-extraction and extraction processes, to-rye provide high selectivity of extraction decomp. components, efficient wastewater treatment and no gas emissions into the atmosphere. Thus, extraction processes are used to recover and separate, for example, Ta and Nb, REE, Ti and In, as well as to obtain high purity AI (see also Leaching).
An important role in the creation of non-waste production is played by the improvement of the hardware design of technol. processes. So, the transition of production
« Wasteless technologist ion is a method of production in which all raw materials and energy are used most rationally and comprehensively in the cycle: raw materials production consumption secondary resources, and any impact on environment do not interfere with its normal functioning. This formulation should not be taken absolutely, i.e. one should not think that production is possible without waste. It is simply impossible to imagine absolutely waste-free production, there is no such thing in nature. However, waste should not disrupt the normal functioning of natural systems. In other words, we must develop criteria undisturbed state of nature. The creation of non-waste industries is a very complex and lengthy process, the intermediate stage of which is low-waste production. Under low-waste production it should be understood such production, the results of which, when exposed to the environment, do not exceed the level permissible by sanitary and hygienic standards, i.e. MPC. At the same time, for technical, economic, organizational or other reasons, part of the raw materials and materials may turn into waste and be sent for long-term storage or disposal.
Principles of non-waste technologies.
When creating non-waste production, a number of complex organizational, technical, technological, economic, psychological and other tasks have to be solved. For the development and implementation of non-waste industries, a number of interrelated principles can be distinguished.
The main one is principle of consistency . In accordance with it, each individual process or production is considered as an element of a dynamic system of everything. industrial production in the region (TPK) and more high level as an element of the ecological and economic system as a whole, including, in addition to material production, other economic and economic activities of a person, natural environment(populations of living organisms, atmosphere, hydrosphere, lithosphere, biogeocenoses, landscapes), as well as man and his environment. Thus, the principle of consistency underlying the creation of non-waste industries should take into account the existing and growing interconnection and interdependence of production, social and natural processes.
Another important principle of creating waste-free production is complexity of resource use . This principle requires the maximum use of all components of raw materials and the potential of energy resources. As you know, almost all raw materials are complex, and on average, more than a third of their number are related elements that can be extracted only through its complex processing. Thus, almost all silver, bismuth, platinum and platinoids, as well as more than 20% of gold, are already obtained as a by-product during the processing of complex ores.
Principle integrated economical The use of raw materials in Russia has been elevated to the rank of a state task and is clearly formulated in a number of government decrees. Specific forms of its implementation will primarily depend on the level of organization of non-waste production at the stage of the process, individual production, production complex and ecological and economic system. One of general principles creation of non-waste production is cyclicity of material sweat shackles. To the simplest examples of cyclic material flows include closed water and gas circulation cycles. Ultimately, the consistent application of this principle should lead to the formation, first in individual regions, and subsequently in the entire technosphere, of a consciously organized and regulated technogenic circulation of matter and the energy transformations associated with it. As effective ways of forming cyclical material flows and rational use energy, we can point to the combination and cooperation of industries, the creation of TPK, as well as the development and production of new types of products, taking into account the requirements for their reuse.
No less important principles for creating waste-free production include requirement to limit the impact of production on the natural and social environment taking into account the systematic and purposeful growth of its volumes and environmental excellence. This principle is primarily associated with the conservation of such natural and social resources as atmospheric air, water, the surface of the earth, recreational resources, public health. It should be emphasized that the implementation of this principle is feasible only in combination with effective monitoring, developed environmental regulation and multi-link environmental management.
The general principle of creating waste-free production is also rationality his organization. The determining factors here are the requirement for the reasonable use of all components of raw materials, the maximum reduction of energy, material and labor intensity of production and the search for new environmentally sound raw materials and energy technologies, which is largely associated with reducing the negative impact on the environment and causing damage to it, including related industries. National economy. The ultimate goal in this case should be considered the optimization of production simultaneously in terms of energy technology, economic and environmental parameters. The main way to achieve this goal is the development of new and improvement of existing technological processes and industries. One example of such an approach to the organization of waste-free production is the disposal of pyrite cinders from the waste products of sulfuric acid production. Currently, pyrite cinders are completely used in the production of cement. However, the most valuable components of pyrite cinders - copper, silver, gold, not to mention iron, are not used. At the same time, an economically viable technology for processing pyrite cinders (for example, chloride) with the production of copper, precious metals and the subsequent use of iron has already been proposed.
In the whole set of works related to environmental protection and rational development natural resources, it is necessary to single out the main directions for the creation of low-waste and waste-free industries. These include integrated use of raw materials and energy resources; improvement of existing and development of fundamentally new technological processes and industries and related equipment; introduction of water and gas circulation cycles (based on efficient gas and water treatment methods); cooperation of production using the wastes of some industries as raw materials for others and the creation of waste-free TPK.
Waste production these are the remains of raw materials, materials, semi-finished products, chemical compounds formed during the production of products or the performance of works (services) and which have completely or partially lost their original consumer properties. Consumption waste products and materials that have lost their consumer properties as a result of physical or moral wear and tear.
Production and consumption wastes are secondary material resources(VMP), which can currently be reused in the national economy. Waste happens toxic and dangerous. Toxic and hazardous waste containing or contaminated with materials of such nature, in such quantities or in such concentrations that they represent a potential hazard to human health or the environment.
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Introduction
Waste-free production is a production in which all raw materials are eventually converted into a particular product and which is simultaneously optimized according to technological, economic and socio-ecological criteria.
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The term "wasteless technology" was first proposed by Russian scientists N.N. Semenov and I.V. Petryanov-Sokolov in 1972. In a number of countries Western Europe instead of "small and wasteless technology", the term "pure or more pure technology" ("pureormorepuretechnology") is used. Wasteless technology - a technology that implies the most rational use of natural resources and energy in production, ensuring the protection of the environment. Waste-free technology is a principle of organizing production in general, implying the use of raw materials and energy in a closed cycle. A closed cycle means a chain of primary raw materials - production - consumption - secondary raw materials.
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In the definition wasteless technology not only the production process is implied. This concept also includes end products, which should be characterized by: Long service life of products, Reusability, Ease of repair, Ease of return to the production cycle or conversion to an environmentally friendly form after failure.
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Basic principles of creating non-waste production
System approach Cyclicity of material flows In accordance with it, each individual process or production is considered as an element of a dynamic system - all industrial production in the region (TPK) and at a higher level as an element of the ecological and economic system as a whole, including, in addition to material production and other economic activities of man, the natural environment (populations of living organisms, atmosphere, hydrosphere, lithosphere, bio-geocenoses, landscapes), as well as man and his environment. Formation, first in individual regions, and subsequently in the entire technosphere, of a consciously organized and regulated technogenic circulation of matter and the transformations of energy associated with it. Limitation of environmental impact This principle is primarily associated with the conservation of such natural and social resources as atmospheric air, water, land surface, recreational resources, and public health.
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System approach Cyclicity of material flows
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Rational organization Comprehensive use of resources The requirement for the reasonable use of all components of raw materials, the maximum reduction of energy, material and labor intensity of production and the search for new environmentally sound raw materials and energy technologies, which is largely associated with reducing the negative impact on the environment environment and damage to it Integrated use of raw materials. Production waste is an unused or underused part of the raw material for one reason or another. Therefore, the problem of the integrated use of raw materials is of great importance both from the point of view of ecology and from the point of view of the economy.
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Comprehensive use of resources Rational organization
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Requirements for non-waste production
Implementation production processes with the minimum possible number of technological stages (devices), since waste is generated at each of them, and raw materials are lost; Creation of energy technological processes application of continuous processes that allow the most efficient use of raw materials and energy; increase (to the optimum) of unit capacity intensification of production processes, their optimization and automation;
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MAIN DIRECTIONS OF WASTE-FREE AND LOW-WASTE TECHNOLOGY.
The main available directions and developments of waste-free and low-waste technology in individual industries industry: Energy. Mining. Metallurgy: ferrous and non-ferrous metallurgy Powder metallurgy
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Energy
Use new methods of fuel combustion, such as fluidized bed combustion, which helps to reduce the content of pollutants in exhaust gases, the introduction of developments for the purification of sulfur and nitrogen oxides from gas emissions; to achieve the operation of dust-cleaning equipment with the highest possible efficiency, while the resulting ash is effectively used as a raw material in the production of building materials and in other industries. A waste-free technology for producing rutile has been developed (can be used in quantum light generators)
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Mining
In the mining industry, it is necessary to: introduce developed technologies for the complete disposal of waste, both in open pit and underground mining; apply more widely geotechnological methods for the development of mineral deposits, while striving to extract earth's surface only target components; use non-waste methods of enrichment and processing of natural raw materials at the place of its extraction; more widely apply hydrometallurgical methods of processing ores.
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Metallurgy
In the ferrous and non-ferrous metallurgy, when creating new enterprises and reconstructing existing industries, it is necessary to introduce waste-free and low-waste technological processes that ensure the economical, rational use of ore raw materials: involving gaseous, liquid and solid production wastes in the processing, reducing emissions and discharges harmful substances with exhaust gases and sewage; processing in full of all blast-furnace and ferroalloy slags, as well as a significant increase in the scale of processing of steel-smelting slags and non-ferrous metallurgy slags; a sharp reduction in fresh water consumption and a decrease in waste water through further development and implementation without
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In non-ferrous metallurgy, the degree of non-waste is judged by the coefficient of the complexity of the use of raw materials (in many cases it exceeds 80%). In the ferrous industry, an enterprise is considered waste-free (low-waste) if this coefficient does not exceed 75%.
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Examples
Zn (zinc) and Fe (iron) Zero Waste Production Flowsheet Zero Waste: Turning Carbon Dioxide into Fuel Researchers at Pennsylvania State University have found a potential solution by turning to the use of sunlight and titanium oxide nanotubes. These two elements are capable of converting carbon dioxide into methane. And already methane can be exploited as a source of energy. Here is a double benefit for you. On the one hand, the content of carbon dioxide in the atmosphere is decreasing, and on the other hand, humanity will not be so dependent on fossil fuels.
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The creation of non-waste production is especially effective on the basis of fundamentally new technological processes.
A coke-free, domain-free method for producing steel, in which the stages that have the greatest impact on environmental pollution are excluded from the technological scheme: blast furnace conversion, production of coke and sinter. This technology provides a significant reduction in emissions of SO2, dust and other harmful substances, reduces water consumption by a factor of three and almost completely utilizes all solid waste. Examples
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The processes occurring during the production of sponge iron in a shaft furnace largely coincide with the processes occurring in a mine blast furnace in the temperature range up to 1000 ° C. Shaft furnaces use lumpy iron ore materials (pellets, lump ore), however, unlike a blast furnace, the charge of a shaft furnace does not contain coke. The reduction of iron oxides is carried out by hydrogen and carbon monoxide blown into the furnace heated to 1000-1100 ° C, and the reducing gas is simultaneously a heat carrier that provides all the heat costs of the process.
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Conclusion
The creation of even the most advanced treatment facilities cannot solve the problem of environmental protection. The true struggle for a clean environment is not a struggle for sewage treatment plants, it is a struggle against the need for such facilities. It is quite obvious that the problem cannot be solved by extensive methods. An intensive way of solving the global environmental problem is a reduction in resource-intensive production and a transition to low-waste technologies. The possibility of stabilizing and improving the quality of the environment through a more rational use of the entire range of natural resources in the context of accelerating socio-economic development is associated with the creation and development of non-waste production.
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Mankind, as a result of its activities, has come to understand that it is necessary to introduce technological processes that give minimal emissions, in which the self-cleaning ability of nature in enough will prevent the occurrence of irreversible environmental changes. The specialists proposed the definition of waste-free technology, which is accepted as the main one for further use:
Wasteless technology is practical use knowledge, methods and means to ensure within the framework of human needs rational use of natural resources, energy and environmental protection.
Wasteless technology means ideal production model , which in most cases cannot be fully realized, but with the development of technical progress, it is getting closer and closer to the ideal. More specifically, a non-waste technological system (WPS) should be understood as such production, as a result of which there are no emissions into the environment. Waste-free production is a set of organizational and technical measures, technological processes, equipment, materials that ensure the maximum and integrated use of raw materials and minimize the negative impact of waste on the environment.
Waste-free production can be characterized in every possible way by the utilization of waste generated in direct technological processes. Low Waste Technology is an intermediate stage of waste-free and differs from it in that it provides a finished product with incompletely recyclable waste.
The tasks for the implementation of waste-free technology follow from the following:
ü the largest part environmental pollution is the result of insufficient development industrial technology;
ü unused production waste is a loss of natural resources;
ü the receipt and use of secondary raw materials (waste) with an increase in the need for natural materials can become an important source of increasing the productivity of social labor;
ü a prerequisite for the rationalization of industrial technology is the development of technical and economic solutions for "closed" technologies (circulation of materials);
ü A single and economical way to solve the main problems in the field of metabolism between man and nature should be carried out on a national scale.
An analysis of domestic and foreign materials shows that wasteless technology can develop in four main directions:
1) creation various kinds drainless technological systems on the basis of existing, implemented and promising cleaning methods. In this case, a sharp decrease in water consumption is achieved, but, as a rule, secondary pollution is formed in the form of solid precipitation or saturated solutions;
2) development and implementation of production and consumption waste processing systems, which should be considered not as an environmental burden, but as a BMP. Please note that when using modern systems water and gas cleaning produces solid waste, which is a complex concentrated mixture of pollutants;
3) organization of fundamentally new processes receiving traditional species products that allow eliminating or reducing the stages of processing or technological stages at which the main amount of waste is generated;
4) development and creation of territorial-industrial complexes (TPK) with a closed structure of material flows of raw materials and wastes inside the TIC, with a minimum of emissions.
Separation of toxic components from exhaust gases and Wastewater was carried out mainly to convert these components into a harmless form and was rarely combined with their reuse. In many cases, attempts have been made to reduce the concentration of toxic wastes when they are released into the biosphere. Measures to reduce waste and waste heat in the production of products, as well as to reuse these wastes, were implemented primarily in order to save materials and energy and were not considered as environmental protection measures.
The constant increase in the use of natural resources, increased environmental pollution require the implementation of a waste-free technology strategy. The basis of this technology lies in the fact that unused production wastes are both underutilized natural resources and a source of environmental pollution. Reducing the amount of waste used in relation to the amount of manufactured products will allow more products to be produced from the same amount of raw materials and, at the same time, will be an effective measure for protecting the environment.
The biosphere provides natural resources from which products are made in the field of production, while waste is generated. In many cases, after appropriate processing, they can be used as secondary raw materials or as secondary energy carriers. If for technical or technological reasons this is impossible or economically unprofitable, then they must be released into the biosphere in such a way that, if possible, they do not harm the natural environment.
Suggested general equation balance by spheres of production and consumption:
R = A(1 - Sm) + S, .
where R is the consumption of natural resources, kg/s; A is the amount of waste generated in the spheres of production and consumption, kg/s; S m – average coefficient of waste utilization, kg/kg; S is the amount of substances accumulating in the areas of production, kg/s.
Reducing the specific unused amount of production waste A (1 - S m) and thus the specific consumption of natural resources is possible by reducing the generated specific quantity(A) production waste or by increasing the waste utilization ratio (S m). The choice of one of the paths depends both on technological possibilities and on economic conditions. The primary goal of wasteless technology is to reduce the amount of unused waste output into the biosphere per unit time so that the natural balance of the biosphere is preserved and the availability of basic natural resources is ensured.
The final achievement of waste-free production is determined by the presence of n the number of stages of processing waste of all types. The system becomes waste-free when nth stage such amount of waste is emitted that does not have a noticeable negative impact on the environment. If the waste at some stages is sent back for processing, at the initial stage it turns out BTS Closed or partially closed type .
· raw materials, semi-finished products, energy, cooling means : maximize the use of waste and waste heat; Minimize the use of raw materials, semi-finished products and labor energy, the extraction and manufacture of which generate relatively large amounts of industrial waste and waste heat, or which are only available to a limited extent (for example, electricity or cooling water); as far as possible, avoid the use of raw materials containing a high proportion of useless impurities;
· Technical equipment : use technical devices with a long service life and low weight, manufactured in accordance with the requirements of waste-free technology; use technical devices with an optimal operating principle, for example, with a high degree separation or with a high coefficient of heat and mass transfer, with minimal pressure loss and low heat loss;
· basic processes : use non-energy-intensive processes with high selectivity; apply highly efficient catalytic processes;
· technology system : apply the principle of countercurrent or circulation; avoid the principle of co-current and mixing;
· process parameters : to choose optimal temperatures reactions; choose small driving forces; exclude limiting technological parameters, for example, temperatures and pressures;
· products : to lay in the design (composition) of the product a low specific gravity, to provide for a long service life, as well as the minimum generation of waste and waste heat during its use; ensure the suitability of the worn out (used) product as a secondary raw material (secondary energy carrier);
· waste, waste heat : receive waste in a recyclable form.
Since these requirements partly contradict each other, and partly are not feasible due to the lack of opportunities, it is necessary to look for the optimum for each technological process, taking into account labor productivity and economy.
One of the promising, profitable and developing areas of using software included in the system of non-waste technologies is their exchange both between enterprises within countries and between states in order to use them in suitable technological processes.
Thus, exports and imports are widely developed polymer waste in the EEC countries, as well as Austria, Switzerland and the Scandinavian countries. Waste polymers are in particular demand: polyethylene, polypropylene, polystyrene, polyvinyl chloride and cellulose acetate. The leading position in the European waste exchange is occupied by Italy (annual import is over 90 thousand tons of polymer waste), Germany (export 65 thousand tons) and France (export 50 thousand tons). Japan, China and other countries most metal requirements are met by importing scrap metal from other countries. China imports garbage from the US to make paper.
Currently, there are two types of intermediary exchanges in Western Europe and the United States: exchanges that provide information on the amount of waste, their qualitative composition and processing methods, and exchanges that directly exchange waste by finding the appropriate consumer.
The successful functioning of such systems, which close the cycle of non-waste technologies in their own way, is possible on the basis of automated means of communication and control that carry out their operations on an interstate scale or within an industrial region. Thus, since the mid-1970s, in Germany and France, through the mediation of exchanges between enterprises, waste wood, paper, cardboard, metals, and other software have been sold. Despite the relatively small so far contacts between the supplier and the consumer, such exchanges are economically beneficial for the state. This is also evidenced by the experience of the United States and Japan, where there is a wide network of intermediary exchanges that promote the introduction of advanced technological processes for the neutralization and processing of industrial waste and the exchange of waste between enterprises.
For rational management integrated system collection, transportation, neutralization and disposal of waste and pollution on the scale of an industrial region, a separate country or a group of countries, it is necessary to have up-to-date information on the location of waste, their quantity, composition and properties, the possibilities of recycling or neutralization. Information retrieval systems make it possible to identify and establish links between "waste - raw materials", "supplier - consumer". focal points by mutual exchange industrial waste for the purpose of their further disposal, for example, are successfully operating in Japan.
The reserves of non-waste technologies are huge. It is estimated that per capita in our country up to 20 tons of various natural raw materials are processed per year, while only 5 ... 10% goes into finished products, the rest is waste, an unused part of the raw materials. During the operation of industrial products, as they wear out or become obsolete, they also go into the category of consumer waste. Thus, almost the entire volume of materials taken from nature is returned to it, but with new properties that lead to a violation of the ecological balance.
An analysis of the results of research work carried out by a number of institutions in the country shows that almost all types of production and consumption waste can be used in the national economy as a secondary raw material for the production of many types of goods. technical purpose and public consumption. The reality and technical feasibility of using waste has been proven, for example, by the practice of many domestic and foreign enterprises. various industries industry.
Currently, territorial connections and combinations of various technological processes with areas of communal consumption are becoming increasingly important for the use of waste and waste heat. Thus, in many cases it is possible to use water first for domestic purposes, and then, after purification, which requires relatively low costs, to use it for production purposes.
Drainless system for industrial use water is special kind BTS, in which at least 90% of it is in the water cycle and no more than 10% is accounted for by fresh water. At the same time, it is necessary that the amount of blowdown water discharged from the system into a reservoir or treatment plant does not exceed 5% of those in the water circulation.
Drainless systems, in turn, are subdivided into systems with complete recycling of components or without disposal , i.e. with storage in special tanks, reservoirs or with injection into underground horizons. An example of a non-drainage system for the industrial use of water can be the Kristall water treatment plants developed by MosvodokanalNIIproekt and implemented in many car fleets of the country, which operate in a closed cycle and save hundreds of thousands of cubic meters of valuable drinking water.
Economic evaluation of BTS efficiency is to determine the economic effect of waste disposal and recycling at all stages, including other industries, as well as to calculate the prevented damage to the environment based on a comparison of BTS and enterprises with traditional technology.
Based on the foregoing, we can conclude that the further development of the economy in the environmental aspect is closely related to solving the problems of a more complete use of natural resources and the creation of recirculating material and energy flows.
From a technological point of view, the introduction of waste-free and low-waste industries will certainly require the creation of new materials and substances, for example, new membrane materials, ion-exchange resins, synthetic flocculants, chemical reagents, as well as apparatus and instruments that will improve or intensify various processes of media separation, neutralization and waste disposal. In order to scale up the introduction of zero-waste technological processes, it is necessary to further improve the ways of using waste, as well as methods economic incentives in order to increase the interest of workers in various industries in the preparation of waste for subsequent processing and disposal. An important incentive is also the planned reduction in the consumption of natural raw materials by the enterprise and the transition to the use of secondary material resources.
For the organization of low-waste and non-waste industrial production, cooperation between enterprises of various industries is of exceptional importance. The most favorable opportunities for cooperating industries are formed in the conditions of a territorial production complex, where a set of interconnected and interdependent proportionally developing objects of various sectors of the national economy is being planned. These facilities were created to jointly solve one or more specific economic problems, they are distinguished by the size of production and a clear specialization on the scale of the country and their economic region. They are concentrated on a limited, necessarily compact territory, which has the necessary set and amount of resources sufficient to solve the corresponding tasks.
In addition, they effectively (from the standpoint of the national economy) use local and external resources, ensure environmental protection, and have a unified production and social infrastructure.
The economic advantages with the correct and optimal development of industrial production allow for the profitable and expedient transportation of waste over relatively short distances within the TIC, which facilitates the solution of many issues related to the territorial location of enterprises.
The integrated development of the TPK proceeds through the gradual organization of interconnected industries, in which the products of one enterprise become raw materials or semi-finished products for another. At the same time, individual industries are being improved in order to reduce the consumption of energy and water, as well as to increase labor productivity and increase the complexity of processing primary raw materials.
Creation of low-waste and non-waste TPK is an important direction in the development of the national economy, the rational use of natural resources and the preservation of ecological balance.
The main directions of waste-free and low-waste technology
Waste-free and low-waste technology is one of the modern directions in the development of industrial production. The emergence of this direction is due to the need to prevent harmful effect industrial waste to the environment. Waste-free production imply the development of such technological processes that provide the maximum possible complex processing of raw materials. This allows, on the one hand, the most efficient use of natural resources, the complete processing of generated waste into marketable products, and, on the other hand, to reduce the amount of waste and thereby reduce their negative impact on environmental systems.
Waste-free and low-waste technology is used in all industries. Them development is underway in the following areas: development and implementation of fundamentally new technological processes that reduce the amount of waste; development and implementation of methods and equipment for processing waste into marketable products; creation of drainless water circulation systems in which water is purified (see Wastewater Treatment).
Low-waste and zero-waste technologies and their role in protecting the environment
Fundamentally new approach to the development of all industrial and agricultural production - creation of low-waste and waste-free technology .
The concept of non-waste technology, in accordance with the Declaration of the United Nations Economic Commission for Europe (1979) means the practical application of knowledge, methods and means in order to provide the most rational use of natural resources and protect the environment.
In 1984, the same UN commission adopted a more specific definition of this concept: “Waste-free technology is a way of producing products (process, enterprise, territorial production complex), in which raw materials and energy are used most rationally and comprehensively in the cycle of raw materials - production - consumer - secondary resources - in such a way that any impact on the environment does not disrupt its normal functioning.
Under zero waste technology they also understand such a method of production that ensures the fullest possible use of the processed raw materials and the waste generated during Tg. The term “low-waste technology” should be considered more accurate than “waste-free technology”, since in the principle “waste-free technology” is impossible, because any technological activity of a person cannot but produce waste, at least in the form of energy. Achieving complete waste-free™ is unrealistic (Reimers, 1990), because it contradicts the second law of thermodynamics, so the term "waste-free technology" is conditional (metaphorical). The technology that makes it possible to obtain a minimum of solid, liquid and gaseous wastes is called low-waste and on present stage development of nano-technological progress, it is the most real. Of great importance for reducing the level of environmental pollution, saving raw materials and energy is the reuse of material resources, i.e. recycling. Thus, the production of aluminum from scrap metal requires only 5% of the energy costs of smelting from bauxite, and the remelting of 1 ton of secondary raw materials saves 4 tons of bauxite and 700 kg of coke, simultaneously reducing emissions of fluoride compounds in the atmosphere by 35 kg ( Vronsky, 1996).
The set of measures to reduce to a minimum the amount of hazardous waste and reduce their impact on the environment, on the recommendation of various authors, includes:
- development of various types of drainless technological systems and water circulation cycles based on wastewater treatment;
- development of systems for processing waste products into secondary material resources;
- creation and release of new types of products, taking into account the requirements of its reuse;
- creation of fundamentally new production processes that allow eliminating or reducing the technological stages at which waste is generated.
initial stage of these complex measures aimed at creating waste-free technologies in the future is the introduction of circulating, up to completely closed, water use systems.
Recycled water supply
Recycled water supply is technical system, which provides for multiple use in the production of waste water (after purification and processing) with a very limited discharge (up to 3%) into water bodies (Fig. 20.1; Ivanov, 1991).
Rice. 20.1. Scheme of circulating industrial and urban water supply: 1 - workshop; 2 - intrashop circulating water supply; 3 - local (workshop) treatment plant, including disposal secondary waste; 4 - general plant treatment facilities; 5 - city; 6 - city sewer treatment facilities; 7 - tertiary treatment facilities; 8 - injection of treated wastewater into
underground sources; 9 - supply of purified water to the city water supply system; 10 - dispersing wastewater discharge into
body of water (sea)
Closed water cycle
A closed water cycle is a system of industrial
Daogr of water supply and sanitation, in which multiple
use of water in the same production
process, is carried out without the discharge of sewage and other waters into
native reservoirs.
One of major areas in the field of creating non-one and low-waste industries is the transition to non-ecological technology with the replacement of water-intensive processes with anhydrous or low-water ones.
The progressiveness of new technological schemes of water supply is determined by the extent to which they have decreased, in comparison with the previously existing ones, water consumption and the amount of buccal water and their pollution. The presence of a large amount of wastewater at an industrial facility is considered an objective indicator of the imperfection of the technological schemes used.
The development of waste-free and water-free technological pro-yuv is the most rational way to protect the environment from pollution, which makes it possible to significantly reduce the anthropogenic load. However, research in this board is just beginning, therefore, in various areas of industry and agriculture, the level of eco-gization of production is far from the same.
At present, certain successes have been achieved in our country in the development and implementation of elements of environmentally friendly technology in a number of branches of ferrous and non-ferrous metallurgy, thermal power engineering, mechanical engineering, and the chemical industry. However full translation industrial and agricultural production on wasteless and waterless technologies and the creation of fully eco-friendly industries are associated with very complex "problems of a different nature - organizational, nano-technical, financial and others, and therefore modern production is still for a long time will consume huge amounts of water for its needs, have waste and bottom emissions.
Waste-free and low-waste production
The creation of even the most advanced treatment facilities cannot solve the problem of environmental protection. The true struggle for a clean environment is not a struggle for sewage treatment plants, it is a struggle against the need for such facilities. It is quite obvious that the problem cannot be solved by extensive methods. An intensive way to solve the global environmental problem is the reduction of resource-intensive production and the transition to low-waste technologies.
The possibility of stabilizing and improving the quality of the environment through a more rational use of the entire range of natural resources in the context of accelerating socio-economic development is associated with the creation and development of non-waste production.
Zero waste production, strictly speaking, is such a production in which all the raw materials are eventually converted into a particular product and which is simultaneously optimized according to technological, economic and socio-ecological criteria. The fundamental novelty of this approach to the further development of industrial production is due to the impossibility of effectively solving the problems of environmental protection and the rational use of natural resources only by improving the methods of neutralization, recycling, processing or disposal of waste.
The concept of non-waste production provides for the need to include the sphere of consumption in the cycle of using raw materials. In other words, products after physical or obsolescence must be returned to the sphere of production. Thus, non-waste production is a practically closed system, organized by analogy with natural ecological systems, the functioning of which is based on the biogeochemical cycle of matter.
When creating and developing non-waste production be sure to use all the components of the raw material. At present, despite the fact that almost all raw materials used in industry are multicomponent, as finished products usually only one component is used. The maximum possible is the integrated use of energy in waste-free production. Here you can also draw a direct analogy with natural ecosystems, which, being practically closed in matter, are not isolated, since they absorb energy that they receive from the Sun, transform it, binding a small part, and dissipate it into the surrounding space.
the most important integral part concepts of non-waste production are also the concepts of the normal functioning of the environment and the damage caused to it by negative anthropogenic impact. The concept of non-waste production emphasizes that, while inevitably affecting the environment, it does not disrupt its normal functioning.
Creation of non-waste production is a long and gradual process that requires the solution of a number of interrelated technological, economic, organizational, psychological and other tasks. These tasks can and should be solved, as it follows from the definition of non-waste production, on various levels Keywords: process, enterprise, production association. The most complete and consistent basic principles of waste-free production can be implemented on regional level when creating non-waste territorial production complexes. In practice, the creation of waste-free industrial production should be based primarily on fundamentally new technological processes and equipment.
Waste-free production involves the cooperation of production with large quantity waste (production of phosphate fertilizers, thermal power plants, metallurgical, mining and processing industries) with the production - consumer of these waste such as building materials companies. In this case waste fully meet the definition of D. I. Mendeleev, who called them “neglected products of chemical transformations, which eventually become the starting point of new production.”
The most favorable opportunities for combining and cooperating various industries are formed in the conditions of territorial production complexes. The most important task is the creation and implementation of fundamentally new technological schemes and processes in which the generation of any waste is sharply reduced or completely disappears.
Disposing of sulfur dioxide contained in the waste gases of thermal power engineering and metallurgy, it is possible to obtain as much sulfuric acid as all the sulfuric acid plants of our country produce annually, i.e., but, in essence, to double the production of this most valuable product of large chemistry. There are already industrial installations for catalytic purification of exhaust gases, which allow you to extract up to 98-99% of sulfur dioxide from smoke at any, even the smallest, content and oxidize it, turning harmful industrial emissions into sulfuric acid. It is also not easy to use the acid obtained in this way in industry: it contains various impurities, and often turns out to be diluted. But in agriculture it can find an unlimited market, as it is a chemical preparation for soils of soda salinity. Sulfuric acid, arbitrarily diluted, with almost any impurities, is suitable for chemical reclamation. This allows you to build more economical, simplified recycling facilities sulfur dioxide.
As an example of a complex waste-free processing mineral raw materials can be cited technological scheme processing of nephelines. From this apatite mining waste, pure alumina is extracted for the production of metallic aluminum, excellent so-called heavy soda, potash, dicalcium belite silicate for high-quality fast-hardening cements, concentrates of rare elements in the form of minerals - sphene, arigine, etc.