Chemistry and energy. Modern energy sources. Energy of the chemical industry Chemical energy

The Russian chemical industry ranks eleventh in the world in terms of production volume. The industry's share in the country's total industrial production is 6%. Chemical enterprises concentrate 7% of fixed assets (fifth place after mechanical engineering, fuel industry, energy and metallurgy), providing 8% of the value of industrial exports and 7% of tax revenues to the budget. Enterprises of the chemical complex are suppliers of raw materials, intermediate products, various materials (plastics, chemical fibers, tires, varnishes and paints, dyes, mineral fertilizers, etc.) for all industries and are capable of having a significant impact on the scale, direction and efficiency of their development.

Russian chemical industry today

Transformations since the beginning of market reforms have significantly changed the structure of chemical production by type of ownership: to date, the chemical complex has the smallest group of enterprises remaining in state ownership. As a result of privatization, controlling stakes in a significant part of chemical enterprises passed into the hands of external investors. These are mainly oil and gas companies.

As industry experts say, the Russian chemical industry needs a qualitative leap, otherwise it will become completely uncompetitive. Among the main factors hindering the development of the industry are problems that are standard for our industry. Firstly, this is the wear and tear of the assets - the technological equipment installed at Russian enterprises is extremely behind modern requirements (the service life of a significant part of it is 20 years or more, the degree of wear and tear of fixed assets is about 46%). Other problems are the discrepancy between the structure of production of the Russian chemical complex and modern trends in the chemical industry of developed countries, as well as the fact that the basis of production of the Russian chemical complex is products with a low degree of processing of primary raw materials.

If we talk about the strategic objectives of the industry, then this is the technical re-equipment and modernization of existing and the creation of new cost-effective and environmentally friendly production facilities, the development of export potential and the domestic market for chemical products and the development of resource, raw material and fuel and energy supply for the chemical complex. Among other tasks, experts name the organizational and structural development of the chemical complex in the direction of increasing the output of high-tech products, as well as increasing the efficiency of R&D and innovative activity of enterprises in the Russian chemical industry.

This is all the more important since in the period 2020 and until 2030, according to an analysis made by specialists from the Ministry of Industry and Trade, the Russian chemical industry will be faced with the task of meeting the demand for new high-tech materials from the mechanical engineering, shipbuilding, medicine, helicopter manufacturing, and aircraft industries , power engineering.

Developments in the space, aviation and nuclear energy sectors will also require new chemical materials, composite materials, sealing materials, soundproofing materials, electrical wires and cables, and coatings. The already high demands on the technical properties of products, such as high strength, resistance to radiation, resistance to corrosion, resistance to high and low temperatures, as well as resistance to aging of materials, will increase.

For example, polymers now occupy second place in the global automotive industry after metals as raw materials for the production of automotive components. In Russia, there is a shortage and limited brand range of all types of produced plastics, which creates a serious barrier to increasing the range of produced auto components.

The share of polymer composites in the total volume of building materials in Russia is also quite low. If “traditional” materials are mainly used in civil engineering, then in such sectors as the construction of bridges, railways, railway tunnels, etc., polymer composites have significant prospects in Russia.

Thus, as experts say, establishing the production of the necessary polymers in Russia can become a significant segment of import substitution. At the same time, the use of chemical products in construction is constantly expanding: these include new insulation materials and additives in structural materials, insulation materials, coatings that produce electricity from sunlight, and road surfaces that allow traffic flow to be measured, etc.

New chemical products are also appearing on the market: plastics with a long life cycle, materials capable of self-diagnosis and self-adaptation, new generation high-tech fibers, self-healing eco-rubber and “smart” nanomaterials that change shape at the user’s request. Experts talk about polymers with the function of active membranes that can sort molecules, about amorphous polymers that can restore damaged coatings, about Arctic fuels that are very important in Russia’s current policy, etc.

Many experts also predict a further increase in the importance of biologically derived materials. In the medium term, mass production of chemical products from renewable resources (“white” chemistry) is expected: biofuels, products from biodegradable polymers, biosensors and biochips. According to preliminary expert estimates, the market for biopolymers (polymers made from renewable resources) will grow annually by 8-10% and by 2020 their share in the total polymer market will be 25-30%.

All this, according to officials from the Ministry of Industry and Trade, can be produced in Russia - if the necessary investments are made in the domestic chemical industry.

Energy and chemistry

If we talk about the connections between chemistry and energy, they are very close: the chemical industry consumes a huge amount of energy. Energy is spent on endothermic processes, transporting materials, crushing and grinding solids, filtering, compressing gases, etc. The production of calcium carbide, phosphorus, ammonia, polyethylene, isoprene, styrene, etc. requires significant energy expenditure. Chemical production together with petrochemical are energy-intensive areas of the industry. Producing almost 7% of industrial products, they consume between 13-20% of the energy used by the entire industry.

However, the achievements of chemistry also work for the energy sector. Already today, chemists are working on issues of maximum and comprehensive energy-technological use of fuel resources - reducing heat losses to the environment, recycling heat, maximizing the use of local fuel resources, etc.

For example, many countries are developing a cost-effective technology for processing coal into liquid (as well as gaseous) fuel. Russian chemists are also working on this problem. The essence of the modern process of processing coal into synthesis gas is as follows. A mixture of water vapor and oxygen is supplied to the plasma generator. Then coal dust enters the hot gas torch, and as a result of a chemical reaction, a mixture of carbon monoxide and hydrogen is formed, i.e. synthesis gas. Methanol is produced from it, which can replace gasoline in internal combustion engines and compares favorably with oil, gas, and coal in terms of environmental impact.

Russia has also developed chemical methods for removing binder oil (contains high molecular weight hydrocarbons), a significant part of which remains in sludge pits. To increase the yield of oil, surfactants are added to the water that is injected into the formations; their molecules are placed at the oil-water interface, which increases the mobility of the oil.

Hydrogen energy, which is based on the combustion of hydrogen, during which no harmful emissions are generated, seems very promising. However, for its development it is necessary to solve a number of problems related to reducing the cost of hydrogen and creating reliable means of storing and transporting it. If these problems are solvable, hydrogen will be widely used in aviation, water and land transport, industrial and agricultural production. Russian scientists are working closely with their European colleagues on these issues.

One of the key areas remains the solution of problems associated with the cost-effective processing of “heavy” high-viscosity oil, as well as heavy residues from oil refineries. The depth of oil refining in EU countries is at least 85%, and this value will increase in the forecast period. At the enterprises of the Russian oil refining complex, the required set of secondary processes for processing heavy fractions of oil is in most cases absent, and the depth of processing is about 70%. Increasing this indicator will allow you to receive additional profits and increase the efficiency of using secondary raw materials.

Already today, the Institute of Petrochemical Synthesis of the Russian Academy of Sciences, together with the Grozny Petroleum Institute (GrozNII), has created a fundamentally new technology for the hydrogenation preparation of tar on nano-sized catalysts, after which it is possible to use conventional highly efficient processes of catalytic cracking or vacuum distillate hydrocracking, i.e. traditional methods of deep oil refining. At the same time, the complexity of oil refining involves both the rational extraction of valuable components from oil (oils, liquid and solid paraffins, neftenoic acids, etc.) and the optimal processing of previously difficult-to-utilize products, such as light gases, asphalts, and sands. The waste-free nature of oil refining, which has become especially acute due to the increasing negative impact of human activity on the environment, includes complete processing of all oil fractions with maximum extraction of useful components: the use of technologies, catalysts and reagents eliminates the formation of harmful emissions and waste.

In addition, gas chemistry remains one of the most interesting areas for Russia, which urgently needs simple and cost-effective technologies for converting natural gas into liquid products, designed for operation directly in gas production areas, including in the polar regions and on the sea shelf.

With the help of the chemical industry, Russia can significantly expand its market share not only of primary energy resources, but also of the much more profitable market of expensive chemical products and environmentally friendly motor fuels. It is in this area that Russia has the greatest chance of entering the high-tech market in the coming years. The transition of the world market to ultra-low-sulfur gasoline and diesel fuels, which affect the improvement of the environment, is an important event involving a huge number of links in economic and government mechanisms. This transition is accompanied by the development of technologies for deep and ultra-deep purification of liquid fractions, as well as the development of new processes for the purification and processing of technological and associated refinery gases. Here Russian chemists could also make their contribution.

The Russian chemical industry interacts especially closely with the energy industry in the field of nuclear energy. Moreover, we are talking not only about the production of fuel elements, but also about more exotic projects. For example, it is for nuclear power plants that in the future they will find another application - for the production of hydrogen. Part of the hydrogen produced will be consumed by the chemical industry, the other part will be used to power gas turbine units switched on at peak loads.

Nanomaterials and biocatalysis

Experts include the development of new technologies and means of radioactive waste disposal as promising technologies in the chemical industry; molecular design, chemical aspects of energy, such as the creation of new chemical current sources, development of technologies for producing fuels from non-petroleum and renewable raw materials, high-energy substances and materials, etc.

In nanochemistry, the most “advanced” areas include nanocatalysis, the production of nanomaterials for receiving, processing and transmitting information, molecular memory media, and the development of nanomodulators.

Biocatalytic technologies are expected to be used for the production of biodegradable and electrically conductive polymers; high molecular weight polymers for enhanced oil recovery and water treatment; anti-corrosion and antistatic coatings for metal structures that are superior in efficiency to paint and varnish coatings; biosensors and biochips that use the principles of highly specific biological perception and recognition for use in medicine, the aerospace industry and the production of computer equipment. You can also mention a new method for separating and purifying chemical mixtures, obtaining and applying powder coatings, water desalination, water and soil purification, including from heavy metals and radionuclides.

As experts say, the development of nano- and biotechnologies will lead to the emergence of a new generation of products with enhanced properties, which, in turn, will lead to their new use in many industries, including the energy sector. These are, for example, new materials for storing hydrogen, improved membranes for desalination and wastewater treatment plants, self-healing coatings, etc.

Thus, in modern conditions, the energy industry increasingly needs the latest chemical technologies, and Russian manufacturers are also responding to this demand.

– Tell us about the new products of your production in the chemical industry used in the energy sector. Which products are most in demand by customers?
Maria Zaitseva, Director of the Nuclear Energy Department of NPP VMP-Neva LLC: – The VMP Research and Production Holding specializes in the development, production and implementation of coatings for long-term protection of metal and concrete.

The produced anti-corrosion and fire-retardant materials, as well as polymer floor coverings, have high technological and performance characteristics, which are achieved through highly effective pigments, chemical and weather-resistant polymers, special fillers and auxiliary additives. We have been working in the energy sector for more than 17 years. Today we draw the attention of industry specialists to a new interesting material that already has positive experience of use at nuclear power plants. VINIKOR® EP-1155D enamel is designed to protect the controlled access area, including the reactor unit. This is the only material in Russia that has passed simulated tests under normal operating conditions of a reactor unit. To date, tests have confirmed the ability of the coating to operate without loss of protective parameters for 50 years. All this allows us to offer this material to designers and operating services of stations, nuclear waste processing plants and storage facilities, wherever there are high Rosatom requirements for the safety of facilities. Another material for energy and hydraulic engineering facilities is ISOLEP®-hydro primer-enamel. It is used to protect metal structures located in the underwater zone and in the zone of variable wetting. Successfully passes full-scale tests in a cooling tower of a nuclear power plant.

The nuclear power plants of US submarines use many chemical elements and synthetic organic compounds. Among them are nuclear fuel in the form of uranium enriched with a fissile isotope; graphite, heavy water or beryllium, used as neutron reflectors to reduce their leakage from the reactor core; boron, cadmium and hafnium, which are part of the control and protection rods; lead, used in the primary protection of the reactor along with concrete; zirconium alloyed with tin, which serves as a structural material for shells of fuel elements; cation exchange and anion exchange resins used to load ion exchange filters, in which the primary coolant of the installation - highly purified water - is freed from particles dissolved and suspended in it.

Chemistry also plays an important role in ensuring the operation of various submarine systems, for example, the hydraulic system, which is directly related to the control of the power plant. American chemists have been working for a long time to create working fluids for this system that are capable of operating at high pressure (up to 210 atmospheres), fire-safe and non-toxic. It was reported that to protect the pipelines and fittings of the hydraulic system from corrosion when flooded with sea water, sodium chromate is added to the working fluid.

A variety of synthetic materials - polystyrene foam, synthetic rubber, polyvinyl chloride and others are widely used on boats to reduce the noise of mechanisms and increase their explosion resistance. Sound-insulating coatings and casings, shock absorbers, sound-insulating inserts in pipelines, and sound-damping pendants are made from such materials.

Chemical energy accumulators, for example in the form of so-called powder pressure accumulators, are beginning to be used (though still on an experimental basis) for emergency purging of main ballast tanks. Solid propellant charges are used on US missile submarines and to support the underwater launch of Polaris missiles. When such a charge is burned in the presence of fresh water, a vapor-gas mixture is formed in a special generator, which pushes the rocket out of the launch tube.

Purely chemical energy sources are used on some types of torpedoes in service and being developed abroad. Thus, the engine of the American Mk16 high-speed steam-gas torpedo runs on alcohol, water and hydrogen peroxide. The Mk48 torpedo under development, as reported in the press, has a gas turbine, the operation of which is ensured by a solid propellant charge. Some experimental jet torpedoes are equipped with power plants that run on fuel that reacts with water.

In recent years, there has often been talk about a new type of “single engine” for submarines, based on the latest advances in chemistry, in particular on the use of so-called fuel cells as an energy source. They are discussed in detail further in a special chapter of this book. For now, we will only point out that in each of these elements an electrochemical reaction occurs, the reverse of electrolysis. Thus, during the electrolysis of water, oxygen and hydrogen are released at the electrodes. In a fuel cell, oxygen is supplied to the cathode, and hydrogen is supplied to the anode, and the current taken from the electrodes goes to a network external to the element, where it can be used to drive the propeller motors of a submarine. In other words, in a fuel cell, chemical energy is directly converted into electrical energy without intermediate high temperatures, as in a conventional power plant chain: boiler - turbine - electric generator.

Electrode materials in fuel cells can include nickel, silver and platinum. Liquid ammonia, oil, liquid hydrogen, and methyl alcohol can be used as fuel. Liquid oxygen is usually used as an oxidizing agent. The electrolyte can be a solution of potassium hydroxide. One West German submarine fuel cell project proposes using high-concentration hydrogen peroxide, which, when decomposed, produces both fuel (hydrogen) and oxidizer (oxygen).

A power plant with fuel cells, if used on boats, would eliminate the need for diesel generators and batteries. It would also ensure silent operation of the main engines, absence of vibration and high efficiency - about 60–80 percent with a promising unit weight of up to 35 kilograms per kilowatt. According to the calculations of foreign experts, the costs of building a submarine with fuel cells can be two to three times lower than the costs of building a nuclear submarine.

The press reported that work was underway in the United States to create a ground-based prototype of a boat power plant with fuel cells. In 1964, testing of such an installation began on the ultra-small research submarine Star-1, its propeller engine power is only 0.75 kilowatts. According to the magazine Schiff und Hafen, a pilot plant with fuel cells has also been created in Sweden.

Most foreign experts are inclined to believe that the power of power plants of this kind will not exceed 100 kilowatts, and their continuous operation time is 1000 hours. Therefore, it is considered most rational to use fuel cells primarily on ultra-small and small submarines for research or sabotage and reconnaissance purposes with an autonomy of about one month.

The creation of fuel cells does not exhaust all cases of application of the achievements of electrochemistry in underwater applications. Thus, US nuclear submarines use alkaline nickel-cadmium batteries, which, when charged, release oxygen rather than hydrogen. Some diesel submarines in this country use alkaline silver-zinc batteries, which have three times the energy density, instead of acid batteries.

The characteristics of disposable silver-zinc batteries for submarine electric torpedoes are even higher. In a dry state (without electrolyte) they can be stored for years without requiring any care. And getting them ready takes literally a split second, and the batteries can be kept charged for 24 hours. The dimensions and weight of such batteries are five times less than equivalent lead (acid) batteries. Some types of torpedoes that are in service with American submarines have batteries with magnesium and silver chloride plates that operate on sea water and also have enhanced performance.

Energy of the chemical industry occupies one of the main places in modern industry. Without her participation, it would be impossible to carry out technological processes. Energy serves to a large extent to ensure human life.

There are different types of energy:

electric;

thermal;

nuclear and thermonuclear;

light;

magnetic;

chemical;

mechanical.

Absolutely all chemical production consumes energy. Industry processes involve either the use or circulation of energy. Electrical energy is used for electrochemical, electrothermal and electromagnetic processes. These are electrolysis, melting, heating, synthesis. For the processes of grinding, mixing, operation of compressors and fans, the conversion of electrical energy into mechanical energy is used.

Thermal energy is used to carry out physical processes that are not accompanied by heating, melting, distillation, drying, that is, chemical reactions. Chemical energy is used in galvanic devices, where it is converted into electrical energy. Light energy is used to carry out photochemical reactions.

Energy fuel base for the chemical industry

IN energy industry chemical industry Fossil fuels and their derivatives represent the main source of energy consumed. The energy intensity of production is determined by the energy consumption per unit of manufactured products.
Energy includes the extraction of energy resources (oil, gas, coal, shale) and their processing, as well as special types of transport. These include oil pipelines, gas pipelines, power lines and product pipelines.

The fuel energy sector is also a raw material base for the petrochemical and chemical industries. All of its products are subjected to heat treatment to separate individual components (for example, coke from coal, ethane, ethylene, butane, propane from oil and gases). Only natural gas is used in its pure form for the production of chemical products such as ammonia and methyl alcohol.

The energy sector is developing dynamically and quickly, provoking the development of scientific and technological progress. The demand for the use of energy resources is growing more and more, and therefore the search for deposits and the creation of new production facilities are priority components of the industry. However, this area leads to numerous problems in economics, politics, geography, and ecology that are global in nature.

The most developing energy segments are the oil and oil refining, as well as the gas industries. The extraction of natural resources occupies a significant place in the world, and their deposits sometimes give rise to conflicts between states. Oil is an important energy carrier; after its processing, a lot of products necessary for human activity are obtained. Their list includes kerosene, gasoline, various types of fuel and petroleum oils, fuel oil, tar and others. The need for the oil refining industry arose with the development of transport and aviation to provide it with fuel. The gas industry is the most progressive and promising area. Natural gas is the main raw material for chemical production and its uses are very different.

The Chemistry exhibition in the fall will present the latest technologies and developments in the field in large volume and scale. chemical industry energy. At this exhibition, manufacturers and consumers can not only get acquainted with the product and assortment, but also enter into new deals and establish connections with both domestic and foreign partners. As experts note, “Chemistry” has a huge impact on the development and promotion of new technologies. In addition, it highlights not only new methods and achievements in science and technology, but also personal and collective protective equipment at work.

The exhibition, organized by the Expocentre Fairgrounds, has been taking place in Moscow since 1965. And Expocentre specialists make it possible to hold such events at the highest level. That is why it is repeatedly chosen as a venue for such events by both domestic and foreign organizers.

VI international competition of scientific and educational projects

"Future Energy"

Competition work

The role of chemistry in the energy sector: preparation of chemically demineralized water

ion exchange method for nuclear power plants

Municipal educational institution gymnasium No. 3 named after.
, 10 "a" class

Leaders:

Laboratory assistant at the KNPP chemical workshop

– physics teacher at Municipal Educational Institution Gymnasium No. 3

Contact phone numbers:

annotation

Kalinin NPP is the largest water consumer in the Udomelsky district.

This paper provides information on the requirements for the quality of drinking and circuit water. Comparative tables and histograms of chemical indicators of drinking, lake and 2nd circuit water are provided. A brief description is given of the results of the visit to the water intake station and chemical workshop of the Kalinin NPP. A brief description of the theory of ion exchange and a description of the basic schemes of chemical water treatment and a block desalting plant are also given; A brief theoretical description of the principle of water purification from radioactive contamination - special water treatment - is also given.

This work helps to increase motivation to study chemistry and physics, and introduces chemical technologies used in the energy sector using the example of the Kalinin NPP.

1.Introduction 3

2. Review of literature on water preparation using method 4

ion exchange

2.1.Principle of operation of nuclear power plants with reactors of the VVER-1000 type 4

2.2. Requirements for water used for

technological needs at NPP 5

2.3. Chemical indicators of the quality of natural and contour waters. 5

2.4.Ion exchange theory 6

2.5.Work cycle of ion exchange resin 9

2.6. Features of the use of ion exchange materials 10

3. Case study 11

3.1.Visit to water intake station 11

3.2.Visit to Kalinin NPP 13

3.3.Description of the concept of chemical water treatment 15

3.4.Description of the circuit diagram

block desalted plant 18

3.5.Theoretical description of the operating principle

special water treatment 20

4. Conclusion 20

5. References 22

1. Introduction

1.1. Goal of the work:

familiarization with the technology of water preparation for nuclear power plants using the ion exchange method and comparison of water quality: for the technological needs of nuclear power plants, drinking and lake water.

1.2. Job objectives:

1. study the requirements for water used for technological needs at a modern nuclear power plant using the example of the Kalinin NPP.

2. become familiar with the theory of the ion exchange method,

3. visit the water intake station in Udomlya and become familiar with the chemical composition of drinking water and lake water.

4. compare the indicators of chemical analysis of drinking water and water of the second circuit of a nuclear power plant.

5. visit the chemical shop of the Kalinin NPP and familiarize yourself with:

¾ with the process of water preparation at chemical water treatment;

¾ with the process of water purification in a block desalting plant;

¾ visit the express laboratory of the second circuit;

¾ familiarize yourself theoretically with the work of special water treatment.

6. draw conclusions about the importance of ion exchange in water preparation.

1.3. Relevance

Russia's energy strategy envisages almost doubling electricity production from 2000 to 2020. With the predominant growth of nuclear energy: the relative share of electricity generation at nuclear power plants over this period should increase from 16% to 22%.

NPP equipment, like no other, is subject to safety, reliability and operating efficiency requirements.

One of the most important factors influencing the reliable and safe operation of nuclear power plants is compliance with the water chemistry regime and maintaining water quality indicators at the level of established standards.

The water chemistry regime of a nuclear power plant must be organized in such a way as to ensure the integrity of barriers (fuel cladding, coolant circuit boundaries, sealed fences, localizing safety systems) in the path of possible spread of radioactive substances into the environment. The corrosive effect of the coolant and other working media on the equipment and pipelines of NPP systems should not lead to a violation of the limits and conditions of its safe operation. The water chemistry regime must ensure a minimum amount of deposits on the heat transfer surfaces of equipment and pipelines, as this leads to a deterioration in the heat transfer properties of the equipment and, as a consequence, a reduction in the service life of the equipment.

2. Review of the literature on water preparation using the ion exchange method

2.1. Operating principle of nuclear power plants with VVER-1000 type reactors

The operating principle of most existing nuclear power plants is based on the use of heat released during the splitting of the 235U nucleus under the influence of neutrons. In the reactor core, under the influence of neutrons, the 235U nucleus splits, releasing energy and heating the coolant - water.

Nuclear fuel transfers thermal energy to the primary circuit coolant, which is water under high pressure (16 MPa), at the outlet of the reactor, the water temperature is 3200. Next, thermal energy is transferred to the secondary circuit water. There is no direct contact between the coolant and the secondary circuit water. The coolant circulates in a closed loop: reactor - steam generator - main circulation pump - reactor. There are four such circuits. In the steam generator, the coolant of the primary circuit heats the water of the secondary circuit until steam formation. The steam enters the turbine, which rotates due to this steam. Such steam is called the working fluid. The turbine is directly connected to an electrical generator, which produces electrical energy. Next, the exhaust steam at low pressure enters the condenser, where it condenses due to cooling by lake water. Then additional cleaning and return to the steam generator. And so the cycle repeats: evaporation, condensation, evaporation.

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rice. 1. Technological diagram of a double-circuit nuclear power plant:

1 – reactor; 2 – turbogenerator; 3 – capacitor; 4 – feed pump; 5 – steam generator; 6 – main circulation pump.

2.2. Requirements for water used for technological needs at nuclear power plants

With the increase in steam and water parameters, the impact of water chemical regimes has increased. This led to an increase in the specific thermal loads of the heating surfaces. Under these conditions, even minor deposits on the internal surfaces of pipes cause overheating and destruction of the metal. High steam parameters (pressure and temperature) increase its dissolving ability against impurities contained in the feed water. As a result, the intensity of drift of the turbine flow path increases, which can lead to a decrease in the efficiency of the units and, in some cases, to a limitation of their power and a reduction in the service life of the equipment.

Elimination of deficiencies in water chemical regimes is necessary not only in case of violations that create an emergency situation, but also in case of seemingly minor deviations from the norms. For example, from operating experience it follows that:

§ deposits of salts and corrosion products on the blades of the high-pressure cylinder of turbines of 300 MW units in an amount of 1 kg cause an increase in pressure in the turbine control stage by 0.5 - 1 MPa (5 - 10 kgf/cm2) and lead to a decrease in turbine power by 5 - 10 MW;

§ deposition of corrosion products on the inner and outer surfaces of the high-pressure heater pipes in an amount of 300–500 g/m2 reduces the feedwater heating temperature by 2–30 C and worsens the efficiency of the unit;

§ deposits in the steam-water path of the blocks increase its hydraulic resistance and energy losses for pumping water and steam. An increase in the resistance of the 300 MW unit path by 1 MW (10 kgf/cm2) leads to an overconsumption of 3 million kWh of electricity per year.

To meet the requirements for water chemistry at nuclear power plants, the following systems are used:

§ chemical water treatment;

§ condensation and degassing system;

§ block desalting plant;

§ installation of corrective processing of the working environment of the first and second circuits;

§ deaerators;

§ steam generator purge system;

§ steam generator purge water treatment plant (special water treatment);

§ primary circuit purge-make-up system.

2.3. Chemical indicators of the quality of natural and contour waters

The water coolant for filling energy circuits and feeding them is prepared from natural waters at water treatment plants of various types and usually contains the same impurities that characterize natural water, but in significantly lower (by several orders of magnitude) concentrations.

The main indicators of water quality include the following.

Content of coarse (suspended) substances , present in circuit waters - in the form of sludge consisting of poorly soluble compounds such as CaCO3 , CaSO4, Mg(OH)2, particles of corrosion products of structural materials (Fe3O4, Fe2O3, etc.), the content of which is determined by filtration through a paper filter with drying at C or an indirect method based on water transparency.

Salinity – the total concentration of cations and anions in water, calculated from the total ionic composition and expressed in milligrams per kilogram. To characterize and control waters and condensates with low salt content in the absence of dissolved gases CO2 and NH3, the indicator is often used electrical conductivity . Condensate with a salt content of about 0.5 mg/kg has a specific electrical conductivity of 1 µS/cm.

General water hardness - total calcium concentration ( calcium hardness) and magnesium ( magnesium rigidity), expressed in equivalent units of milligram-equivalent per kilogram or microgram-equivalent per kilogram:

ZhO = ZhSa + ZhMg

Water oxidability is expressed by the consumption of a strong oxidizing agent (usually KMnO4), required for the oxidation of organic impurities in water under standard conditions, and is measured in milligrams per kilogram of KMnO4 or O2, equivalent to the consumption of potassium permanganate.

Hydrogen concentration indicator ions (pH) of water characterizes the reaction of water (acidic, alkaline, neutral) and is taken into account for all types of water treatment and use.

Electrical conductivity (χ) is determined by the mobility of ions in a solution placed in an electric field; for pure water its value is 0.04 µS/cm, for desalted turbine condensates χ = 0.1 µS/cm (microsiemens per centimeter).

2.4. Ion exchange theory

Preparation of water for filling the circuits of nuclear power plants and replenishing losses in them is carried out using desalted water prepared by chemical desalination in two or three stages of initial low-mineralized water (Nitrogen" href="/text/category/azot/" rel="bookmark">nitrogen N and many other elements. Coal is practically insoluble in water, but upon contact with oxygen dissolved in water, slow oxidation occurs, leading to the formation of various oxidized groups on the surface of the coal, which are tightly bound to the base of the coal. conventionally designate this unchanged base with the letter R, then the structure of such a material can be described by the formula ROH or RCOOH, depending on which oxidized group of hydroxyl OH or carboxyl COOH is formed on its surface during oxidation. These groups are capable of dissociation, i.e. in aqueous. processes occur in the environment:

RCOOH = RCOO - + H+.

If cations, for example calcium, are present in water, then cation exchange processes become possible:

2RCOOH+Ca2+ = (RCOO)2Ca +2 H+.

In this case, calcium ions are fixed on the carbon, and an equivalent amount of hydrogen ions enters the solution. Exchange can also take place for other ions, such as sodium, iron, copper, etc. ions.

2.4.2. Cation exchangers and anion exchangers.

All materials capable of exchanging cations are called cation exchangers. Materials capable of exchanging anions are called anion exchangers. They have other ion exchange groups, usually NH2 or NH, which form NH2OH with water.

Cation exchangers are capable of exchanging positively charged ions (cations) with the solution. The process of exchange of cations between a cation exchanger immersed in water to be purified and this water is called cationization. Anion exchangers are capable of exchanging negatively charged ions with the electrolyte. The process of exchange of anions between the anion exchanger and the treated water is called anionization.

In Fig. Figure 2 schematically shows the structure of ion exchange resin grains. The grain, which is practically insoluble in water, is surrounded by dissociated grains - positively charged for the cation exchanger (Fig. 2, a) and negatively charged for the anion exchanger (Fig. 2, b). In the grain of the ion exchanger itself, due to the separation of ions, a negative charge arises for the cation exchanger and a positive charge for the anion exchanger.

rice. 2. Diagram of the structure of ionite grains.

a) – cationite; b) – anion exchanger; 1- solid polyatomic ion exchanger frame; 2 – stationary ions of active groups associated with the framework (potential-forming ions); 3 – limitedly mobile ions of active groups capable of exchange (counterions).

Most currently used ion exchange materials belong to the category of synthetic resins. Their molecules consist of thousands and sometimes tens of thousands of interconnected atoms. Ion exchange materials are a kind of solid electrolytes. Depending on the nature of the active groups of the ion exchanger, its mobile, exchangeable ions can have a positive or negative charge. When the positive, mobile cation is the hydrogen ion H+, then such a cation exchanger is essentially a polyvalent acid, just as an anion exchanger with an exchangeable hydroxyl ion OH - is a multivalent base.

The mobility of ions capable of exchange is limited by distances at which their reciprocity with immobile ions of opposite charge on the surface of the ion exchanger is not lost. This space limited around the molecules of the ion exchanger, in which there are mobile and exchangeable ions, is called the ionic atmosphere of the ion exchanger.

The exchange capacity of ion exchangers depends on the number of active groups on the surface of the ion exchanger grains. The surface of the ion exchanger is also the surface of depressions, pores, channels, etc. Therefore, it is preferable to have ion exchangers with a porous structure. The grain size of domestic and foreign ion exchangers is characterized by fractions ranging from 0.3 to 1.5 mm with an average grain diameter of 0.5-0.7 mm and a heterogeneity coefficient of about 2.0-2.5.

There are ion exchangers in which almost all of the functional groups contained in their composition or only a small percentage of them undergo dissociation, according to which they distinguish between strongly acidic cation exchangers - capable of absorbing cations (sodium Na+, magnesium Mg2+, etc.); and weakly acidic – capable of absorbing hardness cations (magnesium Mg2+, calcium Ca2+). The division into two groups of anion exchangers is similar: strongly basic - capable of absorbing both strong and weak acids (for example, carbonic, silicon, etc.). and weakly basic - capable of absorbing predominantly anion exchangers of strong acids (, etc.).

2.5. Duty Cycle of Ion Exchange Resin

The ion exchanger layer (ion exchange resin) along the movement of the treated water during the ion exchange process can be divided into three zones.

The first zone is the zone of depleted ion exchanger, since all the counterions located in it are used for exchange for ions of the treated water. In this zone, selective exchange continues between the ions of the water being treated, i.e., the most mobile ions contained in the water displace less mobile ones from the ion exchanger (Fig. 3).

The second zone is called the useful exchange zone. This is where the useful exchange of counterions of the ion exchanger for ions of the treated water begins and ends. In this zone, the frequency of exchange of ions of the treated water for counter ions of the ion exchanger prevails over the frequency of the reverse exchange of ions of the treated water and ions absorbed by the ion exchanger.

The third zone is the zone of idle, or fresh, ion exchanger. The water passing through this layer of the ion exchanger contains only counterions of the ion exchanger and therefore does not change either its composition or the composition of the ion exchanger.

As the filter operates, the first zone - the zone of depleted ion exchanger - increases, forcing the working zone 2 to fall due to the decrease in the zone of fresh ion exchanger 3, and, finally, goes beyond the lower limit of the filter loading. Here the height of the third zone is zero. The concentration of the least sorbed ions appears in the filtrate and begins to increase, and the useful work of the ion exchange filter ends.

Technology of the regeneration process.

The regeneration process of ion exchange filters consists of three main operations:

Loosening the ion exchange resin layer (loosening washing);

Passing a working reagent solution through it at a given speed;

Washing the ion exchanger from regeneration products.

Loosening wash.

During the operation of filters, products of gradual destruction and grinding of ion exchangers always form, which must be periodically removed. This is achieved using loosening washes; this operation is required before each regeneration.

It is very important to comply with the washing conditions, which should ensure a more complete removal of small dusty parts of ion-exchange materials from the filter. In addition, loosening washing eliminates compaction of the material, which impedes the contact of the regeneration solution with the ion exchange resin grains.

Loosening is carried out by a flow of water from bottom to top at a speed that ensures that the entire mass of ion-exchange material is suspended. When the water leaving the filter becomes clear, loosening is stopped.

Skip regeneration solution.

Regeneration and washing of the ion exchanger from regeneration products are usually carried out at the same speed. In this case, the passage of reagents is possible both along the flow of the treated water - in a forward flow, and in the direction opposite to the movement of the treated water - in a countercurrent, depending on the technology adopted.

When regeneration solutions are passed through, the ions absorbed by the ion exchanger are replaced with ions of the regeneration solution (containing H+ or OH - ion). In this case, the ion exchangers are converted to their original ionic form.

There are two types of regeneration: internal and external. Remote regeneration is used in mixed-action filters in a block desalination plant to avoid regeneration water from entering the secondary circuit.

Washing of regeneration product residues.

The last operation of the regeneration cycle - washing - is aimed at removing the remnants of regeneration products from it.

Washing of the filter layer is stopped when certain quality indicators of the washing water are reached. The filter is ready for use.

These processes allow the ion exchanger to be used repeatedly.

2.6. Features of the use of ion exchange materials at nuclear power plants

Removing radionuclides from water by ion exchange is based on the fact that many radionuclides are in water in the form of ions or colloids, which, when in contact with the ion exchanger, are also absorbed by the filter material, but the absorption is physical in nature. The volumetric capacity of resins with respect to colloids is much lower than with respect to ions.

The complete absorption of radionuclides by ion exchangers is influenced by the content in water of a large number of inactive elements, which are chemical analogues of radionuclides.

Under conditions of ionizing radiation, only highly pure ion exchangers in hydrogen and hydroxyl form are used (strong base anion exchangers and strong acid cation exchangers). This is due to the insufficient resistance of ion-exchange materials to the action of ionizing radiation and more stringent requirements for the water regime of the primary circuit of a nuclear power plant.

3. Case study

3.1. Visit to the water intake station

In 1980, the first stage of the water intake station in the city of Udomlya was put into operation. The main task is the extraction and preparation of water for consumer needs. Water from artesian wells is pumped for purification, which includes aeration and filtration. The water is then chlorinated and supplied to consumers.

On December 14, 2007, an excursion to the water intake station took place in order to become familiar with the processes of: water preparation, determining the main indicators of the quality of drinking and lake water.

Determining the pH of solutions using a pH meter at a water intake station.

Preparation of samples for iron determination using a KFK-3 photocolorimeter.

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Determination of chlorides by back titration.

Determination of hardness salts.

The data obtained during joint research with water intake employees is presented in tables.

Table 1. Comparison of quality indicators for lake (using the example of Lake Kubycha) and drinking water.

Index	Unit	lake water	Drinking water
lake Kubych
Chroma
Turbidity





Rigidity
Mineralization

MPC* - maximum permissible concentration - is regulated by GOST water quality.

Histogram 1. pH indicator of Lake Kubycha, drinking water and maximum permissible concentration.

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Histogram 3. Content of hardness salts in Lake Kubycha, drinking water and maximum permissible concentration.

December 25" href="/text/category/25_dekabrya/" rel="bookmark">December 25, 2007, an excursion to the Kalinin Nuclear Power Plant took place in order to get acquainted with the work of the departments of the chemical workshop. During the excursion, we visited the chemical water treatment plant and got acquainted with the technology of chemical production demineralized water. During a visit to the machine room, we became acquainted with the technology for purifying the main condensate of the secondary circuit, with the work of the express laboratory of the secondary circuit, and received data on the quality of the secondary circuit water.

It is interesting to compare some chemical indicators of the quality of the secondary circuit water of the Kalinin NPP and drinking water obtained at the water intake.

Table 2. Comparative characteristics of drinking water and water from the second circuit of the nuclear power plant.

* - data is not indicated, since the hardness concentration is less than the sensitivity of the method for determining this indicator.

Conclusion: 1. As follows from Table 2, the maximum permissible concentration drinking water and control values of secondary circuit water have significant differences. This is due to higher requirements for water used for process needs, necessary for the safe and reliable operation of equipment.

2. Drinking water obtained at the water intake is of high quality, chemical indicators are significantly below the maximum permissible concentration impurities contained in drinking water.

3. Secondary circuit water corresponds to control values. This is achieved by purifying water using the ion exchange method during its preparation and post-purification of condensate in block desalting plants.

Histogram 4. Chloride content in drinking water and secondary circuit water of the Kalinin NPP.

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High requirements for the content of hardness salts in the secondary circuit water are caused by the fact that scale-forming salt deposits appear on the walls of heat exchangers. This leads to a deterioration in heat transfer, a decrease in hydraulic resistance, and a reduction in the service life of equipment.

Histogram 6. Iron content in drinking water and secondary circuit water.

Cooling systems" href="/text/category/sistemi_ohlazhdeniya/" rel="bookmark">cooling systems for generator stator windings, electrolysis tanks, special laundry. Chemical water treatment capacity for demineralized water = 150 m3.

Description of the main technological scheme of the desalting part of chemical water treatment.

The clarified water after the mechanical pre-treatment filter is supplied to a chain of N-cation exchange filters. In the 1st stage H-cation exchanger filter, loaded with a weakly acidic cation exchanger, water is purified from hard ions (Ca2+ and Mg2+). In the 2nd stage H-cation exchanger filter, loaded with a strong acid cation exchanger, water is further purified from the hardness ions and Na+ ions remaining after the 1st stage.

N-cation exchange water after the 2nd stage is collected in partially desalted water tanks of the cation exchange filter.

From a tank of partially demineralized water, pumps send water to a chain of OH-anion filters. In the 1st stage OH-anion filter, loaded with a low-basic anion exchange resin, water is purified from strong acid anions (https://pandia.ru/text/77/500/images/image010_45.gif" width="37" height=" 24 src=">).In the OH-anion filter of the 2nd stage, loaded with a highly basic anion exchanger, the water is further purified from the anions of strong acids and anions of weak acids remaining after the 1st stage (; ).

OH-anionic water after the 2nd stage anion exchange filter is collected in the auxiliary tank.

Desalted water from the auxiliary tank is sent by pump to the 3rd stage of desalting - a mixed-action filter. The mixed-action filter is loaded with a mixture of a strong acid cation exchanger and a strongly basic anion exchanger in a 1:1 ratio. At the 3rd stage of desalting, the desalted water is further purified from cations and anions to the concentrations required by the STP-EO enterprise standard. On the common pipeline, chemically demineralized water after the mixed-action filter is equipped with 2 parallel-connected traps of filter materials (1 - in operation; 1 - in reserve in case of repair of the first) chemically demineralized water from the tank for its own needs and after the mixed-action filter is given to consumers: for replenishment 2 -th circuit to the turbine room; to recharge the 1st circuit in the special building; to the chemical water treatment pre-treatment circuit, to the chemical warehouse, to the special laundry, to the electrolysis room, to the start-up and reserve boiler room, to the chemically demineralized water storage tanks (V=3000 m3).

To increase the reliability of chemical water treatment and create a reserve of chemically demineralized water, chemically demineralized water storage tanks (with a volume of 3000 m3 each) are included in the design of the desalting part of the chemical water treatment.

To prevent corrosion of metal pipelines in concentrated and dilute acid solutions, the piping of the concentrated acid unit and the route for supplying the regeneration acid solution from the mixer to the H-cation exchange filters are made of fluoroplastic-lined pipelines.

Commissioning" href="/text/category/vvod_v_dejstvie/" rel="bookmark">put into operation in August 2007, service life is about 20 years, the radius of distribution of wastewater is about 3 km.

Thus, we can conclude that the commissioning of a deep disposal site eliminates the possibility of discharging industrial non-radioactive wastewater into the environment.

3.4. Description of the schematic diagram of a block desalting plant (condensate purification)

Condensate purification in a block desalting plant is carried out in two stages:

The first stage is the removal of undissolved corrosion products from structural materials using electromagnetic filters loaded with soft-magnetic steel balls;

The second stage is purification from dissolved ionic impurities and colloidal dispersed substances using mixed-action ion exchange filters.

Turbine condensate is supplied by first-stage condensate pumps to an electromagnetic filter, where it is cleaned of mechanical impurities, mainly undissolved corrosion products of structural materials.

After the electromagnetic filter, the condensate enters the suction manifold of the second stage condensate pumps (with the ion exchange part of the block desalting unit turned off), or is sent to a mixed-action filter to clean it from dissolved and colloidal dispersed impurities.

Removal of ferromagnetic and non-magnetic iron oxides retained on the ball load is carried out by washing the electromagnetic filter with demineralized water from bottom to top with the voltage on the coils removed and the balls in a demagnetized state.

If the quality of the condensate behind the operating mixed-action filter is unsatisfactory, the filter is put out for regeneration, and the backup mixed-action filter is put into operation.

The mixed resin removed for regeneration is reloaded into a filter-regenerator, where it is hydraulically divided into cation exchanger and anion exchanger. To convert the cation exchanger and anion exchanger into a working form, they are regenerated.

Fig.5. Scheme of a block desalting plant.

EMF – electromagnetic filter; FSD – mixed action filter; LFM – trap of filter materials.

All regenerative waters are supplied to radiation control tanks and, after radiation control, if the established levels are not exceeded, they are pumped into neutralization tanks for chemical water treatment.

After each mixed-action filter, filters are installed - ion exchanger traps.

During a visit to the Kalinin NPP, the following data were obtained on the operation of the block desalting plant:

100% of condensate is passed through electromagnetic filters; through a mixed-action filter, it is possible to pass both 100% of water and part of it. So, with one working mixed-action filter (cleaning 20% of condensate), the specific electrical conductivity decreased: χ = 0.23 µS/cm - before the block desalting plant and χ = 0.21 µS/cm - after the block desalting plant.

3.5. Theoretical description of the operating principle of special water treatment

Ion exchange filters of the primary circuit, as a rule, operate continuously, and approximately 0.2 - 0.5% of the main water flow in the circuit is transferred to them.

Primary circuit water is purified in a special water treatment plant consisting of a mixed-action filter. It serves both to remove corrosion products from reactor water and to regulate the physical and chemical composition of water (standardized indicators are maintained). The installation of a special water treatment system improves the radiation situation, reducing the radioactivity of the coolant by one or two orders of magnitude.

The circulating water of the primary circuit is supplied to the special water treatment plant from the main circulation pump and returned to the circuit after cleaning.

In a mixed layer for treating radioactive waters, ion exchangers are used with a ratio of cation exchanger and anion exchanger equal to 1:1 or 1:2.

A homogeneous mixture of ion exchangers (charge) allows you to remove from circuit water contaminants that accidentally enter during poor-quality cleaning from reagents of filters of installations associated with circuit replenishment, as well as from decomposition products of ion-exchange materials under the influence of ionizing radiation and high temperature.

When depleted, ion exchangers in special water treatment plants are regenerated: cation exchanger - with nitric acid (in this case it is converted to the H-form), anion exchanger - with caustic soda or potassium hydroxide (transferred again to the OH-form).

Conclusion

Having studied materials on energy production technology at nuclear power plants with VVER-1000 type reactors, we came to the conclusion that one of the most important factors for the reliable operation of nuclear power plants is high-quality prepared water. This is achieved through the use of various physical and chemical methods of water purification, namely through the use of preliminary purification - clarification and deep desalting using the ion exchange method.

I was particularly impressed by the visit to the water intake station, namely the performance of chemical analyzes using instruments and equipment that are not used at school. This increased confidence in the quality of drinking water supplied by the water intake station for the needs of the city. But the quality parameters of the water used at the Kalinin NPP made a greater impression. The technological processes of water preparation in the chemical shop, which we became familiar with during a visit to the Kalinin NPP, aroused great interest.

Water preparation using the ion exchange method allows you to achieve the required values necessary for safe, reliable and economical operation of the equipment. However, this is a rather expensive process: the cost of 1 m3 of chemically desalted water is 20.4 rubles, and the cost of 1 m3 of drinking water is 6.19 rubles. (2007 data).

In this regard, there is a need for more economical use of chemically desalted water, for which closed water circulation cycles are used. To maintain the required water parameters (remove incoming impurities), condensate treatment (on the second circuit) and special water treatment (on the primary circuit) are used. The presence of closed cycles prevents the discharge of primary and secondary circuit water into the environment, and for industrial wastewater there is a neutralization and recycling system, which reduces the anthropogenic load.

Despite the fact that the material presented in the project goes beyond the scope of the school curriculum, familiarity with it motivates high school students to study chemistry more deeply, as well as to make an informed choice of a future profession related to nuclear energy.

Bibliography.

1. , Senina - technological modes of nuclear power plants with VVER: A textbook for universities. – M.: MPEI Publishing House, 2006. – 390 p.: ill.

2. , Martynov regime of nuclear power plants. – M.: Atomizdat, 1976. – 400 p.

3. , Mazo water with ion exchangers. – M.: Chemistry, 1980. – 256 p.: ill.

4. , Kostrikin water treatment. – M.: Energoizdat, 1981. – 304 p.: ill.

5. , Zhgulev energy blocks. – M.: Energoatomizdat, 1987. – 256 p.: ill.

6., Churbanova water quality: Textbook for technical schools. – M.: Stroyizdat, 1977. – 135 p.: ill.

Essay

The role of chemistry in solving energy problems

Introduction

The entire history of the development of civilization is the search for energy sources. This is still very relevant today. After all, energy is an opportunity for further development of industry, obtaining sustainable harvests, improving cities and helping nature heal the wounds inflicted on it by civilization. Therefore, solving the energy problem requires global efforts .

1. The origins of modern chemistry and its problems in the 21st century

chemistry society energy

The end of the Middle Ages was marked by a gradual retreat from the occult, a decline in interest in alchemy and the spread of a mechanistic view of the structure of nature.

Iatrochemistry.

Paracelsus held completely different views on the goals of alchemy. The Swiss physician Philip von Hohenheim went down in history under this name, chosen by him. Paracelsus, like Avicenna, believed that the main task of alchemy was not the search for ways to obtain gold, but the production of medicines. He borrowed from the alchemical tradition the doctrine that there are three main parts of matter - mercury, sulfur, salt, which correspond to the properties of volatility, flammability and hardness. These three elements form the basis of the macrocosm and are associated with the microcosm formed by spirit, soul and body. Moving on to determining the causes of diseases, Paracelsus argued that fever and plague occur from an excess of sulfur in the body, with an excess of mercury paralysis occurs, etc. The principle that all iatrochemists adhered to was that medicine is a matter of chemistry, and everything depends on the ability of the doctor to isolate pure principles from impure substances. Within this scheme, all body functions were reduced to chemical processes, and the alchemist's task was to find and prepare chemical substances for medical purposes.

The main representatives of the iatrochemical direction were Jan Helmont, a doctor by profession; Francis Sylvius, who enjoyed great fame as a physician and eliminated “spiritual” principles from iatrochemical teaching; Andreas Libavi, doctor from Rothenburg.

Their research greatly contributed to the formation of chemistry as an independent science.

Mechanistic philosophy.

With the decrease in the influence of iatrochemistry, natural philosophers again turned to the teachings of the ancients about nature. To the fore in the 17th century. atomistic views emerged. One of the most prominent scientists - the authors of the corpuscular theory - was the philosopher and mathematician Rene Descartes. He outlined his views in 1637 in the essay Discourse on Method. Descartes believed that all bodies “consist of numerous small particles of various shapes and sizes, which do not fit each other so exactly that there are no gaps around them; these gaps are not empty, but filled with... rarefied matter.” Descartes did not consider his “little particles” to be atoms, i.e. indivisible; he stood on the point of view of the infinite divisibility of matter and denied the existence of emptiness.

One of Descartes' most prominent opponents was the French physicist and philosopher Pierre Gassendi.

Gassendi's atomism was essentially a retelling of the teachings of Epicurus, however, unlike the latter, Gassendi recognized the creation of atoms by God; he believed that God created a certain number of indivisible and impenetrable atoms, of which all bodies are composed; There must be absolute emptiness between the atoms.

In the development of chemistry in the 17th century. a special role belongs to the Irish scientist Robert Boyle. Boyle did not accept the statements of ancient philosophers who believed that the elements of the universe could be established speculatively; this is reflected in the title of his book, The Skeptical Chemist. Being a supporter of the experimental approach to determining chemical elements, he did not know about the existence of real elements, although he almost discovered one of them - phosphorus - himself. Boyle is usually credited with introducing the term "analysis" into chemistry. In his experiments on qualitative analysis, he used various indicators and introduced the concept of chemical affinity. Based on the works of Galileo Galilei Evangelista Torricelli, as well as Otto Guericke, who demonstrated the “Magdeburg hemispheres” in 1654, Boyle described the air pump he designed and experiments to determine the elasticity of air using a U-shaped tube. As a result of these experiments, the well-known law of inverse proportionality between air volume and pressure was formulated. In 1668, Boyle became an active member of the newly organized Royal Society of London, and in 1680 he was elected its president.

Biochemistry. This scientific discipline, which studies the chemical properties of biological substances, was first one of the branches of organic chemistry. It became an independent region in the last decade of the 19th century. as a result of studies of the chemical properties of substances of plant and animal origin. One of the first biochemists was the German scientist Emil Fischer. He synthesized substances such as caffeine, phenobarbital, glucose, and many hydrocarbons, and made a great contribution to the science of enzymes - protein catalysts, first isolated in 1878. The formation of biochemistry as a science was facilitated by the creation of new analytical methods.

In 1923, Swedish chemist Theodor Svedberg designed an ultracentrifuge and developed a sedimentation method for determining the molecular weight of macromolecules, mainly proteins. Svedberg's assistant Arne Tiselius in the same year created the method of electrophoresis - a more advanced method for separating giant molecules, based on the difference in the speed of migration of charged molecules in an electric field. At the beginning of the 20th century. Russian chemist Mikhail Semenovich Tsvet described a method for separating plant pigments by passing their mixture through a tube filled with an adsorbent. The method was called chromatography.

In 1944, English chemists Archer Martini Richard Singh proposed a new version of the method: they replaced the tube with the adsorbent with filter paper. This is how paper chromatography appeared - one of the most common analytical methods in chemistry, biology and medicine, with the help of which in the late 1940s - early 1950s it was possible to analyze mixtures of amino acids resulting from the breakdown of different proteins and determine the composition of proteins. As a result of painstaking research, the order of amino acids in the insulin molecule was established, and by 1964 this protein was synthesized. Nowadays, many hormones, medicines, and vitamins are obtained using biochemical synthesis methods.

Quantum chemistry. In order to explain the stability of the atom, Niels Bohr combined classical and quantum concepts of electron motion in his model. However, the artificiality of such a connection was obvious from the very beginning. The development of quantum theory led to a change in classical ideas about the structure of matter, motion, causality, space, time, etc., which contributed to a radical transformation of the picture of the world.

In the late 20s - early 30s of the 20th century, fundamentally new ideas about the structure of the atom and the nature of chemical bonds were formed on the basis of quantum theory.

After Albert Einstein created the photon theory of light (1905) and his derivation of the statistical laws of electronic transitions in the atom (1917), the wave-particle problem became more acute in physics.

If in the 18th-19th centuries there were discrepancies between various scientists who used either the wave or corpuscular theory to explain the same phenomena in optics, now the contradiction has become fundamental: some phenomena were interpreted from a wave position, and others from a corpuscular one. A solution to this contradiction was proposed in 1924 by the French physicist Louis Victor Pierre Raymond de Broglie, who attributed wave properties to the particle.

Based on de Broglie's idea of matter waves, the German physicist Erwin Schrödinger in 1926 derived the basic equation of the so-called. wave mechanics, containing the wave function and allowing one to determine the possible states of a quantum system and their change in time. Schrödinger gave a general rule for converting classical equations into wave equations. Within the framework of wave mechanics, an atom could be represented as a nucleus surrounded by a stationary wave of matter. The wave function determined the probability density of finding an electron at a given point.

In the same 1926, another German physicist Werner Heisenberg developed his own version of the quantum theory of the atom in the form of matrix mechanics, starting from the correspondence principle formulated by Bohr.

According to the correspondence principle, the laws of quantum physics should transform into classical laws when the quantum discreteness tends to zero as the quantum number increases. More generally, the principle of correspondence can be formulated as follows: a new theory that claims a wider range of applicability than the old one must include the latter as a special case. Heisenberg's quantum mechanics made it possible to explain the existence of stationary quantized energy states and to calculate the energy levels of various systems.

Friedrich Hund, Robert Sanderson Mulliken and John Edward Lennard-Jones in 1929 create the foundations of the molecular orbital method. The basis of MMO is the idea of the complete loss of individuality of atoms united into a molecule. The molecule, therefore, does not consist of atoms, but is a new system formed by several atomic nuclei and electrons moving in their field. Hund also created a modern classification of chemical bonds; in 1931 he came to the conclusion that there are two main types of chemical bonds - simple, or ?-communications, and ?-communications. Erich Hückel extended the MO method to organic compounds, formulating in 1931 the rule of aromatic stability (4n+2), which establishes whether a substance belongs to the aromatic series.

Thus, in quantum chemistry, two different approaches to understanding chemical bonds are immediately distinguished: the method of molecular orbitals and the method of valence bonds.

Thanks to quantum mechanics, by the 30s of the 20th century, the method of forming bonds between atoms had been largely clarified. In addition, within the framework of the quantum mechanical approach, Mendeleev’s doctrine of periodicity received a correct physical interpretation.

Probably the most important stage in the development of modern chemistry was the creation of various research centers that, in addition to fundamental research, also carried out applied research.

At the beginning of the 20th century. a number of industrial corporations created the first industrial research laboratories. The DuPont chemical laboratory and the Bell laboratory were founded in the USA. After the discovery and synthesis of penicillin in the 1940s, and then other antibiotics, large pharmaceutical companies emerged, staffed by professional chemists. Work in the field of chemistry of macromolecular compounds was of great practical importance.

One of its founders was the German chemist Hermann Staudinger, who developed the theory of the structure of polymers. Intensive searches for methods for producing linear polymers led in 1953 to the synthesis of polyethylene, and then other polymers with desired properties. Today, polymer production is the largest branch of the chemical industry.

Not all advances in chemistry have been beneficial to humans. In the production of paints, soap, and textiles, hydrochloric acid and sulfur were used, which posed a great danger to the environment. In the 21st century The production of many organic and inorganic materials will increase due to the recycling of used substances, as well as through the processing of chemical wastes that pose a risk to human health and the environment.

2. The role of chemistry in solving energy problems

Energy supply is the most important condition for the socio-economic development of any country, its industry, transport, agriculture, cultural and everyday life.

But in the next decade, energy workers will not yet discount wood, coal, oil, or gas. And at the same time, they must intensively develop new ways of producing energy.

The chemical industry is characterized by close ties with all sectors of the national economy due to the wide range of products it produces. This area of production is characterized by high material intensity. Material and energy costs in production can range from 2/3 to 4/5 of the cost of the final product.

The development of chemical technology follows the path of integrated use of raw materials and energy, the use of continuous and waste-free processes, taking into account the environmental safety of the environment, the use of high pressures and temperatures, and advances in automation and cybernetization.

The chemical industry consumes especially a lot of energy. Energy is spent on endothermic processes, transporting materials, crushing and grinding solids, filtering, compressing gases, etc. The production of calcium carbide, phosphorus, ammonia, polyethylene, isoprene, styrene, etc. requires significant energy expenditure. Chemical production, together with petrochemical production, are energy-intensive areas of the industry. Producing almost 7% of industrial products, they consume between 13-20% of the energy used by the entire industry.

Energy sources are most often traditional non-renewable natural resources - coal, oil, natural gas, peat, shale. Lately they have been depleting very quickly. Oil and natural gas reserves are decreasing at a particularly accelerated pace, but they are limited and irreparable. Not surprisingly, this creates an energy problem.

Over the course of 80 years, some main sources of energy were replaced by others: wood was replaced by coal, coal by oil, oil by gas, hydrocarbon fuel by nuclear fuel. By the beginning of the 80s, about 70% of the world's energy demand was met by oil and natural gas, 25% by coal and brown coal, and only about 5% by other energy sources.

In different countries, the energy problem is solved differently, however, chemistry makes a significant contribution to its solution everywhere. Thus, chemists believe that in the future (about another 25-30 years) oil will retain its leading position. But its contribution to energy resources will noticeably decrease and will be compensated by the increased use of coal, gas, hydrogen energy from nuclear fuel, solar energy, energy from the earth’s depths and other types of renewable energy, including bioenergy.

Already today, chemists are concerned about the maximum and comprehensive energy-technological use of fuel resources - reducing heat losses to the environment, recycling heat, maximizing the use of local fuel resources, etc.

Since among the types of fuel the most scarce is liquid, many countries have allocated large funds to create a cost-effective technology for processing coal into liquid (as well as gaseous) fuel. Scientists from Russia and Germany are collaborating in this area. The essence of the modern process of processing coal into synthesis gas is as follows. A mixture of water vapor and oxygen is supplied to the plasma generator, which is heated to 3000°C. And then coal dust enters the hot gas torch, and as a result of a chemical reaction a mixture of carbon monoxide (II) and hydrogen is formed, i.e. synthesis gas. Methanol is obtained from it: CO+2H2?СH3OH. Methanol can replace gasoline in internal combustion engines. In terms of solving environmental problems, it compares favorably with oil, gas, and coal, but, unfortunately, its heat of combustion is 2 times lower than that of gasoline, and, in addition, it is aggressive towards some metals and plastics.

Chemical methods have been developed for the removal of binder oil (contains high molecular weight hydrocarbons), a significant part of which remains in underground pits. To increase the yield of oil, surfactants are added to the water that is injected into the formations; their molecules are placed at the oil-water interface, which increases the mobility of the oil.

Future replenishment of fuel resources is combined with sustainable coal processing. For example, crushed coal is mixed with oil, and the extracted paste is exposed to hydrogen under pressure. This produces a mixture of hydrocarbons. To produce 1 ton of artificial gasoline, about 1 ton of coal and 1,500 m of hydrogen are spent. So far, artificial gasoline is more expensive than that produced from oil, however, the fundamental possibility of its extraction is important.

Hydrogen energy, which is based on the combustion of hydrogen, during which no harmful emissions are generated, seems very promising. However, for its development, it is necessary to solve a number of problems related to reducing the cost of hydrogen, creating reliable means of storing and transporting it, etc. If these problems are solvable, hydrogen will be widely used in aviation, water and land transport, industrial and agricultural production.

Nuclear energy contains inexhaustible possibilities; its development for the production of electricity and heat makes it possible to release a significant amount of fossil fuel. Here, chemists are faced with the task of creating complex technological systems for covering the energy costs that occur during endothermic reactions using nuclear energy. Now nuclear energy is developing along the path of widespread introduction of fast neutron reactors. Such reactors use uranium enriched in the 235U isotope (by at least 20%), and do not require a neutron moderator.

Currently, nuclear energy and reactor building is a powerful industry with a large amount of capital investment. For many countries it is an important export item. Reactors and auxiliary equipment require special materials, including high frequencies. The task of chemists, metallurgists and other specialists is to create such materials. Chemists and representatives of other related professions are also working on uranium enrichment.

Nowadays, nuclear energy is faced with the task of displacing fossil fuels not only from the sphere of electricity production, but also from heat supply and, to some extent, from the metallurgical and chemical industries by creating reactors of energy technological significance.

Nuclear power plants will find another application in the future - for the production of hydrogen. Part of the hydrogen produced will be consumed by the chemical industry, the other part will be used to power gas turbine units switched on at peak loads.

Great hopes are placed on the use of solar radiation (solar energy). In Crimea, there are solar panels whose photovoltaic cells convert sunlight into electricity. Solar thermal units, which convert solar energy into heat, are widely used for desalination of water and heating homes. Solar panels have long been used in navigation structures and on spacecraft. IN
Unlike nuclear energy, the cost of energy produced using solar panels is constantly decreasing. For the manufacture of solar cells, the main semiconductor material is silicon and silicon compounds. Chemists are now working on developing new materials that convert energy. These can be different systems of salts as energy storage devices. Further successes of solar energy depend on the materials that chemists offer for energy conversion.

In the new millennium, an increase in electricity production will occur due to the development of solar energy, as well as methane fermentation of household waste and other non-traditional sources of energy production.

Along with giant power plants, there are also autonomous chemical current sources that convert the energy of chemical reactions directly into electrical energy. Chemistry plays a major role in resolving this issue. In 1780, the Italian doctor L. Galvani, observing the contraction of the cut off leg of a frog after touching it with wires of different metals, decided that there was electricity in the muscles, and called it “animal electricity.” A. Volta, continuing the experience of his compatriot, suggested that the source of electricity is not the animal’s body: the electric current arises from the contact of different metal wires. The “ancestor” of modern galvanic cells can be considered the “electric pole” created by A. Volta in 1800. This invention looks like a layer cake made of several pairs of metal plates: one plate is made of zinc, the second is made of copper, stacked on top of each other, and between They are placed with a felt pad soaked in dilute sulfuric acid. Before the invention of dynamos in Germany by W. Siemens in 1867, galvanic cells were the only source of electric current. Nowadays, when aviation, the submarine fleet, rocketry, and electronics need autonomous energy sources, the attention of scientists is again drawn to them.

Conclusion

The use of nuclear energy makes it possible to abandon natural coal and oil. As a result, emissions of combustion products are reduced, which could possibly lead to a “greenhouse effect” on Earth. It would seem that an insignificantly small (compared to coal and oil) amount of fuel for nuclear power plants should be safe, but this is far from the case; a striking example is the accident at the Chernobyl nuclear power plant. In my opinion, any method of extracting energy (in any form) from the bowels of the Earth is a combination of positive and negative features, and it seems to me that the non-positive ones predominate.

I did not talk about all the directions of solving the energy problem by scientists around the world, but only about the main ones. In each country it has its own characteristics: socio-economic and geographical conditions, provision of natural resources, level of development of science and technology.

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