RU2814012C2 - Method for regenerating waste organic polymers of arbitrary composition - Google Patents

Abstract

FIELD: recycling of polymers; ecology.

SUBSTANCE: invention relates to complex waste-free recycling of organic polymers. The method includes sorting of polymer waste, mechanical grinding, physical, chemical and biochemical effects using depolymerization, thermal destruction, hydrolysis and microbiological recycling of organic polymers. Processed polymers allow the presence of impurities of thermoplastic copolymers, alloying additives, thermosetting additives, as well as copolymers or block copolymers of substances with polar bonds of carbon and/or hydrogen with heteroatoms. The process is carried out by transforming polymers into monomers on several simultaneously operating interconnected technological lines, which produce either monomer units suitable for polymer synthesis or chemical processing products: carbon, carbon monoxide, calcium carbide, aluminium carbide, hydrogen, methane, acetylene, hydrogen chloride, chlorine, which are used in organic synthesis processes. At the same time, the stoichiometric balance of the entire process of polymer regeneration is maintained, for which the products of polymer destruction, which are of little use for the synthesis of monomer units, and by-products of parallel chemical reactions, which are excessive in terms of the multiplicity of stoichiometric ratios, are subjected to microbiological processing, using them as sources of carbon and/or energy with the production of monomers and oligomers of biological origin, carbon dioxide and water.

EFFECT: expanding the range of produced monomers without the formation of toxic waste, reducing greenhouse gas emissions and implementing the cycle of organic polymers through a series of sequential selective chemical reactions in a closed system with arbitrary organic polymers at the input, and only water, nitrogen and target products at the output.

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Description

The invention relates to the field of ecology, in particular, to the integrated waste-free recycling of organic polymers. The purpose of the invention is to develop a method for recycling waste plastics through their regeneration into recovered commercial products, namely, the method of transforming waste polymers into monomer units with their subsequent polymerization.

Existing methods for recycling polymers - combustion, reuse of fused polymers, biological processing - have a number of disadvantages. Thus, during combustion there is an ineffective dissipation of the energy and material potential of substances in the form of heat and combustion products with the release of greenhouse gases. Mostly thermoplastic polymers are available for recycling and, as a rule, such processing with each repetition leads to a decrease in the performance properties of the substances. As a result, the recycled polymer becomes unusable and is taken out of circulation, most often by incineration or transfer to a landfill. Resol polymers are almost impossible to recycle. In addition, the destruction of polymers in order to obtain new products is carried out using pyrolysis and destructive distillation methods. In this case, liquid distillation products of unstable composition, a mixture of various gaseous substances, and carbon of uncertain purity are obtained. Separating the resulting mixtures into individual compounds is often an unprofitable process. The resulting substances are partially used for the synthesis of complex polymers, for example, carbon plastics, and more often as fuel. The disadvantage of pyrolysis and destructive distillation processes is the limited range of substances obtained from them and the limited scope of their application. The reason is the impossibility of obtaining compounds of the planned composition with an exact chemical formula using these methods.

Among the existing methods of processing with changes in the chemical composition of polymers, the method described in RF patent No. 2385343 dated November 10, 2008 is known. This patent proposes a method for hydrogenation of pyrolysis products of polymers and other organic substances. As a result of saturation, hydrocarbons transform into substances more saturated with hydrogen. Due to chemical kinetics, a mixture of variable composition is formed, consisting mainly of aliphatic compounds. The source of hydrogen is the carbon-water reaction, the dehydrogenation reaction at the pyrolysis stage, hydrogen from external sources. The composition of the complex mixture of hydrocarbons obtained as a result of hydrogenation depends on the chemical nature of the substances subjected to pyrolysis and destructive distillation. The weak point of the known method is the inability to ensure a constant composition of the final product. In addition, the patent does not indicate a method for processing polymers containing halogens, sulfur, and cyanides. The listed substances are sources of toxic waste in the form of gaseous, liquid and solid products, such as hydrogen chloride, sulfur dioxide, hydrogen sulfide, carbon disulfide, cyanogen chloride, chlorophenol, etc.

RF patent No. 2617790 dated March 25, 2014 discusses the production of carbon fibers from the corresponding plastics. Here, the irrational use of the chemical potential of raw materials and the limitation of the range of products obtained are obvious. In RF patent No. 2190659 dated May 19, 2000, the processing of gaseous hydrocarbons into solid polymers also provides a limited list of products.

Microbiological processing of technogenic organic substances is known, which leads to the accumulation of biological waste, or with the participation of a multi-species consortium, a food chain is formed, where each previous species serves as a food resource for subsequent species, which is also the combustion of substances at the biological level with the release of greenhouse carbon dioxide. There are methods for processing organics using producer microorganisms, including genetically modified ones, which make it possible to synthesize useful substances suitable for industrial organic synthesis: alcohols, ketones, carboxylic acids, medicinal drugs, etc. But in practice, these plastic processing technologies are at an embryonic level .

There is a known method for the biological recycling of polymers (RF Patent No. 2686829 dated 01/09/2018), in which the recycled polymers are preliminarily subjected to chemical, physical or biochemical effects, i.e. deep processing with changes in the primary chemical composition and molecular structure. This method is adopted as a prototype.

The method according to RF patent 2686829 has a number of disadvantages. Thus, only substances that do not contain asymmetric atoms that are not complementary to enzymatic systems can be subjected to biological utilization. Complementarity is the mutual correspondence of biopolymer molecules or their fragments, ensuring the formation of bonds between spatially complementary fragments of molecules due to molecular interactions.

In addition, the substance must be soluble in biological media, and the resulting biomass must be utilized. To bioutilize technogenic polymers, it is necessary to significantly change the technological structure of enterprises for processing organic substances. Despite the fact that organic polymers are converted into aliphatic, carbocyclic and heterocyclic compounds, these substances are presented mainly in the form of biopolymers. Additional technical solutions are required for the destruction of biopolymers. A significant disadvantage of bioutilization of polymers is also the release of carbon dioxide, one of the factors of the greenhouse effect. For this reason, there was a need to develop a method that makes it possible to obtain monomers from polymers suitable for processing into compounds widely used in the industrial synthesis of organic polymers in existing technological systems. The optimal way to recycle plastics is to produce various pure substances from waste, which are monomer units that are prone to polymerization and are suitable for the synthesis of various polymers using traditional technologies.

Objective: it is necessary to develop a method that is devoid of the above disadvantages and allows: a) to process waste of any organic polymers, regardless of the structure of their molecules and solubility in biological media and suitable for the regeneration and synthesis of practically significant plastics; b) processed products must fit into existing production technologies for processing technogenic organic substances; c) the process must proceed without the release of greenhouse gases; d) all types of organic polymers must be processed, regardless of the nature of the copolymer compositions, alloying additives, antioxidants, vulcanizers and other components included in their composition. Ultimately, plastics must be regenerated many times over through waste-free recycling. The process diagram is shown in Fig. 1.

The proposed method for regenerating organic polymer waste includes sorting of polymer waste, mechanical grinding, physical, chemical and biochemical effects, including depolymerization, thermal destruction, hydrolysis and microbiological disposal. The technical result of the claimed method is achieved by the fact that the process is carried out by transforming arbitrary polymers into monomer units on several simultaneously operating interconnected technological lines, and

on the first production line, polymers capable of depolymerization to form monomer or oligomer units, polymers containing up to 80 wt. % impurities in the form of thermoplastic copolymers and/or alloying additives, polymers containing up to 80 wt. % thermosetting additives, and/or containing, along with substances without heteroatoms, up to 80 wt. % of copolymers or block copolymers of substances with a polar bond formed by a system of carbon and/or hydrogen with heteroatoms that change the density of the electron cloud at carbon and/or hydrogen atoms in the polymer molecule are loaded separately into a depolymerization container (A), heated to a temperature of 200-300° They are transferred to a gaseous state, condensed by cooling in a condensation chamber, and the finished liquid monomer or oligomer is poured into the receiver; in this case, polymers of the aliphatic diene group, both in the form of individual compounds and in the form of copolymers or block copolymers, are depolymerized in the presence of catalysts at a pressure of 5 * 10 ² -8 * 10 ⁴ Pa, the resulting volatile gaseous depolymerization products are divided into fractions having different temperatures boiling, the remaining flammable gaseous products from the depolymerization vessel (A) are sent to the combustion chamber, generating carbon or carbon monoxide;

on the second production line, a mixture of polymers of any composition, including thermoplastic, thermosetting and filled polymers, except fluorine- and chlorine-containing ones, as well as solid and liquid carbon-containing residue from the depolymerization tank (A) is loaded into the thermal destruction tank (B), heated to 500-1000 °C without air access, volatile gaseous products are directed into the combustion chamber, generating carbon or carbon monoxide; The sulfur dioxide formed during the combustion of sulfur-containing polymers is captured by passing the combustion products through a chamber with kaolin, where at 400-600 ° C the sulfur dioxide reacts with carbon monoxide to form elemental sulfur and carbon dioxide, the carbon dioxide is sent to a carbon dioxide storage tank, the solid residue is in the container thermal destruction (B) is burned at 1000°C to carbon, and carbon containing less than 20 wt. % of mineral impurities are sent to carbide synthesis chambers, and carbon containing over 20 wt. % of mineral impurities, unsuitable for the synthesis of carbides, are converted to carbon monoxide;

on the third technological line, in a separate chamber protected from aggressive gases, chlorine-containing and fluorine-containing polymers are subjected to thermal destruction, which are heated to 500-800°C without air access, gaseous thermal destruction products containing hydrogen chloride are partially passed through water to form hydrochloric acid, and partially oxidize the chloride hydrogen into gaseous chlorine and convert the chlorine into a liquid state, purify the thermal destruction products from residual hydrogen chloride, passing them through calcium carbonate to form calcium chloride, the remaining combustible products are sent to the combustion chamber, generating carbon or carbon monoxide; crushed fluorine-containing polymers are mixed with substances that have a greater chemical affinity for fluorine than carbon, and heated without air access to 500-800°C to obtain products of fluorine compound with the mentioned substances and free carbon; at the same time, the composition of the gases leaving the combustion chamber is continuously monitored by means of control and, using a central computing device with computer programs installed on it, the amount of air supplied to the combustion chamber is automatically changed, and in the mode of generating pure carbon, carbon monoxide is not allowed to appear at the exit of the combustion chamber in the amount more than 0.1-0.2 vol. %, and in the carbon monoxide generation mode they do not allow carbon dioxide to appear at the exit of the combustion chamber in an amount of more than 0.1-0.2 vol. %; the resulting carbon monoxide is sent to the methanol synthesis chamber, and the resulting pure carbon is used for the synthesis of calcium and aluminum carbides, for which pure carbon is sent to three carbide chambers, while part of the carbon is mixed in the first carbide chamber with calcium oxide in a ratio of 1.3-1 ,8 parts by weight of calcium oxide per 1 part by weight of carbon and the mixture is heated to a temperature of 2000-2500°C to obtain calcium carbide and carbon monoxide, part of the carbon is mixed in the second carbide chamber with calcium oxide, calcium carbide is added and the mixture is heated to a temperature of 2000- 2500°C to produce calcium carbide and carbon monoxide, then calcium carbide heated to 1000-2000°C in the second carbide chamber is treated with water to produce calcium carbonate, carbon dioxide and hydrogen, the remaining carbon is mixed in the third carbide chamber with aluminum oxide in the ratio 1.5-1.9 parts by weight of aluminum oxide per 1 part by weight of carbon and heat the mixture to a temperature of 2000-2500°C to obtain carbon monoxide and aluminum carbide; hydrogen, acetylene and methane are obtained from carbides with a dosed supply of water, then processed products polymers obtained on the second and third technological lines: carbon, carbon monoxide, hydrogen, methane, acetylene, chlorine and hydrogen chloride are used in organic synthesis processes to produce monomer units suitable for the synthesis of polymers;

on the fourth production line, polyesters and polyesters are processed, while the polyesters are treated with hydrogen chloride in a polyester regeneration tank (B), obtaining ether monomer units and products suitable for the synthesis of monomer units, excess hydrogen chloride is neutralized with alkali; polyesters are saponified with water or alkali at pressures up to 3 MPa and temperatures up to 270°C, obtaining ester monomer units;

on the fifth technological line, products of polymer destruction that are of little use for the synthesis of monomer units and by-products of parallel chemical reactions, which are excessive in terms of the multiplicity of stoichiometric ratios, are sent to a microbiological utilization reactor containing a culture liquid suitable for the activity of microorganisms, and the mentioned products are subjected to microbiological processing using them as sources of carbon and/or energy for the activity of microorganisms and maintaining the stoichiometric balance of the entire process of polymer regeneration with the production of monomers and oligomers of biological origin, carbon dioxide and water;

at the same time, interconnected processes in the mentioned technological lines are controlled by a central computing device with computer programs installed on it, which, based on data received in feedback mode from sensors, coordinates the flow of substances, their dosage, temperature, pressure, beginning and end of reactions, maintaining optimal conditions for the synthesis of target products.

In the practical implementation of the claimed method, a number of features can be specified.

Thus, to prevent sintering of the polymer mass in the thermal destruction container (B), a disintegrant, calcium oxide hydrate, can be added to the mixture of crushed polymers in an amount of 1-10 wt. %.

In addition, in the mentioned reactor for microbiological utilization of polymers the following regime can be maintained: temperature not higher than 80°C, acidity pH 3-9, concentration per 1 dm3 of culture liquid: oxygen 2-6 mg, nitrogen and potassium sources 12-70 mg each, phosphorus 2.5-6 mg, magnesium, sulfur, calcium 1-5 mg each, trace elements 0.1-1 mg, growth factors 0.01-5 mg, carbon sources in an amount of 0.5-0.7 of the inhibitory concentration at a flow rate in chemostat mode of 0.01-0.5 h ¹ .

In addition, biomass of microorganisms can be isolated from the culture liquid, which is disintegrated and used as a universal substrate for growing genetically modified producer microorganisms that synthesize monomer units, oligomers and biopolymers of biological origin.

In addition, excess heat from heat-releasing reaction chambers can be accumulated by liquid coolants and used in heat-absorbing reaction chambers.

In addition, the continuity of the regeneration process can be maintained by duplicating working volumes with switching containers and chambers that require unloading or loading to duplicate containers and chambers.

In addition, calcium chloride, obtained from hydrogen chloride residues, is used as a carbon dioxide accumulator by passing carbon dioxide and ammonia through a calcium chloride solution and converting calcium chloride into calcium carbonate.

In this case, it is necessary to take into account the properties of the processed polymers and the characteristics of the chemical reactions occurring during the regeneration of polymers. Thus, in practice, not pure polymers are often used, but their copolymers or composite mixtures. For example, polyethylene is used in the form of a copolymer with polypropylene, polyethylene terephthalate, it is also inseparably combined with nylon, nylon, and metal coating. Polystyrene is used in a mixture with plasticizers, or in a mixture with butadiene, or with polymethyl methacrylate and other polymers. Rubbers, polymers based on phenol-formaldehyde resins and other polymer products also have a complex multicomponent composition. There are also ternary copolymers: carboxylate rubbers, copolymers of styrene with methyl methacrylate and acrylonitrile, etc. For this reason, the destruction of polymers by depolymerization or hydrolysis is possible only in relation to individual plastics consisting of a single polymer or having impurities that do not affect the course of the process, composition and quality of the resulting products. It should be taken into account that copolymers and composites have different physical and chemical properties, which can lead to the formation of products of uncertain composition. At the same time, hydrolysis and depolymerization of individual materials suitable for this are necessary, since it opens up the possibility of obtaining monomer units immediately in finished form. In some cases, the most advantageous process is the destruction of complex multicomponent polymers to carbon and carbon monoxide, followed by the reverse synthesis of monomer units from these products. Thus, using depolymerization, hydrolysis, bioutilization and destruction of polymers to carbon and carbon monoxide within reasonable limits, monomer units are obtained from polymer waste, from which almost the entire variety of polymer materials used in technology and everyday life can be constructed. This approach makes it possible to include any polymers produced by industry into the recycling process, with minimal penetration into the environment.

Since organic polymers are very diverse in composition and properties, their regeneration (and not irreversible disposal) requires a set of technological techniques adapted to substances of different chemical compositions: polymers that have served their useful life are used for the synthesis of monomer units, which are then polymerized and returned into a practical environment.

To solve this problem, the claimed method is implemented in a multifunctional installation that is capable of processing any polymers into monomers used in the industrial synthesis of polymers, without significant changes in existing technologies and without releasing harmful products into the environment, which ensures the circulation of polymer compounds in a closed cycle.

An example of an installation that implements a method for regenerating waste organic polymers is shown in the diagram of Fig. 2. The installation consists of three containers, several chambers and a biotechnological complex, which together form five interconnected technological lines, in which simultaneously, using various technologies, the primary preparation of polymers for further processing into commercial organic substances occurs. In accordance with the claims, the installation contains a first production line with a depolymerization tank (A); a second production line, including a thermal destruction tank (B) and a combustion chamber 3 for converting volatile hydrocarbons into carbon or carbon monoxide; a third technological line with a chamber 14 for thermal destruction of chlorine- and fluorine-containing polymers, a cascade of chambers for the use of hydrogen chloride, and with three carbide chambers 6, 7 and 8; a fourth technological line with a tank (B) for processing polyesters; the fifth technological line with reactors 40, 41, 42 for microbiological utilization of by-products of chemical reactions in order to maintain the stoichiometric balance of the entire polymer regeneration system.

The first container (A) is loaded with polymers capable of depolymerization to form monomeric or oligomeric units that form the polymer. Polymers, which are complex copolymers, thermosetting plastics, as well as all other polymers, with the exception of halogen-containing ones, are loaded into the second container (B) for implicit distillation of carbon or for incomplete oxidation of carbon with atmospheric oxygen. In a separate chamber 14 with a subsequent cascade of chambers, chlorine- and fluorine-containing polymers are processed. In the third tank (B), polyesters and polyesters are processed. In the group of chambers 40, 41, 42, bioutilization of polymer processing by-products is carried out in order to obtain monomer units of biological origin. Bioutilization products are feed products enriched with vitamins and protein from unicellular organisms, both paprin and haprin.

All processes are controlled by a central computer complex, according to the computer programs installed on it. The flow of substances is regulated by passage valves, which determine the direction and intensity of the movement of reagents. The valves are equipped with sensors that determine temperature, pressure, chemical composition of substances, and gas meters; the throughput of the valves is also controlled. Valves allow substances to flow in only one direction. In some cases, in the most critical areas, special sensors are used, specifically marked in the diagram. Information from all sensors is transmitted to the control device. Using temperature, pressure, gas meter readings, the computer complex automatically brings the data to a single standard: pressure 0.101 MPa and temperature 0°C. For finer control of the process, if necessary, a system operating in feedback mode is used.

In the first technological line, polymers prone to depolymerization, that is, the process of thermal decomposition of polymer molecules into monomer units without the participation of foreign substances and without the formation of other side compounds, are processed separately in container (A). These include, for example, polystyrene, polymethylene oxide, polymethyl methacrylate and others. At a temperature of 200-300°C, these substances decompose into monomers or oligomers. Since polymer substances prone to depolymerization consist of loosely bound monomer units that form a macromolecule, rupture into individual units occurs at a temperature below the carbonization temperature. In turn, the resulting monomers are quite stable at temperatures of 200-300°C, and their distillation proceeds without changing the chemical composition. In this case, ready-made units of organic monomers are obtained, suitable for the regeneration of polymers, subjected to depolymerization. Some substances are ready-made commercial products, for example, styrene, formaldehyde, methyl methacrylate and others.

It should be taken into account that foreign impurities in the form of thermoplastic copolymers, stabilizers, thermosetting additives during depolymerization may contain chemical elements that form a polar bond with carbon and/or hydrogen and reduce the quality of depolymerization products due to the formation of organic compounds of unpredictable composition. As experiments have shown, such practically important elements include fluorine, chlorine, bromine, nitrogen, oxygen, sulfur, etc., affecting the electron density of carbon and/or hydrogen atoms in polymer molecules. Products of joint depolymerization or thermal destruction of polymers with impurities or are partially carbonized, and/or destructive fragments enter into chemical reactions with each other and/or with depolymerization products of other polymers, forming difficult-to-separate mixtures. Therefore, the proportion of impurities can be 0.1-80% of the composition of the processed polymer. The wide range of impurity concentrations is due to different decomposition temperatures of foreign substances. If the decomposition temperature of impurities is less than or equal to the depolymerization temperature, for example, if the impurity is polyvinyl chloride with a decomposition temperature of 120°C, then the lower the permissible proportion of such a substance should be. The more heat-resistant the impurity, for example, the impurity of polytetrafluoroethylene with a decomposition temperature of 420°C, the higher the permissible proportion of such a polymer in the mixture or as a copolymer. For example, the joint depolymerization of polystyrene and polymethyl methacrylate, polymethyl methacrylate and polymethylene oxide, polystyrene and polychloroprene and/or acrylanitrile and/or polyvinyl chloride and other mixtures gives products of unpredictable composition, since one or more components of the composition contains polar bonds formed by oxygen, nitrogen, chlorine. At the same time, polymethyl methacrylate, polystyrene, polymethylene oxide each individually depolymerize to form monomer units of a strictly defined composition: styrene, methyl methacrylate, formaldehyde.

For other copolymers, the proportion of mineral heat-resistant fillers - chalk, glass fiber, metal oxides and others - at temperatures up to 500°C does not affect the success of the depolymerization process. At the same time, the additive is 5-8 wt. % of freshly prepared aluminosilicate speeds up the process by 20-30% compared to the control. It has been experimentally established that aluminosilicate must be prepared immediately before use, obtaining it through an exchange reaction between aluminum chloride and the sodium salt of metasilicon acid. The most active catalyst is with the addition of aluminum chloride in an amount 10-30% greater than required by the reaction equation. Introduction of promoters in the form of molybdenum or cobalt compounds into aluminum metasilicate in an amount of 0.1-0.5 wt. % increase the yield of monomers by 10-15%.

When the container (A) is operating in the pipeline, valve 1.2 opens (Fig. 1) and gas pump 2.2 is turned on, since substances are formed in gaseous form. Then the depolymerization products enter chamber 1 and condense there, and formaldehyde is captured by water. In this case, valves 1.22 and 1.12 are closed. At the end of the process, valve 1.2 closes and pump 2.2 is turned off. An indicator of the end of the process is the pressure drop in the container (A). If the resulting products are final substances, then valve 1.12 opens and drains into receiver 2. Before changing one substance to another in container (A), valves 1.1, 1.2, 1.22, 1.23 open and valve 1.24 closes. Pump 2.8 is turned on and the system is purged with atmospheric air at a temperature of 100-200°C, which directs residual products into combustion chamber 3. After removing residual products, valves 1.2, 1.1, 1.22, 1.23 are closed, and pumps 2.2, 2.1, 2.8 are stopped.

By slightly complicating the method of separating depolymerization products, it is possible to obtain monomer units suitable for polymerization from copolymers of styrene and isoprene or from copolymers of styrene and butadiene. Their distillation temperature is reduced by creating a vacuum in the container (A) to 5*10 ² -8*10 ⁴ Pa, which is achieved by intensive operation of pump 2.2, which increases the yield of dienes to 50% of their content in the processed mass. The process also occurs with the participation of an aluminosilicate catalyst. For condensation, the depolymerization products are sent to chamber 1, where the temperature is maintained at 50-60°C. Here, condensation of styrene and methyl methacrylate occurs, which enter storage tank 2. Isoprene, in turn, has a boiling point of 34°C, and butadiene is minus 4°C. Gaseous products are pumped by pump 2.8 with valves 1.22, 1.24 open and valve 1.23 closed. In chamber 4 at a temperature of 15-25°C, isoprene condenses, which in liquid form enters storage tank 5 through valve 1.25. After draining the isoprene, butadiene is liquefied under a pressure of 1.5-2 MPa at a temperature of 15-25°C. The resulting depolymerization products can be used to regenerate polymers by polymerization. Non-volatile fillers remain in the container (A), and since their destruction temperature is much higher than 300°C, the liquid and solid residue from the depolymerization container (A) is transferred to the thermal destruction container (B) for deeper processing. Thus, by depolymerization, a distillation effect is achieved to obtain pure products suitable for polymer regeneration.

In the second production line, polymers of any composition, except halogen-containing ones, are loaded into the thermal destruction tank (B). A mixture of polymers is loaded either in order to save on sorting, or for technical and economic reasons in order to obtain the greatest variety of synthesized products. The processed mixture may consist, for example, of various types of rubber, polycarbonate, phenol-formaldehyde polymers, silicone products, polyethylene terephthalate, polypropylene, polystyrene, various complex and simple copolymers and other substances. According to the list and volume of processed polymers, thermal destruction capacity (B) is the main one. Also, processes that are initiated and occur with the participation of products formed in container (B) produce the most numerous number of monomer units by name. The mixture is heated in container (B) to 500-1000°C without air access. A mixture of crushed thermoplastic and thermosetting polymers is sintered into a solid mass at a temperature of 500-1000°C, which slows down the decomposition of the polymers. For this reason, a disintegrant, Ca(OH) _2, is added to the mixture of crushed polymers. Calcium oxide hydrate begins to decompose at 200°C with the release of water vapor and is completely dehydrated at 600°C. In this case, water vapor occupies a volume 1000 times larger than liquid water. To increase the efficiency of the thermal destruction process, container (B) is filled to 20-30% of its volume with crushed polymer mass, to which 1-10 wt. % Ca(OH) ₂ . At the first stage, volatile substances are released, which, with valve 1.27 open, pump 2.12 running and valve 1.29 open, enter combustion chamber 3, where a heater is located to maintain combustion, for example, a metal spiral heated by electric current to 1000-1500°C. The substances coming for combustion from container (B) consist mainly of hydrocarbons. To ensure combustion, air is supplied to combustion chamber 3 by pump 2.15 with valve 1.30 open. Since the ratio of carbon and hydrogen in the combustion mixture is not constant, different amounts of oxygen (air) are required for complete combustion, so the intensity of the air flow must be constantly changed. The target combustion products are either carbon monoxide or carbon. The quantitative ratio of carbon monoxide and carbon is a determining indicator that affects all subsequent processes.

To produce a controlled amount of carbon or carbon monoxide, it is necessary to regulate the flow of air into the combustion chamber. This work is performed by a computing device, for example, a control computer using feedback mode using sensor 3.3 and control unit 4.3. When generating carbon monoxide, sensor 3.3 monitors the content of carbon dioxide, carbon monoxide and water vapor exiting chamber 3. As established in experiments, the appearance of carbon dioxide in the exit gases in an amount of 0.1-0.2 vol. % for up to 8-10 seconds with random instantaneous fluctuations does not disrupt the stability of the combustion process. If more than 0.2 vol. carbon dioxide is detected in the exhaust gases. %, metering unit 4.3 reduces the air supply to combustion chamber 3 in proportion to the amount of excess carbon dioxide. When carbon is oxidized to carbon monoxide, the lack of oxygen leads to the appearance of soot suspended in the gas flow, the suspension is recorded by the photometric sensor 7.1, and the air supply is increased. This is how the carbon monoxide generation system works in the combustion chamber.

When generating carbon, carbon enters the combustion chamber 3 in implicit form, as a mixture of hydrocarbons or other carbon-containing compounds. When generating carbon, the air supply is reduced until carbon monoxide disappears from the readings of sensor 3.3, but water vapor as a product of hydrogen combustion is present. Carbon is obtained in the form of small soot particles. To capture suspended soot, an electric precipitator is installed in combustion chamber 3.

The solid residue in container (B) is also suitable for the production of carbon or carbon monoxide. If the initial mixture of polymers does not contain silicone polymers, sulfur, or non-flammable fillers, then the solid residue of the container (B) is considered pure carbon. Pure carbon is used for the synthesis of calcium carbide and aluminum carbide, since the gases obtained from pure carbides contain a minimum amount of impurities.

The solid residue, contaminated with non-combustible fillers in an amount of more than 20% by weight or sulfur, is used to produce carbon monoxide. To obtain carbon monoxide, air is supplied to the container (B) using pump 2.13 with valve 1.26 open and dispenser 4.2 running. At a temperature of 800-1000°C, incomplete oxidation of carbon by atmospheric oxygen occurs with the formation of carbon monoxide. The maximum carbon dioxide content in the gas flow is maintained at 0.1-0.2 vol. %, and oxygen no more than 0.05 vol. %. The amount of carbon dioxide in the gas flow is measured by sensor 3.2, and air flow is regulated by dispenser 4.2 in feedback mode.

Some polymeric materials that fall into container (B) contain sulfur, for example, ebonite, polysulfide rubbers, sulfur vulcanized rubbers and others. When such polymers are burned in container (B), sulfur dioxide is formed along with carbon monoxide. When sulfur dioxide is detected by sensor 3.4, valve 1.31 opens, valve 1.32 closes, and a mixture of carbon monoxide and sulfur dioxide enters chamber 20. In chamber 20, carbon monoxide reacts with sulfur dioxide at 400-600°C on a kaolin catalyst to form carbon dioxide and elemental sulfur:

SO ₂ + 2СО → 2CO ₂ + S.

Molten sulfur flows into receiver 21, and gas purified from sulfur enters the processing system through open valves 1.33 and 1.34, having previously been cleared of carbon dioxide in carbon dioxide accumulator 6.1. In this case, the calcium oxide in the 6.1 battery is converted into calcium carbonate. If there is no sulfur dioxide in the gas mixture, valves 1.31, 1.33 and 1.34 are closed, and the gas passes through valve 1.32.

In the third technological line for processing chlorine- and fluorine-containing polymers, for example, polyvinyl chloride, polyvinylidene chloride, copolymer of polyvinyl chloride with polymethyl methacrylate, fluoroplastic-4, etc., thermal decomposition produces hydrogen chloride, which destroys metal structures. The route of hydrogen chloride is lined with ceramics or acid-resistant plastics. Work on processing chlorine-containing polymers is carried out in chamber 14 in the following order: the chamber is filled to 0.5-0.7 of its volume with a mixture of chlorine-containing polymers. If copolymers with acrylonitrile are present, then sulfur is added to neutralize the cyanide, and the polymers are heated to 500-800°C without air access. Gaseous products through valve 1.14 with pump 2.10 running enter the condenser chamber 15, where carbon-containing compounds are deposited at a temperature of 15-30°C. Hydrogen chloride, which has a boiling point of minus 85°C, remains gaseous and enters chamber 16 through valve 1.16, where it is absorbed by water to form hydrochloric acid. Sensor 3.1 monitors the flow of hydrogen chloride. As soon as the flow of hydrogen chloride stops, valve 1.16 closes. From chamber 16, hydrogen chloride is supplied through valve 1.17 to chamber 17, where asbestos and copper chloride are present on the catalyst and in the presence of atmospheric oxygen supplied by pump 2.14, a reaction occurs at a temperature of 450°C

4HCl + O ₂ → 2H ₂ O + 2Cl ₂ .

For 1 volume of hydrogen chloride, under the control of dispenser 4.1, 1.2-1.5 volumes of air are supplied. Chlorine enters chamber 18 through valve 1.18, where under a pressure of 0.6-1 MPa at a temperature of 15-30°C it turns into a liquid state and is stored until further use.

Liquid products in chamber 15, with valve 1.16 closed and valve 1.15, 1.28 open, are heated to 500°C and passed in the form of steam through chamber 19 filled with limestone to capture residual hydrogen chloride. Pumping is carried out in active mode using pump 2.11. Next, the products enter combustion chamber 3 for combustion. The pressure drop measured by the sensor in valve 1.28 indicates the completion of the process, valve 1.28 closes and pump 2.11 is turned off. In chamber 14 after heat treatment, mostly carbon remains. If carbon is contaminated with minerals, it is burned to carbon monoxide when the valves are open, pumps and dispenser 4.8 are running, connecting the system to the main line leading to chamber 3.

In chamber 14, the decomposition of fluorine-containing polymers is also carried out. For this purpose, a polymer, for example fluoroplastic 4, is mixed in crushed form with crushed metallic aluminum, the proportion of which in the mixture is 25-30 wt. %, and is heated in chamber 14 without air access to 500-800°C. Since fluorine has a greater affinity for aluminum than for carbon, the end result is a mixture of carbon and aluminum fluoride. The operation is carried out in steel containers placed in chamber 14. In this case, a chemical reaction occurs

3(CF ₂ = CF ₂ ) _n + 4nAl → 4nAlF ₃ + 6 _n C

Aluminum fluoride 4nAlF ₃ can be used to prepare cryolite used in the electrolytic production of aluminum.

Calcium chloride gradually accumulates in chamber 19, which is removed periodically as 20-30% of calcium carbonate converts to chloride. Since the formation of calcium chloride occurs at an indefinite rate, its disposal is carried out periodically as it accumulates in a separate installation, Figure 2. To utilize CaCl ₂ , the following series of reactions is carried out. An aqueous solution of CaCl ₂ is saturated with ammonia, CO ₂ is passed through this solution, which is obtained in carbide chamber 7. After liquefaction, CO ₂ in liquid form is delivered to chamber 43, calcium chloride CaCl ₂ and ammonium hydroxide NH ₄ OH also enter there. The reaction occurs:

CaCl ₂ + 2NH ₄ OH + CO ₂ → CaCO ₃ + 2NH ₄ Cl + H ₂ O

Calcium carbonate CaCO ₃ is insoluble in water and precipitates. Due to the above reaction, carbon dioxide accumulates with the transition of calcium chloride to carbonate. In the future, CaCO ₃ can be used as a filler in polymer products.

The NH ₄ Cl solution, with valve 1.68 open, is pumped by pump 2.31 into chamber 44 (diagram of Fig. 2). Upon completion of pumping, the pump is turned off, valve 1.68 is closed, and the contents of chamber 44 are treated with formaldehyde (source chamber 33):

6H ₂ CO + 4NH ₄ Cl → (CH ₂ ) ₆ N ₄ + 4HCl + 6H ₂ O

The resulting hexamine (CH ₂ ) ₆ N ₄ is a solid, soluble in water, and can be used as a rubber vulcanization accelerator, an accelerator for the curing of phenol-formaldehyde resins, or in the synthesis of polymers. Hydrogen chloride HCl, in turn, is separated from hexamine, then under reduced pressure with valve 1.69 open through a pump 2.32 HCl enters chamber 45, where it is dissolved in water. After hydrogen chloride is removed from chamber 44, valve 1.69 is closed and pump 2.32 is turned off. Hydrogen chloride in the form of an aqueous solution is transferred to chamber 16 for further use.

In the thermal destruction tank (B), in the processing chamber of halogen-containing polymers 14 and in the combustion chamber 3, polymers of various compositions are converted into a limited set of substances. The process figuratively models a funnel or bottleneck, when all the variety of starting substances - polymers of arbitrary composition - are converted into carbon and carbon monoxide, which are used for the synthesis of an unlimited list of polymers.

Distilled carbon from chamber 3, as well as carbon not containing sulfur, phosphorus, cyanides from container (B) and chamber 14, is transferred to chambers 6, 7, 8 and mixed with aluminum oxide in the chamber and calcium oxide in chambers 7 and 8. In chambers 7 and 8, crushed carbon and calcium oxide are mixed in a ratio of 1.3-1.8 parts by weight of calcium oxide per 1 part by weight of carbon. In this case, in chamber 7, calcium carbide is obtained in advance and prepared for the production of hydrogen. Thus, two carbide chambers simultaneously generate carbon monoxide, and one chamber generates hydrogen. In chamber 29, 1.5-1.9 parts by weight of aluminum oxide and 1 part by weight of carbon are mixed. At a temperature of 2000-2500 degrees, a carbide formation reaction occurs

CaO + 3C → CaC ₂ + CO

2Al ₂ O ₃ + 9С → Al ₄ C ₃ + 6СО

This line produces carbon monoxide CO, which must be disposed of. For this purpose, valves 1.8, 1.5 are opened, valves 1.9, 1.3 are closed. In chamber 7, valve 1.6 is closed, valve 1.7 is open, and water is supplied into chamber 7 onto the hot calcium carbide. Through open valves 1.19, 1.34, gas enters chamber 32. Along the way, the gas passes through a carbon dioxide accumulator 6.1, which is a container 6.1 filled with calcium oxide. Carbon dioxide is formed in container (B), in chamber 14 and in chamber 20 during the reduction of sulfur. After the battery 6.1 is saturated with carbon dioxide, the resulting calcium carbonate is transferred to chamber 7, where, when heated, it decomposes to form calcium oxide. Part of the calcium oxide from chamber 7 goes to restore the carbon dioxide accumulator 6.1. The carbide synthesis process becomes the main source of carbon monoxide. Combustion chamber 3 and container (B) at this stage switch to carbon generation. In this case, in combustion chamber 3, the proportion of carbon monoxide to carbon in weight units is maintained in the range of 6.1-14.3%, this is the limiting ratio at which the energy self-sustainment of the process is maintained when burning volatile products. After burning volatile products in container (B), thermal conversion of non-volatile carbon-containing compounds into carbon occurs; this process consumes 5.2-12.4% of the weight units of carbon, which is oxidized into carbon monoxide, and the generated heat ensures the generation of carbon. If the carbon is not pure enough, i.e. contains more than 20 wt. % of non-volatile impurities that are not capable of coking and are not suitable for the synthesis of carbides, then non-volatile carbon-containing residues are used as a reserve of carbon monoxide. It is used by controlled oxidation of carbon-containing residues after the generation of carbon monoxide in the carbide chambers has ceased.

For process continuity, the installation can be equipped with duplicate tanks. Polymers that do not contain non-coking additives and fillers, such as fiberglass, gypsum, chalk, silicon dioxide, metal powders, organosilicon polymers and similar materials are loaded into backup containers. These duplicate tanks become a source of pure carbon for the synthesis of carbides. After the synthesis of carbides in chambers 6 and 8 is completed, valves 1.5 and 1.8 are closed. Completion of the process is determined by the pressure reading on the sensor installed in valve 1.19. In chamber 7 at an elevated temperature of 1000 - 1500°C and with a dosed supply of water through pump 2.6 through dispenser 5.2 and valve 1.10, the following reactions occur:

CaC ₂ + 5H ₂ O → CO ₂ + CaCO ₃ + 5H ₂ + 0.32 MJ

CaCO ₃ → CaO + CO ₂

Through valve 1.7, with valves 1.36 and 1.56 closed, a mixture of hydrogen and carbon dioxide enters chamber 11. The gas mixture, pre-cooled to a temperature of 15-25°C, is periodically compressed to a pressure of 6 MPa in a piston expander or, at a lower pressure, in a turboexpander, in the latter case in continuous mode. In this case, carbon dioxide is liquefied and pumped through open valve 1.20 into chamber 12. In chamber 12 at a pressure of 190 atmospheres, a temperature of 180°C and when ammonia is supplied from the outside, the following reaction occurs:

CO ₂ + 2NH ₃ → (NH ₂ ) ₂ CO + H ₂ O,

the resulting urea is transferred for storage to chamber 13, the process continues cyclically with batchwise or continuous (in the presence of a turboexpander) removal of carbon dioxide, or with periodic opening of valve 1.36 with the release of purified hydrogen into chamber 32, where hydrogen is dosed mixed with carbon monoxide produced in carbide chambers and in chamber 3. In chamber 32 at a pressure of 20 MPa and a temperature of 450°C, a reaction occurs

CO + 2H ₂ → CH ₃ OH.

The resulting methanol is periodically pumped into chamber 33, where it is oxidized with atmospheric oxygen on catalysts - metal oxide, alumina, carbon, etc. - into formaldehyde:

2CH ₃ OH + O ₂ → HCHO + 2H ₂ O.

The completion of the process is recorded by sensor 3.5 for oxygen absorption.

After the synthesis of calcium carbide is completed and it is cooled in chamber 8, valve 1.5 is closed, and water begins to be dosed into chamber 8 by pump 2.5 with valve 1.3 open and pump 2.4 running. Acetylene, obtained by the reaction CaC ₂ + 2H ₂ O → Ca(OH) ₂ + C ₂ H ₂ , and hydrogen chloride from chamber 16 are supplied to chamber 9 with valve 1.55 open and pump 2.3 running. For 1 volume of hydrogen chloride, 1 volume of acetylene is supplied. In chamber 9, a reaction occurs with the formation of vinyl chloride C ₂ H ₂ + HCl → CH ₂ = CHCl. Vinyl chloride is collected in receiver 10. Aluminum carbide, synthesized and cooled in chamber 6, is dosed with water using a 5.3 dispenser and a 2.7 pump with valve 1.11 open. Valve 1.8 closes and valve 1.9 opens. In this case, a reaction occurs in chamber 6 with the release of methane: Al ₄ C ₃ + 12H ₂ O → 4Al(OH) ₃ + 3CH ₄ .

To ensure continuity of the process, containers (A), (B), (C) and chambers 3, 6, 7, 8, 14, 15, 37, 38 must be duplicated. Due to duplication, when the process is completed in some containers or chambers, the exits from them are blocked, work is carried out to unload or load them with reagents, and duplicate containers and chambers are turned on and continue to generate the corresponding products.

Methane enters chamber 22. With valve 1.44 closed and valve 1.40 open, methane is directed into chamber 23, where the reaction occurs at 600°C

2CH ₄ → C ₂ H ₄ + 2H ₂

with the formation of ethylene on a cobalt-molybdenum catalyst. To separate ethylene and hydrogen, the gas mixture enters chamber 24, where, with a dosed supply of water and at elevated pressure, ethyl alcohol is synthesized:

C ₂ H ₄ + H ₂ O → C ₂ H ₆ O.

The alcohol is sent to chamber 25. If necessary, the alcohol can be processed back into ethylene at 360°C in contact with aluminum oxide:

C ₂ H ₆ O → C ₂ H ₄ + H ₂ O.

Excess hydrogen from chamber 24 enters chamber 31. After the synthesis of the planned amount of ethanol, valve 1.40 is closed, methane through valve 1.44 enters chamber 26, where the reaction of its incomplete oxidation on a platinum-iridium catalyst occurs:

4CH ₄ + O ₂ → C ₂ H ₂ + 2CO + 7H ₂ .

The resulting gas mixture is separated. Acetylene is dissolved under pressure in acetone in chamber 27, and a mixture of hydrogen and carbon monoxide enters through valve 1.39 into chamber 32 for the synthesis of methanol on the catalyst zinc oxide and chromium oxide according to the reaction CO + 2H ₂ → CH ₃ OH. Part of the acetylene dissolved in chamber 27 enters chamber 31 along with hydrogen from the ethylene and hydrogen separation chamber 24. In chamber 31, acetylene is dimerized and hydrogen is introduced into the dimer, while butadiene-1, 3 is synthesized by the reactions

a) in the presence of ammonium chloride and copper chloride, the dimerization reaction of acetylene occurs to form vinyl acetylene:

C ₂ H ₂ + C ₂ H ₂ → H ₂ C = CH - C ≡ CH;

b) vinyl acetylene adds hydrogen, forming butadiene-1,3:

H ₂ C = CH - C ≡ CH + H ₂ → CH ₂ = CH - CH = CH ₂ .

After the synthesis of the planned amount of butadiene 1,3, acetylene is processed in chambers 28, 29, 30 into phenol. In chamber 28, benzene 3C ₂ H ₂ → C ₆ H ₆ is synthesized on a nickel catalyst. The benzene is then chlorinated in chamber 29 using chlorine from chamber 18:

C ₆ H ₆ + Cl ₂ → C ₆ H ₅ Cl + HCl.

Next, in the autoclave, chamber 30, benzene chloride is treated with alkali and phenol is obtained:

C ₆ H ₅ Cl + NaOH → C ₆ H ₅ OH + NaCl.

Among the polymers used in practice, there is a group related to polyesters. A peculiarity of this group is that the ester bond is highly polarized, as a result of which this bond undergoes heterolytic cleavage under the influence of external agents: acids, alkalis, water. Polyesters can be either simple or complex. For example: ethers: polyacetaldehyde, polyacetone, polyphenylene oxides and others; esters: alkyd resins, carboxymethylcellulose, polycarbonate, polyethylene terephthalate.

On the fourth production line, in tank (B), the process of destruction of polyesters is carried out. Ethers are easily broken down into monomer units when exposed to acidic factors such as stannous tetrachloride, boron trifluoride, hydrogen bromide, hydrogen chloride and others. At the same time, they exhibit high resistance to alkalis. Halide-containing acid agents serve to introduce halogen atoms into monomer units with the simultaneous decomposition of macromolecules into halogen-containing monomers. An obstacle to the widespread use of this method is the high consumption of reagents. For example, when using the most accessible factor - hydrogen chloride, which is formed in chamber 16 and enters the container (B) through valve 1.63 and pump 2.27, 1-2 parts by weight of hydrogen chloride and the same amount of sodium hydroxide are consumed per 1 weight part of the polymer for binding chlorine in chlorinated compounds. Phenol derivatives are destroyed with the participation of aluminum chloride. The result is monomer units: aldehydes, alcohols, ketones, carbocyclic compounds, etc. It is also possible to use oxidizing agents, but these substances, for example ozone, alkyl peroxides, concentrated hydrogen peroxide, are highly toxic and explosive. Due to the high consumption of reagents or their toxicity, high-temperature processing of ethers in thermal destruction tanks (B) becomes more economically profitable.

In turn, polyesters are capable of reacting with other esters, alkalis, ammonia, water, phenol and its analogues with the breaking of polymer chains and the formation of monomers and oligomers. Experimental studies have shown that the process of destruction of polyesters during saponification with water or alkali leads to rupture at the junction of the alcohol and acid components of the molecules. When exposed to other chemical agents, carboxyl and hydroxyl groups often combine with the active agents to form compounds with ammonia, ethers, phenols and other substances. As a result, a mixture of fragments is formed, suitable for the synthesis of polymers only after a complex procedure of purification and separation, for example, according to the method of processing polyester textile waste RU 2761472, C08J 11/16, 02/19/2018. However, if an excess amount of hydrogen chloride is formed in chamber 16, the destruction of ethers becomes expedient, and the use of water in the hydrolysis process makes the decomposition of esters simple and accessible. At the same time, the processes of processing ethers and esters are complicated by the fact that polyester products used in practice are usually copolymers with substances from other groups of compounds. Of the polyethers that are susceptible to destruction, for example, polyacetates, diepoxides, polyethylene oxide and a number of others. Thus, the destruction of carboxymethylcellulose is carried out in container (B) under the influence of concentrated acid, for example, hydrochloric acid. When exposed to hydrogen chloride from chamber 16, the polyether decomposes due to the destruction of glucosidic bonds, and glucose and glycolic acid are formed. The hydrochloric acid is then neutralized with alkali in container (B). In this case, the difference in molecular weights is used, for glucose 180 c.u., and for glycolic acid 76 c.u., and using a multi-stage selective membrane filter, the substances are separated in chamber 34, the separated reaction products are sent to chambers 35 and 36. From polyesters, in addition to polyethylene terephthalate, polyhexomethylene adipate, polydiphenylene propane carbonate, polyethylene adipate and others are also hydrolyzed. In this case, alcohols of varying complexity and organic acids, or salts of acids, are formed if the process occurs in the presence of an alkali. The most homogeneous complex compound suitable for complete processing is polyethylene terephthalate, used as containers for food products. Of all the destruction methods, the most suitable is hydrolysis with the participation of water or alkali, for example sodium hydroxide. In this case, the water consumption is 2-4 gram molecules per one polyester unit, consisting of an alcohol and acid residue, and the alkali consumption is 2-5 gram molecules per one polyester unit. The supply of alkali from chamber 43 to container (B) is carried out using a pump 2.28, a valve 1.64 and a dosing unit 4.10. Water is supplied by pump 2.29 using a dispenser 5.5 and is regulated by valve 1.65. Products made from other polyesters and their compositions can be either hydrolyzed or exposed to temperature factors in container (B).

As an example, we will give a scheme for processing polyethylene terephthalate (PET) on the fourth technological line. Products made of polyethylene terephthalate: bottles, food containers, trays and other items containing no more than 10-12% impurities of antioxidants, plasticizers, copolymers, are crushed into particles 1-5 mm in size, loaded into container (B) at 0.5-0 .7 volume of this container and fill it with water in the amount of 1.5-2.5 parts by weight of water per 1 part by weight of PET. Due to the loose structure of crushed PET, its gravimetric density is 0.25-0.35 kg/dm ³ . Water is distributed between the particles and does not increase the volume of the mixture. The hermetically sealed container (B) is heated to 200-270°C at a pressure of up to 3 MPa, and after 3-20 hours the reaction is completed. A mixture of ethylene glycol and terephthalic acid is formed in container (B). After cooling the contents of container (B), the reaction products are fed through valve 1.50, which is open at this time, into chamber 34, where they are separated into ethylene glycol and terephthalic acid using a centrifuge. Valve 1.50 closes, and terephthalic acid enters chamber 36 through valve 1.51. Ethylene glycol, in turn, enters chamber 35 through valve 1.52. Next, PET is again formed from ethylene glycol and terephthalic acid due to esterification and polymerization reactions.

Ethylene glycol can also be used to produce other products. From chamber 35, ethylene glycol partially enters chamber 37 through valve 1.53. After ethylene glycol is added in an amount of 0.3-0.4 of the chamber volume, valve 1.53 is closed, and nitric acid or another oxidizing agent is supplied to the chamber. Ethylene glycol is oxidized to glyoxal.

Ethylene glycol is also partially processed into a universal polymer solvent - dioxane. The process occurs in chamber 38, where ethylene glycol enters through valve 1.54 and is exposed to sulfuric acid or other dewatering agent, forming dioxane.

In the fifth technological line, in the group of chambers 40, 41, 42, microbiological processing of gaseous, liquid and solid products of polymer destruction is carried out. This group of chambers also serves as a buffer system for carbon monoxide and hydrogen. During operation of the system, deviations in the required proportions of carbon monoxide and hydrogen production are possible. The fact is that in organic chemistry, reactions never proceed with 100% yield; unused reagents always remain and by-products are formed in parallel reactions. Since preservation of by-products is difficult, they are sent for biological processing.

The formation of by-products can be traced using the example of ethanol processing. Thus, when using a freshly prepared catalyst - aluminum oxide, ethanol decomposition occurs at a temperature of 360 ° C with a yield of up to 96-98% ethylene, up to 1-2% acetaldehyde, as well as other aldehydes and more complex hydrocarbons. As the catalyst ages, the proportion of ethylene in the reaction products can decrease to 80%. In addition, the progress of the reaction depends on temperature. At temperatures up to 500°C, the reaction occurs predominantly with the release of ethylene, and at 650°C, mainly acetaldehyde is formed. Pressure and catalytic poisons also have a significant impact on the composition of reaction products, often inhibiting one reaction and activating another. On the mentioned biotechnological line, due to the biological recycling of organic and inorganic substances, the stoichiometric balance of the entire system is maintained, ensuring the necessary ratio of the reacting substances. Substances that are of little use for producing monomer units are also processed.

The cultivation of microorganisms in chamber 40 is carried out both in the flow-replenishment cultivation mode and in the chemostat mode. The fermenter maintains a temperature of 25-80°C, acidity pH 3-9, with intensive stirring at 300-800 rpm. The optimal oxygen content is 2-6 mg per 1 kg of culture fluid. The content of oxygen and macroelements is monitored using selective electrodes. During the cultivation process, the content of macroelements is maintained: nitrogen, potassium 12-70 mg/dm ³ medium, phosphorus 2.5-6 mg/dm ³ medium, magnesium, sulfur, calcium 1-5 mg/dm ³ medium. Microelements - iron, zinc, manganese, molybdenum, cobalt, boron, copper and others, depending on the specific needs of utilizing microorganisms, are maintained at a concentration of 0.1-1 mg/dm ³ of the medium. If necessary, the medium includes growth factors - vitamins and amino acids at a concentration of 0.01-5 mg/dm ³ medium. Regulation of acidity, concentration of macroelements and microelements is ensured by the automatic supply of the necessary substances in concentrated form. The supply of substances and elements of mineral nutrition, gases is carried out due to the operation of valves 1.35, 1.56, 1.57, 1.59, 1.60 and pumps 2.22, 2.26, 2.18, 2.20. A concentrated solution of mineral salts is contained in chamber 39, the flow rate is regulated by dispenser 4.6. The concentration of supplied carbon and energy sources is maintained no higher than 0.5-0.7 of the concentration that inhibits the growth of microorganisms. The flow rate in the chemostat cultivation mode is 0.01 h ^-1 - 0.5 h ^-1 . Greenhouse carbon dioxide released as a result of the life of organisms is absorbed by carbon dioxide accumulator 6.2. In addition, carbon dioxide can be used to synthesize methane, and the methane can be returned to the bioreactor or organic synthesis system. For this purpose, hydrogen generated in chambers 7 and 26 is used at 250-400°C on nickel or cobalt catalysts according to the reaction:

CO ₂ + 4H ₂ → CH ₄ + 2H ₂ O.

On a biological processing line using microorganisms, in addition to carbon monoxide and hydrogen, it is also possible to bioutilize other organic substances, which in this case act as sources of carbon and energy: methanol, ethanol, glucose, phenol, ethylene glycol, etc. For example, ethylene glycol is pumped in measured quantities from chamber 35 to chamber 40 using pump 2.21 and valve 1.58, controlled by dispenser 4.5. The consumption of carbon and energy sources at the entrance to chamber 40 is controlled by a multi-channel dispenser 4.7. Microorganisms of such genera as Nocardia, Paracocaus, Methanomonas, Sorcina, Pseodomonas, Alcaliganes, Mycobacterium, Desulfovibrio, Sarcina, Bacterium, Bacillus and other non-pathogenic organisms participate in the utilization of substances.

Disintegration of microorganism cells is carried out in chamber 41 by heating the grown biomass at a temperature of 100-120°C in a liquid medium, and at the same time exposure to ultrasound is carried out. The ultrasound intensity, frequency, pulse shape, and exposure duration are determined empirically depending on the size of the cells, their shape and the strength of the cellular structures. After cooling to 30-35°C, enzymes are added for more in-depth disintegration: lipase, amylase, protease, etc. Disintegration processes are carried out with the mixer running at 500-1000 rpm.

It is possible to reduce the impact of CO ₂ on the greenhouse effect by conserving the carbon contained in the biomass of microorganisms. To do this, the grown biomass is subjected to thermal destruction, for example, heating to 600°C. Biomass decomposes to form elemental carbon (soot), water, nitrogen and mineral salts. The resulting pure carbon can be used for the synthesis of carbides, as described above, or can be buried, as a result, the carbon is conserved, and CO ₂ is removed from natural circulation.

The process of synthesis and utilization of carbides is in interaction with the processes occurring on the lines for producing carbon and carbon monoxide, according to the following scheme. During the synthesis of calcium and aluminum carbides in carbide chambers 8 and 6, carbon monoxide is released. At this time, carbon is generated in combustion chamber 3 with its maximum yield, while hydrogen is released in chamber 7 at the same time. After the synthesis of carbides in chambers 8 and 6 is completed, acetylene from chamber 8 is sent to the synthesis of vinyl chloride, and methane from chamber 6 is sent to the synthesis of acetylene, carbon monoxide and hydrogen. At the exit from chamber 27, carbon monoxide and hydrogen are formed in a volumetric ratio of 7 volumes of hydrogen to 2 volumes of carbon monoxide. Methanol synthesis requires 1 volume of carbon monoxide to 2 volumes of hydrogen. In addition to the existing two volumes of carbon monoxide, 7 volumes of hydrogen require another 1.5 volumes of carbon monoxide. For this reason, in the combustion chamber 3, the generation of carbon monoxide is increased by the required amount by increasing the air supply.

When producing carbon in the combustion chamber 3 in the mode of the highest carbon output, the ratio of the weight parts of carbon monoxide and carbon at the output is 6.1-14.3% of carbon monoxide. This range of ratios is necessary for self-sustaining of the process and is achieved by regulating the release of volatile products from chamber 14 and container (B) and dosing the air supply into combustion chamber 3 (dosing units 4.8, 4.2, 4.3). After processing of volatile combustible products, the function of generating carbon and carbon monoxide moves from combustion chamber 3 to chamber 14 and container (B).

Upon completion of the synthesis of carbides and the cessation of the flow of carbon monoxide, chamber 14 and container (B) also become a source of carbon monoxide. At maximum carbon generation, 5.2-12.4% of carbon is burned, at maximum carbon monoxide generation, 100% of carbon is burned. An additional source of carbon monoxide is the process of methane oxidation in chamber 26.

The processing of plastics is accompanied by the release and absorption of large amounts of heat. Heat sources are container (B) and chamber 14 at the stage of producing carbon monoxide, chambers 3 and 26 at the stage of oxidation of carbon and methane, as well as chamber 7 during the generation of hydrogen, chambers 6 and 8 at the stage of cooling of carbides. Heat consumers are container (A) at the depolymerization stage, chamber 14 at the stage of destruction of halogen-containing polymers, chamber 32 for methanol synthesis, chamber 12 for urea synthesis, container (B) at the hydrolysis stage, as well as chambers for biomass synthesis and its sterilization. Chambers 6, 7, 8, which require a temperature of 2000°C and higher at the stage of carbide synthesis, are separately provided with heat. Other heat consumers, with the exception of carbide synthesis, require temperatures up to 400°C. Therefore, it is possible to rationally redistribute excess heat using a pipeline system through which, for example, silicone oil circulates at temperatures up to 400°C, acting as a coolant. The use of coolants allows processes to be carried out in containers (A) and (B) without the use of additional energy sources.

The given examples demonstrate the potential capabilities of the claimed method. During the operation of the considered device, the following substances are synthesized: carbon, carbon monoxide, hydrogen chloride, chlorine, styrene, methyl methacrylate, acetylene, vinyl chloride, methane, hydrogen, urea, methanol, formaldehyde, ethylene, ethyl alcohol, benzene, phenol, sulfur, butadiene, isoprene, ethylene glycol, terephthalic acid, glyoxal, dioxane, methenamine, aluminum fluoride, as well as products of biotechnological synthesis. From the obtained substances it is possible to synthesize polymers used in practical activities: carbon plastics, polyethylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polymethylene oxide, glyoxal polymers, polybutadiene, polyisoprene, phenol-formaldehyde resins, urea-formaldehyde resins, polyethylene terephthalate, etc., as well as copolymers: styrene-butadiene rubber, isoprestyrene rubber.

Taking into account the reactions between substances in the process of organic synthesis, the above list represents a small part of the polymers and copolymers that can be synthesized from the resulting chemical compounds. You can add polycarbonate, polypropylene, polychlorpropene, polychloroprene and others to the list.

In the process of bioutilization of organic substances, a biomass of microorganisms is formed in chamber 40, which is subjected to disintegration and converted into a universal nutrient substrate for producing microorganisms. Based on a nutrient substrate, it is possible to synthesize biogenic, biodigestible polymers, such as physiologically active polymers: hyporin, insulin, interferons, nucleases, gammaglobulin, etc. For household and technical purposes, it is possible to synthesize, for example, unsaturated carboxylic acids that are prone to polymerization in oxygen or in oxygen-free environment, such as oleic, palmitic, lysolic, erythregenic, arachidic acids, etc. Polymerization of these acids produces biodigestible films, bulk products, threads, etc. that are used in practice. In turn, the synthesis of polyesters based on ethylene glycol and carboxylic acids is possible. Polyesters such as alkyd resins, polyalkylene glycol fumarates, polyalkylene glycol maleates, etc. are also synthesized.

It is obvious that the described method for the regeneration and processing of organic substances can be applied equally to both biogenic and technogenic polymers. The resulting organic substances, in addition to the production of polymers from them, can be used directly in the form of monomers in various spheres of human activity: in technology, agriculture, medicine, in household practice and in other areas.

The technical result of the claimed method is to expand the range of produced monomers without the formation of toxic waste, reduce greenhouse gas emissions and implement the cycle of organic polymers through a series of sequential selective chemical reactions in a closed system with arbitrary organic polymers at the input, and only water, nitrogen and target products at the output .

Used sources:

1. Patent RU 2385343, C10B 49/02, 11/10/2008.

2. Patent RU 2617790, В09С 1/06 03/25/2014.

3. Patent RU 2190659, C10G 15/12, 05/19/2000.

4. Patent RU 2686829, C08J 11/00, 01/09/2018.

5. Patent RU 2761472, C08J 11/16, 02/19/2018.

Claims (13)

1. A method for regenerating waste organic polymers of arbitrary composition, including sorting polymer waste, mechanical grinding, physical, chemical and biochemical effects using depolymerization, thermal destruction, hydrolysis and microbiological processing of polymers, characterized in that the process is carried out by transforming polymers into monomer units on several simultaneously operating interconnected technological lines, on the first production line, polymers capable of depolymerization to form monomer or oligomer units, polymers containing up to 80 wt. % of impurities in the form of thermoplastic copolymers and/or alloying additives, polymers containing up to 80 wt. % thermosetting additives, and/or containing, along with substances without heteroatoms, up to 80 wt. % copolymers or block copolymers of substances with a polar bond formed by a system of carbon and/or hydrogen with heteroatoms are loaded separately into a depolymerization container (A), heated to a temperature of 200-300 ° C, they are transferred to a gaseous state, condensed by cooling in a condensation chamber and the liquid is drained monomer or oligomer into the receiver; in this case, polymers of the aliphatic diene group, both in the form of individual compounds and in the form of copolymers or block copolymers, are depolymerized in the presence of catalysts at a pressure of 5⋅10 ² -8⋅10 ⁴ Pa, the resulting volatile gaseous depolymerization products are divided into fractions having different temperatures boiling, the remaining flammable gaseous products from the depolymerization vessel (A) are sent to the combustion chamber, generating carbon or carbon monoxide; on the second production line, a mixture of polymers of any composition, including thermoplastic, thermosetting and filled polymers, except fluorine- and chlorine-containing ones, as well as solid and liquid carbon-containing residue from the depolymerization tank (A), is loaded into the thermal destruction tank (B), heated to 500- 1000°C without air access, volatile gaseous products are directed into the combustion chamber, generating carbon or carbon monoxide; The sulfur dioxide formed during the combustion of sulfur-containing polymers is captured by passing the combustion products through a chamber with kaolin, where the sulfur dioxide reacts with carbon monoxide to form elemental sulfur and carbon dioxide, the carbon dioxide is sent to a carbon dioxide storage tank, the solid residue in the thermal destruction tank (B) is burned to carbon at 500-1000°C, and carbon containing less than 20 wt. % of mineral impurities are sent to carbide synthesis chambers, and carbon containing over 20 wt. % of mineral impurities, unsuitable for the synthesis of carbides, are converted to carbon monoxide; on the third technological line, in a separate chamber protected from aggressive gases, chlorine-containing and fluorine-containing polymers are subjected to thermal destruction, which are heated to 500-800°C without air access, gaseous thermal destruction products containing hydrogen chloride are partially passed through water to form hydrochloric acid, and partially oxidize the chloride hydrogen into gaseous chlorine and convert the chlorine into a liquid state, purify the thermal destruction products from residual hydrogen chloride, passing them through calcium carbonate to form calcium chloride, the remaining combustible products are sent to the combustion chamber, generating carbon or carbon monoxide; crushed fluorine-containing polymers are mixed with substances that have a greater chemical affinity for fluorine than carbon, and heated without air access to 500-800°C to obtain products of fluorine compound with the mentioned substances and free carbon; at the same time, the composition of gases leaving the combustion chamber is continuously monitored by means of control and, using a central computing device with programs installed on it, the amount of air supplied to the combustion chamber is automatically changed, and in the pure carbon generation mode, carbon monoxide is not allowed to appear at the exit of the combustion chamber in an amount of more than 0.1-0.2 vol. %, and in the carbon monoxide generation mode they do not allow carbon dioxide to appear at the exit of the combustion chamber in an amount of more than 0.1-0.2 vol. %; the resulting carbon monoxide is sent to the methanol synthesis chamber, and the resulting pure carbon is used for the synthesis of calcium and aluminum carbides, for which pure carbon is sent to three carbide chambers, while part of the carbon is mixed in the first carbide chamber with calcium oxide in a ratio of 1.3-1 ,8 parts by weight of calcium oxide per 1 part by weight of carbon and the mixture is heated to a temperature of 2000-2500°C to obtain calcium carbide and carbon monoxide, part of the carbon is mixed in the second carbide chamber with calcium oxide, calcium carbide is added and the mixture is heated to a temperature of 2000- 2500°C to produce calcium carbide and carbon monoxide, then calcium carbide heated to 1000-2000°C in the second carbide chamber is treated with water to produce calcium carbonate, carbon dioxide and hydrogen; the remaining part of the carbon is mixed in the third carbide chamber with aluminum oxide in a ratio of 1.5-1.9 parts by weight of aluminum oxide per 1 part by weight of carbon and the mixture is heated to a temperature of 2000-2500°C to obtain carbon monoxide and aluminum carbide; hydrogen, acetylene and methane are obtained from carbides with a dosed supply of water, then the polymer processing products obtained on the second and third technological lines: carbon, carbon monoxide, hydrogen, methane, acetylene, chlorine and hydrogen chloride are used in organic synthesis processes to produce monomer units , suitable for the synthesis of polymers; on the fourth production line, polyesters and polyesters are processed, while the polyesters are treated with hydrogen chloride in a polyester regeneration tank (B), obtaining ether monomer units and products suitable for the synthesis of monomer units, excess hydrogen chloride is neutralized with alkali; polyesters are saponified with water or alkali at pressures up to 3 MPa and temperatures up to 270°C, obtaining ester monomer units; on the fifth technological line, products of polymer destruction that are of little use for the synthesis of monomer units and by-products of parallel chemical reactions, which are excessive in terms of the multiplicity of stoichiometric ratios, are sent to a microbiological utilization reactor containing a culture liquid suitable for the activity of microorganisms, and the mentioned products are subjected to microbiological processing using them as sources of carbon and/or energy for the activity of microorganisms and maintaining the stoichiometric balance of the entire process of regeneration of waste polymers with the production of monomers and oligomers of biological origin, carbon dioxide and water; at the same time, interconnected processes in the mentioned technological lines are controlled by a central computing device with programs installed on it, which, based on data received in feedback mode from sensors, coordinates the flow of substances, their dosage, temperature, pressure, beginning and end of reactions, maintaining optimal conditions for the synthesis of target products; 2. The method according to claim 1, characterized in that to prevent sintering of the polymer mass in the thermal destruction container (B), disintegrant calcium oxide hydrate is added to the mixture of crushed polymers in an amount of 1-10 wt. %. 3. The method according to claim 1, characterized in that in the reactor for microbiological utilization of polymers the temperature is maintained at up to 80°C, acidity pH 3-9, concentration per 1 dm ³ of culture fluid: oxygen 2-6 mg, nitrogen and potassium sources 12 each -70 mg, phosphorus 2.5-6 mg, magnesium, sulfur, calcium 1-5 mg each, trace elements 0.1-1 mg, growth factors 0.01-5 mg, carbon sources 0.5-0, 7 from the inhibitory concentration at a flow rate in chemostat mode of 0.01-0.5 h ^-1 . 4. The method according to claim 1, characterized in that the biomass of microorganisms obtained in the microbiological utilization reactor is isolated from the cultural liquid, disintegrated and used as a universal substrate for growing genetically modified microorganism producers that synthesize monomer units, oligomers and biopolymers of biological origin . 5. The method according to claim 1, characterized in that the calcium chloride obtained in the process of recycling hydrogen chloride is used as a carbon dioxide accumulator, converting calcium chloride into calcium carbonate by passing carbon dioxide and ammonia through a solution of calcium chloride. 6. The method according to claim 1, characterized in that the excess heat of the heat-releasing reaction chambers is accumulated by liquid coolants and used in the heat-absorbing reaction chambers. 7. The method according to claim 1, characterized in that the continuity of the polymer waste regeneration process is maintained by duplicating working volumes, switching containers and chambers that require unloading or loading to duplicate containers and chambers.