RU2389747C1 - Method of producing soot and reactor for realising said method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to petrochemistry. Heated air is fed into an air chamber 2 and then passes into mixing chamber 3, into which fuel gas is fed through a jet device. The fuel-air mixture formed enters a combustion chamber 4. The high-temperature stream of fuel combustion products then converges in a mixing nozzle 6 into which water and raw materials are fed through device 12 in radial penetrating jets under 12-25 atm pressure in one cross section of the converged stream, moving at 250-600 m/s. Water and the raw materials are at temperature not over 95°C and 200-450°C respectively. The stream of reaction mixture formed enters reaction chamber 7, at the end of which the reaction products undergo preliminary hardening. Further, the reaction products enter reaction chamber 8, at the end of which reaction products undergo full hardening with water in zone 9. Cooled reaction products come out of the reactor through pipe 10 and are channelled to a system of devices for separating the end product.

EFFECT: invention enables production of fine-grained, high structure soot with uniform properties with high output of the end product.

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Description

The invention relates to the production of carbon nanostructured carbon black material, which is used as an elastomer filler for the manufacture of tires and rubber technology.

The method includes generating a high-temperature stream of products of complete combustion of hydrocarbon fuel at a pressure of 0.3-1.0 bar, which is fed through the narrowing nozzle into the reaction zone at a speed of 250-600 m / s. In the zone of maximum gas flow velocity with radial penetrating jets, hydrocarbon feed is supplied, which decomposes with the formation of nanosized carbon in the reaction zone and, after quenching, enters the recovery and separation system with the release of the target product.

A distinctive feature of the method is that in the zone of maximum flow rate by radial penetrating jets simultaneously with the feed water is supplied.

A known method of producing soot, including the supply of raw materials to the reactor in the form of an axial flow and an axial flow of an oxidizing agent with the decomposition of hydrocarbon raw materials in an axial feed torch (US patent No. 3832450). In this case, water is supplied to the raw torch by radial jets. In this method, in a feed torch, the feed is still in the liquid phase, but its temperature exceeds the temperature of the supplied water. The process proceeds during the thermo-oxidative pyrolysis of raw materials. The introduction of water into the feed torch in this method allows the generation of soot with increased adsorption of dibutyl phthalate and iodine number. The disadvantage of this method is the low yield of the target product and a high degree of its heterogeneity.

A known method, including burning fuel with air in the combustion chamber, narrowing the combustion products in the mixing nozzle, introducing into it hydrocarbon raw materials and water in an amount of 0.1-0.5 kg / kg of raw materials, expanding the resulting products in the reaction chamber, followed by cooling of the products water (RF patent No. 2077544). Part of the water entering the mixing nozzle is supplied in 0.0005-0.0009 sec after the input of raw materials in the amount of 0.02-0.09 kg / kg of raw material.

A reactor for carrying out the method, comprising a combustion chamber sequentially and coaxially with means for burning fuel with air, a mixing nozzle with raw nozzles and water nozzles radially mounted in the mixing nozzle after the raw nozzles at a distance equal to 4-8 diameters of the mixing nozzle, and the reaction chamber with means for quenching soot and gas products is additionally equipped with a second belt of water nozzles in the mixing nozzle, radially located at a distance of 1.0-1.95 cm diameter nozzle from the place of input of raw materials.

The disadvantage of this method is the mild effect of influence on the formation of structured aggregates.

Closest to the proposed method is the production of soot, including the generation of a high-temperature stream of products of complete combustion of hydrocarbon fuels, the introduction of this stream into a narrowing nozzle at a high speed, and the supply of radial jets of hydrocarbon feedstocks (RF patent No. 2083614, prototype). A distinctive feature of this method is that water jets are fed into the high-speed and high-temperature product stream prior to supplying the raw material jets. The reactor for implementing the proposed method for producing carbon black includes sequentially and coaxially mounted a chamber for displacing fuel with air, a combustion chamber, a mixing nozzle with nozzles for supplying raw materials, and a reaction chamber with nozzles for supplying water for quenching soot and gas products. In addition, it is equipped with nozzles for supplying water radially mounted in the mixing nozzle in front of the raw nozzles at a distance from them equal to 0.1-2.4 of the diameter of the mixing nozzle. The preliminary introduction of water made it possible to obtain soot with an increased adsorption of dibutyl phthalate, but the porosity of the resulting product increased.

The objective of the invention is to provide a method and a reactor for producing highly dispersed, highly structural and properties homogeneous soot with a high yield of the target product.

The proposed method for producing soot involves the generation of high-temperature gases - products of complete combustion under a pressure of 0.3-1.0 bar and an excess of air, the supply of gases of complete combustion of fuel into the nozzle with an exhaust velocity of 250-600 m / s. Hydrocarbon feed is supplied to the zone of maximum flow rate of complete combustion gases by radial penetrating jets. Water is supplied to the same zone in the same section by radial penetrating jets. Raw materials and water are supplied under a pressure of 12-25 bar. The water temperature is not higher than 95 ° C, and the raw material is 200-450 ° C.

The number of raw jets in the nozzle section and water jets in the same section are in the range 2: 2 ÷ 6: 6 depending on the regulation of the required properties of the resulting product.

The mass ratio of the flow of water and raw materials in the narrowed stream of products of complete combustion is 0.05-0.25.

In the resulting highly turbulent flow, thermo-oxidative pyrolysis of the hydrocarbon feed occurs. In this case, evaporating droplets of raw materials and water droplets cross-contact with each other, enhancing the coagulation of the resulting carbon phase with a simultaneous increase in the rate of occurrence of soot forming nanoparticles.

Distinctive features of the method for producing soot are the supply of hydrocarbon raw materials and water with radial penetrating jets at a pressure of 12-25 atm in one cross section of a narrowed stream moving at a speed of 250-600 m / s.

Another difference is the mass ratio of water and raw materials in a narrowed stream of products of complete combustion, which is 0.05-0.25.

The reactor for implementing the proposed method includes sequentially and coaxially installed a chamber for mixing fuel with air, a complete combustion chamber, a separation diaphragm with a mixing nozzle and devices for supplying hydrocarbon feedstocks and water jets in one section, a reaction chamber with quenching devices. A distinctive feature of the reactor is the installation of devices for introducing radial jets of hydrocarbon feedstock and water in one nozzle cross section.

The set of essential features proposed by the application makes it possible to obtain highly dispersed, highly structural, and soot uniform materials with a high yield of the target product.

The speed of the products of complete combustion of the fuel is less than 250 m / s reduces the intensity of the mixing processes and it is possible to reduce the specific surface area of soot. At a speed of movement of gases of full combustion above 600 m / s, the cost of air compression increases.

When the supply pressure of water and raw materials is less than 12 atm, the dispersion efficiency of liquids decreases and coarsening of drops of water and raw materials occurs, which leads to a decrease in the specific surface area of soot. At a pressure of more than 25 atm, the cost of compression increases sharply.

When the temperature of the water supplied to the narrowing nozzle rises above 95 ° C, it may boil, which leads to a decrease in the effect of a change in the properties of soot.

When lowering the temperature of the raw material below 200 ° C, the dispersion efficiency and the effect of the process as a whole decrease. When the temperature of the raw material rises above 450 ° C, boiling of light fractions and a decrease in the efficiency of the process are possible.

Figure 1 presents a schematic diagram of a reactor, a General view.

Figure 2 is a section along aa.

Figure 3 - its cross section along BB

The carbon black reactor includes a housing 1, in which an air chamber 2, a gas-air mixing chamber 3 with a jet burner, a combustion chamber 4, a separation diaphragm with a cooled chamber 5, a mixing nozzle 6, a reaction chamber 7, a reaction chamber 8 and a chamber are arranged sequentially and coaxially quenching 9. In the mixing nozzle 6 on the reactor vessel 1, devices for introducing raw materials and water are mounted radially in one section. At the end of the reaction chamber 7, one or more devices for pre-quenching soot and gas products are radially located on the reactor vessel 1. At the end of the reaction chamber 8, one or several devices for supplying water for the complete quenching of carbon black products are radially mounted on the reactor vessel 1. At the end of the reactor, a pipe 10 is radially mounted on the reactor vessel 1 for outputting carbon black products. The combustion chamber 4, the mixing nozzle 6 and the reaction chamber 7 are formed by a block lining 11 made inside the reactor vessel 1 from highly refractory mullite corundum, corundum or zirconium dioxide.

The proposed reactor operates as follows. An oxidizing agent, for example, air, from a source under a pressure of 0.3-1.0 bar, preheated in any suitable device for this purpose to 500-900 ° C, is fed into the air chamber 2. Then it passes through a coaxial stream into the mixing chamber 3, where axial flow through the jet device serves fuel gas. The resulting air-fuel mixture enters the combustion chamber 4. The resulting high-temperature stream of fuel combustion products is narrowed in the mixing nozzle 6 and through the devices 12, water and raw materials are sprayed into it in the same section from sources under pressure. The resulting stream of the reaction mixture enters the reaction chamber 7, at the end of which the preliminary products of the reaction are quenched. Next, the reaction products enter the reaction chamber 8, at the end of which the water completely quenches the reaction products in zone 9. The cooled reaction products are removed from the reactor through the pipe 10 and then sent to the device system to separate the target product and give it a marketable shape.

Example 1

The experiments were carried out in a reactor with a mixing nozzle diameter of 200 mm. As raw materials used hydrocarbon mixture of the following composition:

Water was introduced at a distance of 300 mm from the radial feed jets. The results of the experiments are given in table 1.

Example 2. The experiments were carried out under the conditions of example 1, but the water supply was carried out in one section of the mixing nozzle. The results of the experiments are shown in the table.

When water was introduced in one section of the mixing nozzle, the adsorption of dibutyl phthalate, the specific external surface, and the specific surface for N ₂ adsorption increased.

Table Comparative indicators of the properties obtained in the experiments of soot Experience Conditions By a known method According to the proposed method Diameter of mixing nozzle, mm 200 200 Raw material consumption, kg / hour 730 730 Fuel consumption, nm ³ / hour 170 170 Process air consumption, nm ³ / hour 4000 4000 Process air temperature, ° С 400 400 Water consumption in a nozzle, kg / hour 180 180 Material temperature, ° С 220 220 Water temperature, ° С 70 70 Temperature in the combustion chamber, ° С 1445 1445 The temperature in the reaction zone, ° C 1520 1520 Specific external surface, STSA (ASTM D 6556), m ² / g 108 130 Specific surface according to N ₂ (NSA, ASTM D6556), m ² / g 110 128 Iodine number, ASTM D 150, mg / g 106 130 Adsorption dibutylphthalate, (DBP, ASTM D 2414), cm ^3/100 g 115 140 Light transmission of toluene extract,% 98 98

Claims (4)

1. The method of producing soot, including the generation of a high-temperature stream of products of complete combustion of hydrocarbon fuel, the narrowing of the stream and the flow of radial penetrating jets of hydrocarbon feed and water into it, decomposition of the feed with the formation of soot and quenching of the reaction products, characterized in that the hydrocarbon feed and water are fed radially penetrating jets under a pressure of 12-25 atmospheres in one cross section of a narrowed stream moving at a speed of 250-600 m / s, and the water has a temperature of not higher than 95 ° C, and the raw material is 200-450 ° C. 2. The method according to claim 1, characterized in that the mass ratio of the flow of water and raw materials in the narrowed stream of products of complete combustion is 0.05-0.25. 3. A reactor for producing soot, including a housing in which a chamber for mixing fuel with air, a chamber for complete combustion of fuel, a separation diaphragm with a mixing nozzle and devices for supplying radial raw and water jets, a reaction chamber with quenching water devices, are arranged in series and coaxially the fact that the device for introducing radial jets of hydrocarbon feedstock and water are located in one cross section of the mixing nozzle. 4. The reactor according to claim 3, characterized in that the number of devices for introducing radial jets of raw materials and water in one section are in the range 2: 2-6: 6.

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