SU1118291A3 - Method of obtaining carbon black from liquid hydrocarbons - Google Patents

Abstract

A method for producing soot from liquid hydrocarbons, including mixing hydrocarbon streams with air, heating the mixture, feeding the mixture as separate streams distributed over the cross section of the reaction zone, and the subsequent thermal degradation of the hydrocarbons in the reaction zone, so that, in order to simplify the process of obtaining various grades of carbon black, the thermal decomposition of hydrocarbons is carried out in air at 9501200 ° C.

Description

The invention relates to the technology of producing various grades of carbon black used as a filler in the vulcanization of rubber, pigment in obtaining black printed colors and for dyeing varnishes, plastics and artificial fibers and, finally, in electrical engineering in the preparation of dry batteries, carbon brushes, coals for arc lamps and electrodes for metallurgical and chemical processes. A method for producing carbon black is known, including spraying heated liquid hydrocarbon (cf) axially into the reaction zone, separately introducing combustion products into the reaction zone, mixing cf with combustion products, and thermal decomposition of cf and combustion products at temperatures up to 1650 ° C. D3 can be applied within fairly wide limits, however, to establish a certain performance by adjusting both the generated annular streams of flue gas requires quite large costs. The closest to the present invention is a method for producing soot from liquid hydrocarbons, including mixing the hydrocarbon streams with air, heating the mixture, feeding the cm as separate streams distributed over the cross section of the reaction zone and the subsequent thermal decomposition of hydrocarbons in the combustion zone. in the reaction zone 2j. The disadvantage of this method lies in the separate supply of liquid hydrocarbons used for carbon black production and flue gas flows, since in this case the process of controlling these flows is complicated and difficult to maintain parameters for obtaining a specific soot grade. In this way, only a few varieties of soot can be obtained, for example, soot for rubber. The purpose of the invention is to simplify the process of obtaining various varieties of soot. This goal is achieved by the fact that, according to a method involving mixing liquid hydrocarbon streams with air, heating the mixture, feeding the mixture as separate streams distributed over the cross section of the reaction zone, and subsequent thermal decomposition of the hydrocarbons in the reaction zone, thermal decomposition of the hydrocarbons in the air environment at 950-200 ° C. Simplification of the process is achieved by the fact that the combustion reaction (exothermic) and the decomposition reaction (endothermic) in the production of carbon black and in place and in time proceed in parallel. In this case, there is no need for additional gas supply for combustion, and all the time the heat necessary for the flow is added. cleavage reactions. As a result, optimal conditions are created for the overall reaction, which, in addition, is favored by the mixing and gasification of hydrocarbons with oxygen-containing gas before the reaction zone. Due to these conditions, the reaction can be carried out at a lower temperature (950-1200 ° C) than in the known method. Therefore, instead of quenching the flue gases by spraying water into them, they can be cooled in a heat exchanger. Since the implementation of the proposed method uses only two components: hydrocarbons and oxygen-containing gas, the transition from producing one soot grade to another is accomplished, without much difficulty, by simply changing the amount of oxygen-containing gas. The more this quantity is, the smaller the particle size of the soot produced (naturally, it also reduces its output). The quality of the carbon black produced by the proposed method can be varied within very wide limits. When carrying out the process, temperatures above 1200 ° C should be avoided, since the reactor is made of stainless steel, the strength of which decreases greatly at higher temperatures. A control device in the installation prevents the temperature from rising above this value. Lower temperatures (below 950 ° C) are also undesirable, as this reduces the soot yield. Therefore, using a regulating device

311

the temperature is strictly maintained within the limits.

According to the proposed method, carbon black of various quality can be obtained with a yield of 10-85% of the injected liquid hydrocarbon.

The method is carried out as follows.

th & adic hydrocarbon (fuel oil) in the form of streams are mixed with air and heated in pre-chambers, the heated soot is served as separate streams distributed over the cross section

914

the reaction chamber (zone), in which, due to the preheating of the mixture, thermal decomposition (partial combustion) of hydrocarbons occurs in air with the formation of soot and flue gases which cool and separate the soot.

The specific modes of implementation of the method and the properties of the soot obtained in the experiments are presented in Table. 1 (when using fuel oil with a specific gravity of 1.06 g / cm, containing, wt.%: Carbon 91; hydrogen 8; sulfur 0.3).

Table D

Operating parameters

The amount of injected fuel oil (12 nozzles), kg / h

The amount of air supplied

The ratio between the quantities of feed vodkha and fuel oil

Fuel oil pressure, bar Fuel oil temperature, ° С Air temperature,

Air pressure, mm water. 1W The temperature in the reaction chamber: in the center of the chamber max. ° C in the air cooler, min.C The temperature in the prechamber, with Depression in the chamber, mm of water. Art. Filter inlet temperature, s

800

800

4,000

3120

5295 1050 I 951 246-25 1146 960 750

Properties of carbon black Soot sample, g

Expenses for idle experience, si

Consumption, j for titration. Seats, cm

Iodine adsorption results,% J2

Adsorption Results

iodo xyo in idle

experience% 0

The surface occupied by iodine on the Cabot table,

Total surface occupied by iodine A X G, m / g

Quality and type Quality (grade)

The diameter of the stream is equal to the diameter of the reaction chamber (2, 4 m), since the mixture is evenly distributed over the entire cross section of the reactor.

table 2

27.5 23.5

39.8 59.1

Continued table. one

0.20 24.6 8.1 16.5

67.1

7-1118291

Adsorption properties of some

from the soot grades obtained in accordance with the invention, the Indicators are given in Table. 2

In addition, 5 intermediate soot grades can be obtained.

Table3

Quality (grade)

Soot indicators

No. 3 No. Oil absorption, ml / g 1.07 1.14 Tensile strength, kgf / cm 295 311 Elongation at break,% 525 575 300% shear modulus 2635 2500 Hardness on uncleaning machine,% 68 73 Elastic recovery at 100 ° C -56.9 50.7 Loss due to abrasion, g 3.65 3.24 The obtained results of the carbon black investigation for rubber production No. 3 and No. 5 are given in Table. (with a vulcanization time of 50 mi. Table Quality (with the Soot Indicators No. 4 No. 8 Surface for 81.8 211.2. nitrogen, Color Depth in indices by nigrometer

Continued table 4 Quality (grade)

soot

№ 4 1 № 8 I

 II

Oil absorption ,.

Oh, 12 1.18 1.24

7.2 6.1 3.5

pH

Ash content, "5% 0.04 0.03 0.02 Moisture content. 0.38 0.23 0.12 The tar content (tar), Z 0.06 0.02 0.01 For the soot for the production of rubber and paint No. 4, No. 8, and No. 11, the physical and chemical data obtained in Table . 4. If the pumped temperature range is not maintained, the above indicators are impaired, especially values related to the surface 12 and N. For the soot grades for rubber production No. 4 and No. 8, the results of two measurements are compared, in which yut air. For the preparation of 1 kg of soot, use: No. 4 10.2 nm of air and 2.4 kg of heavy fuel (fuel oil), i.e. 4.25 nm / kg of yellow fuel (fuel oil) No. 8 25.4 nm and 4.3 kg of yellow fuel (fuel oil), i.e. 5.9 nm / kg of yellow fuel (mazut). According to the above analysis, 10.27 nm / kg of fuel oil is required for complete combustion of heavy fuel, so that the amount of air injected is approximately 4%, 4%, 57.6%, which corresponds to complete combustion of fuel oil the maximum amount of air required. The analysis of residual gases shows that about 9-11 vol.% Of carbon monoxide is present, as is the most common P1829 10

most of the component, while about (17) times the demand

as a fraction of hydrogen, methane and air compared to grade No. 4,

(heavy hydrocarbons) are known-non-carbonated

much smaller. burns and serves to maintain

From the experiments it is clear that 5 temperatures are in the reaction chamber. that depending on the establishment

The relationship between fuel oil and air. Soot production can be a pre-grade. A certain grade is obtained at any time and with reproducible results. For any period of time, the soot grade should be thinner, it should be resumed again in half the light, the ratio should be more same or other varieties of soot containing air. For Grade No. 8 it is only necessary to observe the period that the pre-need for air is preheated.

Claims (1)

METHOD FOR PRODUCING SOOT FROM LIQUID HYDROCARBONS, including mixing hydrocarbon streams with air, heating the mixture, supplying the mixture in the form of separate streams distributed over the cross section of the reaction zone, and subsequent thermal separation of hydrocarbons in the reaction zone, characterized in that, for the purpose of, simplification of the process of obtaining various varieties of carbon black, thermal decomposition of hydrocarbons is carried out in air at 9501200 ° C. GO ζ ©> 1 118291