JP6084063B2 - Production method of carbon black - Google Patents

Description

  The present invention relates to a method for producing carbon black used for various industrial applications such as rubber reinforcement and coloring.

  Carbon black is an industrial product that is used in various applications, such as improving the reinforcing properties of industrial rubber and improving the blackness of ink, and is a raw material for obtaining the properties (particle diameter, structure, etc.) of carbon black corresponding to various applications. In parallel with these, studies on yield improvement have been conducted by various approaches. General carbon black uses ethylene bottom oil or FCC oil alone as a raw material oil, and the yield is about 50 to 55%, but the yield is also known to vary depending on the carbon black physical properties such as particle diameter. ing. However, these physical properties do not depend on the physical properties of carbon black because they have a great influence on the physical properties of the rubber when blended with rubber. There was a need to study a certain manufacturing method.

  In order to solve this problem, first, as an attempt to improve the raw material hydrocarbon spray nozzle, Patent Document 1 uses a nozzle made of a material that can withstand higher temperatures than the conventional one, and protects the nozzle with a cooling jacket so as to be conducted into the furnace. Thus, a technique for introducing the raw material hydrocarbon to a higher temperature part in the furnace is disclosed. However, the technique for improving the spray nozzle and spray method requires the development and maintenance of new materials and equipment, resulting in an increase in manufacturing cost.

  Next, as an attempt to improve the combustion efficiency of the raw material hydrocarbon in the carbon black reactor, it was introduced in Patent Document 2 into a high-temperature combustion gas stream by maintaining the inside of the furnace under a reduced pressure of 1 atm or less. A method is disclosed in which raw material hydrocarbons are quickly vaporized and flow into the production reaction zone in a more completely gasified state. However, this technique also requires a larger facility (equipment for performing suction and exhaust for maintaining the inside of the furnace under a reduced pressure of 1 atm or less) than the attempt of Patent Document 1. In the case of a large manufacturing furnace, it is obvious that a larger suction / exhaust device is required, resulting in an increase in manufacturing cost and a problem of the installation location of the large device.

  As a similar attempt, Patent Document 3 discloses that air to be introduced into a furnace is previously separated into oxygen-enriched air and nitrogen-enriched air, of which oxygen-enriched air is burned as a combustion oxidant for fuel hydrocarbons. A technique for increasing the combustion temperature by introducing it into the region is disclosed. This method touches on the control of the physical properties of carbon black with nitrogen-enriched air, and has some useful aspects, but it handles oxygen-enriched substances. There is a concern that there is a danger of this, it is not common.

  In addition, as a study of the raw material oil itself, Patent Document 4 discloses that a heavy oil fraction obtained by fractionating coal tar and a tar pitch which is a distillation residue have a quinoline insoluble content of 0.7 to 2.0% by weight. In addition, a method is disclosed in which a coke residue is blended and blended within a range of 15 to 40% by weight, or a raw material oil comprising this as a main component is used. Since this raw material oil has a high specific gravity and contains a large amount of an aromatic component, it has a technical effect that contributes to an improvement in the yield of carbon black. However, although the feedstock has an effect of improving the yield, there are problems such as high specific gravity and high viscosity for introduction into the reaction furnace. Furthermore, since the boiling point is as high as 180 ° C. or higher, there is a risk of burns during work.

  In addition, as an attempt to optimize the chemical reaction in the reaction furnace, Patent Document 5 discloses that a gas is used as a cooling medium and is introduced at right angles to the furnace axis in the reaction stop region in the carbon black reactor. Discloses a technique for enhancing the reaction stopping effect, and it is described that carbon black with a small particle diameter can be obtained in a high yield according to this technique. However, compared with water generally used as a cooling medium, other cooling mediums are considered to be costly in terms of maintenance and management, and are accompanied by a significant change in equipment.

JP-A-9-31357 JP 2004-161879 A JP-A-9-87542 Japanese Examined Patent Publication No. 3-48228 Japanese Patent Laid-Open No. 9-40882

  The present invention is a method for producing carbon black that can be easily switched from a general production method by using raw materials that are easy to handle, and that can improve the yield, without using new facilities such as the above-described prior art. The purpose is to provide.

The above problems are solved by the following inventions 1) to 2).
1) Using a carbon black production device comprising a high-temperature combustion gas generation zone, a reaction zone and a reaction stop zone, high-temperature combustion gas is generated by combustion of hydrocarbons in the high-temperature combustion gas generation zone, and then the high-temperature combustion at the upstream end of the reaction zone A raw material oil is spray-introduced into the gas stream to form a reaction gas stream containing carbon black by incomplete combustion or thermal decomposition reaction, and then a quenching medium is introduced into the reaction gas stream in the reaction stop zone. In the method for producing carbon black in which the reaction is terminated by quenching, a mixture of benzene (Bz) and linear unsaturated hydrocarbon (HC) is used as the raw material oil, and the mixing ratio is expressed as [introduced amount of HC]. X carbon number of HC] / [introduced amount of Bz x 6 (carbon number of benzene)] = 0.12 to 0.30 Manufacturing method.
2) The carbon black production method according to 1), wherein the linear unsaturated hydrocarbon has 2 to 6 carbon atoms.

  According to the present invention, it is possible to provide a method for producing carbon black that can be easily switched from a general production method and can improve the yield by using raw materials that are easy to handle without depending on the addition of new facilities.

The figure which shows an example of the manufacturing apparatus suitable for manufacturing the carbon black of this invention.

Hereinafter, the present invention will be described in detail.
The premise of the present invention is that a high temperature combustion gas generation zone, a reaction zone and a reaction stop zone are used to produce a high temperature combustion gas by combustion of hydrocarbons in the high temperature combustion gas generation zone, and then upstream of the reaction zone. At the end, the feedstock oil is sprayed into the high-temperature combustion gas stream to form a reaction gas stream containing carbon black by incomplete combustion or thermal decomposition reaction, and then a quenching refrigerant is introduced into the reaction gas stream in the reaction stop zone The method for producing carbon black, in which the reaction gas stream is rapidly quenched to terminate the reaction, is well known before the present application.

  The present invention is characterized in that, in the above-mentioned known technique, a mixture of benzene and a linear unsaturated hydrocarbon is used as a raw material for carbon black. The production of carbon black by combustion of hydrocarbons is generally due to the fact that carbon black nuclei are generated by the thermal decomposition of a part of the raw material hydrocarbons, and then the remaining raw material hydrocarbons cause a nuclear growth reaction. By using the raw materials specified in the invention, the nucleation rate of the carbon black nucleation stage in the carbon black reactor can be increased, and the yield is high while having the same carbon black physical properties, particularly the same particle diameter. This makes it possible to obtain carbon black.

The mixing ratio of benzene (Bz) and linear unsaturated hydrocarbon (HC) is [HC introduction amount × HC carbon number] / [Bz introduction amount × 6 (benzene carbon number)] = 0.12. ~ 0.30. Within this mixing ratio range, the balance between the amount of carbon black nuclei generated by the linear unsaturated hydrocarbon and the amount of benzene as the raw material for the subsequent growth reaction is good. Is performed in a well-balanced manner, and the yield of carbon black is improved. Here, the introduction amount is the total introduction amount of Bz or HC introduced into the production apparatus.
As the linear unsaturated hydrocarbon used in the present invention, those that generate radicals such as vinyl radical, acetylene radical, propargyl radical and the like are preferable. In view of availability, those having 2 to 6 carbon atoms are preferable. Practically preferred examples include acetylene, methyl acetylene, monovinyl acetylene, divinyl acetylene, diacetylene, triacetylene, ethylene, butadiene and the like.

The merit of using benzene is that it is easier to handle because it is liquid and lower in viscosity than conventional petroleum and coal-based fuels. Moreover, since it is an aromatic hydrocarbon, it has the characteristic of becoming carbon black easily in the growth reaction of carbon black. Further, since it is widely used as a raw material for plastics, resins, adhesives, etc., there is an advantage that it is easily available.
On the other hand, linear unsaturated hydrocarbons such as acetylene, when used alone, are used as raw materials for acetylene black by a partial combustion method in which a part is combusted with air and the rest is decomposed by the heat. Carbon black has different product properties, is difficult to use in a wide range of industrial applications, and the yield is unfavorable. However, when used in combination with benzene, it functions as a nucleus in the carbon black generation reaction, and carbon black can be obtained in a high yield coupled with the subsequent growth reaction by benzene.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited by these Examples.

Examples 1-20, Comparative Examples 1-15
Carbon black was manufactured using the apparatus shown in FIG.
Carbon black was produced by using benzene as the main raw material (introducing raw material 1) and linear unsaturated hydrocarbon as the auxiliary raw material (introducing raw material 2), and changing the type and mixing ratio of the introducing raw material 2.
The apparatus is mainly composed of an alumina reaction tube 1 (inner diameter 16 mm), and in order to heat the inside of the reaction system to a predetermined temperature, in order to surround the reaction tube 1 in order from the upstream of the reaction flow, A reaction electric furnace 2 was arranged. An inlet 5 for the introduced raw material 1 was provided at the upstream end of the reaction furnace, and an inlet 6 for the introduced raw material 2 was provided immediately before the preheating electric furnace 3. Further, an introduction port 7 for nitrogen as a carrier was provided between the introduction port 5 and the introduction port 6. Further, a filter 4 for collecting the produced carbon black was provided at the downstream end of the reaction furnace, and a suction port 8 for sucking and discharging the gas after reaction was provided at the end.
The production procedure was as follows. First, nitrogen was introduced into the reaction tube 1 from the nitrogen inlet 7 to form a nitrogen atmosphere, and the preheating electric furnace 3 and the reaction electric furnace 2 were heated at 600 ° C. and 1400 ° C., respectively.
Next, the introduction raw material 1 and the introduction raw material 2 were introduced from the upstream end of the reaction tube 1 in the raw material types, introduction amounts, and mixing ratios shown in Tables 1 to 8. At that time, the total flow rate in the reaction system was 3 L / min, and the raw material introduction time was 30 min. In addition, the introduction raw material was introduced by adjusting the introduction concentration according to the mixing ratio in order to keep the total carbon supply amount constant in each condition. For example, in the case of Example 1, the number of carbon atoms of benzene and acetylene is 6 and 2, respectively. Therefore, benzene: 1.04 vol% × 6 = 6.24 vol%, acetylene: 0.4 vol% × 2 = 0. From 8 vol%, the total carbon supply amount was adjusted to 6.24 vol% + 0.8 vol% = 7.04 vol%.
While the reaction gas is discharged from the suction port 8, the reaction is performed for 1 hour from the start of the raw material introduction, and then the generated carbon black is collected from the filter 4 to measure the weight, and the raw material introduction amount is reduced to the introduced weight in terms of weight. The rate was calculated. The yield and primary particle size of the obtained carbon black are shown in Tables 1 to 8.
Further, (A) in the table is “introduced raw material 1 concentration (vol%) × 6 (carbon number of benzene)”, and (B) is “introduced raw material 2 concentration (vol%) × carbon number of introduced raw material 2”. Is. In claim 1, the ratio of the introduction amount of the linear unsaturated hydrocarbon (introduction raw material 2) and benzene (introduction raw material 1) is defined, but the introduction raw material 1 and the introduction raw material 2 have a constant concentration during the reaction time. Therefore, if a numerical value obtained by multiplying the respective raw material concentrations by the number of carbons is used, substantially the same ratio as the mixing ratio defined in claim 1 can be obtained. This mixing ratio is shown as “carbon ratio” in the table.

As can be seen from the above results, the yield of carbon black increased when benzene and linear unsaturated hydrocarbon were used within the range of the mixing ratio specified in the present invention.
On the other hand, in the case of a mixing ratio outside the specified range, when a linear saturated hydrocarbon was used, when only benzene was used, the yield was lower than in the examples.
Moreover, since the primary particle diameters of the examples are substantially the same, it has been found that the effects of the present invention can be obtained without depending on the physical properties of the carbon black.
If the present invention is applied, high productivity and high yield are expected in industrial production. In addition, since only the facility for introducing the linear unsaturated hydrocarbon raw material is added to the existing manufacturing facility, the facility cost can be reduced, and the installation area can be saved because the facility is compact.

DESCRIPTION OF SYMBOLS 1 Reaction tube 2 Electric furnace for reaction 3 Electric furnace for preheating 4 Filter for collection 5 Inlet of introduction raw material 1 6 Inlet of introduction raw material 2 7 Inlet of nitrogen 8 Suction inlet

Claims (2)

  Using a carbon black production apparatus comprising a high temperature combustion gas generation zone, a reaction zone and a reaction stop zone, high temperature combustion gas is generated by combustion of hydrocarbons in the high temperature combustion gas generation zone, and then the high temperature combustion gas flow at the upstream end of the reaction zone A raw material oil is sprayed into the reaction gas stream, and a reaction gas stream containing carbon black is formed by incomplete combustion or thermal decomposition reaction, and then a quenching refrigerant is introduced into the reaction gas stream in the reaction stop zone to quench the reaction gas stream. In the method for producing carbon black for terminating the reaction, a mixture of benzene (Bz) and linear unsaturated hydrocarbon (HC) is used as the raw material oil, and the mixing ratio is expressed as [HC introduction amount × HC Carbon number] / [Bz introduction amount × 6 (carbon number of benzene)] = 0.12 to 0.30 Method.   The carbon black production method according to claim 1, wherein the linear unsaturated hydrocarbon has 2 to 6 carbon atoms.