JP2582879B2 - Manufacturing method of furnace carbon black - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to carbon black, and more particularly to a furnace carbon black having a wide aggregate particle size distribution.

[Conventional technology]

Carbon black is produced by incomplete combustion of hydrocarbons such as petroleum, natural gas and other well-known materials at high temperatures. When separated from the reaction gas, the product is a fluffy carbon black powder.

In a typical furnace process for producing carbon black, a fuel and an oxidant, such as air, are reacted to provide a stream of hot combustion gases. The hydrocarbon feed is injected into the hot combustion gas stream, resulting in the formation of carbon black. The temperature of the carbon black containing the gas stream is then reduced by quenching by conventional means such as water spray. The carbon black is separated from the gas stream in which it was suspended, in a known manner such as a cyclone and a filter, then pelletized and dried.

Carbon black is added to a rubber compound to provide reinforcement to the rubber compound. Among the many properties of carbon black that are important to the rubber industry are the aggregate size distributions of carbon black. In the rubber industry, it has been found that for certain purposes, carbon black having a broad aggregate particle size distribution is highly desirable.

Therefore, an object of the present invention is to provide a ΔD50 of carbon black.
It is to provide a method for producing carbon black having a broader aggregate size distribution as measured by increasing values.

(Summary of the present invention)

The method of the present invention comprises a non-preatomized linear stream.
coherent stream, coherent stream without pre-atomization)
Alternatively, the liquid feedstock in the form of a pre-sprayed stream may be stepped in two separate locations [modula
r)] including injecting into the carbon black formation process. Some of the feed is at a point before the combustion gas stream reaches maximum velocity, and upstream of that point,
The fragmentation of carbon black caused by injecting the feedstock into the hot combustion gas stream before the point at which the maximum velocity is reached in the combustion gas stream is no longer observed, and the increase in DBP structure is no longer observed. Injected at the point where the width increase is achieved. The remainder of the feed is injected at the point where the combustion gas stream reaches a maximum velocity.

U.S. Patent Application Serial NO.
At 626,704, the crushed DBP structure of carbon black is charged with the liquid feed into the combustion gas stream at a point before reaching the maximum velocity of the combustion gas stream and before the point at which the maximum velocity of the combustion gas stream is obtained. Teaches that it can be increased by injection, but that the crushed DBP structure of carbon black produced by this method does not increase much as the distance between the feed injection points increases It is not suggested at all.

(Detailed description of the present invention)

Referring to FIG. 1, there is shown a furnace (1) which is an example of a furnace used for producing carbon black using the method of the present invention. The furnace (1) generally comprises four zones: a mixing chamber (3), a combustion zone (10), a transition zone (13) and a reaction zone (31).

The mixing chamber (3) is defined by the wall (4), the outside of the internal separator (9) and the upstream wall (6). A flame maintainer (11) is mounted inside the separator (9) at the upstream end of the separator. The combustion chamber (10) is defined by the inside of the separator (9), downstream of the flame maintainer (11), and at a downstream point (12).
Ends with A conduit (8) is inserted through the wall (6), through which fuel is introduced into the mixing chamber (3).
A conduit (5) is inserted through the side wall (4), through which the oxidant is introduced into the chamber (3). An internal probe (19) is inserted through conduit (8), through which the feedstock is located before the point at which the hot combustion gas stream reaches maximum velocity, and where the hot combustion The resulting carbon black is injected into the furnace where an increase in the CDBP structure of the resulting carbon black caused by injecting the feed into the hot combustion gas stream before the point at which the gas stream reaches maximum velocity is no longer observed. The injection probe (19)
An axially aligned probe, which may be liquid cooled and terminates in an end cap (27). The end cap (27) has a plurality of radially oriented holes (29) around its periphery. Downstream from the combustion chamber (10) is a transition zone (13), which is defined by walls (17). Around the wall (17), a plurality of substantially transversely oriented holes (21) are drilled around, through which the feedstock may be injected into the region (13).

Downstream from the transition zone (13) is a reaction zone (31), which is defined by walls (37). Region (31)
The length and cross section can be varied depending on the desired reaction conditions. In this example, the reaction zone (31) has an inner diameter of 36in. A quench tube (41) is inserted through the wall (37) into the reaction zone (31). Water is injected into the reaction zone (31) through the quench tube (41) to terminate the carbon black forming reaction.

Generally, the method of the present invention for producing carbon black having a broad agglomerate particle size distribution is performed as follows. Appropriate fuel is introduced into the mixing chamber of the furnace through a fuel conduit and a suitable oxidant such as air, oxygen, a mixture of air and oxygen, etc. is introduced through an oxidant conduit. Fuels suitable for reacting with the oxidant stream in the combustion chamber to generate hot combustion gases include hydrogen, carbon monoxide, methane, acetylene, alcohol, kerosene, and liquid carbon, whether gaseous, vaporous or liquid. Materials that can be easily burned, such as hydrogen fuel, are included.

Primary combustion here refers to the amount of oxygen in the first stage of the module process, which is theoretically necessary to completely burn the fuel present in the first stage of the process and form carbon dioxide and water. It is divided by the amount of the oxidizing agent, multiplied by 100 and converted to%. Primary combustion may be in the range of 100-5000%,
Preferred primary or first stage combustion may vary from about 120 to about 300%. In this way, a hot combustion gas stream is generated which flows at a high linear velocity. It has further been found that the pressure differential between the combustion chamber and the reaction chamber is desirably at least 1.0 psi, preferably about 1.5 psi to 10 psi. Under these conditions, a stream of gaseous combustion products having sufficient energy to convert the carbon black producing liquid hydrocarbon feedstock to the desired carbon black product is produced. The product combustion gas resulting from the combustion stage will have a temperature of at least about 2400 ° F., with the most preferred temperature being at least about 1649 ° C.
3000 ゜ F).

The hot combustion gases are propelled downstream and are discharged at a large linear velocity from the downstream end of the combustion chamber, the velocity of which is accelerated by sending the combustion gases into a small diameter enclosed transition region, which transition region is If desired, it may be tapered or tapered. At about the midpoint of the transition zone in the furnace, the combustion gas flow reaches a maximum velocity.

According to the process of the present invention, the liquid feed in an amount ranging from about 20% to about 80%, preferably from about 25% to about 75%, of the total amount of the required liquid hydrocarbon feed is provided by the non-atomized linear stream. Or the point at which the combustion gas stream reaches a maximum velocity, either outwardly or inwardly, substantially transversely from and around the combustion gas stream in the form of a pre-sprayed stream, preferably a non-atomized linear stream. Earlier and upstream, the increased fragmentation DBP structure caused by injecting a portion of the feed into the hot combustion gas stream before the point at which the combustion gas stream reaches maximum velocity Are no longer observed, thereby injecting where a wider aggregate particle size distribution is obtained. If the liquid feedstock is injected outwardly across the hot combustion gas stream before the stream reaches maximum velocity, the feedstock is preferably injected through a feedstock injection probe. At a point where the combustion gas stream reaches a maximum velocity, it ranges from about 20 to about 80% of the total hydrocarbon feed, preferably from about 25 to about 80% of the total feed.
The remaining amount of liquid hydrocarbon feed in the range of 75% is injected. In this regard, the liquid feed is substantially in the form of a plurality of non-atomized linear streams or pre-atomized streams, preferably in a non-atomized form, relative to the flow of the combustion gas stream into the hot combustion gas stream. The fuel gas is injected from the outer or inner periphery of the combustion gas flow in a direction crossing the radial direction. In a preferred embodiment of the method, the feedstock is directed radially relative to the flow of the combustion gas stream through a plurality of transversely directed holes in the wall of the transition zone of the furnace at the point where the combustion gas stream has reached a maximum velocity. And inwardly. Suitable here for use as the hydrocarbon feed are unsaturated hydrocarbons such as acetylene, olefins such as ethylene, propylene, butylene, aromatics such as benzene, toluene, xylene, certain saturated hydrocarbons and kerosene, There are vaporized hydrocarbons such as naphthalene, terpene, ethylene tar, aromatic cyclics and the like. With respect to injecting the feed at the defined locations as described above, the feed may be the same or different.

The amounts of feedstock, fuel and / or oxidizer used herein will be adjusted to provide a% total combustion in the range of about 15 to about 60%, preferably about 15 to about 40%. Total combustion refers to the total amount of oxidizer used in the carbon formation process divided by the amount of oxidizer required to completely burn the entire amount of fuel and feedstock present in that carbon formation process to produce carbon dioxide. , Multiplied by 100 and expressed as a percentage.

Prior to quenching the reaction, sufficient residence time is provided to allow the carbon black forming reaction to take place. One example of quenching is achieved by injecting water through a quench nozzle. However, there are many other methods known in the art to quench the carbon black formation process. The hot effluent gas containing the carbon black product in suspension is then subjected to the conventional steps of cooling, separating and collecting the carbon black. Separation of carbon black from the gas stream is easily accomplished by conventional means such as a precipitator, cyclone separator, bag filter, or a combination thereof.

It has been found that injecting the feedstock at two locations in accordance with the present invention produces a carbon black having a broad agglomerate particle size distribution.

The following test method is used to determine the analytical properties of the carbon black produced according to the present invention.

ASTM D-1510 Iodine adsorption number
Determined according to -81.

Coloring power The coloring power of the carbon black sample was determined according to ASTM D-3265-76.
Determine for industrial coloring carbon black according to a.

Dibutyl phthalate (DBP) absorption number The DBP absorption number of carbon black is determined according to ASTM D-2414-84. The reported results indicate that the carbon black is fluffy or pelletized.

Crushed DBP absorption number (CDBP)
Determined according to D-3493-84.

Aggregate particle size distribution (ΔD50) Aggregate particle size distribution of carbon black sample (ΔD50)
Is determined by the following method. A histogram of the Stokes diameter of aggregates of the carbon black sample versus the relative frequency of occurrence in a given sample is generated. As shown in FIG.
A line (B) is drawn from the peak (A) of the histogram to the X axis in parallel with the Y axis and ends at a point (C) on the X axis of the histogram. The midpoint (F) of the obtained line (B) is determined, and a line (G) is drawn through the midpoint (F) and parallel to the X axis. The line (G) intersects the distribution curve of the histogram at two points D and E. The absolute value of the difference between the two Stokes diameters at two points D and E of the carbon black particles is the ΔD50 value. The data used to draw the histogram is from Tyne, UK
Joy Sablel of And Wear (Toyce Loebl C
o.Ltd.) is used to determine this. The following procedure is a modification of the procedure described in the instruction manual for the Joyce Label Disc Centrifuge, document number DCF4,008, published February 1, 1985, the teaching of which is incorporated herein by reference. And used to determine data.

Procedure Weigh 10 mg of carbon black sample in a weighing container.
Three drops of a surfactant, manufactured and sold by Shell Chemical Company under the trade name NONIDET p-40, are added to the carbon black and the resulting mixture is stirred to produce a uniform paste. Add 50 cc of a solution of 20% anhydrous alcohol and 80% distilled water to the paste and add Heat Systems Ultrasonics, Farmingdale, NY.
nic Inc.) using a W385 type ultrasonic machine
Disperse by ultrasonic energy for 15 minutes.

Prior to the experiment, the following data was entered into a computer that records data from the disc centrifuge.

1) Specific gravity of carbon black, in this case 1.86g / cc
I took it.

2) The volume of the solution of carbon black dispersed in the above solution of water and ethanol, in this case 0.5 cc.

3) The volume of the rotating fluid, in this case 14 cc of water.

4) The viscosity of the rotating fluid, in this case 0.933 centipoise at 23 ° C.

5) The density of the rotating fluid, in this case 0.9975g / cc at 23 ° C
It is.

6) Disk speed, in this case 8,000 rpm.

7) Data sampling interval, in this case 1
Seconds.

While the disk centrifuge operates the stroboscope, 80
Operated at 00 rpm. 14 cc of distilled water is injected into the rotating disk as a rotating fluid. 0 turbidity level
And inject 1 cc of a solution consisting of 20% of absolute ethanol and 80% of distilled water as a buffer. The cut and thrust buttons on the disc centrifuge are then operated to create a smooth concentration gradient between the spinning liquid and the buffer, and the gradient is visually observed. When the gradient becomes smooth so that there is no distinguishable boundary between the two liquids, 0.5 cc of carbon black dispersed in aqueous ethanol solution is injected into the rotating disk and data collection begins immediately. If streamlines occur, stop the experiment. After injecting the carbon black dispersed in the aqueous ethanol solution, the disc is rotated for 20 minutes. Following the rotation for 20 minutes, the disk is stopped, the temperature of the rotating fluid is measured, and the average of the temperature of the rotating fluid measured at the beginning of the experiment and the temperature of the rotating fluid measured at the end of the experiment is obtained from the disc centrifuge. Into the computer that records the data. The data was analyzed according to the standard Stokes equation and represented as a histogram as shown in FIG.

EXAMPLES The method of the present invention for producing carbon black having a broad agglomerate particle size distribution will be more readily understood by reference to the following Example Procedures 1-3. Of course, many other aspects of the present invention will become apparent to one of ordinary skill in the art once the present invention has been fully disclosed. Thus, it will be appreciated that the following working procedures 1-3 are provided by way of example and should not be construed as limiting the scope of the invention.

The furnace illustrated in FIG. 1 illustrates the furnace used in each of the following execution procedures 1 to 3. In execution procedures 1 to 3, the same liquid hydrocarbon was used as fuel. Further implementation steps 1
In 3, liquid hydrocarbons different from those used as fuels were used throughout as feedstock.

Procedure 1 Using the furnace shown in FIG. 1, into the mixing chamber (3)
Air preheated at a temperature of 670 ° C. (1238 ° F.) was introduced at a rate of 3,933 Nm ³ / s (500 mscfh) and liquid hydrocarbon fuel at a rate of 900 / h (238 gallons / h). A stream of hot combustion gases of 154% primary combustion flowing downstream at a high linear velocity was generated. Potassium was added to the combustion gas in the form of an aqueous solution such that 84 ppm of potassium was added to the total amount of feedstock used.

Potassium is added to achieve a given level of structure of the carbon black. In the furnace carbon black process, the addition of potassium to the flow of the combustion gas usually reduces the structure of the carbon black produced by the process when other manufacturing conditions are kept relatively constant. The CDBP value of a carbon black is related to the structure of the carbon black. As the structure of the carbon black decreases, the CDBP value decreases. Therefore, if the amount of potassium added during the production of carbon black increases, the CD of the carbon black produced by the method increases.
The BP value decreases.

Next, 25% of the total feed was introduced in the form of a non-atomized linear liquid stream radially outward through the probe (19) into the hot combustion gas stream before the point at which the combustion gas stream reached maximum velocity. . The probe (19) has an outer diameter of 5.1 cm (2 in) and is vertically oriented at equal angular intervals around its circumference.
A 1/4 in NPT end cap (27) with two 1.78 mm (0.070 in) diameter holes was attached. In this procedure, the probe (19) was positioned such that the end cap (27) had the hole (21) 30 cm (11.8 im) upstream.

The remaining 75% of the feedstock is transferred in a non-atomized linear stream through the twelve holes (21) radially inward into the hot combustion gas stream, at the point where the combustion gas reaches maximum velocity, i. The injection was made at the midpoint of region (13). The transition area (13) is 27.9 cm (11
in) and an inner diameter of 31.5 cm (12.4 in).
Holes (21) oriented transversely, each 1.99mm
(0.078 in) diameter, wall of transition region (13) (17)
At equal angular intervals within a single plane. The entire feed was injected at a total rate of 5439 / hr (1437 gal / hr).

The method was performed to achieve a total combustion of 20.5%. The reaction chamber (31) had a diameter of 91 cm (36 in). The quench nozzle (41) was located about 2.45 m (10 ft) downstream from the hole (21). The analyzed properties of carbon black are reported in the table below.

Example 2 Carbon black was produced using the apparatus, feedstock and method of Example 1. However, the following points were different. The probe (19) has an end cap (27) with a transition region (13)
It was located 50 cm (19.7 in) upstream of the hole (21) and 123 ppm of potassium, based on the total amount of feed used, was added to the hot combustion gas stream in the form of an aqueous solution. The analyzed properties of the carbon black are reported in the table below.

Example 3 Carbon black was produced using the apparatus, feed and method of Example 1. However, the following points were different. The inner pipe (19) is arranged so that the end cap (27) is located 60 cm (23.6 in) upstream of the hole (21), and forms 123 ppm potassium in aqueous solution with respect to the total amount of feed used. At the hot combustion gas stream. The analyzed properties of the carbon black are reported in Table 1 below.

The data in Table 1 show that the process of the present invention results in the production of carbon black with increased ΔD50 values while maintaining substantially the same values for carbon black structure and surface area.

Table 1 shows the CDBP value and ΔD50 value of the produced carbon black, the amount of potassium added, and the separation distance between the injection points of the feedstock in the execution procedures 1 to 3. According to the method of the present invention, in the method of producing carbon black, increasing the separation distance between the feedstock injection points increases the aggregate particle size distribution (ΔD50 value) of the carbon black produced by this method. In particular, the increase in the separation distance between Implementation Procedure 1 and Implementation Procedure 2 (or Implementation Procedure 3) increased the ΔD50 value. In addition, the amount of increase in the separation distance between the execution procedure 2 and the execution procedure 3 also increased the ΔD50 value.

Increasing the separation distance (moving the initial introduction of the feedstock further upstream) also increases the CDBP value of the carbon black produced by the present method. Implementation procedure 2
Is greater than the separation distance used in implementation procedure 1.

In Runs 1-3, different amounts of potassium were added to achieve a certain level of structure of the carbon black. By doing so, the effect of the present invention is that the same amount of potassium is required in Runs 2 and 3 to achieve a certain level of structure of the carbon black, both of which exceed the amount required in Run 1 It is indirectly indicated by noting that The increased amount of potassium used in Runs 2 and 3 compared to the amount used in Run 1 increases the distance between feed injection points in the intervals of Run 1 In doing so, it shows that the structure is still growing. As the separation distance between the feed injection points is further increased, the constant amount of potassium used in Runs 2 and 3 increases the distance between the feed injection points in Runs 2 and 3 to increase the hotness. By injecting a portion of the feedstock before reaching maximum velocity into the combustion gas, CDBP
Indicates that it is no longer triggered.

Although the CDBP values of the carbon blacks produced in Runs 1-3 are approximately the same, the amount of potassium used in Run 2 is greater than the amount used in Run 1. This indicates that the CDBP value of the carbon black produced in Example 2 would have been greater than the carbon black produced in Example 1 without the addition of potassium. A similar comparison can be made between implementation procedure 1 and implementation procedure 3. Similarly, the separation distance used in the execution procedure 3 is larger than the separation distance used in the execution procedure 2. The amounts of potassium used in Runs 2 and 3 are the same, and the CDBP value of the carbon black prepared in Run 3 is approximately the same as the CDBP of the carbon black prepared in Run 2 but slightly larger. . Such results (especially that the change in separation distance only slightly increased the CDBP value) were used in Example 3
The location of the upstream feedstock injection may be as described in claim 1 by "injecting the feedstock into the hot combustion gas stream upstream of the point at which the combustion gas stream reaches maximum velocity. Generated carbon black CD caused
Where the increase in BP is no longer observed ".

Although the present invention has been described with respect to certain embodiments, it should be understood that many changes and modifications may be apparent to those skilled in the art without departing from the scope of the invention.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a typical carbon black production furnace used in the first to third embodiments of the present invention. FIG. 2 is a histogram showing a particle size distribution curve of a carbon black aggregate, illustrating ΔD50 of the aggregate particle size distribution of a carbon black sample. 3 ... mixing chamber, 10 ... combustion chamber, 11 ... flame maintainer, 13 ...
Transition region, 19 ... Probe, 27 ... End cap, 31 ...
… Reaction zone, 41… Quick cooling pipe (nozzle)

Claims (7)

(57) [Claims] 1. A liquid hydrocarbon feedstock comprising reacting a fuel with an oxidant to provide a stream of hot primary combustion gas having sufficient energy to convert a liquid hydrocarbon feedstock for producing carbon black to carbon black. Into the stream of gaseous combustion products in the form of a plurality of non-atomized linear or pre-atomized streams, from ambient, in a direction substantially transverse to the flow direction of the combustion gas stream. Once the gas stream has reached its maximum velocity, it is injected at a pressure sufficient to achieve the necessary permeability for proper shearing and mixing of the feedstock, cracking the feedstock and converting it to hydrocarbons. Thereafter, the carbon formation reaction is terminated by quenching, then cooled, separated and the resulting carbon black is recovered in a modular process for producing furnace carbon black in which the total amount of liquid hydrocarbon feed is reduced. , A sufficient amount to the combustion gas stream,
Injecting the feedstock into the hot combustion gas stream at a point prior to, and upstream of, the point at which the stream reaches its maximum velocity, but before the point at which the stream reaches its maximum velocity. Producing furnace carbon black, characterized by injecting where the increase in CDBP of the resulting carbon black caused by the process is no longer observed, thereby producing a carbon black having a wider aggregate particle size distribution. The above modular method. 2. An amount of about 20% to about 80% of the total amount of liquid feedstock into the combustion gas stream, before the point at which the combustion gas stream reaches maximum velocity, and upstream from that point. Injecting where the increase in CDBP of the product carbon black caused by injecting the feed into the hot combustion gas stream before the point at which the combustion gas stream reaches maximum velocity is no longer observed, The remainder is added when the combustion gas stream has reached a maximum velocity. The method of claim 1. 3. An amount of from about 25% to about 75% of the total amount of liquid feedstock into the combustion gas stream, before the point at which the combustion gas stream reaches maximum velocity, and upstream from that point. Injecting where the increase in CDBP of the product carbon black caused by injecting the feed into the hot combustion gas stream before the point at which the combustion gas stream reaches maximum velocity is no longer observed, The method according to claim 1, wherein the remainder is added when the combustion gas stream reaches a maximum velocity. 4. The method of claim 1, wherein the feed injected into the hot combustion gas stream at the point where the hot combustion gas stream has reached a maximum velocity is in the form of a non-atomized linear stream. . 5. Into the hot combustion gas stream, before the point at which the combustion gas stream reaches a maximum velocity, and upstream therefrom, the point at which the combustion gas stream reaches a maximum velocity. A liquid hydrocarbon feed injected into the hot combustion gas stream substantially where the increase in CDBP of the product carbon black caused by injecting the feed into the hot combustion gas stream is no longer observed. 2. The process of claim 1, wherein the feed is in the form of a non-atomized linear stream. 6. A hot combustion gas stream at a point before the point at which the combustion gas stream reaches a maximum velocity and upstream of the point at which the combustion gas stream reaches a maximum velocity. The liquid hydrocarbon feed injected before where no increase in the CDBP of the resulting carbon black caused by injection of the feedstock into the hot combustion gas stream previously is no longer observed, from the inner periphery of the hot combustion gas stream. 6. The method of claim 5, wherein the injection is to the outside. 7. A point prior to the point at which the combustion gas stream reaches a maximum velocity, and upstream thereof, into the hot combustion gas stream before the point at which the combustion gas stream reaches a maximum velocity. Where the increase in the CDBP of the resulting carbon black caused by injecting the feed is no longer observed, the liquid hydrocarbon feed is introduced into the combustion gas stream.
Injecting in the form of a non-atomizing linear flow substantially transversely from the inside periphery to the outside of the combustion gas stream, at the point where the combustion gas stream reaches a maximum velocity, the hot combustion flows into the combustion gas stream. The process of claim 1 wherein the liquid hydrocarbon feed is injected in a non-atomized linear stream in a direction substantially transversely from an outer periphery to an inner side of the gas stream.