DE2106912C2 - Device for the production of furnace black - Google Patents

Description

The present invention relates to an apparatus for producing furnace soot from a liquid hydrocarbon substance Starting material as well as liquid or vaporous fuels and containing oxygen Gases consisting of a combustion zone containing a burner with a perforated plate, behind which a distributor for the fuels is arranged, one following the combustion zone Injection zone with openings in the wall of the injection zone, the openings being used for insertion devices for the liquid starting material, a reaction zone adjoining the injection zone and a subsequent quenching zone.

In the production of furnace soot, a liquid starting material consisting of hydrocarbons, e.g. B. a petroleum tar, in a turbulent combustion gas, which was created by reacting a liquid fuel with an oxygen-containing gas, such as air. The mixture obtained is then passed into a soot-forming zone, where the starting hydrocarbon is converted into soot. The mixture flowing out of the villus forming the soot is then quenched. Finally, the soot is separated from the gases. Such procedures are detailed in US patents
No. 23 75 795, No. 25 90 660, Ϊ. r. 29 76 127, No. 30 09 784,

No. 30 09 787, No. 30 11 872, No. 31 03 148, No. 32 06 285,
No. 32 44 484, No. 33 07 911, No. 34 10 660, No. 34 60 911
described.

One of the technical difficulties in this process is the introduction of the liquid hydrocarbons used as the starting material into the combustion gases. Those skilled in the art know that the extraction of good furnace soot from oil largely depends on the starting material being distributed rapidly and in the form of uniform droplets in the combustion gas. Unfortunately, the physical and chemical properties of the hydrocarbons used as starting materials make it difficult to distribute them evenly and quickly in the combustion gas. For economic reasons, the raw material used to a large extent is the residue tars from the refining of petroleum. These tars are usually very viscous and consist of mixtures of alkyl hydrocarbons and aryl hydrocarbons with a wide boiling range. Because of their viscosity, such tars are very difficult to distribute evenly. Also, because of the wide boiling range of the ingredients, such tars cannot be easily vaporized. Some of the components of these tars have no fixed boiling points and decompose rather than that they evaporate when the tars warden heated above about 370 ⁰ C. Evaporation methods for simpler liquid mixtures cannot be used with these tars because certain constituents of them decompose before evaporation and lead to undesired coke formation in the device.

Attempts have also been made to improve the distribution of the starting materials mentioned reach. The heavy residue tars have often been preheated to temperatures at which a strong degradation does not take place in order to lower their viscosity and to make pumping and atomizing easier to enable. Various nozzles have also been used that are a particularly good shape for should have the respective procedure. With the help of these nozzles a full or hollow spray cone can be achieved will. Nevertheless, when using this method, difficulties arise due to clogging and coke formation in the devices and uneven introduction of the starting materials.

The US-PS 27 68 067 describes an apparatus for the production of carbon black, in which the to be distributed or to sprayed substances are sprayed directly into the combustion chamber. Again, the distribution is not Sj satisfactory.

% In NL-PS 67 17 709 is a method and a device for cross-flow mixing of a liquid

L · Raw material described with a stream of gaseous combustion products, especially for the production of soot.

Ig 65 in which a mixture of very hot, oxidizing gases with sufficient

i'j the energy and generated under sufficient pressure, this gas mixture due to its energy and his

|| Pressure at very high speed close to the speed of sound in the form of a stream with a transverse

fe! cut which only a small part of the cross section of the elongated, closed main reaction zone

and which is directed axially in the central part of this main reaction zone into the main reaction zone can flow and perpendicularly into the core of the hot combustion gases flowing at high speed shortly before entering the main reaction zone, a multitude of streams of the starting material to be decomposed from points around the periphery of the stream of hot combustion gases

The US-PS 28 51 337 describes an apparatus for the production of furnace soot from a liquid containing hydrocarbons Containing raw material as well as liquid or vaporous fuels and oxygen- ,, the gases, consisting of a combustion zone containing a burner with a perforated plate,

behind which a distributor for the fuels is arranged an injection zone adjoining the combustion zone with openings in the wall dm ' injection zone, the openings belonging to devices for introducing the liquid starting material, a reaction zone adjoining the injection zone and a subsequent quenching zone. In this device, too, the distribution of the starting materials is still unchanged

unsatisfactory.

The object of the present invention is to create a device that distributes the starting materials improved and to enable the evaporation of viscous liquids in the finest distribution, their Components have very different boiling points. This task is solved by a device at the one inlet in the area of the perforated plate for the oxygen-containing gas flow tangentially into the The combustion zone opens, as does each of the introduction devices for the liquid starting material on the one hand a distributor space and a perforated plate arranged in front of it in the direction of the injection zone and ; a combustion zone with an inlet arranged in the region of the plate for the formation of combustion gases

T has fuel and an oxygen-containing gas in the combustion zone and on the other hand a itself

■ U. adjoining the combustion zone entry zone with at least one opening for the introduction of the liquid

; ■; Gen starting material is provided and each entry zone has an opening into the injection zone

K device according to the invention enables the introduction of the starting materials in a more effective, simple and

| £ trouble-free type In particular, residue tars can be used as the starting material. With cer

The device according to the invention for the production of carbon black will produce exceptionally high yields of carbon black

ψ of the desired quality.

ii The drawings illustrate, for example, some embodiments of the invention. the

Fig. 1 shows, in longitudinal section, a device with which the production of carbon black is carried out

I *) can be. the

5k! F i g. 2 shows, on an enlarged scale, a section through the device for introducing the liquid

% Starting material in a device according to FIG. 1.

I? The F i g. 1 and 2 show how the raw material for the production of carbon black is distributed and / or evaporated.

P The figures show two insertion devices 1000 arranged opposite one another.

i | The mode of operation of only one device 1000 is explained for the sake of simplicity

, §) Insertion device 1000 has on the one hand a distribution space 80 and a in the direction of the injection

Perforated plate 60 arranged in front of it, and a combustion zone 10 with in the region of the plate

Ö 60 arranged inlet 160 for the formation of combustion gases from fuel and an oxygen containing

| j trending gas in the combustion zone 10. Lines 120 and 110 are to the manifold 80 and to

§ provided for combustion zone 10. In the combustion zone 10, the combustion of a liquid pulverulent

"Substance with; a gas containing oxygen instead. The gas flow is at the opening 90 for the starting material

§1 passed by. The opening 90 has a non-constricted entry zone through which the substantially

|| liquid hydrocarbon existing feedstock practically across the flow of combustion gases in

$} the entry zone 20 is introduced. The term "transverse direction" means that the liquid is in one

Il angle between about 45 ° and about 135 ° to the longitudinal axis of the entry zone 20 is introduced. Introducing

! | of the starting material at an angle between 45 ° and approximately 95 ° to the longitudinal axis of the entry zone 20

IÜ prefer ';. Instead of the single opening 90 shown, a plurality of such inlet openings can also be provided

|| The inlet zone 20 may be arranged around it, from which radially several contiguous streams of the liquid

Il hydrocarbons can enter the combustion gases from the periphery in the entry zone 20. if

fj the diameter of the entry zone 20 is greater than about 13 mm, it is advisable to

|| development and introduction of the starting materials to use several such openings.

|| The temperature and the flow rate of the combustion gases must be controlled so that they

If of the type ur «d the feed rate of the liquid to be distributed and / or evaporated, and

I ^ correspond to the dimensions of the device used.

Iy That the liquid starting materials in the form of one or more contiguous rays of the scope

;. · '; here in the Stroir. the introduction of combustion gases offers several advantages. Because the beam rope

^{1: are} coherent, no obstacles or baffles are required to prevent the starting materials from flowing into the combustion gases. This is particularly advantageous when the to be processed; Liquid is viscous or contains solids which contaminate the conventional spray nozzles previously used

i ¹ "- could.

: ';. Around the introduced coherent jet or jets of liquid raw material quickly and

It is important that the flow of combustion gases through the entry zone 20 be high Has speed.

Regardless of the number of coherent rays of the starting material introduced "; is it important, that these rays penetrate the stream of combustion gases so that they are before intimate mixing with the Combustion gases do not touch the walls of the device or only touch them impossibly. This condition is achieved, for example, by regulating the flow rate of the combustion gases where the Starting materials are introduced, by the shape and dimension of the device, by the shape and Number of openings for the introduction of the liquid through the amount of liquid introduced

the pressure used for this. These conditions can be carried out according to the knowledge of the person skilled in the art Regulation of one or more of the named variables can be changed. The introduction of contiguous Liquid jets of the feedstock into the combustion gases is likely to be one of the others direct function of the flow velocities and the kinetic energies of the combustion gases and the liquid raw materials. For example, the combustion in zones 10 according to FIGS. 1 and 2 can be used regulate by adding fuel or oxidizing agent. The shape of the device also has one essential for the flow velocity of the combustion gases. When passing the Combustion gases through a narrowed conduit, for example through the entry zones 20 of FIGS. 1 and 2, a considerable acceleration can be achieved. In this particular embodiment of the device

to are the contiguous jets of liquid through lines 100 in the entry zones 20 with a narrowed cross-section introduced where the flow velocity of the combustion gases from the combustion zones 10 reached its maximum. Under these conditions, the liquid starting material is inside distributed about 10 milliseconds after introduction into the stream of the combustion gas. Usually the The time required is considerably less and is less than about a millisecond. The very fast one

f> Distribution allows the use of liquid hydrocarbons that, such as heavy residue tars, would usually be changed or decomposed by the high temperatures.

It has also surprisingly been found that the yields of carbon black obtained using the Device according to the invention is produced, are considerably higher than in similar devices what other means of distribution are used. This increased yield helps improve the device to make it even more economical. Comparisons are made in the example below.

After the rapid distribution of the introduced liquid jets, a further distribution or evaporation of the liquid droplets takes place due to the heat of the combustion gases. These droplets are now surrounded by hot combustion gases, as a result of which their size decreases due to at least partial evaporation at the high temperatures. In order to achieve this, the combustion gases should have a heat content of at least 1 ^{x 10 joules / pc / cm 3} , preferably more than 50 x 10 joules / ^{pc. Cm 3} .

Molecular oxygen is preferably used as the oxidizing agent during combustion. One can use air or other gases with at least about 20 percent by volume molecular oxygen. To the To make better use of the device, and to be able to adapt the method better, one often uses Oxidizing agents with a higher content of molecular oxygen. The oxidizing gas therefore contains preferably at least about 50 volume percent molecular oxygen. Such oxygen-containing gases are Easily available nowadays, and typically contain 95 percent by volume molecular oxygen or more.

Easily combustible vapors or liquids or mixtures thereof can be used as the liquid fuel, for example hydrogen, carbon monoxide, methane, acetylene, alcohols, gasoline. As a rule, those fuels are to be preferred which, in particular hydrocarbons, have a high carbon content. For example, methane-rich natural gas or modified or enriched natural gases are excellent fuels, as are other hydrocarbon-rich gases such as petroleum gases, liquids, and by-products of refining hydrocarbons with two to about four or five carbon atoms in moieküi and heating oils. The heavier and more viscous tars and residual oils should only be used as fuel if pure oxygen or oxygen-rich gas mixtures are used as the oxidizing agent, and if these fuels are diluted or their viscosity is otherwise reduced in order to ensure complete combustion within the To reach the combustion zone.

The ratio of the amount of fuel and oxidizing agent to be added to the combustion zone 10 according to FIGS. 1 and 2 can be adjusted so that the oxidant is between about 50 and about 500 Contains percent of the amount of oxygen required for complete combustion of the fuel is. The oxidizing agent preferably contains between about 80 and about 350 percent of that amount of oxygen which is necessary for the complete combustion of the fuel with the formation of carbon dioxide. The temperature of the combustion can also be regulated d'jrch setting the ratio of fuel to oxygen, by regulating the rate of introduction of the fuel, or by additional Introducing minor amounts of an inert gas such as carbon dioxide or nitrogen into the combustion zone.

so when the oxidizing agent contains more oxygen than to completely burn the fuel is required, and if the liquid to be vaporized or atomized is combustible, for example a

is a hydrocarbon-containing oil or a tar, then this starting material reacts after being introduced into the Combustion gases with the remaining free oxygen.

If a distributed and / or vaporized hydrocarbon is to be converted into soot, it must be included brought into contact with a hot combustion gas and / or a gas stream containing oxygen will. This mixing takes place according to FIGS. 1 and 2, within the injection zone 350. If one uses an oxygen-containing gas stream, it does not need to be preheated. As a rule, however, one uses a hot stream of combustion gases. The combustion zone 200 therefore contains a burner. At this Combustion becomes a liquid fuel such as liquid methane through line 220 into manifold 230

If the fuel is a gas, it is preferably directed through the openings 260 of the perforated plate 250 led into the combustion zone 200. A gas stream containing oxygen, for example air, is passed through line 210 and inlet 240 are introduced into zone 200. To stabilize the combustion, the oxygen-containing gas stream is preferably introduced tangentially into the combustion zone 200, where it passes through Rotation stabilizes the combustion reaction

After the introduction of a stream from the combustion product and / or from the oxygen-containing Gas in the combustion zone 200, this flow is conducted through the injection zone 350. There, the liquid starting material consisting essentially of hydrocarbons across the openings 150 in the Gas flow introduced. This insertion in the transverse direction takes place at an angle of about 45 ° up to about

135 ° in each case in the downstream direction to the longitudinal axis of the injection zone 350. The starting material is distributed within the walls of the insertion device 1000. Although only one insertion device 1000 can be used, at least two such devices are preferably arranged so that they d ^; e Introduce starting materials at the same level in the scope of the combustion gases and / or the oxygen-containing gases in the injection / onc 350.

If combustion is allowed to take place in combustion zone 200, the proportions of fuel and oxygen-containing gas introduced into combustion zone 200 can be controlled so that there is between about 50 and about 500 percent required for complete combustion of the liquid fuel Oxygen are present. If the amount of oxygen is less than 100% of the stoichiometrically required amount, the combustion gas contains little or no molecular oxygen. These hot combustion gases are also used to convert the distributed raw material introduced into them. If the combustion is carried out in such a way that oxygen quantities of more than 100% of the stoichiometric quantities are used, the combustion gas contains free molecular oxygen which reacts with part of the atomized starting material. The oxygen concentration is preferably kept between about 80 and about 350% of that amount which is theoretically necessary for complete combustion of the liquid fuel. The temperature of the combustion can be regulated by regulating the ratio of fuel to oxygen, by the feed rate of the fuel or by additionally introducing appropriate amounts of inert gases such as carbon dioxide or nitrogen.

In order to obtain carbon black, it is also necessary that the hydrocarbon used as the starting material is in an environment with a temperature above approximately 1300 ° C., preferably above approximately 1650 ° C., in the zone which forms the carbon black. The total heat generated by the burns in the combustion zones 10 and 200 should generally be sufficient to heat the reaction mixture above about 1300 ° C. This is particularly important when the combustion gas does not contain any free molecular oxygen. When using excess oxygen in the combustion zone, it is often sufficient that the combustion gas has a temperature of less than! 300 ⁰ C. an increase in temperature is achieved by reacting part of the distributed starting material with the excess oxygen.

The reaction mixture in the injection zone 350 according to FIGS. 1 and 2 are therefore in such a state that soot can arise. For this, it is only necessary that a sufficient residence time is provided in the soot-forming zone in order to allow this to arise. The reaction mixture can be withdrawn from the lower end 410 of the injection zone 350 into a reaction zone 510. According to FIG. 1, the reaction chamber 450 is in open communication with the downstream end of the injection zone 350. The reaction zone 510 should generally contain no obstructions and be larger in cross-section than the downstream end 410 of the injection zone 350. The upstream end of the reaction zone 510 should have a cross-section several times, for example four times, larger than the downstream end 410 of the injection zone 350. The desired residence time for the formation of soot under the given operating conditions can therefore be controlled by a suitable choice of the length and cross-section of the reaction zone 510. The the exact residence time for each case naturally also depends on the particular reaction conditions and on the type of carbon black to be produced. In the case of the conventional process, a residence time of less than about 1 millisecond to several seconds, preferably from 1 to 100 milliseconds, is sufficient for most of the customary carbon blacks.

In order to stop soot formation, spray nozzles 610 are arranged at suitable locations in the quench zone 550 . In FIG. 1, two such spray nozzles 610 are shown. The liquid to be sprayed, usually water, is fed to these spray nozzles 610 through the lines 620. The formation of soot is interrupted by the quench, and the mixture exiting the quench zone 550 consists of a hot aerosol of soot suspended in the combustion gas. After leaving the zone 550, the aerosol is treated further in the usual way by further cooling and separating off the solid particles.

The reaction chamber 450 can be constructed from conventional refractories. However, it is preferable that the entire device for the production of carbon black consists of a substance with a high thermal conductivity, for example metal, and that cooling jackets 50, 290, 400, 500 and 600 are provided through which a suitable coolant such as Water can be circulated, for which purpose the inlet openings and outlet openings 130 and 140, 300 and 310,360 and 370,460 and 470,560 and 570 are used. The aforementioned cooling jackets are between the walls. 30 and 40, 2.70 and 280.380 and 390.480 and 490 as well as 580 and 590 .

example 1

In this example, an apparatus according to FIGS. 1 and 2 used. The main dimensions were the following:

Combustion zone 200

Internal diameter of the combustion zone 200 20.5 mm

Total length, measured from the center of the plate 250 1 22 cm

Length measured from the center of the inlet 240 9.4 cm

Injection zone 350

Inner diameter of the injection zone 350 20.5 mm

Total length from flange to flange i 52

Diameter of the opening 150 6.5 mm

Distance of the opening 150 from the downstream end 410 3.8 cm

Introducer 1000

Internal diameter of the combustion zone 10 9.5 mm

Diameter of the entry zone 20 6.5 mm

Total length from the plate 60 to the opening 150 6.6 cm

Length of entry zone 20 3.2 cm

Diameter of the opening 90 0.65 mm

Distance from opening 90 to opening 150 2.5 cm

Distance from the center of the plate 60 to the center of the inlet 160 1.3 cm

ίο reaction chamber 450

See Table I (2nd continuation).

Deterrent zone 550

Total length from flange to flange 15.2 cm

Distance of the spray nozzles 610 from the upstream flange 7.6 cm

The following Table I contains the variables of the apparatus of the invention and the process conditions for each attempt to produce carbon black, as well as the yields, surface areas and properties of the carbon blacks obtained. Experiments 14 and 15 do not correspond to the present invention and are only given for the purpose of comparison. In these experiments, the liquid starting material was introduced into the oxygen-containing gas stream in the injection zone 350 by means of the usual atomization processes. In Trials 14 and 15, the introducers 1000 were completely removed and replaced with conventional nozzles. If one compares the result of these tests, for example, with the results of tests 13 and 13, in which similar carbon blacks were produced, one can see what improvements the invention brings with it.

In all experiments, oxygen was used as the oxidizing agent, methane as the fuel and nitrogen as the inert Diluent used.

As a liquid starting material which was introduced through the openings 90, a residue tar was used from the catalytic cracking of a petroleum refinery, which has the following properties:

API gravity at 15.6 ° C (ASTM-D-287) -4.5

Specific gravity at 15.6 ^° C (ASTM-D-287) 1.092

Viscosity (SSU) at 54 ° C (ASTM-D-88) 516.2

Viscosity (SSU) at 99 ° C (ASTM-D-88) 61.4

Carbon content, weight percent 90.87

Hydrogen content, weight percent 7.4

Sulfur content, weight percent 1.98

In Table I is the yield of carbon black in percent, based on the amount of carbon introduced, expressed.

Table I.

Attempt no. Combustion zone 200 supplied amount ratio of Nitrogen as supplied amount oxygen Oxygen to Diluents fuel m ³ / pc. Fuel (° / c; m ³ / pc. mVSL 45.8 150 22.1 1 153 48.1 180 22.4 2 13.4 39.6 213 22.6 3 93 39.6 300 22.6 4th 6.6 31.7 160 22.6 5 9.9 39.6 148 22.6 6th 13.4 39.6 148 22.6 7th 13.4 39.6 148 22.6 8th 13.4 39.6 216 22.6 9 93 42.4 - 22.6 10 - 42.4 - 22.6 11th - 39.6 160 22.6 12th 12.4 39.6 213 22.6 13th 93 57.5 160 22.4 14th 17.7 56.6 155 22.4 15th 18.2

Table I (!. Continuation)

Amounts supplied to each of the infeed devices 1000

Attempt no. supplied amount Diameter length / ugcreported amount ratio of supplied amount of surface fuel (cm) oxygen Oxygen to liquid starting material mVg m ^y / h VAT. fuel (%) VAT. 1 2.4 9.3 190 4.05 2 4.2 5.1-30.4 8.5 100 4.05 121 3 8.5 5.1-30.4 17.0 100 4.81 124 4th 4.2 5.1-30.4 6.8 80 3.79 131 5 4.2 5.1-30.4 13.6 160 3.51 148 6th 4.2 5.1-30.4 17.0 200 4.42 156 7th 4.2 5.1- 60.8 17.0 200 3.82 3) 0 8th 4.2 5.1-60.8 17.0 200 4.53 428 9 8.5 7.6-60.8 17.0 100 4.70 124 ! 0 10.6 7.6-60.8 17.0 80 3.90 129 ti 12.5 5.1-15.2 19.8 80 5.24 137 12th 5.3 5.1-15.2 17.0 160 4.70 126 13th 8.5 5.1-30.4 17.0 100 4.70 178 14th 5.1-60.8 * 4.13 154 15th * 2.5-121.6 * * 3.62 162 Tabe.le 1 (2nd continuation) 5.1-60.8 161 Soot forming reaction zone 450 Try Ni Dwell time between the opening 150 and the spray nozzles 610 Milliseconds 1 2.6 2 2.6 3 2.7 4th 3.4 5 3.7 6th 5.5 7th 6.0 8th 12.8 9 12.9 10 2.2 11th 1.8 12th 2.6 13th 6.0 Properties of the end product 14th 2.5 Yield of carbon black 15th 5.0 % 30.5 28.9 25.4 28.0 28.5 36.6 26.2 48.8 46.2 36.1 39.2 51.2 47.2 44.0 39.5

The examples show that different carbon blacks,
can also produce those with very small particle sizes in unexpectedly high yields.

Instead of the starting material used, others can also consist essentially of hydrocarbons
existing fluids can be used to produce carbon black. Other combinations of oxygen-containing gases and liquid fuels can also be used.

The carbon blacks produced can be used for many purposes. This also includes the usual uses as Ve; Tonics, fillers, pigments, stabilizers against short-wave radiation in rubber, Plastics, paints, lacquers and printing inks.

The carbon blacks produced can also be post-treated in order to better adapt them to their intended use.
They can be shaped into pellets in the wet or dry state, for example, by treating them with
Ozone, air, oxidizing mineral acids partially oxidize, transform into graphite by heating, with steam
treat or grind.

For this purpose 2 sheets of drawings

Claims (1)

Claim: Device for the production of furnace soot from a liquid, hydrocarbon-containing starting material and liquid or vaporous fuels and gases containing oxygen, consisting of a combustion zone which contains a burner with a perforated plate, behind which a distributor for the fuels is arranged and an injection zone adjoining the combustion zone with openings in the wall of the injection zone, the "openings belonging to devices for introducing the liquid starting material, a reaction zone adjoining the injection zone and a subsequent quenching zone, characterized in that an inlet (240) in the area of the perforated ίο Plate (250) for the oxygen-containing gas stream opens tangentially into the combustion zone (200) , and each of the introduction devices (1000) for the liquid starting material on the one hand has a distribution space (80) and a perforated plate arranged in front of it in the direction of the injection zone (350) (60) and a combustion zone (t0) with an inlet (160) arranged in the region of the plate (60) for the formation of combustion gases from fuel and an oxygen-containing gas in the combustion zone (10) and, on the other hand, a connection to the combustion zone (10) adjoining entry zone (20) with at least one opening (90) for introducing the liquid starting material is provided and each entry zone (20) has an opening (150) into the injection zone (350).