DE2113425C3 - Process for the production of furnace carbon black - Google Patents

Description

. to create the desired particle fineness of carbon blacks during production in the furnace process.

It has now surprisingly been found that

te T determined using the iodine adsorption method

fineness _of carbon blacks to methane and acetylene

stop of the exhaust gas leaving the furnace reactor

is inversely proportional.

The invention accordingly relates to a method for

Production of furnace carbon black under ongoing quan-

tcative ultrared spectroscopic analysis of the

ases from the reactor to the components methane

* di or acetylene and analysis-dependent quantity

clung from the operating system flowing into the reactor

«Open, which is characterized by the fact that one

m Keeping constant through iodine adsorption

characterized the particle fineness of the soot the amount • At least one of the fuel gas and soot-

hS inversely proportional to the methane resp.

Arptvlenrneß size or the amount of combustion

CfT directly proportional to the methane or acetylene

Set a desired one to remain constant

STorotion value regulates.

_Z ^J taf? 3ysierende exhaust gas before the introduction of i "that the infrared measuring device carefully soot and freed the Ultrarotanalysator of Meßwerden to the respective gases to be analyzed SW concentration" set. En She prefers in voreingeste.hen intervals matically calibrated and corrected, thus vcr-S can mean that with a preset

done by red spectroscopy. The method presented in this patent specification therefore serves one purpose other than the procedure according to the invention. Furthermore, from DT-OS 15 92 954 (or the one with FR-PS 15 22 141), which is identical in content, describes a process for the production of soot by partially \ vomiting of a carbonaceous material in a partial combustion zone is known, according to which for the calculation of the surface size of the product the carbon monoxide content of the effluent this zone by means of a chromatographic analyzer and the ratio of oxygen to the carbonaceous material that is in the oie zone is given, depending on the carbon monoxide content to be regulated. .

Apart from the fact that in our own tests carried out on a large-scale technical scale, a regulation based on the CO content of the exhaust gas has proven to be less precise and reliable, and the claimed regulation over methane and acetylene, the last-mentioned uterus levels with regard to the relation between the amount of Exhaust gas componentc and the soot surface do not justify reliable statements because the course of t and surface, as it is shown in the IaDeIIe on p. 9 _fe e / .e fet, contradicts the statement of M g. 3 stands above DT-OS 15 92 954. While namljch according to FIG. 3, a high CO content au ^ "^^ area corresponds, it is feer in the table Auts ^. ae vice versa From this it follows that ν, “d DT OS

Transfer values of furnace carbon blacks even in the finest samples.

Writing 34 71 260 the thermal conductivity of a soot reactor exhaust gas as a measure of its hydrogen content _for controlling the iodine adsorption of the soot is shown, however, that the wirmelitktivkeic or the hydrogen content is not a measurable variable that can be used for process control, because even with reactor settings, at which result in soot with very different iodine adsorption (changes of, for example, 15 mg / g), no significant changes in heat

conductivity occur

^ 5

explained.

Example 1 ^ ^^ of _{the fine-grained FurnilC} e-soot

was used with the following amounts in a RuB reactor known type.

oil quantity 59 » ¹ J ¹

Atomizing air volume '^ ^ ⁿ \

Combustion _air. · 2.UUNm .11

Aqueous additive solution to the oil

added ..L

Refined gas quantity ι

Temperatures are, however, as already explained above, precisely the disturbance variables that occur most frequently in operational terms.

GB-PS 8 06 092 describes a process for the production of carbon blacks with gle.chble.bendem, colonimetrically determined extract content, with the _{deteriorating and} the air temperature

. «J ^ Je Rub

The effect of rain on open-air systems will result from _{the dcr} jemperatu

^ ^^^ _'L thus runs to a disturbance d .. the v ° rgewa _{«f) ju, n dcm Abg; iS}

ngsluft

Kohlw.ssers.oH

hiekeitsd ^ e (which was in dei ,, _s es, _t , U and _e «e, eM,

2. an ultra-red absorption device (which is selectively based on the following Table 1 and A b b. 1, the methane content is set and calibrated), changing the iodine adsorption and the combined gas

3. an ultraredabsorption device (which is selective for the setting when the combustion air temperature changes - acetylene content was set and calibrated). to be taken.

Tabel

Relationship between the gas composition and the iodine adsorption in the production of Fumace soot with variation of the combustion air temperature (CH ₄ and C ₂ H ₂ content above ultrared absorption, H ₂ content above

Thermal conductivity measured)

CH ₄ content

(Percent by volume) ... iodine adsorption (mg / g)

C ₂ H ₂ content

(Percent by volume) ... iodine adsorption (mg / g)

0.045 0.048 0.050 0.060 0.062 0.065 0.069 0.070 150 146 147 145 143 14? 140 139 149 139 148 0.031 0.032 0.033 0.034 0.037 0.038 0.039 153 152 150 146 143 140 139 148 149 140 147 139 14.90 14.98 15.00 15.10 150 149 147 143 147 140 140

0.071 139

H ₂ content

(Percent by volume) ... iodine adsorption (mg / g)

While the thermal conductivity and the hydrogen content on changes in the iodine adsorption of 15 mg / g do not react significantly at all, result from the ultrared absorption for the methane, Acetylene and carbon monoxide contents exact correlations between iodine adsorption and gas analysis.

Example 2

35

As described under Example 1, the amount or temperature of one of the starting materials was determined step by step e (, gas, oil, air) changed. The thermal conductivity of the gas discharging the soot was thereby determined tracked (hydrogen content) and the ultra-red absorption (adjusted to methane and acetylene content) also monitored.

The measured values obtained were matched with the iodine adsorption values of the carbon black produced at the same time related. In turn, finely divided furnace carbon black was produced. The setting data has been changed as follows:

Oil volume 656 to 605 l / h

oil temperature 207 to 22O ⁰ C

Refinery gas volume 95 to 125 Nm ³ / h

Combustion air volume ... 2150 to 2250 Nm ³ / h Combustion air temperature 420 to 47O ⁰ C

Only the amount of atomizing air was ^{kept constant at 150 Nm 3} / h. The results are in the following Tables 2, 3 and 4, and in A b b. 2 to reproduced

Tabel

Relationship between the measured hydrogen content and the iodine adsorption during furnace soot manufacture when various setting dates are changed (H ₂ measured via thermal conductivity)

Variation in the amount of oil

H ₂ (percent by volume)

Iodine adsorption (mg / g)

Variation of gas amount

H ₂ (percent by volume)

Iodine adsorption (mg / g)

Variation of the amount of combustion air

H _a (volume percentage)

Iodine adsorption (mg / g)

Variation of oil temperature

H ₂ (percent by volume)

Iodine adsorption (mg / g)

Variation of combustion air temperature

H ₂ (percent by volume)

Iodine adsorption (mg / g)

14.98 153

14.60 157

14.75 158

14.78 152

14.93 150

15.05 151

14.67 156

14.85 157

14.86 150

14.95 148 15.06 150

15.12 152

15.00 152

14.91 149

15.10 143

15.36 143

15.28 150

15.12 148

15.00 147

14.95 139

15.40 140

15.33 147

15.47 137

15.40 146

Tabel

Relationship between the measured methane content and the iodine adsorption during furnace soot production when various setting data change (CH ₄ measured via U R adsorption)

Variation in the amount of oil

CH ₄ (volume percentage)

Iodine adsorption (mg / g)

Variation of gas amount

CH ₄ (volume percentage)

Iodine adsorption (mg / g)

Variation of combustion air temperature

CH ₄ (volume percentage)

Iodine adsorption (mg / g)

Variation of the amount of combustion air

CH ₄ (volume percentage)

Iodine adsorption (mg / g)

Variation of oil temperature

CH ₄ (volume percentage)

Iodine adsorption (mg / g)

0.035 152

0.018 158

0.044 149

0.032 156

0.046 148

0.039 150

0.030 154

0.050 147

0.044 150

0.050 147 0.050
147

0.048
148

0.063
144

0.051
147

0.063
144

0.068 141

0.060 145

0.070 140

0.066 143

0.069 142

0.078 137

Tabel

Relationship between the measured acetylene content and the iodine adsorption during furnace carbon black production when various setting data are changed (CjH ₂ measured via UR analysis)

Variation in the amount of oil

C ₂ H ₂ (volume percent)

Iodine adsorption (mg / g)

Variation of gas amount

C ₂ H ₂ (volume percent)

Iodine adsorption (mg / g)

Variation of the amount of combustion air

C ₂ H ₂ (volume percent)

Iodine adsorption (mg / g)

Variation of oil temperature

C ₂ H ₂ (volume percent)

Iodine Adsorplion (mg / g)

Variation of combustion air temperature

C ₂ H ₂ (volume percent)

Iodine adsorption (mg / g)

0.033 150

0.024 157

0.023 158

0.031 150

0.031 150

0.035 148

0.028 153

0.026 155

0.035 146

0.034 146 0.038
140

0.032
150

0.029
150

0.037
143

0.037
142

0.042 136

0.035 146

0.034 144

0.042 139

0.039 138

0.036 142

It can be seen clearly and unambiguously that for the ultrared absorption corresponding to the methane and Acetylene content of the exhaust gas shows a clear connection between iodine adsorption and gas composition exists (A b b. 3, 4), that on the other hand for the thermal conductivity and the so measured Hydrogen content the correlation is by no means sufficient (A b b. 2). From this it can be seen that the thermal conductivity and the hydrogen content are not suitable for those that usually occur during operations Volume and temperature fluctuations to regulate constant iodine adsorption. Ultrared absorption detectors, calibrated for the methane and acetylene content, on the other hand, give the opportunity to timely changes in iodine adsorption to be discovered and adjusted again by hand or automatically.

Example 3

This example shows an arrangement that can be used particularly successfully. the Arrangement is in A b b. 5 shown. In the reactor (1) is preheated by heat exchange Air (3) introduced and reacted with the hydrocarbon feed oil (4) and gas (2). To At the end of the reaction, the mixture is quenched in a known manner with water (5). At the Oven exit or in front of the Abscheideanlagc is the

509 644/127

Exhaust gas withdrawn via a porous probe (6), the soot being retained. The exhaust is then freed of the initially vaporous water in several stages, namely it is only released through the cooler (7) and coarse separator (8), then passed through the filter (9) and the measuring gas cooler (10). After passage Another filter (II), the pump (12) and the Regulierrotameter (13), the gas is in the actual Ultrared analyzer (14) given. The analyzer is connected to the calibration device (17), which is shown in a calibration gas is applied to the analyzer at preset intervals and changes to the amplifier (15), changes in air pressure, etc. are automatically corrected. The gas concentration is indicated at (16) and reproduced in writing at (19). The gas analysis value works via the gas analysis controller (20) on the oil flow regulator (21). This oil flow regulator actuates the oil valve (22) and corrects it the total amount of oil flowing in such a way that the gas analysis is kept constant. It is only regulated a partial flow of the oil, while the main amount is kept constant by the valve (23). That Valve (22) is provided with a maximum and minimum contact. When the maximum amount is exceeded and when the minimum amount is not reached, the main valve (23) is actuated to control the control valve (22) again in the. Retrieve control range. The quantities of oil flowing are through the facilities (24 to 27) displayed, registered and totaled. The present controller is with the above Examples adjusted so that there are fluctuations in the exhaust gas composition determined by the analyzer and thus the soot quality automatically adjusts the quantity of one of the input materials (here Öi) takes place, so that gas composition and soot quality on the superior Setpoint can be corrected. The most important thing is that with this arrangement it is unimportant whether the fluctuations in the amount of gas, gas quality, of the air temperature or air volume or other reasons.

It is easy to see that the invention does not address the automatic correction of soot quality durth oil volume control is limited, but that in the same way by a bypass gas volume control or a bypass air volume control the desired success could be achieved. It is also easy to see that there is also a gas analysis display in place of the automatic control can occur, with the necessary adjustments being made to the quantities used by hand will.

Example 4

A finely divided furnace black was produced with the following setting conditions:

Combustion air volume 2200 Nm ³ / h

Combustion air temperature ... 470 ⁰ C

Atomizing air volume 150 Nm ³ / h

oil quantity 585 l / h

oil temperature 212 ° C

Refinery gas quantity 110 Nm ³ / h

The soot oil used has the following key figures:

Elemental analysis: weight percent

Carbon 92.39

Hydrogen 5.84

Nitrogen 0.72

Oxygen 1.42

Sulfur 0.69

Density in kg / 1

at 20'C 1.14

at 210 ^u C 1.00

Beginning of boiling 270 ° C

Distillation 10% at 310 ⁰ C

50% at 35O ^Ü C

Distillation residue 2.7%

Conradsontesl 1.5%

The refinery gas used shows the following mean analysis:

Hydrogen 4 percent by volume

Methane 95 percent by volume

Nitrogen 0.2 percent by volume

Acetylene, methane 0.2 percent by volume

Calorific value 9400 Kcal / Nm ³

Density 0.72

For a period of 2.5 days, the production of this carbon black ran in the usual manner that the Setting conditions were controlled according to the iodine adsorption values. The control exists in general in that, according to the soot test values obtained, the total amount of oil by small amounts (5 l / h) can be increased or decreased as required. For a period of another 2.5 days were on the other hand, the setting conditions are controlled in accordance with the gas analysis indicated by the ultrared analyzer. The ultrared analyzer was set to the methane content. The fluctuation range of iodine adsorption of the carbon black produced can be found in the following list:

Conventional driving style without gas analysis

38 iodine adsorption values

Mean value 150.4 mg / g

Standard deviation 3.01 mg / g

Driving style with gas analysis

39 iodine adsorption values

Mean value 150.9 mg / g

Standard deviation 1.71 mg / g

It can be clearly seen that the fluctuation range of iodine adsorption for the produced carbon black (marked by the standard deviation) has decreased to almost half if according to the invention is driven after the gas analysis.

Example 5

Under the same conditions as in Example 4, a furnace soot with an iodine adsorption setpoint was again produced of 150 mg / g. The monitored period was limited to 20 hours each in which 17 iodine adsorption values were determined.

20 hours were without gas analysis with an ultrared analyzer driven, 20 hours on the other hand with gas analysis by an ultra-red analyzer. The ultrared analyzer was adjusted to the methane content. The measured values are reported below:

Iodine adsorption with gas analysis hours without gas analysis (mg / g) (mg / g) 152.2 O 148.1 152.5 1 154.4 150.0 2 148.8 150.0 3 150.0 150.0 4th 150.0 5 152.5 148.9 7th 153.7 148.1 9 152.5 148.1 11th 154.9 - 12th 154.4 149.4 13th 151.2 149.4 14th 150.0 149.4 15th 148.8 149.4 16 148.8 149.4 17th 146.4 149.4 18th 148.8 149.4 19th 150.5 149.4 20th 154.4 149.7 Average 151.1 1.11 Standard deviation 2.63 Number of iodine 17th adsorption value c 17th

The effectiveness of the standard deviation obtained for the two test sections is determined by the Clearly recognizable method of operation according to the invention. The mean spread is when working without Gas analysis more than twice as large as when working with gas analysis. An additional optical Demonstration of the values is given in Fig. 6.

According to the examples given above, by continuously monitoring the composition of the waste control and control of the soot quality are carried out in soot reactors. The seamless one Continuous registration directly at the production site of the soot is common, no matter how frequent Consider soot test. Tracking the concentration of Methane, acetylene or carbon monoxide and several of these gases in combination.

Another advantage of continuous gas analysis and the automatic control of one of the Input materials through gas analysis should still be listed. Short-term changes to the furnace equipment are usually very difficult to find. Pulsating constipation in the oil breakdown facilities, short-term build-up and breakdown of layers of coke, irregular Quenching water atomization, deposits of soot in the furnace chamber, changes caused by flaking wall components etc. can be observed immediately with the claimed device. This allows an immediate cessation of disruptive changes in the furnace, while otherwise the furnace is up to complete coking or even to the destruction of the furnace wall is continued without the changes that have occurred are noticed.

In addition 5 sheets of drawings

Claims (2)

1 2 air and the sum of fuel gas and Rußrohsloff Patent claims: decreases the particle fineness and the iodine adsorption number of the produced soot. 1. Process for the production of furnace carbon black In the commercial production of carbon black, it is important, with ongoing quantitative ultrared spectroscopy, to lead carbon blacks of a specific, possibly scopical analysis of the exhaust gas from the reactor, constant particle fineness and thus the same components as methane and / or acetylene bender I odadsorptionszahi to produce. For this and analysis dependent quantity control of the bottom is in the Rußherstellern a substantial reactor incoming supplies, characterized effort for consistent dosing of the Begekennzeichnet in that the _constant-10 operating materials of the driven by the iodine adsorption-characterized raw material, fuel gas, combustion air and Rußhalten. the particle fineness of the soot minimizes the amount, but in practice it cannot be avoided At least one of the fuels fuel gas and raw soot means that there are constant fluctuations in the quality of the soot substance inversely proportional to methane or occur. The reasons for this are, for example, in Acetylenmeßgröße or the quantity of encryption ₁₅ changes in temperature and humidity combustion air directly proportional to the methane intake for the process, or acetylene measured variable to keep one constant. But other factors can also interfere. So can- the desired iodine adsorption value. due to the slightest deposits on the dust covers 2. The method according to claim 1, characterized in that the ultrared devices automatically calibrated and corrected for the fuel gas, combustion air and soot raw materials in preset ₂₀ substance-quantity measurements, and changes in the measured values intervals and thus the entered quantities occur. Also, changes to the quantity of a substance are effected and the small auxiliary flow of operating substance becomes effective when fluctuations in the temperature of the main carbon black fuel flow are preset. Mostly to improve the economic 25 speed, the combustion air intended for the process is preheated in tube exchangers. Within this The soot-containing gas runs in countercurrent and pipes cools down in the process. Soot deposits often form on the heat exchanger tubes, what 30 reduces the heat transfer due to the insulating effect of the soot. As a result, one obtains The invention relates to a method for producing a change in the temperature of the preheated Treatment of furnace soot under running quantitative air, even if the sucked in ultrared spectroscopic analysis of the exhaust gas from cold air has a constant temperature. Similar the reactor on the components methane and / or 3 .; Effects can also be caused by rain or acetylene at night and analysis-dependent volume control cooling and similar influences occur; particularly supplies flowing from the reactor. Outdoor systems can be affected. Most of today's soot requirement is ultimately the evenness of the by manufacturing according to the furnace soot process, the chemical and physical composition of the covered. This is characterized by the fact that operating materials to be used in 40 are critical. So must closed, brick-lined furnaces, fuel gas, often Raflinerie combustion air in the manufacture of furnace soot and Kubrohstoff in suitable feed gas can be used as fuel gas. This gas points quantities with excess air caused to react both in its calorific value and in its utilization, that the desired soot quality is produced. The need for combustion air is noticeable from time to time The most important contribution to the resulting 4.5 fluctuations. Soot carbon is produced by the injected soot for the reasons described above raw material, which normally an oil with high sources of interference, Represents aromatic content. The soot falls as a result of which undesirable fluctuations in the iodine suspension in a still flammable exhaust gas. adsorption numbers of the soot produced result. Typical furnace rub exhaust gases contain water as well as water Steam still nitrogen, hydrogen, carbon monoxide, time the iodine adsorption of the produced soot in the Carbon dioxide, methane and acetylene. To be determined in the laboratory and As the main characteristic of the fineness of a soot, any deviations are then corrections to the considered its surface size. To be carried out in the technical operating materials used. This measure use and in specifications, which require a lot of time between manufacturers, as a soot sample is delivered and consumers for the determination of fines from the production plant in a laboratory Coordinated the heat and surface area of the soot, examined it there and then determined it the iodine adsorption number of the soot has to be reported back to the system. introduced (ASTM D 1510-65, DIN draft 53582). In systems with high soot emissions, the Around a soot with a certain iodine adsorption number 60 but in the meantime already a large amount outside must be the relationship between the oxidation and the specification, i.e. unusable by means of (air or oxygen-containing gas) to the soot. The difficult to burn components (fuel gas and carbon black raw material) are even greater when starting up a furnace carbon black plant. To adjusted correctly. If the consumption is increased, production with the help of laboratory soot ratio between combustion air and the total of 65 examinations is correctly set, are often erroneous Fuel gas and soot raw material, the soot fineness increases considerable amounts of waste soot, and the iodine adsorption number of the soot; The invention is therefore based on the object Reduction of the ratio between combustion and a control process to keep it constant