DE2404925A1 - METHOD OF MANUFACTURING SYNTHETIC BAKING COAL - Google Patents

Description

The invention "relates to a process for the production of
synthetic chopped coal and / or pitch by coking heavy hydrocarbons at a temperature above the temperature at which the cracking process begins.

There is a shortage of coal for the production of metallurgical coke, such as B. Blast furnace coke. This is why coke, which was produced by coking petroleum residue oil, is sometimes used as coal for the production of metallurgical coke. The conventional coke, which is produced by coking petroleum residual oil by the delayed coking process or the
Fluid coking process or the like. Can be produced, however, has only poor baking properties and low fluidity, which limits the miscibility of such a coke (green coke) and therefore this coke only serves as a carbon source with a low ash content. So far, no method is known with which a synthetic caking coal with excellent caking properties and with a high fluidity can be produced, which can serve as a starting material for the production of metallurgical coke such as blast furnace coke and which can be used from the residual oil
and thermally cracked oil can be produced.

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It is therefore the object of the present invention to provide a method for the production of synthetic baking coal and / or Pitch (binder pitch), which is used as the starting material for the Production of metallurgical coke such as blast furnace coke can be used to create.

According to the invention, this object is achieved in that the heavy hydrocarbons are pretreated by extraction and / or thermal cracking and / or catalytic cracking subjected to the aromaticity fa to a value of to increase at least 0.4 or that you can use a residual oil of the atmospheric distillation or a residual oil from vacuum distillation with thermally cracked tar of high aromaticity mixed to an increased aromaticity fa of at least 0.4 to achieve, after which the product of this pretreatment is coked,

where the aromaticity fa is defined by the following equation

f a =

G / H - \ (Ha / H) - I (Ho / H)

C / H

wherein

C / H is the ratio of carbon atoms to hydrogen atoms (measured by elemental analysis) means and where Ha / H is the ratio of the hydrogen atoms of the aliphatic Hydrocarbon groups in the α-position to the aromatic ring to the total hydrogen atoms (measured by NMRmLt higher Resolution) means and where

Ho / H means the ratio of the hydrogen atoms of the aliphatic hydrocarbon groups in the β-position or in positions further away from the aromatic ring to the total hydrogen atoms (measured by NMR with high resolution). The method was developed by JK Brown, WR Ladner, Fuel 39, ⁸ ? (1960).

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One can generally use heavy hydrocarbons, such as atmospheric Residual oil and / or vacuum residual oil from the pretreatment undergo. A metallurgical coke with high moisture or rigidity is obtained.

In conventional processes, the starting material is coked with or without admixture of the recycled oil. In conventional methods of making electrode coke, a heavy oil component in a cracked oil formed by the coking reaction is thermally cracked and recycled. However, no improvement in the baking properties of the raw coke obtained (green coke) is observed, although an improvement in the needle-like crystals is observed. In the process according to the invention, the residual oil is subjected to a pretreatment. Here the oil is extracted, thermally cracked or catalytically cracked or the like. This is done to increase the aromaticity fa to a value of more than 0.4 or at least 0.4. Alternatively, the residual oil can be mixed with thermally cracked tar, which has a high aromaticity, to bring the aromaticity to at least 0.4 or more than 0.4 and then the mixture is coked with a synthetic caking coal being improved baking properties is achieved ".

According to the invention, the aromaticity fa can be increased by various conventional methods, such as, for. B. by extraction, thermal cracking or catalytic cracking or the like. Solvents can be used during the extraction which selectively extract those hydrocarbons that have a high proportion of aliphatic hydrocarbons such as light hydrocarbons such as propane, butane, pentane, hexane or the like. In this case, that will The raffinate obtained during the extraction is used as the starting material for the production of the synthetic baking coal. On the other hand, however, one can also use those solvents which selectively those hydrocarbons extract, which contain a high proportion of aromatic carbon

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Have hydrogen, such as dimethyl sulfoxide, diethylene glycol, SuIfolan, methyl carbamate or the like. In this case the extracted material is used as raw material for the production of synthetic tacking charcoal.

Grazing to increase aromaticity is preferred carried out under such conditions that the polycondensation reaction of the cracked oil is low. The thermal cracking of the residual oil of vacuum distillation bottom product obtained from petroleum in the "visbreaking" process or The residual oil from thermal short-term cracking in a vacuum can be used as a starting material for the production of synthetic Baking charcoal serve according to the present invention. Performing the pretreatment increases the aromaticity. It is prefers to increase the aromaticity to more than 0.4 (fa). The baking properties of synthetic charcoal are the greater, the stronger the aromaticity (with lower Polycondensation reactin) is increased in the pretreatment.

It is also possible to produce a synthetic baking charcoal with good baking properties by Residue oil with about $ 10 to $ 90 thermally cracked tar mixed. The thermally cracked tar preferably has high molecular weight aromatic components and an aromaticity fa of 0.5 to 1.0. It is made by thermal cracking of oil, which is obtained from the coking of heavy hydrocarbons. Through this admixture the aromaticity fa of the mixture is increased. The mixture is then coked.

If a raw material with a high content of polycondensed aromatic ring compounds is used, the pretreatment for the production of the synthetic charcoal can be reduced. The aromaticity fa of a thermally cracked oil, which is obtained as a by-product of naphtha Grack method (fraction with a boiling point greater than 450 ⁰ C) is 0.75. When using a naphtha orrack tar

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pretreatment to increase the aromaticity can be omitted. On the other hand, the residual oil from the vacuum distillation of Kuwait petroleum has only a low content of polycondensed aromatic ring compounds and the aromaticity fa is 0.3. The pretreatment to increase the aromaticity fa to at least 0.4 or more than 0.4 gives good results. A heavy hydrocarbon from petroleum, such as, for. B. the residual oil which is obtained in the atmospheric distillation of petroleum or the residual oil which is obtained in the vacuum distillation or residual oil which is obtained in the thermal or catalytic cracking or the like. It can also all other heavy hydrocarbons, such as. B. natural asphalt, shale oil, coal tar, tar sand or the like. Can be used. The reaction temperature of carbonization is in the present invention preferably in the range of about 410-490 ⁰ C. The lower limit can be extended up to the temperature at which the cracking of the feedstock begins. The upper temperature limit is not critical. The temperature can be above 500 ⁰ G, although at a greatly increased coking temperature certain stream parts occur, such as. B. Coke deposit in the tubes. According to the invention, a synthetic baking charcoal is produced which has a high swelling index (free swelling index). This means better baking properties. In Example 2, the expansion index is 6 compared to the low expansion index of Comparative Example 1. The expansion index is measured in accordance with Japanese Industrial Standard M8801-1972 (ASTM D-720-67). The pluidity of the synthetic charcoal, which is obtained in the process according to the invention, is significantly higher than that of natural charcoal. According to Example 1, for. B. the softening temperature below 300 ⁰ O and the maximum fluidity is higher than 28,000 ddpm and the solidification temperature is 518 ⁰ G (measured according to ASTM D1812-69). When carrying out the method according to the invention, these advantages can generally be expected. The heavy oil produced during the pretreatment

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can be used for the production of lubricating oil fractions and also as a raw material for the desulfurization of gas oil.

example 1

A residual oil of vacuum distillation of Kuwait crude oil having a specific gravity of 1.0176 (at 25/25 ⁰ C); A softening point of 31 ⁰ G, a penetration of 315 (at 25 ⁰ G), a Conradson carbon value of 21.1 wt 100 mm and an inner diameter of 100 mm introduced in order ^{to extract hydrocarbons with 34 wt .- $ aliphatic components at 60 0} C and at a pressure of 30 kg / cm (nitrogen pressure) and at a ratio of butane to residual oil of the starting material of 10 .

The properties of the extracted oil are summarized in Table 1. 10 kg of the residual oil obtained with a specific weight of 1.0563 (at 25/25 ⁰ G), with a softening point of 60 ⁰ C, with a penetration of 15 (at 25 ⁰ C), with a Conradson carbon value of 29.6 wt. - ° ß> and with an fa value of 0.45 are placed in a 20 l reactor and
Coked at atmospheric pressure.

Given 20 1 reactor and for 3 h at 430 ⁰ C under

The yield of the obtained synthetic caking coal is 46 ° and the swelling index i (free swelling index) (Japanese Industrial Standard 8801-1972 M) of the synthetic-caking coal is 5 X and the volatiles (Japanese Industrial Standard 8812-1972 M) are 29.1 1 °.

When carrying out the iluidity test on the synthetic caking charcoal using a Gieseler plastometer (Japanese Industrial Standard M 8801-1972) it is shown that the synthetic caking charcoal has a softening point of below 300 ⁰ C and a maximum flowability of more than

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28,000 DDPM and a solidification temperature of 518 ⁰ C.

Furthermore, the box test (Japanese Industrial Standard M 8801-1972) is carried out on the synthetic baking charcoal. The drum index or drum strength (Japanese Industrial Standard K 2151-1972) is measured. Of the Coke obtained from a standard mixture shows a drum

30th
Index of D ~, - 93.1. If one part of the Japanese natural baking charcoal, which is contained at 15% by weight in the standard mixture, is replaced by synthetic baking charcoal (10% by weight)

30 is replaced, a drum index of D ^ ₁ - 92.9 is obtained.

The results are shown in Table 3.

Table 1 example 1

Extracted Oil Yield 34

Viscosity (cst: 98.9 ⁰ C) 47.80

specific gravity (25/25 ⁰ C) 0.9397

Example 2

10 kg of residual oil from the vacuum distillation of Kuwait petroleum are placed in the reactor according to Example 1 and ^{thermally cracked at 420 °} C. under a pressure of 50 mmHg absolute for 30 min for pretreatment, a residual oil with an fa value of 0.65 in a yield of 40 fo is obtained. The Riickstandsöl obtained with a high fa value (0.65) is added to the reactor and coked h at atmospheric pressure at 420 ⁰ C during the third The results are shown in Table 3.

Example 3

A residual oil from the vacuum distillation of Kuwait petroleum according to 'Example 1 is in a thermal cracking unit for continuous

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natural cracking at a capacity of 6 kg / h in order to carry out a "visbreaking" process. The product obtained is distilled, 71% of a fraction having a boiling point of more than 450 ^° C. and an fa value of 0.42 being obtained. 100 g of the fraction are introduced into a 200 ml reactor and coked h under atmospheric pressure at 420 G ⁰ during the fifth The results are shown in Table 3.

Example 4

A residual oil from the vacuum distillation of Kuwait petroleum according to Example 1 is sprayed into a catalytic Fluid Craek unit. In this unit the catalyst, which contains silicic acid or silicon oxide, is present in a fluidized bed. It is carried out a high-temperature cracking (600 ⁰ C, 0.5 see dwell time). The cracked oil obtained is distilled, a fraction with a boiling point of more than 450 ^° C. being obtained. The fa value is 0.53 and the Conradson Carbon value is $ 31.2 wt. 100 g of this fraction are introduced into a 200 ml reactor and coked h at 430 ⁰ C during the third The results are shown in Table 3.

Example 5

The residual oil from the vacuum distillation of Kuwait petroleum according to Example 1 is coked to give a thermally cracked oil. The thermally cracked oil is distilled, a fraction with a boiling point of more than 200 ^° C. being separated off. 3 l of the fraction are placed in a 5 l autoclave made of stainless steel and thermally ^{cracked at 500 °} C. for 1 h and under a pressure of 100 kg / cm. The properties of the oil obtained are shown in Table 2. 30 g of a thermally cracked tar with a boiling point of more than 350 ^° C. and an fa value of 0.72 (a fraction of the thermally cracked oil) is mixed with 70 g of the residual oil

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the vacuum distillation of Kuwait crude oil mixed .öle mixture is placed in a 300 ml stainless steel reactor and coked h under Atmosphärendruek at 430 ⁰ C during the third The results are summarized in table 3.

gabeile 2

Properties of the thermally cracked

Tar

Fraction with a boiling point of

more than 200 ⁰ C

specific gravity (15/4 ⁰ C) 1.0310 fraction

initial boiling point ( ⁰ G) 181

105 ⁽⁰ C) 258

30 $ C ° G) 352

$ 50 ⁽⁰ C) 391

Endpoint ( ⁰ Q) 400 f Analysis of the components

saturated component 11.7 ®ew. $ aromatic component 74.5 Sew. ^ Har zkoHiponent e 13.8

Matching example 1

100 g of residual oil from the Yakimim distillation of Kuwait — Petroleum according to Example 1 is placed in a 200 ml reactor, at 430 ° ö under atmospheric crack - during 4 & coked. the Results are shown in Table 3 ZEE.

Match example 2

Secraektes heavy oil, which is obtained as a Sebenprodtukt in Hiapiitlia cracking, is distilled bath the fraction with a boiling point of more than 425 ° G tin-a fa value of. 0.75

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is disconnected. 10og the fraction are placed in a 200 ml-Iieaktor and at 420 ⁰ C for 5 h under Atmosphärendruek carbonized. The results are shown in Table 3.

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Table of baking properties and other properties of synthetic "baking charcoal"

example 1 example *** 3 4th VJl Comparative example 2 · ** ■ * · * 1 2 Type of source material *** naphtha-
Crack
tar

Pre-treated product

Pretreatment Butane-
Extra
tion Vacuum-
Cracking 46 76 Vis-
brea-
king kataly
table
Cracking no no no I. Yield (boiling point:> 450 ° C.) wt. 5 < Ό 66 40 29.1 25.0 71 23 - 100 100 I. fa 0.45 0.65 5 1/2 6th 0.42 0.53 0.43 0.30 0.75 Coking conditions Temperature ( ⁰ C) 430 420 420 430 430 430 420 Pressure (mmHg) 760 760 760 760 760 760 760 Time (h) 3 3 5 3 3 4th 5 Properties of synthetic charcoal Yield ($) 44 37 33 30th 41.6 NJ volatile components (^) 27.1 30.1 24.8 20.6 38.0 O Swelling index 4th 5 5 0 6th 925

Continuation table

example 1 example ■ x-x-x- 3 4th VJl Comparative example 2 **** 1 2 Type of source material *** naphtha-
Crack tar

Fluidity test

Excalation temperature ( ⁰ C) below 320

300

maximum fluidity

temperature * ( ⁰ C) 431 458 maximum fluidity above

(ddpm) 28 000 11

Solidification ^{temperature (0} C) 518 503 Coke strength (D ^) * ♦ 92.9 93.3

under
300

428

below none below 300 expansion

435

above above above "
000 28 000 28 000

521

512

412

above 28

524

maximum flowability: The temperature specification is an estimated value if the
maximum flowability is above 28,000 ddpm.

Coke strength: The test is carried out with coke samples, which are in the box test
(JIS M 8801-1972). Part of the natural Japanese coking coal
(15% by weight in standard mixture) is replaced by synthetic coking coal
(10 wt .- # in the test mixture).

Residual oil from vacuum distillation of Kuwait petroleum

70% by weight? '«Residual oil from the vacuum distillation of Kuwait petroleum
30 wt .- $ thermally cracked tar.

Claims (5)

PATENT CLAIMS 1. Process for the production of synthetic "Baking coal or pitch by coking heavy hydrocarbons at a temperature above the temperature at which the graying begins, characterized in that a starting material with an aromaticity fa of more than 0.4 is coked,
where fa is defined by the equation below O / H - 1 (Ηα / Η) - \ (Ho / H) C / H where G / H is the ratio of carbon atoms to hydrogen atoms and that Ratio Ha / H the ratio of hydrogen atoms in aliphatic Indicates hydrocarbon groups in α-position to the aromatic ring to the total hydrogen atoms and where Ho / H is the ratio of the hydrogen atoms of the aliphatic Hydrocarbon groups in the ß-position from the aromatic ring or in one further away from the aromatic ring Indicates position to the total hydrogen atoms. 2. The method according to claim 1, characterized in that that a starting material with a fa value of more than 0.4 is used, which is obtained by extraction of a Residual oil with a solvent consisting of light Hydrocarbons, to remove the hydrocarbons with a high content of aliphatic! Hydrocarbon content was produced. 3. The method according to claim 1, characterized in that that a starting material with a fa value of more than 0.4 is used, which is obtained by extraction of Residual oil with a solvent which is hydrocarbon 409832/0858 extracted substances with a high aromatic hydrocarbon content. 4. The method according to claim 1, characterized in that a starting material with an fa value of more than 0.4 is used, which is caused by, thermal Cracking or by catalytic cracking. 5. "The method according to claim 1, characterized in that that a starting material with an fa value of more than 0.4 is used, which is obtained by mixing a residual oil and a thermally cracked tar with a high aromatic hydrocarbon content and a fa value of 0.5 Ms 1.0. 409832/0858