DE2404925C3 - Process for the production of synthetic baking coal - Google Patents

Description

fa =

c7h

whereby

C / H indicates the ratio of the carbon atoms to the hydrogen atoms and the ratio Ho / H indicates the ratio of the hydrogen atoms in aliphatic hydrocarbon groups in «position to the aromatic ring to the total hydrogen atoms and where Ho / H is the ratio of the hydrogen atoms in the aliphatic hydrocarbon groups in ß - indicates position of the aromatic ring or in a position further away from the aromatic ring relative to the total hydrogen atoms

2. The method according to claim 1, characterized in that a starting material with a fa value greater than 0.4 is used, which is obtained by extracting a residual oil with a Solvent, consisting of light hydrocarbons, to remove the hydrocarbons with a high content of aliphatic hydrocarbons.

3. The method according to claim 1, characterized in that a starting material with a fa value of more than 0.4 is used, which is obtained by extracting residual oil with a Solvent containing hydrocarbons with a high aromatic hydrocarbon content extracted.

4. The method according to claim 1, characterized in that a starting material with a fa value of more than 0.4 is used, which by thermal cracking or by catalytic Cracking was made.

5. The method according to claim 1, characterized in that a starting material with a 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 to 1.0 was established.

Coal for making metallurgical coke. The conventional coke, which is produced by coking Petroleum residue oil through the delayed coking process or the fluid coking process or the like can be produced However, it has only poor baking properties and low fluidity, which makes it miscible of such a coke (green coke) is limited, and therefore this coke only serves as a carbon source with a low ash content so far it is not

ίο known method with which a synthetic baking Coal with excellent baking properties and great fluidity can be produced in, which as a starting material for the production of metallurgical coke, such as. B. Blast furnace coke can serve and

is which from the residual oil and thermally cracked oil can be produced.

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

This object is achieved in that the heavy hydrocarbons are a Undergoes pretreatment by extraction and / or thermal cracking and / or catalytic cracking to increase the aromaticity fa to a value of at least 0.4, or that a residual oil of the atmospheric distillation or a residual oil from vacuum distillation with thermally cracked tar high aromaticity mixed in order to achieve an increased aromaticity fa of at least 0.4, whereupon the product of this pretreatment is coked, where the aromaticity fa is given by the equation below is defined

The invention relates to a method for producing synthetic baking coal and / or pitch by coking of heavy hydrocarbons at a temperature above that temperature where the cracking process begins.

There is a shortage of coal for the production of metallurgical coke, such as B. Blast furnace coke. Therefore one uses partly coke, which was produced by coking petroleum residue oil, as

fa =

C / H- _T i

C / H

wherein

C / H means the ratio of carbon atoms to hydrogen atoms (measured by elemental analysis) and where H «/ H means the ratio of the hydrogen atoms of the aliphatic hydrocarbon groups in the aromatic ring to the total hydrogen atoms (measured by high-resolution NMR) 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 has been described by JK Brown, WR Ladner, Fuel 39, 87 (1960).

One can generally use heavy hydrocarbons, such as atmospheric residual oil and / or vacuum residual oil, subject to pre-treatment. A metallurgical coke with high strength or is obtained Stiffness

In conventional processes, the starting material is recycled with or without admixture Oil coked In conventional processes for the production of electrode coke, a heavy oil component is used thermally cracked in a cracked oil which is formed by the coking reaction and returned. However, no improvement in the baking properties of the product obtained is observed Raw coke (green coke), although an improvement in the needle-like crystals is observed. At the

In the process according to the invention, the residual oil is subjected to a pretreatment. This is where the oil extracted, thermally cracked or catalytically cracked. This is done to increase the aromaticity f a to a value greater than 0.4. Alternatively, the residual oil can be thermally cracked tar, which has a high aromaticity, can be mixed Bring the aromaticity to more than 0.4, and then the mixture is coked, with a synthetic one baking coal is achieved with improved baking properties.

In the extraction, solvents can be used which selectively extract those hydrocarbons which have a high proportion of aliphatic hydrocarbons, such as light hydrocarbons, l. B. propane, butane, pentane, hexane. In this case, the raffinate obtained during the extraction is used as the starting material for the production of synthetic baking coal.On the other hand, one can also use solvents that selectively extract those hydrocarbons that have a high proportion of aromatic hydrocarbons, such as dimethyl sulfoxide, diethylene glycol, tetramethylene sulfone or methyl carbamate In this case, the extracted material is used as a raw material for the manufacture of the synthetic baking charcoal

The cracking to increase the aromaticity is preferably carried out under such conditions in which the polycondensation reaction of the cracked oil is low Residual oil from vacuum distillation of petroleum in the visbreaking process of the bottoms product or the residual oil during thermal short-term cracking in a vacuum can be used as the starting material for the Serving production of the synthetic baking charcoal according to the invention. When performing the pretreatment, the aromaticity is increased to more than 0.4. The baking properties of synthetic charcoal are greater, the stronger the aromaticity (at low polycondensation reaction) is increased in the pretreatment.

It is also possible to use a synthetic charcoal with: produce good baking properties by using residual oil with about 10 to 90% thermally mixed with cracked tar. The thermally cracked tar preferably has aromatic components of high molecular weight and flavor; fa from 0.5 to 1.0. It is created 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 having 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 the cracking process gasoline (fraction with a boiling point greater than 450 ⁰ C), is 0.75. When a gasoline cracking tar is used, a 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 higher than 0.4 gives good results. as The starting material for the process according to the invention can be a heavy hydrocarbon from petroleum, such as B. the residual oil, which is obtained in the atmospheric distillation of petroleum or the Residual oil, which is obtained in vacuum distillation or residual oil, which is obtained from thermal or catalytic cracking is obtained. All other heavy hydrocarbons can also be used Materials such as natural asphalt, shale oil, coal tar or tar sand are used. The reaction temperature of carbonization is according to the invention is preferably in the range of 410-490 ⁰ C, the lower limit can be extended up to the temperature at which the Starting material cracking begins. The upper temperature limit is not critical. The temperature can be above 500 ^° C., although certain disadvantages occur at a greatly increased coking temperature, such as, for. B. Coke deposition in the tubes. Inventiveness a synthetic baking charcoal is made, which has a high expansion index. This means better baking properties. In the example 2 is the swelling index is 6 compared to the low swelling index of comparative example 1. The swelling index is measured according to Japanese Industrial Standard M8801-1972 (ASTM D-720-67). The fluidity of the synthetic baking coal, which is obtained in the process according to the invention, is significantly higher than that of natural charcoal. According to

Example 1 is e.g. B. the softening temperature below 300 ° C and the maximum fluidity is higher than 28,000 ddpm and the solidification temperature is 518 ° C (measured according to ASTM D1812-69). When carrying out the method according to the invention can

) 5 these advantages are generally expected. That at the Pre-treatment heavy oil can be used for the production of lubricating oil fractions and also as a starting material for the desulphurisation of gas oil.

example 1

A residual oil from the vacuum distillation of Kuwait petroleum with a specific weight of 1.0176 (at 25/25 ⁰ C); a softening point of 31 ° C, one

4 ¹ S penetration of 315 (at 25 ° C.), a Conradson coking residue of 21.1% by weight and an fa value of 0.30 is carried out in a countercurrent extractor with a length of 2100 mm and an internal diameter of 100 mm introduced to hydrocarbons

v) with 34% by weight of aliphatic components at 60 ° C and at a pressure of 30 kg / cm ² (nitrogen pressure) and with a ratio of butane to residual oil des

Extract starting material from 10. The properties of the extracted oil are in table

1 compiled. 10 kg of the residual oil obtained with a specific gravity of 1.0563 (at 25/25 ° C), with a softening point of 60 ° C with a penetration of 15 (at 25 ° C.), with a Conradson coking residue of 29.6

bo% by weight and with an fa value of 0.45 are in given a 20-1 reactor and coked for 3 h at 430 ° C under atmospheric pressure.

The yield of the synthetic charcoal obtained is 46% and the expansion index

b5 (Japanese Industrial Standard M 8801-1972) der synthetic baking charcoal is 5i and its volatile components (Japanese Industrial Standard M 8812 -1972) amount to 29.1%.

When performing the fluidity test on the synthetic baking charcoal using a Gieseler plastometer (Japanese Industrial Standard M 8801-1972) shows that the synthetic Baking charcoal has a softening point below 300 ° C and a maximum flowability of more than 28,000 ddpm and a solidification temperature of 518 ° C.

Furthermore, the box test (Japanese Industrial Standard M 8801 - 1972) with the synthetic baking Charcoal It is the drum index or drum strength (Japanese Industrial Standard K 2151 - 1972). The coke obtained from a standard blend shows a drum index from DJjJ 93.1. If you are a part of the Japanese baking natural charcoal, which is 15% by weight in the standard mixture, with synthetic Baking charcoal (10 wt .-%) replaced, so my Drum Index of Di§ 923- The results are in Table 3 compiled

Table 1 example 1

Extracted Oil Yield 34

Viscosity (cSt: 98.9 ° C) 47.80

Specific gravity (25/25 ° C) 0.9397

Example 2

10 kg of residual oil from the vacuum distillation of Kuwait petroleum are put into the reactor according to Example 1 given and at 420 ° C under a pressure of 50 mm Hg absolute for 30 min for pretreatment thermally cracked, a residual oil having an fa value of 0.65 being obtained in a yield of 40% will. The resulting residual oil with a high fa value (0.65) is added to the reactor and at 420 ° C coked for 3 h at atmospheric pressure. the The results are shown in Table 3.

Example 3

A residual oil from the vacuum distillation of Kuwait petroleum according to Example 1 is converted into a thermal Cracking unit for continuous cracking with a capacity of 6 kg / h given to a viscosity breaking process to be carried out. The product obtained is distilled, with one 71% of a fraction with has a boiling point of more than 450 ° C and an fa value of 0.42. 100 g of the fraction are in placed in a 200 ml reactor and kept at 420 ° C during Coked for 5 hours under atmospheric pressure. 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 cracking unit. In this unit, the catalyst, which contains silica or silicon dioxide, is in the fluidized bed. It is carried out a high-temperature cracking (600 ⁰ C, 0.5 see dwell time). The cracked oil obtained is distilled, whereby a fraction with a boiling point of more than 450 ° C is obtained. The fa value is 0.53 and the Conradson coking residue is 31.2% by weight. 100 g of this fraction are introduced into a 200 ml reactor and for 3 h at 430 ³ C coked The results are summarized in Table 3

Example 5

ίο The residual oil from the vacuum distillation of Kuwait petroleum according to Example 1 is coked with a thermally cracked oil being obtained. The thermally cracked oil is distilled, a fraction with a boiling point of more than 200 ^° C. being separated off.

31 of the fraction are placed in a 5-1 autoclave made of stainless steel and thermally ^{cracked at 500 ° C. for 1 hour and under a pressure of 100 kg / cm 2.} The properties of the oil obtained are summarized in Table 2. 30 g of a thermally cracked oil 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 from the vacuum distillation of Kuwait petroleum. The mixture is placed in a 300 ml reactor made of stainless steel and ^{coked at 430 °} C. for 3 hours under atmospheric pressure.

Table 2

Properties of the thermally cracked tar
Fraction with a boiling point higher than 200 ° C

Specific weight (15/4 ° C)
Boiling analysis

Onset of boiling ( ⁰ C)

10% (C.

30% (X)

50% C C)

End of boiling point ( ⁰ C)

Analysis of the components
saturated component
aromatic component
Resin component

1.0310

181
258
35?
391
400 t

ll, 7% by weight
74.5% by weight
13.8% by weight

Comparative example 1

100 g of residual oil from the vacuum distillation of Kuwait petroleum according to Example 1 is placed in a 200 ml reactor given and coked at 430 ° C under atmospheric pressure for 4 h. The results are in Table 3 compiled

Comparative example 2

Cracked heavy oil, which is a by-product of gasoline cracking, is distilled and the Fraction with a boiling point of more than 425 ° C. and units fa value of 0.75 is separated off. 100 g of the Fraction are placed in a 200 ml reactor and at 420 ° C for 5 hours under atmospheric pressure coked. The results are shown in Table 3.

7 8

Table 3

Baking properties and other properties of synthetic bridging charcoal

example 2 46 76 3 4th 5 Comparative example 2 1 Original painting 29.1 25.0 1 Type of ***) ***** Petrol- ***) crackleer Pre-treated product Vacuum- Viscose cataly no no Pretreatment butane crack activity table no extrak refraction Cracking tion 40 71 23 - 100 Yield (b.p .:> 150C ) 66 100 Wt% 0.65 0.42 0.53 0.43 0.75 fa 0.45 0.30 Coking conditions 420 420 430 430 420 Temperature ("C) 430 760 760 760 760 430 760 Pressure (mm Hg) 760 3 5 3 3 760 5 Time (h) 3 Properties of synthetic charcoal 4th Yield (%) 44 37 33 41.6 volatile constituents 27.1 " 30.1 24.8 30th 38.0 20.6

Swelling index 57 ₂ 6

Fluidity test

Softening temperature below 320 300

(O

maximum fluidity 431 temperature *) (C)

maximum fluidity above

(ddpm) 28,000

Solidifying temperature 518 (C)

Coke strength (£ $) **) 92.9

458

11000

503

93.3

308 below below no er- below

300 300 softening 300

432 428 435 same as 412

above above above like above

28,000 28,000 28,000 28,000

524 521 512 same as 524

*) Maximum flowability: The temperature is an estimated value if the maximum flowability is above

28,000 ddpm.

**) Coke resistance: The test is carried out with coke samples which were obtained in the box test (JIS M 8801 - 1972). Part of the natural Japanese coking coal (15% by weight in the standard mixture) is replaced by the synthetic coking coal (10% by weight 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% by weight thermally cracked tar.

Claims (1)

Patent claims: 1. A process for the production of synthetic baking coal or pitch by coking heavy hydrocarbons at a temperature above that temperature at which cracking 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