JP4820186B2 - Method for producing coking binder - Google Patents

Description

  The present invention relates to a method for producing a coke caking additive used in coke coking coal to supplement the caking property of coke coking coal.

It is indispensable to use bituminous coal showing caking property called coking coal as coking coal used for coke production (hereinafter, this may be referred to as coking coal).
However, coke coking coal exhibiting such strong caking properties is more expensive because of limited resources compared to power coal.

For this reason, in order to make it possible to use coal with insufficient caking properties as raw coal, a technology for blending coal-based or petroleum-based pitches into raw coal as a caking additive to supplement caking properties is widely known. ing.
The former coal-based pitch is a coal tar pitch made from coal tar obtained by dry distillation of caking coal, and the latter petroleum-based pitch includes propane deasphalted asphalt (PDA), asphalt pitch (ASP), etc. It has been known.
Petroleum pitch generally has a high sulfur content, and it is said that coal pitch is superior to petroleum pitch from the viewpoint of the familiarity with coal from the viewpoint of chemical structural characteristics.
Various techniques of this kind have been proposed, and there is no limit to enumeration.

On the other hand, technology for producing caking materials using raw coals with low caking properties such as sub-bituminous coal and lignite with a low price and huge amount of resources (hereinafter sometimes referred to as non-caking coal) Has also been considered.
For example, there is a technology in which steam coal is hydrogenated at a temperature of 420 ° C. or higher and a high pressure of 70 atm or higher in the presence of an iron-based disposable catalyst, and an American SRC-I process is known as a representative example. (For example, refer to Patent Document 1 and Non-Patent Document 1).
JP 58-24301 Steel Handbook, Volume II Steelmaking and Steelmaking, published on December 25, 1982, p212

  However, since the SRC-I process is a reaction under high temperature and high pressure, the cost of the apparatus is high, and since the hydrocracking reaction proceeds to a high degree, liquefied oil and hydrocarbon gas such as methane are also produced as a by-product, There is a problem that the yield of the binder of the main product is limited to about 50%. In addition, there is a problem that the consumption of expensive hydrogen is large and the cost of the deashing process is high. For this reason, this method has not yet been commercialized.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a novel and suitable method for producing a coking binder for coke using raw coal having low caking properties as a raw material.

  The problems in the method for producing a coking binder from non-caking coal are summarized as follows: (1) reduction of production equipment costs, (2) reduction of hydrogen consumption used in the reaction, and (3) caking. It is three of material yield improvement. As a result of various studies on means for solving these problems at the same time, the present inventors have conceived that it can be achieved for the first time by a two-stage pyrolysis hydrogenation reaction using a hydrogenated heavy solvent, and completed the present invention. did.

In order to achieve the above object, the method for producing a coking binder according to the present invention includes a coking binder used in the coke raw coal in order to supplement the coking raw coal. In the manufacturing method of
The non-caking steaming coal is converted into a heavy component having caking properties through a two-stage hydrogenation reaction using a tubular reactor and a tank reactor in this order in the presence of a hydrogenated heavy solvent. Features.

  In the method for producing a caking binder according to the present invention, the reaction in the tubular reactor is performed at a temperature of 350 ° C. to 400 ° C., for a reaction time of 60 seconds to 300 seconds, and for the reaction in the tank reactor. It is characterized by being carried out at a temperature of 350 ° C. to 400 ° C. and a reaction time of 10 minutes to 60 minutes, respectively.

  Moreover, the manufacturing method of the caking additive for cokes which concerns on this invention is the said hydrogenated heavy solvent, Aromaticity index 0.5-0.6, the heavy oil whose boiling point is 220 to 540 degreeC, and the said for coke. A heavy fraction having a boiling point of 220 ° C. to 540 ° C. in coal tar generated when the caking material is blended with coking raw material coal and dry-distilled is used as a raw material, and hydrotreated to an aromaticity index of 0.5 or less. It is at least one of things.

  Moreover, the manufacturing method of the caking additive for cokes which concerns on this invention mix | blends the said hydrogenated heavy solvent 90 mass%-40 mass% with respect to the said non-caking general coal 10 mass%-60 mass%. It is characterized by being subjected to a reaction.

  Moreover, the manufacturing method of the caking additive for cokes which concerns on this invention adds 1 mass part or less of an iron-type catalyst with respect to 100 mass parts of the said non-caking hot coal, It is characterized by the above-mentioned.

  Moreover, the manufacturing method of the caking binder for coke which concerns on this invention sends coke oven gas to a tank reactor, and makes it react in hydrogen and a carbon monoxide atmosphere under the pressure of 0.5 MPa-1.5 MPa. It is characterized by.

In the method for producing a caking binder according to the present invention, a non-caking steaming coal is subjected to a two-stage hydrogenation reaction in the presence of a heavy hydrogenated solvent to obtain a heavy component that becomes a caking additive. The present invention provides a novel and suitable method for producing a coking binder for coke using raw coal having low cohesiveness as a raw material.
In addition, according to the method for producing a coking binder according to the present invention, the cost of the manufacturing apparatus is low, the manufacturing cost is low due to low consumption of hydrogen used in the reaction, and the binder yield. Is expensive.

  The method for producing the coking binder according to the present invention will be described below.

The method for producing a coking binder according to the present invention uses a non-caking coal as a raw material as a first stage for rapid heating and short-time reaction in a tubular reactor, and a long-term reaction in a tank reactor as a second stage. Is converted into a caking material which is a heavy component having caking properties by a two-stage pyrolysis hydrogenation reaction.
Thereby, since it can be set as a mild reaction temperature, the excessive decomposition | disassembly of non-caking coal is suppressed, and the production | generation of liquefied oil and hydrocarbon gas hardly arises. For this reason, expensive hydrogen consumption is suppressed to 1 part by mass or less per 100 parts by mass of non-caking hot coal.
Due to the above action mechanism, most of the by-products are carbon dioxide gas and water, so the yield of the binder is not only about 80%, but also the softening region and viscosity required as the performance of the binder. (Melting viscosity), hydrogen donating properties, dissolving power, carbonization yield, etc. All the functions such as the conventional ones are exhibited.

  The manufacturing method of the caking binder for coke according to the present invention will be described in more detail with reference to the schematic manufacturing process diagram shown in FIG.

The raw material non-caking coal is fed into the tubular reactor 10 while being mixed with a hydrogenated heavy solvent. At this time, the hydrogenated heavy solvent is 90% by mass to 40% by mass with respect to 10% by mass to 60% by mass of non-caking hot coal, and preferably 35% by mass to 45% by mass of non-caking hot coal. A pipe type containing about 60% by mass of a hydrogenated heavy solvent to about 40% by mass of non-caking hot coal, more preferably about 40% by mass of heavy hydrogenated solvent. Feed to reactor 10.
The hydrogenated heavy solvent used here is preferably a heavy oil having an aromaticity index of 0.5 to 0.6 and a boiling point of 220 ° C to 540 ° C. The heavy hydrogenated solvent is preferably a heavy fraction having a boiling point of 220 ° C. to 540 ° C. in the coal tar generated when coking caking material is mixed with coke raw coal and dry-distilled. Preferably, it may be hydrotreated to have an aromaticity index of 0.5 or less (coal tar heavy oil). Alternatively, the hydrogenated heavy solvent may be a mixture of these heavy oils.
Moreover, when 1 mass part or less of a fine powder disposable iron-type catalyst is added with respect to 100 mass parts of non-caking general coal, and it uses for reaction, hydrogenation reaction will advance more. Examples of the iron-based catalyst that can be used include inexpensive iron ore, pyrite (main component FeS ₂ ), hematite (main component Fe ₂ O ₃ ), limonite (main component FeOOH), and the like. Examples thereof include iron hydroxide (αFeOOH) and γ iron oxyhydroxide (γ-FeOOH).

The tubular reactor 10 is preferably rapidly heated under conditions of a temperature of 350 ° C. to 400 ° C., a reaction time of 60 seconds to 300 seconds, more preferably a temperature of about 380 to 400 ° C. and a reaction time of about 200 seconds.
The mixture leaving the tubular reactor 10 is a tank reactor 12, preferably a temperature of 350 ° C. to 400 ° C., a reaction time of 10 minutes to 60 minutes, more preferably a temperature of about 370 to 390 ° C., a reaction time of 30 minutes. It is heated to the thermal decomposition temperature of steaming coal under sufficient reaction conditions. Thereby, carbon dioxide gas and water are generated. The active hydrogen in the nascent stage from the hydrogenated heavy solvent reacts with the thermal decomposition fragment generated at this time, and a thermal decomposition hydrogenation reaction occurs.
At this time, in the case where an apparatus for producing a binder (range shown by a solid line in FIG. 1) is provided adjacent to the coke oven 14, the gas (COG) generated from the coke oven 14 is fed into the tank reactor 12 at a low pressure. By doing so, a hydrogen source can be obtained. In this case, it is preferable to react in a hydrogen and carbon monoxide atmosphere under a pressure of 0.5 MPa to 1.5 MPa.
The coal reactant obtained in the tank reactor 12 is continuously extracted, and carbon dioxide gas and water are fractionated by the flash drum 16.

The remaining column bottom oil of the flash drum 16 from which carbon dioxide gas and water have been fractionated is separated in the reduced pressure distillation column 18, for example, under reduced pressure heavy oil conditions at a column bottom temperature of 310 ° C to 350 ° C and a pressure of 5 kPa to 15 kPa. And the binder is extracted from the bottom of the vacuum distillation column 18.
The reduced-pressure heavy oil is sent to the solvent hydrogenation reaction tower 20, hydrogenated with hydrogen, and recycled as a hydrogenated heavy solvent.
In addition, when a caking additive manufacturing apparatus adjoins the coke oven 14, hydrogen in coke oven gas (COG) can be utilized for hydrogenation of a pressure-reduced heavy oil.

  The binder obtained in the vacuum distillation tower 18 has a boiling point range of 500 ° C. or higher in terms of normal pressure, a softening point of 150 ° C. or higher, and a property close to a hard pitch. For this reason, when a caking production apparatus is installed in a coke factory, the caking material from the vacuum distillation tower 18 can be added to coal in a hot molten state, thereby saving energy. However, in this case, an apparatus is required for kneading the binder and coal particles under heating so that the two become compatible. That is, after kneading with steaming coal in the kneader 22 without cooling and solidification, it is blended with charging coal in the mixer 24 and charged into the coke oven 14 to increase the use ratio of low-cost steaming coal and improve coke strength. There are effects such as. On the other hand, when the binder production apparatus and the coke factory are not adjacent, after the binder is cooled and solidified, it is transported to the coke factory, pulverized to an appropriate particle size, and passed through the kneader 22. Without mixing with general coal in the mixer 24, it is added to the charging coal to the coke oven 14. Thereby, the caking property filling effect can be enjoyed. That is, there are effects such as an increase in the use ratio of low-cost steam coal and an improvement in coke strength.

As described above, the caking material manufacturing apparatus can use a large amount of hydrogen generated from a coke plant, and therefore does not require a hydrogen generator. In addition, coal tar, which is a raw material for heavy hydrogenated solvents, generated at a coke plant can be used as it is.
In addition, when the caking plant is installed in the coke factory, the coke factory is fully equipped with existing coal handling facilities, and there is no need to install new equipment for unloading, transporting, and blending coal. There are many advantages.

  Reactions of Example 1 and Example 2 in which a binder was produced using Tanitoharum coal (Indonesia: subbituminous coal) as a raw material under two typical reaction conditions of 370 ° C. and 390 ° C. as the second stage reaction temperature Table 1 shows the conditions, and Table 2 shows the yield of the reaction product. In Table 2, “daf” means dry ash free (anhydrous ashless base).

When the second-stage reaction temperature in Example 1 is 370 ° C., the hydrogen consumption is higher than that in the case where the second-stage reaction temperature in Example 2 shown as a comparative example is 390 ° C. and the hydrogenation reaction proceeds. It can be seen that the progress of the decarbonation gas and the dehydration reaction is low, and as a result, the yield of the binder is higher.
Next, Table 3 shows the elemental analysis values of the tanitoharum charcoal used as a raw material and the produced binder. In addition, the obtained coal was added with 6% by mass of the binder to the coal, and the coal without addition of the binder for comparison was subjected to dry distillation in a test coke oven under predetermined conditions. Table 4 shows the drum strength index of the obtained coke. When the second stage reaction temperature of Example 1 is 370 ° C., the hydrogen content and the oxygen content are somewhat higher than when the second stage reaction temperature of Example 2 is 390 ° C., but the difference in coke strength is I can't see it.

It is the schematic of the manufacturing process of the caking additive for cokes of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tube type reactor 12 Tank type reactor 14 Coke oven 16 Flash drum 18 Vacuum distillation tower 20 Solvent hydrogenation reaction tower 22 Kneader 24 Mixer

Claims (6)

In the method for producing a coking binder used in the coke raw coal to supplement the caking property of the coke raw coal,
The non-caking steaming coal is converted into a heavy component having caking properties through a two-stage hydrogenation reaction using a tubular reactor and a tank reactor in this order in the presence of a hydrogenated heavy solvent. A method for producing a coking binder which is characterized.   The reaction in the tubular reactor is performed at a temperature of 350 ° C. to 400 ° C. for a reaction time of 60 seconds to 300 seconds, and the reaction in the tank reactor is performed at a temperature of 350 ° C. to 400 ° C. for a reaction time of 10 minutes to 60 minutes. The method for producing a caking binder according to claim 1, wherein the method is performed.   When the hydrogenated heavy solvent blends heavy oil having an aromaticity index of 0.5 to 0.6 and a boiling point of 220 ° C. to 540 ° C. and the coking caking material into coking raw coal and dry-distilled. A heavy fraction having a boiling point of 220 ° C to 540 ° C in the generated coal tar is used as a raw material and is at least one of those hydrotreated to an aromaticity index of 0.5 or less. The manufacturing method of the caking additive for cokes of 1.   2. The coking viscosity according to claim 1, wherein 90% by mass to 40% by mass of the heavy hydrogenated solvent is blended with respect to 10% by mass to 60% by mass of the non-caking steaming coal and used for the reaction. A method for manufacturing a binder.   The caking binder according to any one of claims 1 to 4, wherein 1 part by mass or less of an iron-based catalyst is added to 100 parts by mass of the non-caking coal, and used for the reaction. Manufacturing method. 6. The coke oven gas is fed into a tank reactor and reacted in a hydrogen and carbon monoxide atmosphere under a pressure of 0.5 MPa to 1.5 MPa. Manufacturing method for caking materials for coke.

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