JP4184713B2 - Method for increasing production of chemical products in coke oven - Google Patents

Description

【００２８】
【表２】

【００２９】
【発明の効果】
本発明は、高炉用コークス製造方法におけるＣＯＧやコールタール生産の自由度を拡大するとともに、低価格劣質炭の使用比率増大やコークス強度の向上などの効果を発揮する。また、石炭液化油の一部を化成品として利用する場合で石炭液化プラントを単独に建設し稼動させる場合は、専用の化成品工場を新設する必要があるが、コークス工場に隣接して併設することにより、コークス工場に付設されている化成品工場が利用できるばかりではなく、石炭の液化条件の緩和が可能になることにより、石炭液化プラントの建設費やランニングコストの削減に寄与し、石炭液化の実用化を高めるものである。
【図面の簡単な説明】
【図１】本発明による石炭液化油から輸送用燃料と化成品を製造する概略の全体製造フローシートである。
【符号の説明】
１ 石炭
２ 液化油由来の重質分（減圧重質油）
３ 水素
４ 石炭液化物
５ 塔頂流出物
６ 液化ナフサ
７ 常圧軽油
８ 常圧蒸留塔Ｂの塔底油
９ 減圧重質油
１０ 液化残渣
１１ コークス炉用装入炭
１２ ガス（ＣＯＧ）
１３ コールタール
１４ コークス
１５ 化成品
１６ 輸送用燃料（基材）
Ａ 石炭液化反応塔
Ｂ 常圧蒸留塔
Ｃ 減圧蒸留塔
Ｄ コークス炉[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for increasing the production of chemical products from a coke oven, and in particular, by adding atmospheric pressure light oil and liquefaction residue from a coal liquefaction method to a coke oven charging coal, the problem in the coke production method and the problem in the coal liquefaction method are simultaneously achieved. The present invention relates to a method for increasing the production of chemical products to be solved.
[0002]
[Prior art]
In the coke production method, a so-called by-product recovery coke oven that recovers dry distillation by-products is the mainstream. The gas discharged from the coke oven riser is sequentially cooled and refined in a gas purification facility, and dry distillation byproducts such as purified COG and coal tar are recovered. Since the purpose is to produce coke, the quality and production volume of carbonization by-products are subordinate. Also, in the coke production method for blast furnace, since the carbonization temperature is relatively high, the aromatic index (fa) of coal tar becomes excessively high, and the graphitization reactivity of pitch coke may be reduced accordingly. is there.
[0003]
JP-A-8-231961 discloses a method for adjusting the production volume and quality of coal tar in a coke oven for producing blast furnace coke. In this method, a part or all of coal tar and / or pitch produced in the system is added to the charging coal, and the added tar and / or pitch is converted into gas or coke. More coal tar is reduced.
[0004]
By the way, although coal liquefaction technology has been developed with the goal of transporting fuel such as gasoline and diesel, it has been difficult to put into practical use because the construction cost and running cost of the coal liquefaction plant are high. In addition, coal liquefied oil has an excess of aromatic components compared to petroleum-based fuels, and the need for additional steps such as hydrorefining and catalytic reforming was another factor that increased the economic burden. Furthermore, a method of using liquefied oil as a high-value-added chemical product can be considered, but a process for separating and extracting a target chemical component is necessary.
[0005]
Coal liquefaction methods, especially continuous direct coal liquefaction methods, not only require large amounts of expensive hydrogen for the hydrocracking of coal, but also require iron-based catalysts to increase the yield of liquefied oil. Usually, about 3 wt% is added per coal. In addition, crude liquefied coal oil (liquefied oil distilled in an atmospheric distillation tower), which is a product oil, has a higher content of naphthene rings and 1 to 3 ring aromatic compounds than petroleum. Upgrade (refining) is necessary, which is a factor that deteriorates economic efficiency. In other words, refining equipment for refining coal liquefied crude oil such as liquefied naphtha and atmospheric light oil (AGO) produced from the atmospheric distillation column is indispensable, and the vacuum heavy oil distilled from the vacuum distillation column is used for coal liquefaction. Although it is used as a circulating solvent, the current situation is that the vacuum liquefaction residue is still being searched for.
[0006]
[Problems to be solved by the invention]
Problems in the blast furnace coke manufacturing method include increasing the use ratio of low-priced inferior coal with large coke cost performance and improving coke strength to maintain stable blast furnace operation. In addition, establishment of a method for independently controlling the production amount of coke oven gas (COG) and coal tar as by-products and their quality is also a major issue. On the other hand, for the practical application of coal liquefaction technology, the upgrade process such as hydrorefining is omitted or simplified, and strict conditions for improving the yield of liquefied oil (catalyst amount and hydrogenation amount There are various problems such as mitigating (increase) and effective utilization of the liquefaction residue.
Under such circumstances, an object of the present invention is to provide means for simultaneously solving the problems in the above-mentioned coke production method and the practical application of coal liquefaction technology.
[0007]
[Means for Solving the Problems]
As a result of various studies on means for simultaneously solving the problem in the coke production method and the problem in coal liquefaction, the present inventors have conceived the present invention that can be achieved only by combining a coke factory and a coal liquefaction plant.
[0008]
That is, the method for increasing the production of a chemical product in a coke oven according to the present invention is a coke production method equipped with a facility for recovering coal by-product by distillation, and adding a product derived from the coal liquefaction method to the coke oven charging coal It is characterized by doing.
[0009]
Here, the product derived from the coal liquefaction method to be added to the above-described charging coal of the present invention is at least a liquefaction residue, and preferably an atmospheric gas oil and a liquefaction residue. Further, the boiling range of normal pressure light oil is desirably 220 to 350 ° C., and the boiling range of one liquefaction residue is desirably 500 ° C. or higher in terms of normal pressure.
Furthermore, the addition amount of the product derived from the coal liquefaction method to the coke oven charging coal is 0.5 to 6 wt%, preferably 1 to 5 wt%, and most preferably around 3 wt%.
[0010]
Moreover, the coal liquefaction method of the present invention has a coal liquefaction plant attached to the coke oven plant, and at least a part of the product obtained from the coal liquefaction plant is added to the coke oven charging coal, It is characterized by omitting or simplifying an upgrade process such as a hydrorefining process.
As a result, the construction cost and running cost of the coal liquefaction plant can be reduced, increasing the possibility of practical application.
[0011]
According to the present invention, the product derived from the coal liquefaction method is added to the coke oven charging coal and dry-distilled, whereby the additive is pyrolyzed in the coke oven and partly becomes coke, with the remainder being gas. , Converted into tar components. These are discharged from the coke oven riser in a mixed state with COG and coal tar accompanying the dry distillation of the coke oven charging coal. For this reason, it is possible to increase the production of chemical products such as BTX, phenol, cresol, naphthalene, etc. by the amount of conversion products derived from the additive to the charging coal, and the recovery and subsequent chemical product processing will be performed at the existing chemical product plant. The equipment can be used as it is.
[0012]
That is, the construction of equipment for separating and extracting the target chemical component can be omitted. On the other hand, from the viewpoint of manufacturing blast furnace coke, it is possible to increase the production amount of coke oven gas (COG) and coal tar as main products and coke as a by-product, and to control their quality.
Further, according to the present invention described above, in the conventional coal liquefaction process, the liquefaction residue, which has been considered extremely difficult to treat, can be used as a coal tar, and thus as an effective chemical product, by utilizing a coke oven. It was possible.
[0013]
Also, in the conventional coal liquefaction process, in order to increase the yield of liquefied oil such as liquid naphtha (for gasoline) and AGO (for diesel), the amount of catalyst such as pyrite and the amount of hydrogenation are increased, and the reaction temperature and pressure are increased. Although it has been necessary to set the conditions to be higher, in the present invention, these conditions can be remarkably relaxed. Further, the upgrade (refining) equipment that has been conventionally required can be omitted or simplified.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the flow sheet of FIG.
First, the coal liquefaction method of the present invention is not particularly limited. (1) A high-pressure hydrocracking method using a catalyst such as iron and reacting with hydrogen at high temperature and high pressure, for example, 500 ° C. and 300 atm, and (2) coal tar system. (3) Decomposition and extraction method in which extraction is performed by heating at 350 to 450 ° C near the coal decomposition temperature, and (3) Decomposition at around 450 ° C in the presence of an iron-based catalyst in the presence of hydrogen and a solvent. Examples thereof include a hydrogenation extraction method in which hydrocracking or hydrogenation is also performed along with extraction, and (4) a low temperature carbonization method in which carbonization is performed at a low temperature of about 600 ° C.
Among these, (3) the hydrogenation extraction method is most preferable for the present invention in that a large-scale treatment is easy as a continuous coal liquefaction method.
[0015]
FIG. 1 shows an example of the above hydrogenation extraction method combined with a coke oven as a coal liquefaction method. Usually, coal 1 is coal in the presence of a heavy component (depressurized heavy oil) 2 and hydrogen 3 derived from high-boiling liquefied oil, and an iron-based catalyst for increasing the yield of liquefied oil if necessary. By being charged into the liquefaction reaction tower A and heated in the vicinity of the coal decomposition temperature, a coal liquefaction reaction occurs due to the solvent extraction action and the hydrocracking action. The liquefied coal 4 obtained here is continuously extracted and fractionated in the atmospheric distillation column B, and the top effluent 5 such as gas / water, liquefied naphtha 6 and atmospheric gas oil (AGO) 7 is obtained. Fractionated.
[0016]
The remaining bottom oil 8 of the atmospheric distillation tower B from which these were fractionated is the heavy oil 9 under reduced pressure in the vacuum distillation tower C at a tower bottom temperature of 310 to 350 ° C. and a pressure of 5 to 15 KPa. The liquefaction residue 10 is extracted from the bottom of the slag. Here, the above liquefied naphtha 6 is adjusted as necessary and used as a transportation fuel (base material) 16, and the reduced pressure heavy oil 9 is used as a circulating solvent to the coal liquefaction reactor A. One or both of atmospheric pressure light oil (AGO) 7 and the liquefaction residue 10 from the bottom of the vacuum distillation column are to be added to the coke oven charging coal of the present invention.
[0017]
The coke oven charging coal 11 to which the liquefaction residue 10 from the vacuum distillation column C and, if necessary, the atmospheric gas oil (AGO) 7 are added, is charged into a known chamber-type coke oven D and is usually added. Is subjected to high temperature carbonization under the dry distillation conditions (1000 to 1200 ° C.) to obtain gas (COG) 12, coal tar 13, coke 14 and the like. The coal tar 13 is appropriately recovered as a chemical product raw material 15 including light oils and sent to a chemical product manufacturing facility.
[0018]
Here, the liquefaction residue 10 from the vacuum distillation column C has a boiling point range of 500 ° C. or higher in terms of normal pressure, a softening point of 150 ° C. or higher, and has properties close to a hard pitch, so it was added to the coke oven charging coal. In this case, the caustic filling effect can be enjoyed. That is, there are effects such as an increase in the use ratio of low-cost inferior coal and improvement in coke strength. Even if the addition rate is too low, the caustic supplementing effect cannot be exhibited. Further, if the addition rate is too high, it exceeds the equipment capacity of the existing chemical product factory, so it is optimal to add 0.5 to 6 wt%, preferably 1 to 5 wt%, most preferably around 3 wt%.
[0019]
Here, when the coal liquefaction plant is located alone, in order to improve the yield of liquefied oil, it is necessary to set the reaction temperature around 450 ° C. and the addition rate of the iron-based catalyst around 3 wt% / coal, and the hydrogen consumption is 5-6 wt% / daf-coal (anhydrous, ashless-based coal), but when co-located in a coke plant, coke is added by adding liquefaction residue to the charging coal even if the liquefied oil yield is low. Since it can be recovered as a by-product by distillation in the furnace, the liquefaction conditions can be relaxed up to about 1 to 2 wt% / coal of the iron-based catalyst addition rate. Further, by reducing the reaction temperature to about 430 ° C., the hydrogen consumption can be suppressed to about 4 wt% / daf-coal.
Among the coal liquefaction products, the liquefied naphtha 6 and the hydrogenated naphtha in the solvent hydrogenation step have a boiling range of C4 to 220 ° C., and can be used as the transport fuel (base material) 16 as they are.
[0020]
【Example】
Hereinafter, although an example of the present invention is given and explained, the present invention is not limited at all by this example.
[0021]
Comparative Example 1
Table 1 shows the standard liquefaction conditions and the yield and properties of the main liquefaction products made from Tanitoharum coal (Indonesia: subbituminous coal). The total yield of atmospheric pressure light oil and liquefaction residue was 43.0 wt%, and the yield of liquefied naphtha was 26.0 wt%.
[0022]
Example 1
Total pressure gas oil (AGO) obtained under standard liquefaction conditions using Tanitoharum coal (Indonesia: sub-bituminous coal) shown in Comparative Example 1 as raw material and charged coal used for blast furnace coke production 3 wt% was added. Table 1 shows the yield, properties and coke strength of the main carbonization by-product when this charged coal is carbonized under the standard production conditions for blast furnace coke.
The COG and tar yields were significantly increased as compared with Comparative Example 2 below due to the decomposition and low molecular weight decomposition of the atmospheric gas oil and the liquefaction residue. In addition, the aromatic index fa slightly decreased, and the contents of BTX, phenol and cresol clearly increased. The coke strength was increased by 0.4 points from the standard by adding 3 wt% of atmospheric pressure light oil and liquefaction residue. Incidentally, when the aromatic index fa is excessively high, it is not preferable for the pitch coke properties (CTE or the like) in the lower step, but an effect of reducing and improving fa by adding a liquefaction residue is also expected.
[0023]
Comparative Example 2
Table 1 shows the standard production conditions of the blast furnace coke under the same conditions as in Example 1, the yield of the main dry distillation byproduct, and the properties, except that no atmospheric pressure light oil (AGO) and liquefaction residue were added in Example 1. Show. The yield of coal tar was 3.6 wt%, the aromatic index fa was 0.968, and the contents of BTX, phenol and cresol were around 1 wt%. Further, the coke strength was 85.0 under the condition (standard) in which tar was not added.
[0024]
Example 2
A total of 3 wt% of atmospheric gas oil and liquefaction residue obtained under liquefaction conditions under a lower catalyst than that of Comparative Example 1 using Tanitoharum coal as a raw material were added to the charging coal supplied for blast furnace coke production. Table 2 shows the yield, properties, and coke strength of the main carbonization by-products when this charged coal is carbonized under the standard production conditions for blast furnace coke. Since the liquefaction conditions were under a low catalyst, the yields of liquefied naphtha and atmospheric gas oil were lower than those in Comparative Example 1, but the yield of liquefied residue was increased. Molecularization further increased COG and tar yield over Example 1. The fa of the tar produced was further reduced, but the contents of BTX, phenol and cresol were almost the same as in Example 1. Moreover, coke strength increased by 0.6 points from the standard by adding 3 wt% of atmospheric pressure light oil and liquefaction residue.
[0025]
Example 3
Normal pressure light oil and liquefaction residue obtained under liquefaction conditions under a lower catalyst than that of Comparative Example 1 using Tanitoharum coal as a raw material were added in a total of 6 wt% to the charging coal used for blast furnace coke production. Table 2 shows the yield, properties, and coke strength of the main carbonization by-products when this charged coal is carbonized under the standard production conditions for blast furnace coke.
The liquefaction conditions in this case were the same as in Example 2, but the COG and tar yields were further increased from Example 2 because the total addition rate of atmospheric gas oil and liquefaction residue to the charged coal was 6 wt%. . Although the fa of produced tar was further reduced, the content of BTX, phenol and cresol was slightly increased as compared with Example 2. Further, by adding 6 wt% of the normal pressure light oil and the liquefaction residue, the caking strength was excessive, and the coke strength slightly decreased from the standard.
[0026]
Example 4
Under the liquefaction conditions with a lower reaction temperature and a lower catalyst than those of Comparative Example 1 using Tanitoharum coal as a raw material, the yields of liquefied naphtha and atmospheric gas oil were significantly reduced, but the yield of liquefied residue was maximized. In this case, the atmospheric pressure light oil and liquefaction residue obtained were added in a total amount of 3 wt% to the charging coal used for blast furnace coke production. Table 2 shows the yield, properties, and coke strength of the main carbonization by-products when this charged coal is carbonized under the standard production conditions for blast furnace coke.
In this case, the liquefaction conditions were the same as in Examples 2 and 3, but the yield of liquefied naphtha and atmospheric gas oil was minimized by lowering the reaction temperature. Since the rate increased, COG and tar yield further increased from those in Example 2 due to decomposition and low molecular weight decomposition of the liquefaction residue added to the charging coal. The fa of the tar produced was also lower than that in Example 2, but the contents of BTX, phenol and cresol were almost the same as those in Examples 1 and 2. Further, the coke strength was increased by 0.7 points from the standard by adding 3 wt% of atmospheric pressure light oil and liquefaction residue.
[0027]
[Table 1]

[0028]
[Table 2]

[0029]
【The invention's effect】
INDUSTRIAL APPLICABILITY The present invention expands the degree of freedom of COG and coal tar production in the blast furnace coke manufacturing method, and exhibits effects such as an increase in the use ratio of low-cost inferior coal and improvement in coke strength. In addition, when a part of coal liquefied oil is used as a chemical product and a coal liquefaction plant is to be constructed and operated independently, it is necessary to establish a dedicated chemical product factory, but it will be adjacent to the coke factory. As a result, not only can the chemicals factory attached to the coke factory be used, but also the liquefaction conditions of the coal can be relaxed, which contributes to the reduction of construction costs and running costs of the coal liquefaction plant. This will improve the practical use of
[Brief description of the drawings]
FIG. 1 is a schematic overall production flow sheet for producing transportation fuel and chemical products from coal liquefied oil according to the present invention.
[Explanation of symbols]
1 Coal 2 Heavy oil derived from liquefied oil (depressurized heavy oil)
3 Hydrogen 4 Coal liquefaction 5 Tower top effluent 6 Liquefaction naphtha 7 Atmospheric pressure oil 8 Atmospheric distillation column B bottom oil 9 Decompressed heavy oil 10 Liquefaction residue 11 Coke oven charging coal 12 Gas (COG)
13 Coal tar 14 Coke 15 Chemical product 16 Fuel for transportation (base material)
A Coal liquefaction reaction tower B Atmospheric distillation tower C Vacuum distillation tower D Coke oven

Claims (3)

A product derived from the coal liquefaction method is added to the coke oven charging coal in the coke production method equipped with a facility for recovering coal dry distillation by-products so that the addition amount is in the range of 0.5 to 6 wt%. a method of obtaining a dry distillation to chemical products, reduction in the coke oven, wherein the product is obtained in combination with atmospheric gas oil obtained from atmospheric distillation and obtained that liquefied residues from vacuum distillation How to increase production of products.   The product derived from the coal liquefaction method is a liquefaction residue obtained from the bottom of the vacuum distillation column by subjecting the column bottom oil obtained by atmospheric distillation to vacuum distillation at a column bottom temperature of 310 to 350 ° C. and a pressure of 5 to 15 KPa. A method for increasing the production of a chemical product in a coke oven according to claim 1.   The method for increasing the production of a chemical product in a coke oven according to claim 1 or 2, wherein the normal pressure gas oil has a boiling range of 220 to 350 ° C and the liquefaction residue has a boiling range of 500 ° C or higher in terms of normal pressure.

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