JP2015183143A - Low sulfur solid carbon body production process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing, by a physical method, a solid carbon body that has a low sulfur content, without carrying out the heat treatment at high temperature.SOLUTION: Provided is a low sulfur solid carbon body production process, characterized in including: a calcination step for heating a solid carbon body containing sulfur, at 800 to 1500°C to produce heat-treated product; a pulverization step for pulverizing the heat-treated product to produce pulverization-treated product; and a sieving step for sieving the pulverization-treated product to separate the large particle size content from the pulverization-treated product and produce low sulfur solid carbon body.

Description

  The present invention relates to a method for producing a low sulfur solid carbon body that obtains a solid carbon body having a low sulfur content from a solid carbon body having a high sulfur content.

  Since solid carbon bodies such as petroleum coke and coal used for fuel contain sulfur, SOx which is an environmental pollutant is discharged during combustion. Since SOx originates from sulfur present in the solid carbon body, a solid carbon body having a low sulfur content is required.

  Methods for removing sulfur from carbon-containing compounds are roughly divided into three methods: physical methods, chemical methods, and biological methods. As a physical method, there are a method of heat treatment at a high temperature (Non-patent Document 1) and a method of removing iron sulfide contained in ash at the same time as removal of ash called coal preparation. Chemical methods include hydrogen desulfurization under high pressure using hydrogen as a desulfurizing agent (Non-patent Document 1), and a method using an alkali such as sodium hydroxide and potassium hydroxide (Non-patent Document 1, Patent Document). 1, Patent Document 2), a method using an alkalizing agent (Patent Document 3), and the like. Examples of biological methods include a method using a microorganism having an ability to decompose an organic sulfur compound as a desulfurization agent (Patent Documents 4 and 5).

Japanese Patent Laid-Open No. 3-27595 JP 2002-516380 A JP 2001-181654 A JP-A-6-184557 Japanese Patent Laid-Open No. 8-100185

Desulfurization of petrole cake: A Review, Hassan Al-Haj-Ibrahim and Badie I. Morsi, Ind. Eng. Chem. Res. , 1992, 31, 1835-1840

  Although chemical methods enable desulfurization at a relatively low temperature and high efficiency, in order to use a desulfurizing agent, a step of washing the solid carbon body after desulfurization and a step of recovering the desulfurizing agent are required, and the process is complicated. Therefore, there is a problem that the processing cost becomes high. In addition, the biological method can perform desulfurization at normal temperature and pressure, but has a problem that the reaction rate is slow and maintenance of microorganisms as a desulfurization agent is necessary.

  On the other hand, physical methods can be processed by simple processes compared to chemical methods and biological methods. However, desulfurization accompanying ash removal by coal preparation can remove only the sulfur content resulting from iron sulfide, so the sulfur removal rate is low, and desulfurization by heat treatment is 1500 ° C. in order to achieve a high sulfur removal rate. There is a problem that it is necessary to perform heat treatment at a high temperature exceeding (Non-patent Document 1).

  Accordingly, an object of the present invention is to provide a method for obtaining a solid carbon body having a low sulfur content without performing a heat treatment at a high temperature by a physical method.

The above problems are solved by the present invention described below. That is, this invention heats the solid carbon body (1) containing sulfur at 800-1500 ° C. to obtain a heat-treated product,
Crushing the heat-treated product to obtain a pulverized product;
Classifying the pulverized product and separating a large particle size from the pulverized product to obtain a low sulfur solid carbon body (2);
It provides the manufacturing method of the low sulfur solid carbon body characterized by having.

  According to the present invention, it is possible to provide a method of obtaining a solid carbon body having a low sulfur content without performing a heat treatment at a high temperature by a physical method.

The method for producing a low sulfur solid carbon body of the present invention comprises heating a solid carbon body (1) containing sulfur at 800 to 1500 ° C. to obtain a heat-treated product,
Crushing the heat-treated product to obtain a pulverized product;
Classifying the pulverized product and separating a large particle size from the pulverized product to obtain a low sulfur solid carbon body (2);
It is a manufacturing method of the low sulfur solid carbon body characterized by having.

  The calcination step according to the method for producing a low sulfur solid carbon body of the present invention is a step of heating the solid carbon body (1) containing sulfur to obtain a heat-treated product.

  The solid carbon body (1) containing sulfur that is heat-treated in the calcination step is a carbide obtained by carbonizing a substance containing carbon, and is an aggregate of solid carbon.

  The sulfur-containing solid carbon body (1) that is heat-treated in the calcination step contains sulfur, and the sulfur content of the sulfur-containing solid carbon body (1) is preferably 2 to 15% by mass, Especially preferably, it is 4-11 mass%.

  Solid carbon bodies containing sulfur that are heat-treated in the calcination step (1) include mineral carbon bodies such as petroleum coke and coal produced by pyrolyzing and carbonizing heavy components in crude oil; Polyphenylenesulfur produced by pyrolyzing and carbonizing a synthetic resin containing sulfur such as coconut shell charcoal produced by carbonizing sawdust, vegetable carbon such as sawdust charcoal, polyphenylene sulfide, polyethersulfone, etc. Examples thereof include sulfur-containing resin charcoal such as fido charcoal and polyethersulfone charcoal. Among these, as the solid carbon body (1) containing sulfur to be heat-treated in the calcination step, a mineral carbon body is preferable, and petroleum coke is particularly preferable.

  Moreover, as solid carbon body (1) containing sulfur, the petroleum coke obtained by thermally decomposing | disassembling the hydrocarbon raw material produced | generated in a petroleum refining process with a thermal decomposition apparatus is mentioned. The following is an example of a method for producing petroleum coke containing sulfur as a raw material for a calcination step by pyrolyzing a hydrocarbon raw material produced in an oil refining process (hereinafter referred to as a method for producing petroleum coke) (Also described as (1)).

  The method (1) for producing petroleum coke is a method for obtaining petroleum coke by pyrolyzing hydrocarbon feedstock produced in the petroleum refining process with a thermal cracking apparatus.

  In the petroleum coke production method (1), the hydrocarbon feedstock to be pyrolyzed is an atmospheric distillation residue obtained by subjecting crude oil to atmospheric distillation, or a vacuum distillation after subjecting an atmospheric distillation residue to vacuum distillation. Residue oil, mixed oil of atmospheric distillation residue oil and vacuum distillation residue oil, or mixed oil of one or more of atmospheric distillation residue oil and vacuum distillation residue oil with other hydrocarbon oil (1) It is done.

  There is no restriction | limiting in particular in the atmospheric distillation residue oil which concerns on hydrocarbon feedstock, and it is a residue part after carrying out the atmospheric pressure distillation and isolate | separating an evaporation fraction. There is no restriction | limiting in particular in the vacuum distillation residue oil which concerns on hydrocarbon feedstock, It is a residue part after carrying out vacuum distillation of the atmospheric distillation residue oil, and isolate | separating an evaporation fraction. The hydrocarbon feedstock oil may be a mixed oil of atmospheric distillation residue oil and vacuum distillation residue oil. When the hydrocarbon feedstock oil is a mixture oil of atmospheric distillation residue oil and vacuum distillation residue oil, The mixing ratio of the distillation residue oil and the vacuum distillation residue oil is not particularly limited, and is appropriately adjusted.

  The crude oil used as the distillation raw material for atmospheric distillation residue oil is not particularly limited, and examples of crude oil types include, for example, Arabian Heavy, Arabian Medium, Arabian Light, Arabian Extralite, Kuwait, Basra, Oman, Marban, Mubaras Blend. , Zakum, Upper Zakum, Qatar Land, Qatar Marine, Umshaif, Shiri, Kafuji, Espo, etc., any one or a combination of two or more.

  The hydrocarbon feedstock is a mixed oil of at least one of atmospheric distillation residue oil and vacuum distillation residue oil and another hydrocarbon oil (1), that is, atmospheric distillation residue oil and other hydrocarbon oil. Mixed oil of (1), mixed oil of vacuum distillation residue oil and other hydrocarbon oil (1), or mixed oil of atmospheric distillation residue oil, vacuum distillation residue oil and other hydrocarbon oil (1) It may be. When the hydrocarbon feedstock is a mixed oil of at least one of atmospheric distillation residue oil and vacuum distillation residue oil and another hydrocarbon oil (1), the other hydrocarbon oil (1) is the present invention. For example, a slurry oil in a fluid catalytic cracking process, an ethylene cracker residue oil, or the like may be used.

  In the production method (1) of petroleum coke, although it is the conditions for the pyrolysis treatment, the pyrolysis temperature is preferably 490 to 510 ° C, particularly preferably 495 to 505 ° C, and the pressure during the pyrolysis treatment (Gauge pressure) is preferably 0.01 to 0.6 MPaG, particularly preferably 0.05 to 0.4 MPaG. Moreover, the atmosphere of a thermal decomposition process is steam. Moreover, when excessive foaming is recognized during a thermal decomposition process, an antifoamer may be thrown in. As the antifoaming agent, generally, a silicon-based antifoaming agent or the like can be used.

  The sulfur content in the dry state of petroleum coke (solid carbon body containing sulfur (1)) obtained by carrying out the production method (1) of petroleum coke is 5 to 12% by mass, preferably 6 to 10% by mass. is there. Petroleum coke obtained by carrying out the production method (1) of petroleum coke is obtained by thermal decomposition treatment of hydrocarbon feedstock, but usually contains about 1 to 12% by mass of water, so that oil in a water-containing state is obtained. If the mass of coke is used as a reference for calculating the sulfur content, the calculated value of the sulfur content in the petroleum coke varies depending on the water content of the petroleum coke. Therefore, in calculating the sulfur content in petroleum coke, water-containing petroleum coke is dried at 200 ° C. ± 10 ° C. for 4 hours (according to JIS M 8811), and the mass of the resulting dried petroleum coke is measured. The sulfur content in the petroleum coke is calculated based on the mass of the dried petroleum coke. That is, the dry sulfur content of petroleum coke is the mass of sulfur in petroleum coke relative to the mass of dry petroleum coke.

  Petroleum coke obtained by carrying out the method (1) for producing petroleum coke may be hydrated during collection from the inside of the pyrolysis apparatus. Moreover, when extracting petroleum coke from the inside of a thermal decomposition apparatus, it may extract | collect after pulverizing petroleum coke with a water jet. Therefore, you may dry the extract | collected petroleum coke at 100-1500 degreeC from the inside of a thermal decomposition apparatus.

  Petroleum coke has a granular shape generally called shot coke and a large massive porous shape generally called sponge coke, but the petroleum coke used as the solid carbon body (1) containing sulfur is Further, it may be shot coke, sponge coke, a mixture thereof, or a pulverized product thereof.

  In the calcination step, the heating temperature when heating the solid carbon body (1) containing sulfur is 800 to 1500 ° C, preferably 900 to 1200 ° C. When the heating temperature in the calcination step is in the above range, a solid carbon body having a low sulfur content is obtained.

  In the calcination step, the heating time when heating the solid carbon body (1) containing sulfur is appropriately selected, but is usually 0.5 to 6 hours, preferably 1 to 4 hours, particularly preferably 1 ~ 3 hours. In the calcination step, the atmosphere when heating the solid carbon body (1) containing sulfur is an inert gas atmosphere such as nitrogen gas, helium gas, or argon gas.

  As described in “Chemicals and Industry of Carbon Materials”, Isao Mochida, published by Asakura Shoten, September 10, 1990, first edition, first print, pp. 88-89, carbon-containing substances must be 400 ° C. When heated at higher temperatures, a pyrolysis reaction occurs. By this reaction, a low molecular weight compound is generated as a decomposition product, and is distilled from a substance containing carbon. In the carbon-containing substance, reactions such as recombination of radicals generated by bond cleavage, heavy bonds, and aromatization occur to produce heavy aromatic hydrocarbons. The substance containing is carbonized into a solid carbon body.

  Further, when the heating temperature rises and the solid carbon body is heated at 800 to 1500 ° C., macropores are formed in the solid carbon body due to generation and reduction of decomposition products in the solid carbon body, and the constituent aromatic molecules Expansion of the conjugated system occurs, the density increases, and a solid carbon body with higher hardness is obtained. At the same time, micropores and cracks are formed. Such heating is generally called calcination.

  Further, when the heating temperature rises and the solid carbon body is heated at a temperature exceeding 1500 ° C., all volatile elements other than carbon are discharged from the solid carbon body toward the graphite crystal, and the growth of the laminated structure and Development progresses. This is generally called graphitization.

  In the method for producing a low sulfur solid carbon body of the present invention, the solid carbon body (1) containing sulfur is heated at 800 to 1500 ° C., preferably 900 to 1200 ° C. in the calcination step, thereby containing sulfur. The solid carbon body is densified. And, in the heat-treated product obtained by performing the calcination step, that is, in the solid carbon body having a high density, there are a portion where sulfur is present and a portion where sulfur is not present, and the solid material is high in density. In the carbon body, the portion where sulfur is not present is more fragile and more easily pulverized than the portion where sulfur is present. That is, by performing the calcination step, in the solid carbon body, a portion that is easily pulverized and a portion that is not easily pulverized are formed, and a portion that does not have sulfur is easily pulverized, and sulfur is present. The part which becomes is difficult to be crushed.

  The pulverization step according to the method for producing a low sulfur solid carbon body of the present invention is a step of pulverizing a heat-treated product obtained by performing a calcination step to obtain a pulverized product.

  In the pulverization step, a method for pulverizing the heat-treated product may be dry pulverization based on any of compression, shearing, impact or grinding, or wet pulverization such as ball mill pulverization. In the pulverization step, when wet pulverization is performed, water, ethanol or the like is used as a solvent. In the pulverization step, when wet pulverization is performed, the pulverized product is dried, preferably at 100 to 250 ° C., after wet pulverization.

  The classification step according to the method for producing a low-sulfur solid carbon body of the present invention classifies the pulverized product obtained by performing the pulverization step, and separates the large particle size from the pulverized product, thereby reducing the low-sulfur solid carbon body. This is a step of obtaining (2).

  In the present invention, the term “large particle size” means the portion of the entire pulverized product having a larger particle size, and the pulverized product has a specific particle size as a boundary and is larger than the specific particle size. When divided into a particle having a diameter and a particle having a particle diameter equal to or smaller than the specific particle diameter, the particle having a particle diameter larger than the specific particle diameter is indicated.

  In the classification step, examples of the method of classifying the pulverized product include air classification and sieving.

  In the pulverized product obtained by performing the pulverization step, particles having a high sulfur content are distributed in the larger particle size, and particles having a low sulfur content are distributed in the smaller particle size. The solid carbon body having a low sulfur content can be obtained by separating the carbon dioxide, and the value of which particle size is used as the boundary between the large particle size and the low sulfur solid carbon body (2) is appropriately selected. The That is, in the classification step, the solid carbon body as a raw material, that is, the sulfur content of the solid carbon body (1) containing sulfur that is heat-treated in the calcination step, the heating conditions in the calcination step, and the pulverization step Depending on the crushing strength, the sulfur content of the low-sulfur solid carbon body (2) to be produced, etc., which particle size value is used as the boundary between the large particle size and the low-sulfur solid carbon body (2), Select as appropriate.

  In the classification step, it is easy to obtain a solid carbon body having a low sulfur content by separating a particle size of 0.001 to 50 μm from the pulverized product by classification to obtain a low sulfur solid carbon body (2). This is preferable.

  In the classification step, the ratio of the large particle size separated from the pulverized product by classification is preferably 30 to 95% by mass, particularly preferably 50 to 80% by mass, based on the total amount of the pulverized product. . When the ratio of the large particle size separated from the pulverized product by classification to the total amount of the pulverized product is in the above range, a solid carbon body having a low sulfur content is easily obtained. The ratio (mass%) of the large particle size separated from the pulverized product by classification with respect to the total amount of the pulverized product is a value calculated by “(large particle size / total amount of pulverized product) × 100”. It is.

  The low sulfur solid carbon body (2) obtained by the method for producing a low sulfur solid carbon body of the present invention has a lower sulfur content than the solid carbon body (1) containing sulfur that is heat-treated in the calcination step. . The sulfur content of the low sulfur solid carbon body (2) is preferably 1 to 7% by mass, particularly preferably 1 to 6% by mass.

  The present inventors heated the solid carbon body (1) containing sulfur at 800 to 1500 ° C., preferably 900 to 1200 ° C., so that densification occurred in the solid carbon body and the density was increased. In the solid carbon body, it was found that the portion where sulfur is not present is more fragile and more easily pulverized than the portion where sulfur is present.

  And in the manufacturing method of the low sulfur solid carbon body of this invention, using the change of the physical property of the solid carbon body containing sulfur by such calcination, in the calcination process, the solid carbon body containing sulfur ( 1) is heated at 800 to 1500 ° C., preferably 900 to 1200 ° C., and the solid carbon body containing sulfur is densified, whereby the solid carbon body is easily pulverized without containing sulfur. Sulfur content by forming a part and a part that is difficult to pulverize containing sulfur, and pulverizing the solid carbon body (heat-treated product) containing sulfur in such a high density in the pulverization step A portion with a high sulfur content is obtained by separating a portion with a small particle size into a particle with a small particle size and a portion with a high sulfur content into a particle with a large particle size and separating the large particle size by classification in the classification step. Separating the sulfur content of By obtaining a partial There, it is possible to obtain a low sulfur solid carbon body.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

<Sulfur-containing solid carbon body (1)> Raw material for heat treatment of calcination step Shot coke obtained by pyrolyzing the vacuum distillation residue was obtained by drying at 200 ° C. ± 10 ° C. for 4 hours. Petroleum coke A (sulfur content: 8.1% by mass) was pulverized with an agate mortar so that the total amount was 18 mesh or less (opening size: 1000 μm), and petroleum coke A (particle size: 1000 μm or less) Was obtained as a solid carbon body (1A).

Example 1
5 g of the solid carbon body (1A) obtained above was sampled, put in an alumina crucible, heated to 1000 ° C. at a heating rate of 5 ° C./min in an argon gas atmosphere, and further heated at 1000 ° C. for 2 hours. .
Next, the obtained heat-treated product was pulverized for 10 seconds at a rotational speed of 35000 rpm using an electric mill (manufactured by Osaka Chemical Co., Ltd., model number PM-2005).
Subsequently, the obtained pulverized product was classified using 500 mesh (size of sieve opening: 25 μm), and a sieved product (particle size of 25 μm or less) was obtained as a low sulfur solid carbon body (2A).
The yield of the low sulfur solid carbon body (2A) was 26% by mass, and the sulfur content was 5.9% by mass. In addition, a yield is the mass ratio (%) of the low sulfur solid carbon body (2A) obtained by performing the classification process with respect to the solid carbon body (1A) which is a raw material of a calcination process.

(Sulfur content analysis)
Measured by combustion / infrared absorption method.

(Example 2)
The pulverized product is classified using 500 mesh (size of sieve opening: 25 μm), and instead of obtaining the material under the sieve (particle size of 25 μm or less) as a low-sulfur solid carbon body (2A), pulverization treatment The product is classified using 400 mesh (sieving size: 38 μm) and 500 mesh (sieving size: 25 μm), and 400 to 500 mesh (particle size 25 to 38 μm) is classified as a low-sulfur solid carbon body. The same procedure as in Example 1 was carried out except that (2B) was obtained.
The yield of the low sulfur solid carbon body (2B) was 10% by mass, and the sulfur content was 7.0% by mass.

(Comparative Example 1)
It was set as the comparative example 1 by making the solid carbon body (1A) obtained above into a comparative sample. That is, the calcination process, the pulverization process, and the classification process were not performed.

(Comparative Example 2)
5 g of the solid carbon body (1A) obtained above was sampled, placed in an alumina crucible, heated to 1000 ° C. at a heating rate of 5 ° C./min in an argon gas atmosphere, and further heated at 1000 ° C. for 2 hours. A solid carbon body (2a) was obtained.
The yield of the solid carbon body (2a) was 90% by mass, and the sulfur content was 7.6% by mass.

(Comparative Example 3)
5 g of the solid carbon body (1A) obtained above was collected and pulverized for 10 seconds at a rotational speed of 35,000 rpm using an electric mill (manufactured by Osaka Chemical Co., Ltd., model number PM-2005).
Subsequently, the pulverized product was classified using 500 mesh (a sieve opening size: 25 μm) to obtain a product under a sieve (particle size of 25 μm or less).
Next, the classified product is put into an alumina crucible, heated to 1000 ° C. at a heating rate of 5 ° C./min in an argon gas atmosphere, and further heated at 1000 ° C. for 2 hours to obtain a solid carbon body (2b). Got as.
The yield of the solid carbon body (2b) was 23% by mass, and the sulfur content was 7.5% by mass.

  According to the present invention, a solid carbon body having a low sulfur content can be provided by a simple physical method.

Claims (4)

A solid carbon body (1) containing sulfur is heated at 800-1500 ° C. to obtain a heat-treated product,
Crushing the heat-treated product to obtain a pulverized product;
Classifying the pulverized product and separating a large particle size from the pulverized product to obtain a low sulfur solid carbon body (2);
A process for producing a low-sulfur solid carbon body characterized by comprising:   The method for producing a low-sulfur solid carbon body according to claim 1, wherein a particle size of 0.001 to 50 µm is obtained by classification in the classification step.   3. The low-sulfur solid carbon body according to claim 1, wherein the solid carbon body (1) containing sulfur is a mineral-based carbon body, a plant-based carbon body, or a sulfur-containing resin charcoal. 4. Manufacturing method.   The ratio of the large particle size separated from the pulverized product in the classification step is 30 to 95% by mass with respect to the total amount of the pulverized product. The manufacturing method of the low sulfur solid carbon body of description.