JPH0452316B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing gaseous olefins and monocyclic aromatic hydrocarbons using heavy hydrocarbons as raw materials, and more specifically, pyrolyzing heavy hydrocarbons in the presence of hydrogen or hydrogen containing hydrogen sulfide, After separating and removing high boiling point substances from the obtained decomposition products,
The present invention relates to a method for obtaining gaseous olefins and monocyclic aromatic hydrocarbons in high yields by steam pyrolysis or by steam pyrolysis after hydrogenation treatment in the presence of hydrogen and a catalyst. Conventionally, in the production of gaseous olefins such as ethylene, propylene, and butadiene, which are basic raw materials in the petrochemical industry, and monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene, oil field gas and naphtha, which is a byproduct of oil refining, have been used. Light hydrocarbons such as Among these, naphtha is treated as particularly superior because it has a high yield of the gaseous olefins and monocyclic aromatic hydrocarbons mentioned above, and also produces a small amount of low-value heavy fuel oil as a by-product. Ta. However, in recent years, there has been a shortage of light hydrocarbons such as naphtha due to the rapid development of the petrochemical industry and the progress of motorization, a decline in the yield of light hydrocarbons due to heavier crude oil, and a sharp rise in crude oil prices. Due to various factors, the amount of light hydrocarbons supplied from petroleum refining as a preferred raw material for pyrolysis has become insufficient, and its price has soared. The economics of obtaining family hydrocarbons have declined significantly. Therefore, in order to solve these industrial structural problems, in recent years, after hydrogenation treatment using heavier hydrocarbon oils such as kerosene, light oil, and vacuum distilled light oil, steam pyrolysis Various attempts have been made to produce petrochemical raw materials by. However, in these methods, the various oils used as raw materials are obtained as petroleum products, and the circumstances of supplying raw materials are the same as in the case of light hydrocarbons such as naphtha. On the other hand, a method is known in which the vacuum distillation residue, which is a heavy hydrocarbon, is deasphalted with a solvent, and the deasphalted oil is mixed with vacuum distillation light oil to be hydrotreated, and this hydrotreated oil is subjected to steam pyrolysis. It is conceivable to produce petrochemical raw materials by using However, in this solvent deasphalting method, a large amount of deasphalting residue containing asphaltene is produced as a by-product, and the problem of effective utilization of this residue remains, and the yield of petrochemical raw materials cannot be significantly improved. Furthermore, as a method for guiding heavy hydrocarbons such as atmospheric distillation residues to petrochemical raw materials,
Various proposals have been made to actively reduce the vacuum distillation residue by a fixed-bed or fluidized-bed hydrocracking method in which a reactor is filled with a granular catalyst. However, at present, a highly economical technology has not yet been realized, as the asphaltene and heavy metals contained in the residue inevitably shorten the catalyst life, and increase hydrogen consumption. . Furthermore, as a method of actively lightening heavy hydrocarbons, it is also possible to apply a pyrolysis method to obtain treated oil that can be used as a petrochemical raw material. however,
If a conventional pyrolysis method were used to achieve a high degree of lightening, so-called severe coking would occur, forcing the operation to be shut down. It only applies to lightening.
Therefore, in order to improve this point, a so-called hydrovisbreaking method using hydrogen has been proposed, but even when the hydrogen pressure is as high as 300 kg/cm ² , it does not have a sufficient coking suppression effect. I can't get it. In addition, the so-called coker method has been proposed, in which coke is actively produced and lightened, but in addition to the problem of disposing of a large amount of coke produced as a by-product, the increase in the amount of gas due to excessive decomposition causes light A decrease in oil yield cannot be avoided. On top of that,
The resulting pyrolyzed light oil has many aromatic and olefin components and is of poor quality, and in order to use it as a treated oil for steam pyrolysis, it must be subjected to severe hydrogenation treatment. There is a need. In this way, with conventional technology, even if it is attempted to lighten high boiling point substances by catalytic treatment of heavy oil, it is not only possible to reduce impurities such as sulfur and heavy metals contained in the oil, but also due to the presence of basic polymer compounds in particular. As a result of the marked decline in the acid performance of the catalyst, there is a problem that the decomposition activity caused by the acidity of the catalyst does not last.
In addition, in the method of thermally decomposing hydrocarbons without a catalyst,
It is known that the reaction rate increases as the molecular weight increases, but it is extremely difficult to increase the decomposition rate due to the high coke formation and polycondensation reaction rate that occur as a by-product during decomposition. . Therefore, among the various methods for producing gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbons, when heavy hydrocarbons such as atmospheric distillation residues and vacuum distillation residues are used as feedstock, In both cases, technical and economic issues remain unresolved. The present inventors have endeavored to overcome the drawbacks of such conventional methods and to develop a method for producing gaseous olefins and monocyclic aromatic hydrocarbons economically and in high yields using heavy hydrocarbons as raw materials. As a result of repeated research, heavy hydrocarbons containing transition metal compounds and ultrafine particulate matter are thermally decomposed in the presence of hydrogen or hydrogen containing hydrogen sulfide, and high-boiling point products are extracted from recovered light hydrocarbon oil. After separating and removing the oil, heavy hydrocarbons can be separated from heavy hydrocarbons by steam pyrolysis, or by steam pyrolysis of the recovered hydrotreated oil by hydrogenation in the presence of hydrogen and a hydrogenation catalyst. We have discovered that it is possible to obtain useful petrochemical raw materials economically and in high yields, while at the same time suppressing the deterioration of the residue and significantly reducing its amount.
Based on this knowledge, we have completed the present invention. That is, the present invention provides (A) a heavy hydrocarbon,
Fine ceramics and ultrafine particulate materials with an average particle diameter of about 5 to 500 mμ selected from the group consisting of gas-phase carbonized materials and an oil-soluble transition metal compound are added, and the heavy (B) A step of separating and removing high boiling point substances from the light hydrocarbon oil; (C) A hydrocarbon oil from which high boiling point substances have been separated and removed. Gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbons are characterized by comprising a step of steam pyrolysis of the mixture alone or with other petroleum fractions to recover gaseous olefins and monocyclic aromatic hydrocarbons. A method for producing aromatic hydrocarbons, and step (A), step (B), and step (C) in which hydrocarbon oil from which high boiling point substances have been separated is hydrotreated in the presence of a hydrogenation catalyst to produce a hydrogenated oil. and (D) a step of steam pyrolyzing the hydrotreated oil alone or by mixing it with other petroleum fractions to recover gaseous olefins and monocyclic aromatic hydrocarbons. The present invention provides a method for producing gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbons. The heavy hydrocarbons used in the method of the present invention are:
Crude oil or the residue of atmospheric distillation or vacuum distillation of crude oil, and also includes shale oil, tar sands extracted oil, coal liquefied oil, and the like. Such heavy hydrocarbons usually contain large amounts of impurities such as sulfur compounds, nitrogen compounds, asphaltenes, and heavy metals, as well as heavy fractions with high boiling points that cannot be converted into petrochemical raw materials as they are. , their quantity and quality vary greatly depending on the oil well producing the crude oil. however,
According to the present invention, it can be carried out regardless of the type of raw material, and the economic effect is greater as more fractions are converted as heavy hydrocarbons, for example, more fractions with a boiling point of 520°C or higher at atmospheric pressure. . The method of the present invention involves adding an oil-soluble transition metal compound and ultrafine particulate matter to heavy hydrocarbons, and thermally decomposing the heavy hydrocarbons in the presence of hydrogen or hydrogen containing hydrogen sulfide, and separating high-boiling substances. It consists of three steps: a step of decomposition and a step of steam pyrolysis, or it consists of four steps with a hydrogenation step between the step of separating and removing high boiling point substances and the step of steam pyrolysis. It has the following features compared to the conventional technology. That is, in the thermal decomposition step in the method of the present invention, polycondensation, which is a side reaction, occurs due to the effect of the transition metal compound and ultrafine particulate matter added to the heavy hydrocarbon raw material and hydrogen or hydrogen containing hydrogen sulfide. Reactions and coke-forming reactions are suppressed and scaling (coking) in the equipment, especially in the reaction zone, is prevented, so that useful light oils are economically and stably obtained from heavy hydrocarbons, as well as in high yields. This has the great advantage of being able to prevent deterioration of the properties of light oil and high boiling point residues. This is especially true when using atmospheric distillation residue oil or vacuum distillation residue oil of paraffin base crude oil such as Minas crude oil and Daqing crude oil, which are known as heavy crude oils. In other words, these heavy residual oils are heavy oils that have conventionally been considered relatively difficult to decompose to a high degree of lightness through coking, etc., but with the present invention, they can be made into a type of heavy oil with an excellent property of parafinic properties. It becomes possible to utilize the characteristics as they are and perform highly lightweight decomposition.
Therefore, in the next separation process, the lightened fraction obtained by residual pressure or vacuum distillation is directly subjected to steam pyrolysis without going through a further hydrotreating process to produce petrochemical raw materials. Since it becomes possible to obtain hydrogen gas sufficiently, facilities such as a hydrogenation treatment apparatus are not required, and furthermore, the amount of hydrogen consumed can be reduced, which brings about great effects. Moreover, the high-boiling point residual oil separated and removed in the separation process can be used as a liquid fuel in almost the same way as heavy oils obtained directly from crude oil, and can be used as a fuel source when carrying out this process or in general boilers. Furthermore, in the method of the present invention, after the separation step,
When supplying a light fraction from which high boiling point substances have been separated and removed to a hydrotreating process, substances contained in heavy hydrocarbons that are poisonous to the hydrogenation catalyst must be removed in advance. Therefore, the hydrogenation treatment of polycyclic aromatic rings in the hydrogenation process can be carried out while maintaining the activity and life of the catalyst at a high level. This not only guarantees a high yield of petrochemical raw materials in the steam pyrolysis process, but also significantly reduces carbon deposition in the steam pyrolysis reactor, increasing the regeneration interval of the reactor, etc. A large economic effect will be generated. Furthermore, hydrotreated pyrolysis oil can be subjected to steam pyrolysis without fractional distillation, so petrochemical raw materials can be obtained in high yields and there is little by-product fuel oil. It also has some characteristics. In the thermal decomposition step in the method of the present invention, an oil-soluble transition metal compound or a substance having a hydrogenation catalytic effect obtained by converting these transition metal compounds by the action of hydrogen or hydrogen sulfide and heat, and an average particle size of about 5 to 500 mμ are used. It is necessary that ultrafine particulate matter in the range of . These two components do not need to be specially prepared in advance to form a composite, and it is sufficient to add them separately to the heavy hydrocarbon raw material. That is, even if each is added separately, when the transition metal compound reacts in the reaction zone or at a stage before the reaction zone and is converted into a substance having a hydrogenation catalytic effect, they interact with the ultrafine particulate material. It is thought that the material system will automatically change into a material system that performs the specified function. It is necessary that the added ultrafine particulate material be present in a dispersed state in the heavy hydrocarbon. The term "dispersed state" as used herein means a state in which solid particles are substantially present in a liquid or a state in which a solid phase is discontinuously distributed in a continuous liquid phase, such as a sol, colloid, slurry or This includes what is called a paste state. Further, as a material system having a predetermined function, the thermal decomposition products obtained by the present invention or the heavy residues obtained by fractionating the thermal decomposition products by distillation etc. can be reused as they are, or these It is also possible to reuse the solids separated and recovered. In the above-mentioned oil-soluble transition metal compounds, the transition metals include all transition elements in the periodic table of elements, but are particularly selected from vanadium, chromium, iron, cobalt, nickel, copper, molybdenum, silver, and tungsten. metals selected from the group consisting of metals and mixtures thereof are preferred. Among these transition metal-containing compounds, examples of oil-soluble compounds include cyclopentadienyl groups,
So-called π-complexes containing allyl groups as ligands, organic carboxylic acid compounds, organic alkoxy compounds, diketone compounds such as acetylacetonate complexes, carbonyl compounds, organic sulfonic acid or organic sulfinic acid compounds, xanthines such as dithiocarbamate complexes Examples include acid compounds, amine compounds such as organic diamine complexes, phthalocyanine complexes, nitrile or isonitrile compounds, and phosphine compounds. Particularly preferred oil-soluble compounds include fatty acids such as stearic acid and octylic acid, which are highly soluble in oil, do not contain heteroelements such as nitrogen and sulfur, and are relatively easy to convert into hydrogenation catalytic substances. Examples include compounds of the group carboxylic acids. Further, it is preferable that the molecular weight of the compound is small because the amount to be used relative to the required amount of transition metal can be reduced. Ultrafine particulate materials with an average particle diameter in the range of about 5 to 500 mμ that can be present in a dispersed state in heavy hydrocarbons are conventional solid catalysts or carriers used for solid catalysts commonly known in the art; And compared to these mere pulverized products, it shows the following excellent effects. In other words, (1) high dispersion and large free movement can be ensured in the reaction zone, providing a uniform reaction field without localization, and (2) there is little zoning in the reaction zone, eliminating the possibility of attached or deposited polycondensation. (3) Formed from transition metal compounds, such as asphaltene, coke spray cursor, coke, etc., can be easily discharged out of the reaction zone in a highly dispersed and suspended state to prevent clogging in the reaction zone. Examples include preventing the agglomeration of the hydrogenation catalytic substances and highly dispersing them to increase the activity of the hydrogenation catalytic substances. Moreover, the most important feature of the ultrafine particulate material is that it has an extremely large external surface area compared to conventional substantially porous solid catalysts and supports. Even when conventional solid catalysts and supports are pulverized, they are usually widely distributed in the range of several micrometers to several + micrometers, and the outer surface area is extremely small, and the expected effect is mostly on the inner surface inside the pores. be. However, when a reaction occurs inside the pores, the diffusion rate of the reactant becomes a problem, and a concentration gradient of the reactant is created between the center of the particle and the vicinity of the surface, resulting in a non-uniform reaction site. Therefore, the effective coefficient is always a problem, and physical structures such as pore distribution and crushed particle size distribution greatly affect performance. Moreover, when heavy hydrocarbons are used as raw materials, substances with large molecular weights such as asphaltene-like substances, porphyrin-like substances containing heavy metals, and coke precursors and coke that are generated can reach the inside of the pores. The inner surface, which is essentially dependent on the pores, becomes more likely to block the pores near the surface.
It only works a little and doesn't have the desired effect. On the other hand, the ultrafine particulate material in the present invention is a material system that is not substantially porous or is not expected to be porous, and only the large outer surface acts effectively to obtain a certain shape. Demonstrates the effect of As the particle size becomes smaller, the outer surface area becomes dramatically larger; for example, in the case of a particle size of 10 to 50 mμ, the outer surface area becomes about 300 to 60 ^{m 2} /g, and the degree of effect is extremely excellent. Fine ceramics and gas-phase carbonized materials are examples of ultrafine particulate materials that can satisfy such properties. Examples of fine ceramics include ultrafine particles of silicic acid, silicates, alumina, titania, and the like. Among these, ultrafine particles of silicic acid and silicates are a group of many types of substances commonly called white carbon, and are used for thermal decomposition of silicon halides, thermal decomposition of silicic acid-containing substances, and organic silicon compounds. Dry manufacturing method such as thermal decomposition of
and decomposition of sodium silicate with acid, decomposition of sodium silicate with ammonia salts or alkali salts, generation of alkaline earth metal silicate from sodium silicate and then decomposition with acid, and conversion of sodium silicate solution into ion exchange resin. Ion exchange, pressurized decomposition of organogel, decomposition of silicon halide with water, decomposition of sodium silicate solution with silica by-product in the lime superphosphate production process, production using natural silicic acid or silicate. , by a wet manufacturing method such as by reacting sodium silicate with a hydroxide such as calcium hydroxide or calcium chloride or aluminum chloride or sodium aluminate, or by treating quartz or silica gel with calcium hydroxide in an autoclave. be synthesized. The particle size of the fine ceramics thus obtained can be measured using an electron microscope, and varies depending on the type, but is approximately 5 to
It is within the range of 50mμ, and its surface area is
The outer surface area calculated from the particle size measured with an electron microscope and the specific surface area determined by the gas adsorption method (BET method) are approximately 50 to 400 m ² /g.
is within the range of On the other hand, examples of gas-phase carbonized substances include carbon black, pyrolytic carbon, and the like. Unlike fine ceramics, this gas-phase carbonized material can be combusted, which is advantageous when the heavy residue of the product after the lightening reaction is used as boiler fuel or the like. Liquid phase or solid phase carbonized substances have too large a particle size and are unsuitable for use in the method of the present invention, whereas this vapor phase carbonized substance has a particle size that is similar to that of the present invention. Since most of them fall within the particle size range, they can be used as is.
Among these, carbon black includes a wide range of types produced as gas-phase carbonized substances, and its manufacturing methods include oil-arnece method, gas furnace method, channel method, thermal method, acetylene black method, and by-product carbon black. There are methods such as the Lampblack method and the Lampblack method. The particle size of such carbonaceous substances can be measured using an electron microscope, and varies depending on the type, but is about 9 to
500 mμ, within the range of approximately 9 to 100 mμ excluding the thermal method, and the surface area is the outer surface area calculated from the particle size measured with an electron microscope and the specific surface area determined by the gas adsorption method (BET method). is almost the same and is within the range of about 5 to 400 m ² /g. As described above, the ultrafine particulate material used in the present invention is generally synthesized artificially by a relatively special method compared to solid catalysts and supports known in the art. be. When the ultrafine particulate material in the present invention is added to the raw material heavy hydrocarbon, it may be added directly as it is, or a concentrated solution dispersed in another medium may be added. The liquid containing the ultrafine particulate material may be subjected to mechanical manipulation using a stirrer, ultrasonic waves, a mill, etc. to improve dispersibility, or may be further treated with a dispersant such as a neutral or basic phosphonate or Metal salts such as phenates, calcium or barium sulfonates, succinimides, succinic esters, benzylamine, polypolar polymer compounds, and the like may be added. In the method of the present invention, when the transition metal compound and the ultrafine particulate material are added separately to the heavy hydrocarbon, the amount of the transition metal compound added is preferably based on the weight of the heavy hydrocarbon in terms of metal. Ten~
1000 ppm, more preferably in the range of 50 to 500 ppm, and the amount of ultrafine particulate material added is preferably 0.05 to 10%, based on the weight of heavy hydrocarbons.
More preferably, it is in the range of 0.1 to 3%. Further, even when the two types of components are prepared in advance to form a material system that exhibits a predetermined function, it is desirable to use the amounts of each within the ranges described above. If the amount of transition metal compound is less than 10 ppm based on heavy hydrocarbons in terms of metal, and the amount of ultrafine particulate matter is less than 0.05% by weight, polycondensation reaction and coke formation reaction which are side reactions A sufficient suppressing effect cannot be obtained, and a sufficient scaling (caulking) preventing effect cannot be obtained. On the other hand, if the amount of the transition metal compound exceeds 1000 ppm in terms of metal, and the amount of ultrafine particulate matter exceeds 10% by weight, no improvement in effectiveness is observed in relation to these amounts, which is rather undesirable. There is a risk of side reactions, solid/liquid phase separation in the reaction zone, and associated clogging phenomena. The thermal decomposition conditions in the method of the present invention depend on the properties and amounts of the heavy hydrocarbon used as a raw material and the transition metal compound and ultrafine particulate matter added thereto, but the reaction temperature is 400 to 550°C. A range of 430-520°C is used.
In a high temperature range exceeding this temperature range, thermal decomposition progresses too much and the production of coke and gas becomes significant, and there is virtually no raw material to be lightened, while in a low temperature range below this temperature range, thermal decomposition The speed tends to be significantly slower. The reaction pressure used is in the range of 30Kg/ ^cm2 to 300Kg/ ^cm2 , preferably 50Kg/ ^cm2 to 250Kg/ ^cm2 . This thermal decomposition can be carried out either batchwise or continuously, but the reaction time or residence time of heavy hydrocarbons in the reactor is in the range of 1 minute to 2 hours, preferably 3 minutes to 1 hour. A range of is good. These processing conditions do not each take an appropriate value independently, but are related to each other, so the preferable range may change depending on the case. Further, in carrying out thermal decomposition, the preferable amount of hydrogen is supplied so that the volume ratio to the raw material heavy hydrocarbon is in the range of 100 to 5000 Nm ³ /K, more preferably in the range of 500 to 2000 Nm ³ /K. However, in general, it is desirable to operate by replenishing the amount of hydrogen that corresponds to the amount of hydrogen consumed. As the supplied hydrogen, either highly pure hydrogen or a mixed gas containing a large amount of hydrogen can be used. Also, when using hydrogen containing hydrogen sulfide,
It is sufficient to use a total amount corresponding to the above-mentioned amount, but the hydrogen sulfide content is preferably about 1 to 10 mol%. The reactor type for continuous reaction can be a tube reactor, tower reactor, or tank reactor, but in these, the ultrafine particulate matter is not made into a packed bed or boiling bed, but dispersed. It is desirable to carry out the suspension reaction in this state. Suspension reaction has a simpler reactor structure, it is easier to control the temperature of the reaction, there is no change in performance over time, and clogging due to coking is less likely to occur. In addition,
Since high-temperature, short-time reactions are relatively easy, superficial velocity can be increased, unit throughput can be increased, and hydrogenation activities such as nuclear hydrogenation can be suppressed, making chemical hydrogen consumption relatively small. can. The separation step in the present invention is necessary for separating and removing high boiling point substances from the light hydrocarbon oil recovered in the pyrolysis step and supplying it to the next step, the steam pyrolysis step or the hydrotreating step. It is. The high boilers separated and removed in this step can be used as a fuel source. As a method for separating high-boiling substances, commonly used high-pressure gas separation, atmospheric distillation, vacuum distillation, and solvent deasphalting can be employed. In addition, in this process, as necessary, naphtha fraction (boiling point up to 200℃), kerosene fraction (boiling point 200-343℃), vacuum gas oil fraction (boiling point 343-545℃), etc. These various light fractions that have been fractionated and separated can be directly or separately subjected to hydrogenation treatment, and then subjected to steam pyrolysis. In the method of the present invention, the hydrogenation catalyst used when carrying out the hydrotreating step can be a known catalyst for hydrotreating petroleum fractions and heavy oil, preferably metals from group b of the periodic table. Catalysts each containing one or more metals selected from group metals, such as nickel-molybdenum, cobalt-molybdenum, and nickel-tungsten, supported on an inorganic porous carrier can be used. desirable. These metal species are usually used as oxides or sulfides, and examples of inorganic porous carriers include alumina, silica, silica-alumina, zeolite, zeolite-containing alumina, alumina-boria, silica-alumina-titania, etc. It will be done. These catalysts are used for hydrogenation of thermally cracked oil from which poisonous substances such as alpha-artene and metals have been removed, so the larger the surface area of the carrier, the better the activity. Unlike oil treatment catalysts, there is no need to particularly increase the pore volume of large pores. Hydrotreating conditions in this step can be arbitrarily selected depending on the heavy hydrocarbon raw material and the properties of the catalyst, but the reaction temperature is 250 to 480°C, preferably
It is in the range of 300-450℃. When the reaction temperature exceeds 480°C, thermal decomposition of side reactions progresses too much, increasing carbon deposition on the catalyst, increasing hydrogen consumption due to increased gas generation, and decreasing liquid yield.
If the temperature is lower than 250°C, the reaction rate will be significantly reduced. The reaction pressure is 30 to 300Kg/cm ² , preferably 50 to 250Kg/cm 2 .
It is in the range of Kg/cm ² and is largely related to the hydrogenation ability of the catalyst. Furthermore, the liquid hourly space velocity (LHSV) is 0.1~
5.0hr ^-1 , preferably in the range of 0.2 to 3.0hr ^-1 ,
Further, the amount of hydrogen supplied is in the range of a volume ratio of 200 to 2000 Nl/l to the hydrotreated raw material oil. Each of these conditions does not take an appropriate value on its own, but they are interrelated, and include not only the properties of the raw oil and catalytic activity, but also the requirements from the next step, the steam pyrolysis step. A suitable range is selected depending on. Pyrolysis product oil from which high-boiling substances have been separated and removed in the separation process or hydrotreated oil recovered in the hydrotreating process are used as feedstock oil in the steam pyrolysis process, but each distillate is fractionated depending on the purpose. It is also possible to carry out steam pyrolysis of the fractions individually or in mixtures with other petroleum fractions. The steam pyrolysis method used in the steam pyrolysis step in the method of the present invention is not particularly limited, and various methods can be adopted. It can also be used with some modification. The reaction conditions in this steam pyrolysis step include a steam/hydrogenation weight ratio of 0.2 to 2.0, preferably
The range of 0.4-1.5, the thermal decomposition temperature is 700-900℃, preferably the range of 750-900℃, the residence time is 0.05-2.0
seconds, preferably in the range of 0.1 to 0.6 seconds. The products obtained by this steam pyrolysis reaction are guided from the cracking tube to a quenching heat exchanger for heat recovery, and then separated and purified to produce gaseous olefins, monocyclic aromatic hydrocarbons, and Raw fuel oil and other by-product hydrogen and hydrocarbons are obtained. When carrying out the method of the present invention, the hydrogen used in the thermal decomposition process, the separation and removal process of high-boiling substances, the hydrogenation process, etc. may contain hydrogen gas separated from each process as the case may be. After removing hydrogen sulfide and ammonia, it is desirable to circulate the hydrogen sulfide and ammonia and supply it to each process, usually replenishing the amount of hydrogen consumed. In this case, the hydrogen source may be hydrogen by-produced by steam pyrolysis, or hydrogen obtained by steam reforming of by-product hydrocarbon gas or by-product fuel oil. Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. FIGS. 1 and 2 are different examples of process diagrams for carrying out the method of the present invention.
To explain the method of the present invention according to the steps shown in the figure, raw material heavy hydrocarbon to which a transition metal compound and ultrafine particulate matter have been added is pressurized by a feed pump, and hydrogen or hydrogen containing hydrogen sulfide is pumped through line 1. The pressure of the heavy hydrocarbons is increased by the compressor and introduced into the thermal cracker 3 through lines 2, where the heavy hydrocarbons are lightened, and the resulting lightened products are rapidly cooled through line 4 and It is sent to separator 5. This high-pressure gas-liquid separator usually consists of two stages: a hot separator and a cold separator. Hydrogen-rich gas from the cold separator is discharged through line 6, and if necessary, after being pressurized to a predetermined pressure, it is recycled to the pyrolysis device 3. be done. The liquid from the hot separator and the cold separator does not need to be particularly preheated, and is supplied to the normal pressure flushing device 8 through the line 7. Next, a take-out pipe 9 is inserted from the lower part of this normal pressure flushing device 8.
The atmospheric distillation residue taken out is further sent to the vacuum flushing device 10 for treatment. The vacuum flushing device 10 is equipped with a vacuum generator to lower the operating temperature and is operated under reduced pressure, and in some cases steam distillation is used as an auxiliary means by blowing steam from the bottom of the column to lower the partial pressure of the oil. can. The atmospheric distillate oil from the atmospheric pressure flashing device 8 and the vacuum distillate oil from the vacuum flashing device 10 are mixed through lines 13 and 14, respectively, after removing off gas from lines 11 and 12, respectively, and then flowing into line 15. be introduced. On the other hand, the vacuum distillation residue taken out from the lower part of the vacuum flushing device 10 through the extraction pipe 16 may be used as a liquid fuel as it is, but it may also be introduced into the solid separator 17 and subjected to a solid separation operation. . The solid separator 17 is
Examples include centrifuges, filters, solvent settlers, and combinations thereof. A portion of the vacuum distillation residue or solids or solids that have been further cleaned and dried (not shown) are added to the raw material heavy hydrocarbons via line 18 and recycled. The vacuum distillation residue liquid from which most of the solids have been removed in the solids separator 17 is discharged through a line 19 and can be used as liquid fuel. The distillate introduced into the line 15 is pressurized by a supply pump, supplied to a hydrotreater 20, and hydrogenated by hydrogen pressurized by a compressor from a hydrogen line 21. The hydrogenated product is cooled to a predetermined temperature by heat exchange or the like, and sent through line 22 to high-pressure gas-liquid separator 23 where it is separated into gas and liquid. The separated hydrogen rich gas is sent to line 24.
If necessary, the pressure is increased to a predetermined pressure.
It is circulated to the hydrotreating apparatus 20. On the other hand, the hydrotreated liquid is depressurized through the line 25 and introduced into the gas-liquid separation liquid 26, and after the Takai off-gas at vapor pressure is discharged from the line 27, it is sent to the steam pyrolysis device 29 via the line 28. . Here, the decomposition products are thermally decomposed by steam, and the decomposition products are taken out through line 30, cooled, separated, and purified to be recovered as gaseous olefins, monocyclic aromatic hydrocarbons, by-product hydrogen, by-product fuel oil, etc. . The process diagram of FIG. 2 shows a case where the hydrogenation treatment step is not required, and is a process diagram in which the reference numerals 20 to 28 in FIG. 1 are omitted. EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 The vacuum distillation residual oil of Minas crude oil (100% by weight of fraction with a boiling point of 520°C or higher) was used as the raw material, and the inner diameter was 40 mm.
Thermal decomposition was carried out using a flow-through type high-pressure apparatus having a reactor equipped with a stirrer equipped with three three-blade turbine-type stirring blades in a tank-type high-pressure vessel with a height of 100 mm. As a component added to the raw oil, 200ppm of nickel octylate is added to the raw oil as nickel.
Oil furnace carbon black [average particle diameter 20 mμ by electron microscope (EM), specific surface area 120 m ² /g by BET method] is 2% by weight based on raw oil.
Each was added, and the raw material oil was thoroughly stirred and supplied to the reaction tower. The reaction conditions were: temperature 495℃, pressure 200Kg/cm ² , residence time (cold liquid base) 20
Thermal decomposition was carried out at a hydrogen/feedstock oil ratio of 2000 Nl/l and a stirrer rotation speed of 1000 rpm. The resulting thermal decomposition product from which gas components were removed was distilled under normal pressure and reduced pressure to separate and remove high-boiling substances with a boiling point of 520°C or higher. Distillate with a boiling point of less than 520°C is processed using an external heat tube cracker, with an inlet temperature of 550°C, an outlet temperature of 830°C,
Steam pyrolysis was carried out under the conditions of an outlet pressure of 0.8 Kg/cm ² G, a steam/oil weight ratio of 1.0, and a residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. As a result of the implementation, the product recovered in the pyrolysis process has a C ₁ to C ₄ gas content of 5.8 as feedstock oil.
The amount of liquid hydrocarbons was 94.2% by weight, the amount of asphaltene (defined as insoluble in hexane and soluble in tetrahydrofuran) was 2.1% by weight, and the amount of coke (defined as insoluble in tetrahydrofuran) was 1.0% by weight. In addition, the amount of coking (scaling amount) on the inner wall of the reactor was very small at 40 ppm based on the total feed weight of feedstock oil. Further, the hydrogen consumption amount was 110 Nl per kg of raw material. In the next separation process, the GO ^- (boiling point 343℃>) fraction obtained by atmospheric distillation is 45.2% by weight based on the starting material oil, and the VGO (boiling point 343-520℃) fraction obtained by vacuum distillation is the starting material oil. The vacuum distillation residue (VR) was 20.0% by weight. Therefore, the lightening rate in the pyrolysis process is: (1 - fraction of fraction with a boiling point of 520℃ or higher in the product/ratio of fraction with a boiling point of 520℃ or higher in the feedstock) x 100% by weight: 80% by weight and boiling point of 520℃
The yield of lighter liquid fractions is less than GO ^- and VGO
The total weight is 74.2% by weight. The results of the final step, steam pyrolysis, are shown in Table 1, along with the yields of the main chemical raw materials (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Example 2 A distillate with a boiling point of less than 520°C obtained by performing the same thermal decomposition step and separation step as in Example 1 was used as a raw material oil,
A fixed bed reactor was filled with an alumina-supported cobalt-molybdenum catalyst containing 4% by weight of cobalt oxides and 14% by weight of molybdenum oxides with a surface area of 240 m ² /g and a pore volume of 0.53 ml/g. After pre-sulfiding using a hydrogenation reactor, hydrogen/raw oil ratio 1000Nl/l, temperature 390
Hydrogenation was carried out under the conditions of 150 Kg/cm ² , LHSV 1.0 hr ^-1 and the hydrogenated oil was recovered. The recovered hydrotreated oil was treated using an external heating tube cracker as in Example 1, with an inlet temperature of 550°C, an outlet temperature of 830°C, an outlet pressure of 0.8 Kg/cm ² G, a steam/oil weight ratio of 1.0, and a retention rate of 1.0. Steam pyrolysis was carried out for 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. As a result of the example, the thermal decomposition result and the separation result are the same as in Example 1, and the yield of the hydrotreated oil excluding the gas component in the next hydrotreating step is the same as that in the hydrotreating step. It was 99.3% by weight based on the raw material oil. The properties of the recovered hydrotreated oil are shown in Table 2 together with the properties of the light hydrocarbon oil having a boiling point of less than 520°C after the separation step. The results of subjecting the hydrotreated oil to the final step of steam pyrolysis are shown in Table 1, along with the yield of the main chemical feedstocks (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Comparative Example 1 The pyrolysis process was carried out in the same manner as in Example 1 except that the two types of components were not added to the feedstock oil, but a phenomenon of blockage due to coking of the reactor occurred in the initial 2 hours of operation, resulting in stable operation. could not be implemented. Boiling point under pyrolysis conditions that allow stable operation
The yield of the liquid fraction below 520°C was 34.1% by weight, which was less than half of that in Example 1. After removing the gas components that were able to operate stably in the pyrolysis process, the pyrolysis products were distilled at normal pressure and reduced pressure in the separation process, and the distillate with a boiling point of less than 520°C was subjected to hydrogenation treatment in the same manner as in Example 2. The operation of the process and steam pyrolysis process was carried out. The results of the steam pyrolysis are shown in Table 1 along with the yields of the main chemical feedstocks (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Comparative Example 2 The same hydrogenation equipment as in Example 2 was used for the thermal decomposition process, and the surface area contained 6% by weight of nickel oxide and 19% by weight of tungsten oxide.
Using a 70 wt% silica/30 wt% alumina supported nickel-tungsten catalyst with a pore volume of 230 m ² /g 0.37 ml/g, the temperature was 380°C and the reaction pressure was 200 kg/g as conditions that the catalyst activity did not deteriorate significantly in the initial stage of operation.
cm ² G, LHSV0.5hr ^-1 , hydrogen/raw oil ratio 2000Nl/
The experiment was carried out using the following conditions. Boiling point in this case
The yield of liquid fraction below 520°C was only 16.5% by weight. The obtained liquid fraction was subjected to a steam pyrolysis step in the same manner as in Example 1. The results of the steam pyrolysis are shown in Table 1, along with the yields of the main chemical feedstocks (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. As is clear from the results of Examples 1 and 2 and Comparative Examples 1 and 2, the method of the present invention decomposes heavy hydrocarbons to obtain a high yield of raw material to be fed to steam pyrolysis, It can be seen that this is an excellent method for obtaining a high yield of petrochemical raw materials. Moreover, the boiling point obtained in the separation process of the present invention is 520
The kinematic viscosity of residual oil above ℃ is as low as 22cst at 150℃.
In addition, its combustibility on a thermobalance is the same as that of Minas vacuum distillation residue oil, which is the raw material oil, and it can be used satisfactorily as a fuel oil. Example 3 The vacuum distillation residue of Daqing crude oil (100% by weight of the fraction with a boiling point of 520° C. or higher) was used as the feedstock oil, and was thermally cracked using the same flow-through high pressure equipment as in Example 1. As ingredients added to the raw oil, 500 ppm of copper naphthenate as copper, wet process silicic acid [average particle size 15 mμ]
(EM method), specific surface area 210m ² /g (BET method)]
Each weight% was added, and the raw material oil was thoroughly stirred and supplied to the reactor. The reaction conditions were a temperature of 490℃ and a pressure of 150Kg/ ^cm2.
Adopts a residence time (cold liquid base) of 20 minutes, a hydrogen/raw oil ratio of 2000Nl/l, and a stirrer rotation speed.
Thermal decomposition was carried out at 1000 rpm. The resulting thermal decomposition product from which gas components were removed was distilled under normal pressure and reduced pressure to separate and remove high-boiling substances with a boiling point of 520°C or higher. Distillate with a boiling point of less than 520°C is processed using an external heat tube cracker, with an inlet temperature of 550°C, an outlet temperature of 830°C,
Steam pyrolysis was carried out under the conditions of an outlet pressure of 0.8 Kg/cm ² G, a steam/oil weight ratio of 1.0, and a residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. As a result of the pyrolysis step and the separation step, the lightening rate was 81.4% by weight, the yield of lightened liquid fraction with a boiling point of less than 520 ° C. was 76.0% by weight, and the amount of coke produced was 1.4% by weight. The amount of coking on the inner wall of the reactor during the pyrolysis process was very small at 20 ppm based on the total feed weight of feedstock oil. Furthermore, the amount of hydrogen consumed in the pyrolysis step was 100 Nl per kg of raw material.
The results of the final step of steam pyrolysis are shown in Table 1, along with the yields of the main chemical raw materials (main gaseous olefins and monocyclic aromatic hydrocarbons) per starting material. Example 4 Vacuum distillation residue of Arabian Light crude oil (boiling point
Using 100% by weight of the distillate above 520°C as the raw material,
Thermal decomposition was carried out using the same flow-through high pressure apparatus as in Example 1. As components added to the raw oil, 500 ppm of vanadium acetylacetonate and 3% by weight of dry process silicic acid [average particle size 12 mμ (EM method), specific surface area 230 m ² /g (BET method)] were added, and the raw oil was added. was sufficiently stirred and supplied to the reactor. The reaction conditions are temperature 480℃, pressure 200Kg/
^cm2 , residence time (cold liquid basis) 25 minutes, hydrogen/
The raw material oil ratio was 2000Nl/l, and the rotation speed of the stirrer was 1000rpm for thermal decomposition. The resulting thermal decomposition product from which gas components were removed was distilled under normal pressure and reduced pressure to separate and remove high-boiling substances with a boiling point of 520°C or higher. Distillate with a boiling point of less than 520°C is processed using an external heat tube cracker, with an inlet temperature of 550°C, an outlet temperature of 830°C,
Steam pyrolysis was carried out under the conditions of an outlet pressure of 0.8 Kg/cm ² G, a steam/oil weight ratio of 1.0, and a residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. As a result of the pyrolysis step and the separation step, the lightening rate was 74.7% by weight, the yield of lightened liquid fraction with a boiling point of less than 520 ° C. was 68.9% by weight, and the amount of coke produced was 1.0% by weight. The amount of coking on the inner wall of the reactor during the pyrolysis process was very small at 200 ppm based on the total feed weight of feedstock oil. Further, the hydrogen consumption amount in the pyrolysis process was 170 Nl per kg of raw material. The results of the final step, steam pyrolysis, are shown in Table 1, along with the yields of the main chemical raw materials (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Example 5 A distillate with a boiling point of less than 520°C obtained by performing the same thermal decomposition step and separation step as in Example 4 was used as a raw material oil,
Same as Example 2 using an alumina-supported nickel-molybdenum catalyst having a surface area of 230 m ² /g and a pore volume of 0.60 ml/g, containing 4% by weight of presulfurized nickel oxide and 14% by weight of molybdenum oxide. Hydrogenation treatment was carried out using a flow type hydrogenation reactor. The reaction conditions were a hydrogen/raw oil ratio of 1000Nl/l,
The temperature was 400°C, the pressure was 200Kg/cm ² , and the LHSV was 0.8hr ^-1 . The recovered hydrotreated oil was processed using an external heating tube cracker at an inlet temperature of 550°C, an outlet temperature of 830°C, an outlet pressure of 0.8 Kg/cm ² G, and a steam/hydrogenated oil weight ratio.
Steam pyrolysis was carried out under the conditions of 1.0 and residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. As the implementation results, the thermal decomposition results and separation results are the same as in Example 4, and the yield of the hydrotreated oil excluding the gas component in the next hydrotreating step is the same as that of the raw material in the hydrotreating step. It was 99.0% by weight based on the oil. The properties of the recovered hydrotreated oil are shown in Table 2 together with the properties of the light hydrocarbon oil having a boiling point of less than 520°C after the separation step. The results of subjecting the hydrotreated oil to the final step of steam pyrolysis are shown in Table 1, along with the yield of the main chemical raw materials (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil.

【table】

【table】

[Table] Example 6 Nickel stearate as nickel
1000ppm, oil furnace method carbon black [average particle diameter 15mμ (EM method), specific surface area 200cm ² /
Arabian Light vacuum gas oil (normal pressure boiling point 343-520℃) containing 10% by weight of
3 kg was charged into a pressure-resistant autoclave, and hydrogen containing 5 mol% hydrogen sulfide was charged at a charging pressure of 100 kg/cm ² .
The reaction temperature was 420℃ while stirring at 1000rpm.
The reaction was carried out for 1 hour. After the reaction, the contents were filtered, washed and extracted with tetrahydrofuran,
A solid was obtained by drying. This solid was added to 10% by weight of vacuum distillation residual oil of Minas crude oil (100% by weight of fraction with normal pressure boiling point of 520°C or higher), which had been dissolved under heating, and highly dispersed using ultrasound. This dispersion was added to the same Minas vacuum distillation residual oil as above to a solid concentration of 2% by weight, and thoroughly stirred. Using the same reaction apparatus and reaction conditions as in Example 1, thermal decomposition was carried out. . The recovered pyrolysis products were subjected to a separation step, a hydrotreating step, and a steam pyrolysis step using the same equipment and conditions as in Example 2 to obtain olefins and monocyclic aromatic hydrocarbons. Ta. As a result of the pyrolysis step and the separation step, the lightening rate was 81.6% by weight, the yield of lightened liquid fraction with a boiling point of less than 520 ° C. was 75.6% by weight, and the amount of coke produced was 0.8% by weight. The amount of coking on the inner wall of the reactor during the pyrolysis process was very small at 40 ppm based on the total feed weight of feedstock oil. The yield of the hydrotreated oil excluding gas components in the next step, the hydrotreating step, is 99.4% compared to the feedstock oil in the hydrotreating step.
It was in weight%. The results of subjecting the hydrotreated oil to the final step of steam pyrolysis are shown in Table 3, along with the yield of the main chemical raw materials (main gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Example 7 The product liquid recovered in the thermal decomposition step of Example 1 was subjected to atmospheric distillation and vacuum distillation to separate and remove the fraction with a boiling point of 520°C or lower, the residue was filtered under heating, and the filtrate was extracted with tetrahydrofuran. After drying the residual solid matter, vacuum distillation residual oil of Minas crude oil (boiling point
100% by weight of the distillate above 520°C) to a total concentration of 4% by weight, and further added 0.5% by weight of a dispersant mainly composed of calcium salt of petroleum sulfonate, stirred thoroughly, and prepared as in Example 1. Thermal decomposition was carried out using the same reactor and reaction conditions. The recovered pyrolysis products were subjected to a separation step, a hydrotreating step, and a steam pyrolysis step using the same equipment and conditions as in Example 2 to obtain olefins and monocyclic aromatic hydrocarbons. Ta. As a result of the pyrolysis step and the separation step, the lightening rate was 81.8% by weight, the yield of lightened liquid fraction with a boiling point of less than 520 ° C. was 75.4% by weight, and the amount of coke produced was 1.6% by weight. The amount of coking on the inner wall of the reactor during the pyrolysis process was very small at 140 ppm based on the total feed weight of feedstock oil. The yield of hydrotreated oil excluding gas components in the next hydrotreating process is based on the feedstock oil in the hydrotreating process.
It was 99.2% by weight. The results of subjecting the hydrotreated oil to the final step of steam pyrolysis are shown in Table 3, along with the yield of the main chemical raw materials (main gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Example 8 The product liquid recovered in the thermal decomposition step of Example 1 was subjected to atmospheric distillation and vacuum distillation to separate and remove the fraction with a boiling point of 520°C or lower. (100% by weight) to 4% by weight
Furthermore, molybdenum naphthenate was added as molybdenum to 500 ppm based on the raw material oil, and dry process silicic acid [average particle size 8 mμ (EM method), specific surface area 350 m ² /g (BET method) )〕
Add to the raw material oil at a concentration of 0.5% by weight,
The raw material oil was thoroughly stirred and thermal decomposition was carried out using the same reaction apparatus and reaction conditions as in Example 1. The recovered pyrolysis products were subjected to a separation step, a hydrotreating step, and a steam pyrolysis step using the same equipment and conditions as in Example 2 to obtain olefins and monocyclic aromatic hydrocarbons. Ta. As a result of the thermal cracking step and the separation step, the lightening rate was 75.8% by weight, the yield of lightened liquid fraction with a boiling point of less than 520 ° C. was 69.7% by weight, and the amount of coke produced was 2.0% by weight. The amount of coking on the inner wall of the reactor during the pyrolysis process was very small at 180 ppm based on the total feed weight of feedstock oil. The yield of hydrotreated oil excluding gas components in the next hydrotreating process is based on the feedstock oil in the hydrotreating process.
It was 99.4% by weight. The results of subjecting the hydrotreated oil to the final step of steam pyrolysis are shown in Table 3, along with the yield of the main chemical raw materials (main gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil.

【table】

[Table] Example 9 Atmospheric distillation residual oil of Minas crude oil (100% by weight fraction with a boiling point of 343°C or higher, 45% by weight of a distillate with a boiling point of 520°C or higher)
was used as a starting material, and thermal decomposition was carried out using the same flow-through high pressure apparatus as in Example 1. Molybdenum naphthenate is used as molybdenum as two components added to raw oil during thermal decomposition.
100ppm, oil furnace method carbon black [average particle size 15mμ (EM method), specific surface area 200m ² /g
(BET method)] were added, and the thermal decomposition conditions were: temperature 490℃, pressure 150Kg/cm ² , residence time (liquid cold base) 18 minutes, hydrogen/feedstock oil ratio.
Adopts 1500Nl/l and the rotation speed of the stirrer
I went at 1000rpm. The resulting thermal decomposition products, excluding gas components, are subjected to normal pressure and vacuum distillation to separate and remove high-boiling substances with a boiling point of 520°C or higher, in the same manner as in Example 1.
The distillate at a temperature below 520°C was subjected to steam pyrolysis to obtain olefins and monocyclic aromatic hydrocarbons. The results of the steam pyrolysis of Example 9 are shown in Table 4, along with the yields of the main chemical feedstocks (mainly gaseous olefins and monocyclic aromatic hydrocarbons) per starting feedstock oil. Examples 10, 11 Atmospheric distillation residue of Arabian Light crude oil (boiling point
Using 100% by weight of the fraction with a boiling point of 343°C or higher and 46% by weight of a fraction with a boiling point of 520°C or higher as starting materials, thermal decomposition was carried out using the same flow-through high-pressure apparatus as in Example 1. In the case of Example 10, iron carbonyl was added as iron as the two types of components added to the feedstock oil during pyrolysis.
800ppm, channel method carbon black [average particle diameter 14mμ (EM method), specific surface area 300m/g
(BFT method)] were added, and in the case of Example 11, cobalt resin acid was added at 300 ppm as cobalt, thermal process carbon black [average particle diameter 180 mμ (EM method), specific surface area 15 m/g
(BET method)] was added in an amount of 6% by weight. The thermal decomposition conditions are 470℃ temperature and 200℃ pressure.
Kg/cm ² , a residence time (liquid cold base) of 30 minutes, a hydrogen/raw oil ratio of 2000 Nl/l, and a stirrer rotation speed of 1000 rpm. The resulting thermal decomposition product from which gas components were removed was distilled under normal pressure and reduced pressure to separate and remove high-boiling substances with a boiling point of 520°C or higher. The obtained distillate with a boiling point of less than 520°C is used as a raw material oil,
The same flow as in Example 2 was carried out using an alumina-supported nickel-molybdenum catalyst having a surface area of 270 m ² /g and a pore volume of 0.75 ml/g, containing 5% by weight of presulfurized nickel oxide and 20% by weight of molybdenum oxide. Hydrogenation treatment was carried out using a type hydrogenation reactor. The reaction conditions were a hydrogen/raw oil ratio of 1000Nl/l,
The temperature was 395°C, the pressure was 180Kg/cm ² , and the LHSV was 0.8hr ^-1 . The recovered hydrotreated oil was processed using an external heat tube cracker at an inlet temperature of 550°C, an outlet temperature of 830°C, an outlet pressure of 0.8 Kg/cm ² G, and a steam/hydrogenated oil weight ratio.
Steam pyrolysis was carried out under the conditions of 1.0 and residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons. The results of the steam pyrolysis of Examples 10 and 11 are shown in Table 4, along with the yields of the main chemical raw materials (main gaseous olefins and monocyclic aromatic hydrocarbons) per starting stock oil.

【table】

【table】 [Brief explanation of the drawing]

FIGS. 1 and 2 each show different examples of process diagrams for carrying out the present invention. Code 3 in the diagram
1 is a thermal decomposition device, 5 is a high pressure gas-liquid separator, 8 is a normal pressure flash device, 10 is a reduced pressure flash device, 17
2 is a solid separator, 20 is a hydrotreating device, 23 is a high-pressure gas-liquid separator, 26 is a gas-liquid separator, and 29 is a steam pyrolysis device.

Claims (1)

[Scope of Claims] 1 (A) Heavy hydrocarbons, ultrafine particulate materials with an average particle size of about 5 to 500 mμ selected from the group consisting of fine ceramics and gas-phase carbonized materials, and oil-soluble transition metal compounds. and thermally decompose the heavy hydrocarbon in the presence of hydrogen or hydrogen containing hydrogen sulfide,
A step of recovering light hydrocarbon oil, (B) a step of separating and removing high boiling point substances from light hydrocarbon oil, and (C) converting the hydrocarbon oil from which high boiling point substances have been separated and removed, alone or with other petroleum fractions. mixed with steam pyrolysis,
1. A method for producing gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbons, comprising a step of recovering gaseous olefins and monocyclic aromatic hydrocarbons. 2 Claims that at least a part of the solids separated from the light hydrocarbon oil recovered in the (A) process or the high-boiling substances separated and removed in the (B) process are reused in the (A) process. The method described in paragraph 1. 3. The method according to claim 1, wherein at least a part of the high-boiling substances separated and removed in step (B) is recycled and used in step (A). 4 Add ultrafine particulate matter with an average particle diameter of approximately 5 to 500 mμ selected from the group consisting of fine ceramics and gas-phase carbonized substances and an oil-soluble transition metal compound to heavy hydrocarbons, and contain hydrogen or hydrogen sulfide. a step of thermally decomposing the heavy hydrocarbon in the presence of hydrogen and recovering a light hydrocarbon oil; (B) a step of decomposing and removing high boiling point substances from the light hydrocarbon oil; (C)
A step of hydrotreating the hydrocarbon oil from which high boilers have been separated in the presence of a hydrogenation catalyst and recovering the hydrotreated oil; and (D) a step of recovering the hydrotreated oil alone or with other petroleum fractions. 1. A method for producing gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbons, comprising the steps of steam pyrolysis and recovering gaseous olefins and monocyclic aromatic hydrocarbons. 5 Claims that at least part of the solids separated and recovered from the light hydrocarbon oil recovered in the (A) process or the high boiling point substances separated and removed in the (B) process is reused in the (A) process. The method described in Section 4. 6. The method according to claim 4, wherein at least a part of the high-boiling substances separated and removed in step (B) is recycled and used in step (A).