JPS59147084A - Production of gaseous olefins and monocyclic aromatic hydrocarbons - Google Patents

Abstract

PURPOSE:After the pyrolysis of heavy hydrocarbons combined with a coking inhibitor in the presencke of hydrogen, the high-boiling fraction is removed, hydrogenation is effected in the presence of a hydrogenation catalyst, the gaseous products are removed, then the remaining fraction is subjected to steam cracking to obtain the titled compounds economically in high yield. CONSTITUTION:Heavy hydrocarbon 1 combined with a coking inhibitor is pyrolyzed in the pyrolyzer 3 in the presence of hydrogen 2 under conditions of 380- 550 deg.C temperature, 30-300kg/cm<2> pressure and 1-210 minute residential time and the formed gas 6 is separated from the pyrolysate 4 by means of high- pressure gas separator 5. Then, the residue is subjected to distillation using distillators 7 and 12 to separate the high-boiling fractions 11. The treated mixture is hydrogenated in the hydrogenator 15 in the presence of a catalyst and hydrogen 14 at 250-500 deg.C and 30-300kg/cm<2> and 0.05-5.0hr<-1> 1sv at a hydrogen/ pyrolysate ratio of 100-2,000Nl/l. The liquid product is steam-cracked under conditions of 700-900 deg.C, 0.05-2.0 second residential time, and 0.2-2.0 steam/ liquid product weight ratio in the cracker 18 and the objective compounds are obtained from the product 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a production method for producing gaseous olefins and monocyclic aromatic hydrocarbons using heavy hydrocarbon oil as a raw material (7,
More specifically, heavy hydrocarbon oil is thermally cracked under hydrogen co-σ, high-boiling substances are separated and removed from the resulting decomposition products, and then hydrotreated in the presence of hydrogen and a catalyst, followed by steam heat treatment. The present invention relates to a method for obtaining gaseous olefins and monocyclic aromatic hydrocarbons in high yield by decomposition.

Traditionally, ethylene, which is a basic raw material in the petrochemical industry,
In the production of casseous olefins such as propylene and butadiene, and monocyclic aromatic hydrocarbons such as hibenzene, toluene, and xolene, light hydrocarbons such as oilfield gas and oil refining byproducts such as soot are mainly used. It's coming. Among these, naphtha is treated as particularly superior because it has a high yield of the above-mentioned gaseous olefins/monocyclic aromatic hydrocarbons and also produces a small amount of low-value heavy fuel oil as a by-product. It's here.

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 by petroleum refining as the preferred raw material for pyrolysis has become insufficient, and its price has continued to rise. The economics of obtaining hydrocarbons have declined significantly.

Therefore, in order to solve these industrial structural problems, in recent years, heavier hydrocarbon oils such as kerosene, light oil, vacuum vaporized light oil, etc. are used for hydrotreating, followed by steam pyrolysis. Two attempts have been made to produce petrochemical raw materials by this method.

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, vacuum distillation residual oil, which is a heavy hydrocarbon oil, is subjected to solvent deasphalting (
7. A method of hydrotreating the deasphalted oil by mixing it with vacuum distilled gas oil is known, and it is possible to produce petrochemical raw materials by subjecting this hydrotreated oil to steam pyrolysis. However, with this solvent deasphalting method, a large amount of deasphalted residual oil containing asphaltenes is produced as a by-product, and the problem of effective utilization of this residual oil remains, and the yield of petrochemical raw materials cannot be significantly improved.

Furthermore, as a method for guiding heavy hydrocarbon oils such as atmospheric distillation residues to petrochemical raw materials in a slightly more advantageous manner, we have developed a fixed-end reaction system (RI fluidized bed method) in which a granular catalyst is filled in a reactor. Various methods have been proposed to actively reduce the residue from vacuum distillation using chemical decomposition methods.However, at present, the catalyst life may be shortened due to asphaltenes and heavy metals contained in the residue. However, because hydrogen consumption is unavoidable and hydrogen consumption increases, highly economical technology has not yet been realized.

As a way to proactively lighten heavy hydrocarbon oil, it is also possible to apply pyrolysis to obtain processed oil that can be used as a petrochemical raw material. However, when attempting to achieve a high degree of weight reduction using conventionally known thermal decomposition methods,
Since the so-called severe coking phenomenon occurs and the operation has to be stopped, this method is usually only applied to lightening where coking is not a big problem.

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/cri, sufficient coking suppression cannot be achieved. No effect can be obtained. Unfortunately, a so-called coker method has been proposed in which coke is actively produced and lightened, but in addition to the problem of disposing of the large amount of coke that is produced as a by-product, there is an increase in the amount of gas due to excessive decomposition. A decrease in oil yield cannot be avoided. In addition, the resulting pyrolyzed light oil has a large amount of aromatic and olefin components and is of poor quality. It is necessary to perform conversion processing.

Generally, from heavy hydrocarbon oils to olefins and monocyclic -y''
In order to obtain the most aromatics, (1) selectively lighten high boilers (e.g., residues with a boiling point of 550°C or higher); ℃
(2) Hydrotreating d
It is necessary to satisfy the two requirements of actively carrying out hydrogenation of the rings of polycyclic aromatics (rather than a mere desulfurization reaction).

However, in the conventional technology, even if it is attempted to lighten high boiling point substances by catalytic treatment of heavy oil, not only impurities such as sulfur and heavy metals contained in the oil but also the presence of basic polymer compounds, etc. As a result of the marked decrease 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 the method of thermally decomposing fresh hydrocarbons without a catalyst, the reaction rate is lower than that due to their large molecular weight. Known to be a dog) 1. However, it is extremely difficult to increase the decomposition rate due to the high coke formation and polycondensation reaction rate that occur as a secondary product during decomposition.

As described above, among the various methods for producing gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbon oils, there are methods in which heavy hydrocarbon oils such as atmospheric distillation residues and vacuum distillation residues are used as feedstocks. In all cases, technical and economic issues remain unresolved.

The present inventors have overcome the drawbacks of such conventional methods [7
As a result of intensive research into a method for producing gaseous olefins and monocyclic aromatic hydrocarbons economically and in high yields using heavy hydrocarbon oil as a raw material, we have developed a method for producing gaseous olefins and monocyclic aromatic hydrocarbons in the presence of hydrogen. After thermally decomposing heavy hydrocarbon oil and then separating and removing high boiling point substances from the thermally decomposed product, the resulting thermally decomposed product is hydrogenated to F in which hydrogen and hydrogenation catalyst coexist. By cracking, for the first time, useful petrochemical raw materials can be obtained economically and in high yield from heavy hydrocarbon oil, while at the same time causing the deterioration of by-product fuel oil, which is a residual oil with low value. The inventors have discovered that the production amount can be significantly reduced, and the present invention has been completed based on this knowledge.

That is, in the present invention, (A) heavy hydrocarbon oil to which a coking inhibitor has been added is heated to a temperature of 380 to 550 in the presence of hydrogen.
'C1 pressure 30~300 K9/cn! , a step of thermally decomposing under condition f-+ for a residence time of 1 to 120 minutes, (in the above step Bl?4) a step of separating and removing high boiling point substances from the thermal decomposition products; (C) a step of separating and removing high boiling point substances from the thermal decomposition products; The separated and removed thermally decomposed product was heated in the presence of a hydrogenation catalyst at a temperature of 250 to 500°C, a pressure of 30 to 300 K9/crl, and a liquid hourly space velocity of 0.
05-5. Ohr-', hydrogen/thermal decomposition product ratio 100~
Hydrotreating under the conditions of 2000 Nt7t and separating and removing hydrogen-containing gaseous products from the hydrogenated product obtained in step 0))(C), and then subjecting the liquid product to a temperature of 700 to 900 °C, residence time 0.05-2.0
a step of recovering gaseous olefins and monocyclic aromatic hydrocarbons from the resulting product after steam pyrolysis under conditions of a steam/liquid product weight ratio of 0.2 to 2.0. The present invention provides a method for producing heavy hydrocarbons characterized by the following.

The method of the present invention consists of two steps: a step of thermally decomposing heavy hydrocarbon oil in the coexistence of additives and hydrogen, a step of separating and removing high boiling point substances, a hydrotreating step, and a steam pyrolysis step. It has the following superior features compared to conventional technology.

That is, in the method of the present invention, by thermally decomposing heavy hydrocarbon oil to which a coking inhibitor has been added in the coexistence of high-pressure hydrogen, side reactions are significantly suppressed and high-boiling substances can be selectively decomposed. The high boiling point residues undergo a reforming effect and are operated as relatively low viscosity liquids.
It has the great advantage of being able to be used as boiler fuel oil.

Furthermore, in the method of the present invention, high-boiling substances are preliminarily separated and removed from the raw material to be supplied to the hydrotreating process in the separation process, so that the hydrogenation catalyst contained in the heavy hydrocarbon oil may be poisoned. As a result, the hydrogenation 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 precipitation in the steam pyrolysis reactor and increases the reactor amputation interval. There will be a huge economic impact. On the other hand, since the hydrotreated pyrolyzed oil undergoes steam pyrolysis without fractional distillation, it is possible to obtain a high yield of 100% oil [Higakugen 4:1] and as a by-product. ! ', 'R/llll
There are also four temple signs: mo and tonai.

The heavy hydrocarbon oil used in the method of the present invention refers to crude oil or residual oil from atmospheric distillation of crude oil (or residual oil from vacuum distillation), and also includes tar sand crude oil, coal liquefied oil, and the like. Such heavy hydrocarbon oil usually contains impurities such as sulfur compounds, nitrogen compounds, asphaltenes, heavy metals, etc.
It contains a large amount of heavy fractions with high boiling points that cannot be converted into petrochemical raw materials.The quantity and quality of these differ greatly depending on the crude oil produced.

When attempting to economically obtain gaseous olefins and aromatic hydrocarbons as much as possible, which is the objective of the method of the present invention, the hydrogen content of heavy hydrocarbon oil is relatively high. There are a lot of Barrafinic crude oils, such as Minas crude oil and Daqing crude oil, or their atmospheric distillation residues! Vacuum distillation residual oil and the like are preferred because they consume less hydrogen. These varaffinic crude oils are known to be relatively difficult to crack using conventional cracking methods.

As coking inhibitors added to the heavy hydrocarbon oil in the pyrolysis step of the process of the invention, transition metal compounds are preferred, especially those selected from iron, cobalt, nisochenopechrome, molybdenum, tungsten, barium and copper. Metal compounds are suitable.

These compounds may be used alone or in combination with
Mixtures may also be used; oil- or water-soluble compounds are still preferred.

Examples of oil-soluble compounds include so-called π-complexes containing ncropentadienyl groups, allyl groups, etc. as ligands, organic carboxylic acid compounds, organic alkokene compounds, diketone compounds such as acetylacetonate complexes, carbonyl compounds, and organic sulfonic acids. Alternatively, examples thereof include organic sulfinic acid compounds, gyzanthic acid compounds such as dithiocarbamate complexes, amine compounds such as organic diamino complexes, nitrile or innitrile compounds, and phosphine compounds. Examples of water-soluble compounds include carbonates, carboxylates, sulfates, nitrates, hydroxides, halides, and complex salts such as ammonium heptalybde 1. Particularly suitable oil-soluble compounds include organic carboxylic acid compounds such as stearic acid and octylic acid, and particularly suitable water-soluble compounds include sulfates.

When these metal compounds are added to raw material oil, oil-soluble ones may be added as they are, but water-soluble ones are preferably dissolved in water and added as an aqueous solution. In this case, it is advantageous to add a dispersant such as a surfactant to the aqueous solution since this improves the dispersibility of the heavy hydrocarbon oil and the aqueous solution. This metal compound is desirably added in an amount ranging from 50 to 8000 ppm based on the weight of the raw material oil in terms of metal.

If this amount is less than 50 ppm, a sufficient coking suppressing effect cannot be obtained, and even if it exceeds 8000 ppm, no improvement in the effect is observed, and there is a risk that undesirable side reactions may occur. be.

When carrying out the present invention, the thermal decomposition conditions in step (A) depend on the properties of the heavy hydrocarbon oil and metal compound used as raw materials, but the reaction temperature is 38
A range of 0 to 550°C is used, preferably a range of 400 to 520°C. In a high temperature range exceeding this temperature range, thermal decomposition progresses and the formation of plow coke and gas becomes significant, while in a low temperature range below this temperature range, the rate of thermal decomposition tends to slow down significantly.

The reaction pressure is 30 K2/crA ~ 300
K9/cni, preferably 50 Kt/cnl
A range of ~250 KfJ/cnt is used.

This thermal decomposition can be carried out either batchwise or continuously, but the reaction time or residence time of the heavy hydrocarbon oil in the reactor is in the range of 1 minute to 2 hours, preferably 3 minutes to 1 hour. Good time range. 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. Furthermore, the preferable amount of hydrogen for carrying out thermal decomposition is such that the volume ratio to the raw material heavy hydrocarbon oil is 100 to 5,0 OONffl"/A/
! and more preferably 200 to 2,000 N
It is generally desirable to supply the hydrogen so that t is in the range of /we, and to replenish the hydrogen in an amount commensurate with the amount of hydrogen consumed.

The hydrogen supplied to this thermal decomposition step may be highly pure hydrogen or cycle hydrogen generated from several steps, and generally a mixed gas containing a large amount of hydrogen may also be used.

Separation process 8 of step (B) in the method of the present invention is carried out in the above-mentioned (
From the thermal decomposition products obtained in step A1, high boiling point substances are separated and removed (necessary for supplying them to the next step (C), the hydrogenation process. The high boiling point substance can be handled as liquid fuel oil and can be used in the main manufacturing process, or can be used separately for acid boilers.

As a separation method in this step, commonly used high pressure gas separation, normal pressure distillation, vacuum distillation, etc. can be employed.

In this process, as necessary, in addition to high-boiling substances, naphtha fraction (boiling point 200 h), kerosene fraction (boiling point 200-343℃ fraction), and light and heavy fractions are added. (
It is also possible to remove the pyrolyzed oil (boiling point 343-450° C. fraction) and feed the resulting thermally cracked oil to the next hydrotreating step. These separated light fractions can be directly or separately hydrotreated and then subjected to steam pyrolysis.

When separating thermal decomposition products by flap distillation,
Preheated hydrogen gas is added to the lower part of the flash distillation apparatus, and is separated into a vapor stream and a flash distillation residual oil under high temperature and pressure, and after removing high boiling point substances from the residual oil by vacuum distillation, There is also a method of adding the obtained reduced pressure fraction to the previous vapor stream and supplying it to the hydrotreating step. This frasso/
The motive behind the distillation separation method is that the pressure loss is extremely low.
By being able to operate the three steps of pyrolysis, separation, and hydrotreating at substantially the same pressure, there is no need for an intermediate compressor required for hydrogen separation and recycling, and the pyrolysis products are Since the amount of heat retained in the reaction system can be used as is, the reaction operation of the entire reaction system can be simplified and energy consumption can be reduced, which is highly effective from an economic standpoint. In this case, the use of the hydrogen added 7' is determined by the operating conditions of the flash distillation apparatus, and is used in the next hydrotreating step. It is preferable to add hydrogen within a range that does not exceed the mixing ratio of hydrogen and oil.

As the catalyst used in step (C) of step (hydrogenation treatment) in the method of the present invention, which is used once a month in two steps, any known catalyst for the hydrotreatment of petroleum fractions and heavy oils can be used, preferably from Vl of the periodic table. Catalysts containing one or more metals selected from Group +) metals and Group II metals, such as nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, etc., supported on an inorganic carrier. It is desirable to use it. These metal species are usually used as sulfides, and examples of inorganic carriers include alumina, silica, silica-alumina, zeolite, and alumina-boria.

These catalysts are used in the hydrogenation process of thermally cracked oil from which substances such as alfalutin and metals have been removed.
] Therefore, as a physical property of the carrier, the larger the surface area, the better the activity, but unlike the high metal-containing oil treatment catalyst, it is not necessary to particularly increase the pore volume of large pore diameters.

The hydrotreating conditions in this step can be arbitrarily selected depending on the properties of the raw material heavy hydrocarbon oil and the catalyst, but the reaction temperature is 250 to 500°C, preferably 300 to 450°C.
℃ range. When the reaction temperature exceeds 500 °C, the thermal decomposition of side reactions progresses too much, leading to increased carbon deposition on the catalyst, increased hydrogen consumption due to increased gas generation, and decreased liquid yield. If the temperature is lower than 250°C, the reaction rate will be significantly reduced.

The reaction pressure is in the range of 30 to 300 K47cni, preferably 50 to 250 K7/cnI,
It is closely related to the hydrogenation ability of the catalyst. In addition, liquid hourly space velocity (
LHsv) is sail 05-5. Ohr', preferably O
-1 to 3.0 hr-', and the hydrogen supply amount is still in the range of 100 to 2 oo
It is in the range of ONt/l. These conditions do not each take an appropriate value independently, but are interrelated, and include not only the properties of the raw oil and the catalytic activity,
The preferred range for C is selected in response to the requirements of the next step, the steam pyrolysis step.

The hydrotreated oil thus obtained is processed into the following I
- It is used as a feedstock oil for steam pyrolysis in the [
Although it is possible to perform fractional distillation according to the requirements and subject each fraction to steam thermal decomposition, it is usually preferable to directly perform steam thermal decomposition without fractional distillation.

There is no particular restriction on the format of the steam heat component (yr) used in step (1)) in the method of the present invention, and various heat angles can be used. (The above method can be adopted, and it is also possible to use one of the existing naphtha cracking furnaces, such as an external heating tube type thermal fractionating furnace, or with some modifications.

The reaction conditions in this steam pyrolysis step are such that the steam/hydrotreated oil weight ratio is 0.2 to 2.0, and r↓0.
/1-1.5 range, thermal decomposition temperature 700-900℃,
Preferably in the range of 750~QOO℃, residence time [)
, 05 to 2.0 seconds, preferably 0.1 to 0.6 seconds.

The products obtained by this steam pyrolysis reaction are guided from the fractionating tube to a quenching heat exchanger for heat recovery, and then separated and purified to produce gaseous olefins, monocyclic aromatic hydrocarbons, and by-products. 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 recycle it and supply it to each process, and usually to replenish the amount of hydrogen consumed. In this case, the hydrogen source may be hydrogen 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.

Figures 1 and 2 are different examples of process diagrams for carrying out the method of the present invention. First, the method of the present invention will be explained according to the process shown in Figure 1. Heavy hydrocarbon oil 1 (is in pyrolysis unit 3 along with hydrogen 2)
After the hydrogen 6 is removed from the resulting thermal angle 1r product 4id in a high-pressure gas fraction PiII reactor 5, it is supplied to an atmospheric distillation device 7. The atmospheric distillation residual oil 8 which comes out of this atmospheric distillation apparatus is further separated and removed by the vacuum distillation apparatus (2) to remove the vacuum distillation residue 11. A mixture 13 of atmospheric distillate oil 9 and vacuum distillate oil 1.0 is supplied together with hydrogen 14 to a hydrotreating apparatus 15 to be hydrotreated. Hydrotreated oil [6 is the gas product 1 containing hydrogen in the high pressure gas separator 17
After removing 9, the liquid product 20 is decomposed together with water vapor in a steam pyrolysis device 18. Next, the steam pyrolysis product 21 is partially purified to separate and recover gaseous olefins, monocyclic aromatic hydrocarbons, by-product hydrogen, by-product fuel oil, and the like.

Next, the method of the present invention will be explained according to the steps shown in FIG. 2. The raw material heavy hydrocarbon oil 1 (ri,
Hydrogen 2 consisting of IJ cycle hydrogen and supplementary hydrogen 20 is decomposed in a thermal decomposition device 3, and the obtained thermal component W (product 4 is directly introduced into a flash distillation device 6 and supplied from the lower part of this device. It is flat distilled together with hydrogen 5 and separated into a vapor stream 8 and a flash residue 7.

From this residual oil, the vacuum distillation residual oil 9 is further separated and removed by a vacuum distillation device 12. The mixture [1] of the vacuum distillate 10 and the vapor stream 8 is supplied to the hydrotreater 15 with hydrogen for cooling or hydrogen amount adjustment added from the lie/21 as required. Hydrogen gas 17 is separated and recycled from the hydrotreated product 13 in a high-pressure gas separator 14, and the obtained liquid hydrotreated oil 20 is supplied to a steam pyrolysis device 18 together with steam. The steam pyrolysis product 19 is separated and purified to separate and recover gaseous olefins, monocyclic aromatic hydrocarbons, by-product hydrogen, by-product fuel t1 oil, and the like.

The method of the present invention consists of four steps: a step of pyrolyzing heavy hydrocarbon oil in the coexistence of additives and hydrogen, a step of separating and removing high boiling point substances, and a step of pyrolyzing the hydrotreated oil [culm and steam]. For the first time, this has made it possible to obtain high-yield petrochemical thick phases such as high-value gaseous olefins and monocyclic aromatic hydrocarbons from heavy hydrocarbon oils9, and its technical and economical aspects are Fruit (#: 1, (keme and thick.

Next, the present invention will be described in more detail with reference to Examples, but it is to be understood that the present invention is limited by the following.

\ / 7・' / Example 1 Vacuum distillation residual oil of Minas crude oil (fraction 9 with a boiling point of 550°C or higher)
1%) was thermally decomposed using a flow-type pressurization device having a reactor equipped with a stirrer in a seed-shaped high-pressure container with an inner diameter of 40 mm and a height of 500 mm. Nickel octylate was added to the raw oil obtained in this way at a concentration of 500% as nickel to the raw oil.
It was added so that it became ppm. As reaction conditions, temperature 49
The thermal decomposition was carried out at 5° C., a pressure of 150 9/cJ G, a residence time of 2 minutes, a hydrogen/raw oil ratio of 500 N/-/l, and a stirrer rotation speed of: 300 rpm.

The obtained thermal decomposition product was subjected to distillation under normal pressure and reduced pressure to separate and remove high-boiling substances with an M fluorination point of 550° C. or higher.

Distillate with a boiling point of 550°C or less is 550°C as nickel oxide.
% by weight, surface area containing 20% by weight as molybdenum oxide 270 n? / ? Using a flow type hydrogenation reactor with an inner diameter of 18 mm in which a fixed bed reactor was filled with an alumina-supported nickel molybdenum catalyst with a pore volume of 0.75 m1/f/, hydrogen/raw material oil conversion 100 ONt/11 temperature 400°C
, pressure 200 to 7/cJG, LH8VO,,8hr
Hydrogenated with 'Tea Juice'.

The obtained hydrotreated oil was heated to 7/c7IteG using an external heating tube cracker at a population temperature of 550°C, an outlet temperature of 830°C, an outlet pressure of 0.8, and a steam/hydrogenated oil weight ratio of 1.0. ,
Steam pyrolysis was performed under conditions of a residence time of 0.2 seconds to obtain olefins and monocyclic aromatic hydrocarbons.

The yield rate of the fraction below 550℃ in the thermal decomposition process is 7
The amount of 2N was %.

The steam pyrolysis results are shown in Table 1.

Comparative Example 1 The same procedure as Example 1 was carried out except that nickel octylate was not added. As a result, a clogging phenomenon occurred due to coking trouble in the reactor, and stable operation could not be carried out. The yield of the fraction with a boiling point of 550° C. or lower under conditions that allowed stable operation without adding additives was 44% by weight.

Comparative Example 2 The same procedure as in Example 1 was carried out except that nickel octylate was not added and nitrogen was used instead of hydrogen. As a result, a clogging phenomenon occurred due to coking trouble in the reactor, and stable operation could not be carried out. Under conditions that allowed stable operation of this system, the yield of the fraction with a boiling point of 550° C. or lower was 34% by weight.

Comparative Example 3 The same hydrotreating equipment as in Example 1 was used, and an alumina-supported cobalt-tungsten catalyst with a surface area of 220 m2/f containing 4% by weight of cobalt oxide and 15% by weight of tungsten oxide was used. Conditions where catalyst activity does not deteriorate significantly at the initial stage are temperature 380°C, reaction pressure 200Kg/cJGXLH8V0.5hr=', hydrogen/
Hydrogenation treatment was carried out under conditions of a feedstock oil ratio of 200 ONt/l.

In this case, the yield of the fraction with a boiling point of 550°C or less is 17% by weight.
It was nothing more than

As is clear from these results, it can be seen that the present invention is excellent as a method for decomposing heavy hydrocarbon oil and obtaining a high yield of raw material to be supplied to steam pyrolysis. Moreover,
The kinematic viscosity of the residual oil with a boiling point of 55C)°C or higher obtained in the present invention is as low as 2Q cst at 150°C, and its flammability on a thermobalance is the same as that of Minas vacuum distillation residue oil, which is the feedstock oil, and is a fuel oil. It can be fully used as an oil.

Comparative Example 4 After distilling the thermal decomposition product that could be operated stably in Comparative Example 1 at normal pressure and reduced pressure, the fraction with a boiling point of 550°C or lower was subjected to the same hydrotreating process and steam pyrolysis process as in Example 1. went. The results of steam pyrolysis are shown in Table 1.

Comparative Example 5 The hydrotreated oil obtained in Comparative Example 3 was distilled at normal pressure and under reduced pressure, and then the fraction with a boiling point of 550° C. or lower was subjected to steam pyrolysis in the same manner as in Example 1. The results are shown in Table 1.

It is clear from Table 1 that the yield of distillates above 200°C is clear: The method of the present invention has a much higher yield of petroleum 1 and 1 oil, and an extremely small amount of by-product fuel oil, so its effectiveness is obvious. It is.

Example 2 Molybdenum stearate was added to the atmospheric distillation residual oil of Arabian Light crude oil at a concentration of 500 ppm as molybdenum, and the mixture was placed in the same reactor as in Example 1 at a hydrogen/feedstock oil ratio of 5ooNt//. ! , a decomposition temperature of 460° C., a decomposition pressure of 200 Kg/cntG, and a residence time of 20 minutes for thermal decomposition. At this time, hydrogen preheated to 460°C was further added to the gas-liquid separation tank installed at the outlet of the reaction tube, and the hydrogen was supplied so that the hydrogen/feedstock oil ratio was 1300 ub/b in total. Hydrocarbon oil was entrained and separated with hydrogen gas. Next, the pyrolysis product oil from which the light hydrocarbon oil was separated was subjected to vacuum distillation, and the vacuum distillation residual oil having a boiling point of 550° C. or higher was separated.

A fraction with a boiling point of 550°C or less obtained by vacuum distillation and a light hydrocarbon oil entrained and separated with hydrogen gas are mixed to form a surface area of 2L8tt containing 6% by weight of nickel oxide and 19% by weight of tungsten oxide. /9, pore volume 0.55
Using an alumina-supported nickel to tungsten catalyst of m1/f and using the same flow-through hydrogenation reactor as in Example 1, the hydrogen/feedstock oil ratio was 130 ON t/l and the temperature was 390°C.
, pressure 150Kg/c++fG, LH8VO, 8h
Hydrogenation was carried out under r-1 conditions.

The obtained hydrogen atom was subjected to steam pyrolysis under the same conditions as in Example 1 to obtain olefins and monocyclic aromatics.

The starting material, Arabian Light atmospheric distillation residual oil, contained 55% by weight of the fraction with a boiling point of 550° C. or lower, whereas the fraction after thermal decomposition was 85% by weight.

The results of steam pyrolysis are shown in Table 2. 1, Table 2 Example;
In the case of Example 3, ferrocene was added to make it 2000 ppm as iron, and in the case of Example 4, cobalt naphthenate was replaced with cobalt to give loooppm. Example 5
In the case of 11000p chromium resinate as chromium
In the case of Example 6, ammonium tungstate hydrate was added as tungsten and 2
In the case of Example 7, vanadium acetylacetonate was added to give a concentration of 700 ppm as vanadium, and in the case of Example 8, copper stearate was added as copper to give a concentration of 500 I) pm. 1100
The reaction was carried out using the same reaction apparatus as in Example 1, using the same amount as in Example 1. All thermal decomposition reaction conditions were a temperature of 485°C and a pressure of 2ooKq/ct.
! a, residence time 2Qmin, hydrogen/raw oil ratio 70ONt
/l, and the rotation speed of the stirrer is 3000 rpm.
A thermal decomposition reaction was carried out.

The thermal decomposition products were distilled at normal pressure and under reduced pressure to separate and remove high-boiling substances with a boiling point of 550° C. or higher.

Table 3 shows the yield of each fraction with a boiling point of 550°C or less.

Table 3 Distillates with a boiling point of 550°C or less were treated using the same reactor and fixed bed catalyst as in Example 1, and the reaction conditions were hydrogen/hydrogen/
Raw material oil ratio xooooNt/z, temperature 395°C, pressure 150
Kg/crlG, LH3VO, 8hr-' was employed for hydrogenation treatment. Each of the obtained hydrotreated oils was subjected to steam pyrolysis using the same reaction apparatus and reaction conditions as in Example 1. The results are shown in Table 4.

[Brief explanation of drawings]

1 and 2 are different examples of process diagrams for carrying out the present invention, in which reference numeral 3 denotes a thermal decomposition apparatus, 12 a vacuum distillation apparatus, 15 a hydrotreating apparatus, and 18. 1 is a steam pyrolysis device, 7 in FIG. 1 is an atmospheric distillation device, and 6 in FIG. 2 is a flash distillation device. Patent applicant: Asahi Kasei Industries Co., Ltd. Agent: Akira Agata

Claims (1)

[Claims] 1(A) In the presence of hydrogen, heavy hydrocarbon oil to which a coking inhibitor has been added is heated at a temperature of 380 to 550°C and a pressure of 30 to 30°C.
0 K9 / ctl, a step of thermally decomposing under conditions of residence time 1 to 120 minutes, (B> step of separating and removing high boiling points from the thermal decomposition product obtained in the above step, (C) removing high boiling points The separated and removed thermally decomposed product is heated at a temperature of 250 to 500 °C and a pressure of 3 to 300 K9/c in the presence of a hydrogenation catalyst.
tl, liquid space velocity 0.05-5. Ohr-', hydrogen/
Hydrotreating under conditions of a thermally decomposed product ratio of 100 to 20 (10 Nt/l) and separating and removing hydrogen-containing gaseous products from the hydrogenated product obtained in step (D)(0). Then, the liquid product was subjected to steam pyrolysis under the conditions of a temperature of 700 to 900 °C, a residence time of 0.05 to 2.0 seconds, and a steam/liquid product concentration ratio of 0.2 to 2.0. A method for producing gaseous olefins/and monocyclic aromatic hydrocarbons from heavy hydrocarbon oil, characterized by comprising a step of recovering gaseous olefins and monocyclic aromatic hydrocarbons from the produced product. 2 ( A) In the process, the coking inhibitor added to the heavy hydrocarbon oil is a transition metal compound.
The method described in section. 3. The method according to claim 2, wherein the transition metal compound is at least one metal compound selected from iron, cobalt, nickel, chromium, molybdenum, tungsten, vanadium, and copper. 4. The method according to claim 1, wherein the amount of the additive in step 4(A) is in the range of 50 to 8000 ppm based on the weight of the raw material oil in terms of metal. In step 5(B), the high boiling point substances to be separated and removed have a boiling point of 5
The method according to claim 1, wherein the temperature is 50°C or higher.