JPS59115387A - Thermal cracking of heavy oil - Google Patents

Abstract

PURPOSE:To carry out thermal cracking at a relatively low temperature and produce light oil with good yield, by effecting thermal cracking of heavy oil under specified conditions. CONSTITUTION:Steam (or steam-containing gas) is fed into a thermal cracking reactor 1 through a pipe 5. A porous substance in fine powder having a pore volume of 0.2-1.5cm<3>/g, a specific surface area of 5-1,500m<2>/g, an average pore diameter of 100,000-10,000Angstrom and a weight-average diameter of 0.025- 0.25mm., is fluidized and is brought into contact with heavy oil supplied through a pipe 6 for thermal crackig of the oil. After removal of fine particles in a cyclone 8 and a dephlegmator 9, the product is separated into a receiving vessel 11. The fine particles deposited on coke are carried to a gasification section 2 of a regeneration reactor 100 by a gas from a pipe 17 through an ejector 15 and are fluidized by steam (or steam-containing gas) from a pipe 17 to gasify a part of the deposited coke. The produced gas is taken out of the system after removal of fine particles in a cyclone 18 and a dephlegmator 19. 70% or more of the fine powder is recycled to the reactor 1 through a pipe 21, an ejector 22 and a pipe 24 and the remainder is sent to a combustion chamber 3 of a reactor 100.

Description

Detailed Description of the Invention Background Technical Field of the Invention The present invention is directed to thermally decomposing heavy hydrocarbon oil (hereinafter simply referred to as heavy oil) using a fluidized bed to produce light hydrocarbons that are mainly liquid at room temperature. (hereinafter simply referred to as light oil). More specifically, the present invention includes a thermal decomposition process in which heavy oil is brought into contact with fine powder of a porous body fluidized by a water vapor-containing gas to thermally decompose the fine powder, and This invention relates to a regeneration process in which coke adhering to the fine powder is burned or gasified and removed while being fluidized by a gas containing gas or water vapor, and to an improvement in a method in which the fine powder is circulated.

Prior Art Previously, some of the present inventors discovered that in the thermal decomposition of heavy oil using a fluidized bed, the weight average diameter of the fluidized particles was 0.04.
This thermal decomposition can be carried out with good fluidity by using a fine powder that is approximately 0.12 m in diameter, contains 5 to 50% by weight of particles of 0.044 rtm or less, and is substantially spherical. Demonstrate efficiency and ability to perform under the conditions;
This is done using the fluid thermal decomposition method (Fluid Thermal Cr
(Japanese Patent Application Laid-Open No. 51-10587)
(see publication).

In addition, in a similar manner, the fine powder was prepared with a pore volumetric force of 0.1 to L5m3/9- and a specific surface area of H to 150 mm.
0 m/P, and the weight average diameter is 0.025~
0.25B, showing that by making it thermally stable, this thermal decomposition can be carried out more efficiently.
The pores of the porous body absorb heavy oil in liquid form, exhibiting excellent effects such as promoting thermal decomposition reactions and suppressing the production of high carbon solids (hereinafter simply referred to as coke). He discovered this and called it the capacitance effect (Japanese Unexamined Patent Publication No. 1983)
-Refer to Publication No. 1873).

Furthermore, in the same way, heavy oil has a heat content of 7V! In a method in which the fine powder of the porous body extracted from the thermal decomposition step is brought into contact with an oxygen-containing gas to gasify and remove the coke attached to the fine powder, the flow rate of both processes is An effective mode of arranging layers adjacent to each other on both sides of a thermally conductive partition wall was shown (see Japanese Patent Laid-Open No. 158291/1983).
.

By the way, there are already many examples and patents of methods for performing particle circulation between the thermal decomposition step and the regeneration step. In the fluid catalytic cracking method (FCC method), which is mainly used to obtain gasoline from light oil, the thermal cracking step and the regeneration step are each carried out using a fluidized bed reaction method, and a relatively large amount of catalyst particles are circulated between them. are doing. In addition, in the fluid coking gasification method (hereinafter simply referred to as the flexi coking method), which produces synthesis gas from heavy oil together with light oil, the pyrolysis step and regeneration step (
The generated coke particles are circulated between the combustion section and the gasification section, and a heating section is added if necessary. In the flexi-coking method, coke particles heated to a high temperature in the combustion section are distributed and circulated to the thermal cracking process and the gasification process, respectively, and the necessary reaction heat is supplied to each by the sensible heat (Japanese Patent Laid-Open No. 57 -1081
(See Publication No. 93). Furthermore, coke particles are circulated between the pyrolysis process and the gasification section to supply the heat necessary for the pyrolysis reaction, and furthermore, coke particles are circulated between the gasification section and the combustion section to generate gas. There is a method of supplying the heat necessary for the reaction (see t# Publication No. 57-76090).

- SUMMARY OF THE INVENTION The present invention relates to an improvement over the prior invention on the part of the inventors described above.

That is, the heavy oil pyrolysis method according to the present invention comprises a pyrolysis step in which heavy oil is brought into contact with a porous fine powder fluidized by a steam-containing gas and thermally decomposed; A method in which a substance is fluidized with a molecular oxygen-containing gas or a water vapor-containing gas and the powder is circulated, and is characterized by carrying out these steps under the following conditions: .

(1) Fine powder has a pore volume of 0.2 to 1.5 cm3
/g, a specific surface area of 5 to 1500 m2/g, an average pore diameter of 10 to 10,000X, and a weight average diameter of 0.025 to 0.25u, Moreover, it must be a porous fine powder that maintains these properties stably even at the operating temperature.

(2) The pore volume of the fine powder recycled from the regeneration step to the pyrolysis step and of the fresh fine powder added as necessary is greater than or equal to the volume of the heavy oil supplied.

(3) The regeneration step consists of a combustion section and a gasification section from which the generated gas can be taken out separately and the fine powder can be circulated between them.

(4) The amount of the fine powder to be circulated between the thermal decomposition step and the regeneration step is small (70% by weight is recycled between the thermal decomposition step and the gasification section of the regeneration step).

(5) The circulation amount of the fine powder between the combustion section and the gasification section in the regeneration step is at least equal to the OCR of the supplied heavy oil.

(6) In the combustion section of the regeneration step, the fine powder comes into contact with the molecular oxygen-containing gas and part of the adhering coke is combusted, and the temperature of the fine powder is at least (material) lower than the temperature in the gasification section. ℃ high temperature.

(7) In the gasification section of the regeneration step, the fine powder comes into contact with a steam-containing gas, and part of the adhering coke is gasified, so that the temperature of the fine powder is at least 100° C. higher than the temperature in the pyrolysis step. Being at high temperature.

Effects In the present invention, a porous fine powder is used;
By dividing the regeneration process into a gasification section and a combustion section, the advantages of both can be enjoyed. First, by using a porous material in the form of fine powder, a uniform and smooth fluid state can be obtained, and since the attached coke remains in the pores of the particles, the particles do not stick to each other, resulting in extremely fluidity. There are many benefits, including better performance. The main points are listed as follows.

(a) Less grinding of fine powder and less wear on equipment.

(b) Operational operations such as fluidization, particle circulation, and transportation are easy. (c) The thermal decomposition reaction proceeds at a relatively low temperature, there is little precipitated coke and by-product gas, and the yield of light oil is high. ) The regeneration reaction proceeds at a relatively low temperature and high-quality product gas is obtained.Furthermore, the main advantages of dividing the regeneration process into a gasification section and a combustion section are as follows.

(@ A high-quality product gas suitable as a raw material gas for synthesis can be obtained.) The basic process of the present invention, which does not require oxygen or can significantly reduce oxygen consumption, is to convert heavy oil into porous, finely powdered solid particles. a pyrolysis step of pyrolysis by contacting with a fluidized bed;
A regeneration process in which the fine powder particles extracted from this are regenerated.
The fine powder particles are circulated between these two steps, and the regeneration step consists of gasification of the coke adhering to the fine powder particles using water vapor and combustion using molecular oxygen.

The present invention is designed to operate this basic process under optimal operating conditions.

Differences from previous inventions The present invention uses a porous fine powder similar to some of the previous inventions by the inventors mentioned above, but its embodiment is different. Yoriaki Moto also points out that the FCC method is different from the FCC method in that it is catalytic cracking and its mode, and the flexi coking method is different from the FCC method in that it uses relatively coarse particles as circulating particles. They are different in that they use coke, and in their implementation and purpose.

More specifically, in the present invention, like some of the inventors' previous inventions, a porous fine powder is used. The fine powder has a pore volume of 0.2 to 1.5 crrL3/z and a specific surface area of 5 to 1500 m2/L! -, are microspherical particles with an average pore diameter of 10 to 10,000λ, and a weight average diameter of 0.025 to 0.25 M, and these properties are stable even at the operating temperature. It is necessary that it is a fine porous powder that drips. Are these property values within the range of the prior invention?
Although it has been reduced, it is intended to effectively implement the present invention.

In the present invention, the pore volume of the fine powder circulated from the regeneration step to the pyrolysis step and the fresh fine powder added as necessary is greater than or equal to the volume to which heavy oil is supplied;
is necessary. If heavy oil is supplied beyond this condition,
Heavy oil overflows from the pores to the particle surface, making the particle surface sticky and easy to adhere to, making it impossible to obtain the uniform fluid state that is characteristic of a fine powder fluidized bed.

In the present invention, the regeneration process consists of a combustion section and a gasification section, and the gas generated from each of these sections can be gradually taken out, and the fine powder can be circulated between them. It is necessary to be something. According to such a regeneration process, a low-grade combustion gas with a small calorific value and a high-grade generated gas with a large calorific value can be obtained separately. Although such a method itself has been conventionally used in the aforementioned flexible coking method and other methods, its application to a fine powder fluidized bed as in the present invention has not been found.

In the present invention, it is necessary to reduce the amount of circulation of the fine powder between the pyrolysis step and the regeneration step (both 70% by weight). According to this method, 1. The fine powder reaches the gasification section with coke, which is generated by thermal decomposition and has a relatively large amount of volatile content and is easily gasified, attached to it, so that there is no interaction with the fluidizing gas. The gasification reaction progresses easily and relatively high-quality product gas is obtained.The circulation of the fine powder between the pyrolysis step and the regeneration step is preferably such that the entire amount is transferred between the pyrolysis step and the regeneration step. There is no problem even if it is done in

In the present invention, the amount of circulating fine powder between the combustion section and the gasification section in the regeneration step must be at least 20 times the weight of the conradone residual carbon (hereinafter simply referred to as OCR) of the supplied heavy oil. (Preferably, it is 40 times or more by weight.) In the present invention, heavy oil (p CCR refers to an amount equal to g adheres to fine powder and specifically, precipitates in pores), a part of which is gasified in the gasification section, and the remainder is combusted. part is burned by the fluidizing gas. According to this method, a large amount of heated fine powder is circulated between the combustion section and the gasification section, so that the amount of heat required for the gasification reaction is transferred from the combustion section to the sensible heat of the fine powder. and will be supplied. In the present invention, since the fluidity of the fine powder is extremely good, it is easy to increase the amount of circulating particles between the combustion section and the gasification section. Temperature difference can be low (low).

It is necessary that a portion of the powder be combusted so that the temperature of the fines is at least 50'C higher than the temperature of the gasification section. It is important that the temperature between the combustion section and the gasification section be 50"C or higher in order to sufficiently advance combustion and to effectively transfer heat between the two.

In the present invention, the fine powder comes into contact with steam-containing gas in the gasification section of the regeneration step, and a part of the adhering coke is gasified, so that the temperature of the fine powder is lower than the temperature in the pyrolysis step. A temperature as high as 100°C is required.

It is important that the temperature of the gasification section is 100° C. or more higher than that of the thermal decomposition process in order to sufficiently advance the gasification reaction and to effectively transfer heat between the two.

In some embodiments of the present invention, the fine powder is transported from the regeneration step to the pyrolysis step using steam or steam-containing gas, and some or all of the heavy oil is supplied thereto to increase the A part of the thermal decomposition reaction of heavy oil can proceed by bringing it into contact with the fine powder fluidized at a high speed.Also, in another embodiment of the present invention, it is possible to advance a part of the thermal decomposition reaction of heavy oil from the gasification part of the regeneration process. The fine powder is transported to the combustion section using a molecular oxygen-containing gas, and a part of the precipitated coke can be combusted while the fine powder is fluidized at high speed.

Raw Material Heavy Oil In the present invention, the term "heavy oil" refers to hydrocarbons (usually mixtures) with an OCR of about 3 or more, and also includes those that are solid at room temperature.

The raw material heavy oil that can fully enjoy the effects of the present invention has a relatively high OCR, for example, about 5 or more, preferably about 10 or more.

Specific examples of suitable raw material heavy oil include heavy crude oil, residual oil obtained by atmospheric distillation of crude oil (hereinafter simply referred to as atmospheric residual oil), and residual oil also obtained by vacuum distillation (hereinafter simply referred to as vacuum residual oil). ), deasphalt oil, oil base coal oil, tar sand oil, and liquefied coal oil.

Fine Powder The fine powder used in the present invention is as defined above.

Specific examples of fine powder suitable for the present invention include mainly F
Degraded products of silica-alumina catalysts used in the CC method, degraded products of aluminosilicate-zeolite catalysts, carriers for alumina and siliceous fluid catalysts, special spherical activated carbon, etc., and mixtures thereof, etc. However, as long as it has the properties mentioned above (
, but not limited to these. Moreover, it is not necessary to have a catalytic effect on the decomposition reaction of heavy oil.

Particularly preferred among the above fine powders is an alumina carrier for a fluidized catalyst. It is highly heat resistant and exhibits very little change in particle properties during use.

In the present invention, the "pore volume" of the fine powder particles refers to the total volume of pores contained in a porous body per unit weight, and is usually obtained by heating and boiling the porous body in a liquid such as water. It is then taken out and measured when the surface is just dry, and is calculated by dividing the weight increase by the specific gravity of the liquid.

Pyrolysis Process The reactor for pyrolysis is a vertical vessel containing a fluidized bed of fine powder, usually an elongated cylinder. At the lower end of the reactor is an inlet for steam-containing gas, at the middle is an inlet for raw oil, and at the upper end is an outlet for pyrolysis products through recovery equipment for scattered particles such as a cyclone and a despreg. In the reactor,
Further, an inlet for mainly circulating particles from the regeneration process and an outlet for circulating particles mainly to the regeneration process are provided. It should be noted that an insert such as a heat exchanger or a perforated plate may be appropriately provided in the reactor.

The temperature of the fluidized bed for thermal decomposition is suitably about 350 to 600°C. The preferred temperature is 400-550°C, in which the yield of product oil is highest. It is preferable that raw material oil, steam-containing gas, etc. be appropriately preheated before being fed. The "steam-containing gas" introduced to perform thermal decomposition while maintaining a fluidized state is a mixture of pure steam, carbon dioxide, carbon oxide, hydrogen, hydrocarbons, nitrogen, and mixtures thereof, in addition to pure steam. It may be something you have done. The amount of pure steam fed is 1 to 1 compared to the amount of heavy oil fed.
00 weight ratio, preferably 5 to 50 weight ratio.

If it is less than that, the yield of produced oil will decrease, and if it is more than that, it is uneconomical.

The amount of fine powder recycled from the regeneration step to the pyrolysis step is determined in relation to the amount of heavy oil supplied for pyrolysis.

That is, the pore volume of the regenerated fine powder particles and the fresh fine powder particles added as necessary (the addition position may be in the pyrolysis light device, the regenerator or other parts) is greater than or equal to the volume of the heavy oil to be supplied. have to adjust. here"
"Volume of heavy oil supplied" means r゛Supplied amount of heavy oil (
weight) divided by its density at the feed temperature. If such a correlation is expressed on a weight basis, the amount of fine powder circulated between the pyrolysis step and the regeneration step is usually about 0.5 to 10 times the amount of heavy oil supplied, and 1 to 10 times the amount by weight of the heavy oil supplied.
It is desirable that the amount is 5 times the weight.

The amount of fine powder to be circulated between the pyrolysis step and the regeneration step must be such that 70% by weight or more of the fine powder is circulated to the gasification section of the regeneration step.

The rate at which the gas components in the fluidized bed rise is 5 as the superficial velocity.
~160cm/sec is normal, and 10~80cm/sec
The most suitable flow conditions are obtained at a rising speed of the order of seconds. Although the pressure is not particularly limited, it is usually from normal pressure to about 10 kg/cm2.

Pyrolysis product The product oil obtained from the pyrolysis process of the present invention is liquid at room temperature, and is, for example, a naphtha fraction (boiling point, 170°C or less).
, kerosene fraction (boiling point, 170-340°C), gas oil fraction (
boiling point, 340-540°C) and heavy oil fraction (boiling point, 5
40°C or higher). Since the method of the present invention is based on a thermal cracking reaction, the produced oil contains a small amount of naphtha fraction, unlike conventional catalytic cracking, and a large amount of middle distillates such as kerosene and gas oil fractions. In addition, heavy oil fractions are extremely rare.In addition to such oils that are liquid at room temperature, thermal decomposition produces a calorific value of approximately 5.0 (1 to 1 (1,000 kcal)).
/Nm" of by-product gas is generated.

Regeneration process The regeneration reactor consists of a gasification section and a combustion section.

As described above, the gasification section and the combustion section are such that the generated gas can be taken out separately, and the fine powder to be treated there can be circulated between them.

For this purpose, both parts may be constructed as separate devices and piping may be arranged so that fine powder can circulate between them, or both parts may be housed in a single device. Also...(I prefer the latter.) Further, the fine powder from the pyrolysis step may be introduced into the combustion section first, or may be introduced into the regeneration section first (the latter is preferred). It can also be introduced into both parts separately.

In a preferred embodiment, the combustion section and the gasification section are vertical vessels, typically elongated circular columns, containing a tilted pulverulent fluidized bed. In particular, the combustion section may be significantly elongated. At the lower end of the reactor in the gasification section, there is an inlet for water vapor or water-vapor-containing gas, at the upper end there is an outlet for the produced gas through a cyclone, detupleg, etc., and an inlet for circulating particles from the pyrolysis process and the combustion process. Discharge ports etc. to those processes are provided. It should be noted that an insert such as a heat exchanger or a perforated plate may be appropriately provided in the reactor.

The temperature of the fluidized bed in which the gasification reaction takes place is approximately 600 to 900°C.
, preferably about 650 to 850°C. If the temperature is lower than that, the gasification reaction will not progress sufficiently, while if the temperature is higher than that, it is not only unnecessary but also causes the temperature of the combustion zone to be higher than that, thereby reducing thermal changes in the properties of the fine powder used. There is a risk that it will proceed.

It is preferable that the water vapor-containing gas introduced in order to maintain a fluidized state and proceed with the gasification reaction be sent for preheating as appropriate. In addition to pure water vapor, "water vapor-containing gases" include:
A mixture of pure water vapor, carbon gas, carbon oxide, hydrogen, hydrocarbons, nitrogen, and mixtures thereof may also be used.

Furthermore, if oxygen, air, etc. are mixed, the temperature of the combustion section will be lowered and the amount of circulating particles will be reduced, making operation easier. At this time, the amount of molecular oxygen fed is less than or equal to the relative weight of the amount of water vapor fed, preferably less than 5 weight. The rising speed of gas components in the fluidized bed is 5 to 160 as superficial velocity.
crIL/sec, preferably about 10 to 80 cbsec. Although there is no particular limit to the pressure, it is usually about 1 from normal pressure.
To 0! 9/It is true.

On the other hand, at the lower end of the reactor in the combustion section, there is an inlet for molecular oxygen-containing gas, and at the upper end, there is an outlet for combustion gas that passes through a cyclone, detupleg, etc., and an inlet and outlet for circulating particles, mainly from the gasification section. etc. are provided. Note that there is no problem in providing an insert such as a heat exchanger or a perforated plate as appropriate in the reactor.

The temperature of the fluidized bed in which the combustion reaction takes place is approximately 700 to 1000°C.
, preferably about 750 to 950°C. At temperatures lower than that, not only is the combustion reaction insufficient, but
The heat generated by combustion cannot be effectively transferred to the gasification section. On the other hand, temperatures higher than this may cause thermal changes in the properties of the fine powder used.

Preheated air is usually used as the molecular oxygen-containing gas introduced to maintain a fluidized state and advance the combustion reaction. Hydrocarbons, carbon oxides, hydrogen, water vapor, oxygen, etc. may be mixed with the air. Since the combustion reaction in the fluidized bed progresses more easily than the gasification reaction, the rate of rise of gas components in the fluidized bed can be significantly increased compared to the gasification reaction, usually 15 to 1500 crrL/sec, preferably 20
~1000 cIrL/sec. At this time 15~
In the range of about 20 h/sec, a normal fluidized state (dense fluidized bed) is exhibited, but in the range of about 200 α/sec or more, the particle density of the fluidized bed decreases, resulting in a so-called dilute fluidized bed state. When such a diluted fluidized bed is employed, the combustion reaction can be carried out in the particle circulation pipe between the gasification section and the gasification section without providing a combustion section as a special device.

The amount of particle circulation between the gasification section and the combustion section in the regeneration process is determined by the conditions described above, but is usually at least 1 times the amount of heavy oil fed, preferably 5 times the amount by weight. That's it.

Regeneration Step In the produced gas regeneration step, combustion gas is obtained from the combustion section and produced gas is obtained from the gasification section.

Air is usually used as the oxygen-containing gas in the combustion section, so the combustion gas contains a lot of nitrogen and carbon dioxide, and a small amount of carbon oxide, hydrogen, etc., and has a calorific value of about 500 kcal.
/Nm3 or less low calorific value gas can be obtained.

In the gasification section, water vapor-containing gas is used.

Here, the "water vapor-containing gas" includes water vapor added with oxygen gas or air. When only water vapor is used, a high calorific value gas rich in hydrogen and carbon monoxide and having a calorific value of about 2,000 kcal/Nm or more can be obtained. When oxygen or air is used together with water vapor, the quality of the produced gas decreases, but the amount of heat required for the gasification reaction can be reduced, so the amount of heat transferred by circulating particles from the combustion section is reduced, and accordingly, the amount of heat transferred from the combustion section by circulating particles is reduced. This provides the advantage of lowering the temperature and reducing the amount of circulating particles. In addition, when using a mixture of water vapor and air, it is also possible to obtain a product gas containing an appropriate amount of nitrogen and having a composition suitable for ammonia synthesis.

The flowsheet diagram shows an example of a flowsheet for carrying out pyrolysis according to the present invention.

In the figure, 1 is a pyrolysis reactor for pyrolyzing heavy oil, 2 is a gasification section for gasifying and removing coke attached to fine powder during the pyrolysis reaction, and 3 is also for removing by combustion. This is the combustion section for the reactor, and both sections are the regeneration reactor 100. 4 is a cooler for cooling the products of thermal decomposition and separating them into produced oil and by-product gas.

Steam or steam-containing gas is fed into the pyrolysis reactor 1 from the bottom through a pipe 5, and raw material heavy oil is fed alone or together with water vapor or the like from a pipe 6. The fine powder filled in the pyrolysis reactor is fluidized by the above-mentioned feed material, and the pyrolysis reaction mainly proceeds above the feeding position of the raw material heavy oil, and below it there is a perforated plate (no As the product oil flows down through the fine powder 7, the product oil retained in the pores of the fine powder is stripped.

The thermal decomposition products are removed from entrained fine particles by a cyclone 8 and a depleg 9 provided at the top of the column, and then passed through a pipe 10 to a cooler.

The condensed liquid, ie, produced oil, is separated into a receiver 11, and the uncondensed gas, ie, by-product gas, is taken out of the system through a pipe 12.

The fine powder with coke attached as a result of the thermal decomposition is discharged from the bottom pipe 13, and is sent to the gasification section of the regeneration reactor through the pipe 16 by the ejector 15 using gas such as steam from the pipe 14. It will be done.

The coke-adhered fine powder sent from the pyrolysis reactor and filled into the gasification section of the regeneration tower is fluidized by steam or steam-containing gas from pipe 17, and a part of the adhering coke is gasified. be done. The produced gas is taken out of the system through a pipe pipe after removing accompanying fine particles by a cyclone 18 and a depletion plate 19 provided at the top of the gasification section. The fine powder that has undergone the gasification reaction is discharged from the bottom, and a part of it passes through the pipe 21 to reach the ejector B, and is transported by gas such as steam from the pipe B to the pyrolysis reactor via the pipe A. It is circulated. Further, the remaining part of the fine powder discharged from the bottom after the gasification reaction reaches the ejector 26 through the pipe line 5, and the water vapor from the pipe nail or the molecular oxygen-containing gas such as air is used to drain the pipe public. After that, it is sent to the combustion section.

The fine powder (containing the remainder of the adhering coke) sent from the gasification section and filling the combustion section is fluidized by air and other molecular oxygen-containing gases from pipe 4, and the remainder of the adhering coke is be removed by burning.

The combustion gas passes through the cyclone f and the despreg 31, removes accompanying fine particles, and is taken out of the system through the pipe line 32. Fines from the combustion section are circulated through an overflow pipe to the gasification section.

Examples Example (1) Experimental apparatus An experimental apparatus similar to that shown in the drawing was used. The thermal decomposition reaction tower has a cylindrical shape with an inner diameter of 5.4 crrL and a height of the fluidized bed section of approximately 1.8 crrL, and the feeding pipe for raw material heavy oil is 0.6 crrL from the lower end.
1.2 m above it is mainly a thermal decomposition reaction zone, and about 0.6 m below it is a stripping zone. In the strip area, five perforated plates with an opening area of about 20% of the horizontal cross-sectional area of the fluidized bed were installed at intervals of 10 cIL. The regeneration reaction tower has an internal t of J4cr in the gasification section! L,
The height of the fluidized bed section is approximately 1.0m, and the diameter of the combustion section is 8.1α.
, the height of the fluidized bed section is approximately 0.5 m. All equipment is made of stainless steel.

(2) Experimental conditions Approximately 8 liters of fine powder of alumina porous material for use as a fluidized catalyst carrier was filled as fluidized particles, and the flow rate was approximately 3.5 liters/hour between the thermal decomposition process and the gasification section of the regeneration tower. Approximately liter/hour was circulated between the gasification section and the combustion section of the regeneration section. 150 g/hour of steam preheated to about 400°C is fed from the feed pipe at the bottom of the pyrolysis reactor, and the temperature is heated to about 400°C along with 585 g/hour of heavy oil preheated to about 300°C from the feedstock feed pipe. 100 g/h of preheated steam was fed in. For transportation from the pyrolysis reactor to the gasification section, steam preheated to about 400° C. was fed at a rate of about 100 g/hour.

Approximately 400℃ from the inlet pipe at the bottom of the gasification section of the regeneration reactor
120 g/h of preheated steam was fed in.

Additionally, air at about 50'C was fed into the combustion section at a rate of 670 liters/hour.

At this time, the fluidized bed temperature in the pyrolysis section was set to 450°C, the fluidized bed temperature in the gasification section was set to 780°C, and the fluidized bed temperature in the combustion section was set to 800°C.
The temperature was kept constant at 90°C. Note that the pressure is normal pressure.

The thermal decomposition product was cooled to room temperature with water and brine, and the produced oil was condensed with water and separated from by-product gas.

The raw material heavy oil is vacuum residual oil and has the following properties.

Specific gravity = 1,026, heavy oil fraction (boiling point 540°C or higher) =
93 weight ratio, 0CR = 21.9 weight ratio, sulfur content = 5.9
Weight % The fine powder used had the following properties.

Bulk density = 0.39 g 7cm3, pore volume -1.3
60m3/FZ % specific surface area = 320m2/g, average pore diameter -26OA, weight average diameter = 0.068 mm (3) Experimental results Produced oil yield per raw material heavy oil 70.1% by weight Composition of produced oil Naphtha Distillate (boiling point 170°C or lower) 16% by weight Kerosene fraction (boiling point 170°C to 340°C) 36 Diesel oil fraction (boiling point 340 to 540°C) 44 Heavy oil fraction (boiling point 540°C or higher) 4 By-product gas amount 5ON liter/hour Composition H
258 capacity CH416// C2H6, C2H49〃 C3HB, C3H68〃 Total 100 II Produced gas (dry) 190 N +) liter/
Time composition CO213 Capacity Co 29 //H256〃 Total 100〃 Combustion gas (dry) 74 ONl, liter/hour Composition CO214 Capacity Chi CO10/' N274〃 Others 2 〃 Total 100 ll Note that some of the circulating particles were sampled. When carbon in the deposits was measured using a conventional method, the following values were obtained.

Particles in the pyrolysis process 11% by weight Particles in the gasification section of the regeneration tower 4'' Particles in the combustion section of the regeneration tower 3 Example 2 The experimental equipment and most of the experimental conditions were the same as in Example 1, and the difference was that the regeneration tower We added pure oxygen along with water vapor to the gasification section at 7 hours, reduced the amount of air fed to the combustion section by 490 liters/hour, and reduced the amount of particles circulating from the gasification section to the combustion section in the regeneration tower. As a result, the pyrolysis process was almost the same as in Example 2, and the combustion gas in the regeneration process was 565 liters/hour with a similar composition. changed as follows.

Generated gas amount 230 liters/hour Composition C
O219 Capacity Co 35 //H244
tt H2S, N2 2 /total 10
0〃

[Brief explanation of drawings]

The drawing is a flowchart illustrating one embodiment of the invention. 1... Pyrolysis reactor, 100... Regeneration reactor, 2.
... Gasification section, 3... Combustion section. Applicant's agent Kiyoshi Inomata

Claims (1)

[Scope of Claims] 1. A pyrolysis step in which heavy oil is brought into contact with the fine powder of a porous body fluidized by a water vapor-containing gas to thermally decompose the fine powder, and the fine powder from this step is heated with molecular oxygen. Thermal decomposition of heavy oil is carried out under the following conditions, in a method in which the fine powder is adhered to the fine powder while being fluidized by a gas containing gas or a gas containing water vapor. Method. (1) Fine powder has a pore volume of 0.2 to 1.5c11L
3/g, a specific surface area of 5 to 1500 m2/g, an average pore size of 10 to 1o, ooo X, and a weight average diameter of 0.025 to 0.25 mm. Moreover, it must be a porous fine powder that maintains these properties stably even at the operating temperature. (2) The pore volume of the fine powder recycled from the regeneration step to the pyrolysis step and of the fresh fine powder added as necessary is greater than or equal to the volume of the heavy oil supplied. (3) The regeneration step consists of a combustion section and a gasification section from which the generated gas can be taken out separately and the fine powder can be circulated between them. (4) The amount of the fine powder circulated between the thermal decomposition process and the regeneration process is small (70% by weight in total is recycled between the thermal decomposition process and the gasification part of the regeneration process. 5) The circulation amount of the fine powder between the combustion section and the gasification section in the regeneration step is at least 20 times by weight the CCR of the supplied heavy oil. (6) In the combustion section of the regeneration step When the fine powder comes into contact with the molecular oxygen-containing gas, a part of the attached coke is burned, and the temperature of the fine powder is at least 50°C higher than the temperature in the gasification section. (7) Regeneration. In the gasification section of the process, the fine powder comes into contact with a steam-containing gas, and a portion of the attached coke is gasified, so that the temperature of the fine powder is at least 100°C higher than the temperature in the pyrolysis step. 2. The method according to claim 1, wherein the molecular oxygen-containing gas in the combustion section of the regeneration step is air. 3. The water vapor-containing gas in the gasification section of the regeneration step is oxygen or (and) The method according to any one of claims 1 to 2, which is steam to which air has been added. 4. The thermal decomposition step is to reduce the rate of rise of the gas component to 200 fi/200 fi/2. The method according to any one of claims 1 to 3, which comprises thermally decomposing the heavy oil while fluidizing it for more than a second.5. The first method according to claim 1, which comprises burning a part of the coke attached to the fine powder while fluidizing the material with an oxygen-containing gas by keeping the rate of rise of the gas component at 200 ff 7 seconds or more. ~
The method according to any one of Item 4.