JPS5821952B2 - Method for producing light oil and hydrogen from heavy oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing light oil and hydrogen from heavy oil.

The present inventors first catalytically cracked heavy oils such as atmospheric distillation residue oil and vacuum distillation residue oil in the presence of nickel ore to remove heavy metals contained in the heavy oil. I invented a method to reduce the weight (Japanese Patent Application Laid-Open No. 1987-10)
202), subsequent research has shown that when the above-mentioned heavy oil is catalytically cracked in the presence of laterite, the yield of cracked oil is slightly lower than when using the above-mentioned nickel ore; The amount of coke produced increases with the progress of carbonization, and if the laterite on which coke has been deposited is heated in a gas stream, the iron oxide in the laterite is reduced extremely quickly, and therefore the reduced laterite is reduced. I learned that hydrogen is easily generated when it comes into contact with steam.

Conventionally, heavy oil is catalytically cracked to lighten it in the presence of a catalyst in which oxides of metals such as nickel and vanadium are supported on bauxite, and coke is deposited on the catalyst. A method has been proposed (see Japanese Patent Publication No. 50-30596) for producing gaseous hydrocarbon and hydrogen-rich gas by contacting a deposited catalyst with steam.

However, since the catalyst used in this method is a so-called synthetic catalyst, its deterioration is inevitable in the reaction at high temperatures, and the cost is high.

Furthermore, in this method, the catalyst on which coke has been deposited is directly brought into contact with steam, so the hydrogen concentration in the gas exiting from the gasification zone does not become very high.

An object of the present invention is to provide a method that can advantageously produce light oil and hydrogen from heavy oil by eliminating the above-mentioned drawbacks.

The present invention will be explained in detail below.

The main characteristics of the present invention are that laterite is used as a catalyst when lightening heavy oil by catalytic cracking, and that laterite on which coke has been deposited by catalytic cracking is reduced and then brought into contact with steam to convert it into hydrogen. The goal is to generate rich gas.

The heavy oil used as a starting material in the present invention includes residue oils made of heavy petroleum hydrocarbons such as atmospheric distillation residue oil, vacuum distillation residue oil, etc., but cheap high-boiling point residue oils with high Conradson carbon are used. is advantageously applied.

In addition, laterite used as a catalyst in the present invention is naturally abundant in tropical and subtropical regions, and can be applied without any chemical treatment by simply crushing, granulating, and calcining it. Therefore, it is extremely advantageous in terms of catalyst preparation and economy compared to conventional synthetic catalysts.

Incidentally, laterite is rich in aluminum hydroxide and iron hydroxide, and generally contains 30% or more of iron, but in the present invention, laterite with a higher iron content is preferable, and in particular, laterite is heated at 1000°C for 3 hours. A material containing 40% by weight or more of iron oxide as Fe when fired can be advantageously applied.

Although it is possible to catalytically crack heavy oil in the presence of the above-mentioned laterite using a fixed bed method, industrially it is better to adopt a fluidized bed method. introduced into a fluidized bed maintained at a pressure of 5 kg/cJG, while the natural laterite was crushed and
The granules are granulated to an average particle size of microns and calcined at a temperature of 900° C. or higher, and then introduced into the fluidized bed and brought into contact with them.

In addition, in preparing the above-mentioned laterite catalyst, natural laterite may be treated with acid or alkali.

As the cracking reaction due to the above contact progresses, heavy metals are removed and light cracked oil and coke are produced.

Decomposition generation generated in this way? The coke is recovered from the system together with the coke fluidizing gas, while the produced coke is deposited on the tatterite catalyst.

The amount of coke deposited on the catalyst increases as the catalytic cracking progresses, but in the present invention, it is preferable to adjust the amount of coke deposited to 4% to 15% by weight relative to the catalyst. In particular, it is preferably around 10% by weight.

If the amount of coke deposited above is too small, the iron in the laterite will not be reduced sufficiently in the next step. On the other hand, if the amount of coke deposited on the catalyst is too large, the activity of the catalyst will decrease and the yield of cracked oil will decrease. (G) is preferable because it causes a decrease in coke and the solidification of the coke on the catalyst becomes insufficient, which becomes a medium and causes the formation of coarse particles due to the adhesion of particles.

The laterite catalyst on which coke has been deposited as described above is then heated to a temperature of 750 DEG to 950 DEG C. in a stream of gas such as air, steam, or nitrogen gas, to bring it into a reduced state very quickly.

The manner in which the laterite becomes reduced is considered to be due to iron oxide in the laterite being reduced according to the following formulas (1) to (3).

Fe2O3+C-, Fe3O4+CO+002...
...(1) Fe304 +O-+FeO+ 00
+ 002=・−・−・−(2) FeO10−→Fe
+ 00 + 002 ""・(3) The higher the reaction temperature and the greater the amount of coke deposited on the catalyst, the more advantageous the above reduction reaction is. This is economically undesirable since it has a considerable influence, and therefore it is preferable to apply a temperature of 750 to 950°C.

As for the amount of coke deposited, as described above, the characteristic of laterite is that sufficient reduction is achieved with a coke deposit amount of 4 to 15% by weight.

In addition, in the above reduction, the entire system is heated by partial combustion of coke, and the iron in the catalyst is reduced according to the above reaction formulas (1) to (3). Similarly, it is advantageous to carry out the process in a fluidized bed.

That is, at a temperature of 750 to 950 °C, O to 5 kg/
A laterite catalyst on which coke has been deposited is fed into a fluidized bed zone maintained at a pressure of crA G, and air is introduced to partially burn a portion of the coke to supply heat for the entire system. to reduce.

Note that exhaust gas containing carbon dioxide and carbon monoxide (see reaction formulas (1) to (3)) produced by the above reaction is discharged to the outside of the system.

Next, the laterite catalyst reduced as described above is brought into contact with steam.

Through this contact, hydrogen is generated according to the following formulas (4) to (6).

Fe+H20→FeO+H2・・・・・・・・・・・・
・・・・・・(4) FeO+ H20→Fe3O4+H
2・・・・・・・・・・・・・・・・・・(5) Fe3
04 + H20→Fe2O3+ H2"・""...
・(6) Although the above reaction is advantageous from an equilibrium point of view at a low temperature, from the viewpoint of actual operation, it is preferable to adopt a temperature between the decomposition temperature and the catalyst regeneration temperature;
A temperature of 800°C is suitable.

In addition, the reaction operation is preferably carried out in a fluidized bed method, in which the reduced laterite and steam are fed to a gasification zone, and the temperature in the zone is 600 to 800°C, and 0 to 5 kg/kg is fed into the gasification zone.
Both are brought into contact while being maintained at a pressure of c1tG, and hydrogen is generated according to reaction formulas (4) to (6).

Also in the gasification zone, part of the coke on the laterite reacts with iron oxide to cause reduction of iron, but the reduced iron is quickly oxidized by steam.

As described above, since the oxidation reaction of iron mainly occurs within the gasification zone, the hydrogen concentration in the produced gas taken out of the system becomes extremely high, generally reaching 65% by volume or more on a dry basis.

The laterite in which iron has been oxidized as described above is recycled to the heavy oil catalytic cracking process for reuse.

As can be understood from the above, the laterite used in the present invention is (1) inexpensive, (2) has a high coke yield, and iron content is easily reduced by coke, and (3) there is little change in catalyst activity. It has excellent properties as a catalyst for cracking and lightening heavy oils such as.

The actual operating system of the present invention will be explained below with reference to process diagrams shown in the accompanying drawings.

In the figure, heavy feedstock oil is transported through pipe 1 to the lower part of cracking tower 2 at a temperature of 450~600℃ and O~5kg/crr.
The mixture is introduced into a fluidized bed maintained at a pressure of tG.

In the fluidized bed, granular laterite is fluidized by fluidizing gas introduced from the pipe 3.

Note that although steam is usually used as the fluidizing gas, decomposed exhaust gas may also be used.

In the cracking tower 2, the heavy oil is catalytically cracked by laterite into cracked oil and coke.

Heavy metals have been removed and the lightened cracked oil is taken out in gaseous form from the pipe 4 together with the fluidizing gas.

On the other hand, coke is deposited on the laterite and sent to the regeneration tower 6 via the transfer pipe 5.

The regeneration tower 6 has a temperature of 750 to 950°C and a pressure of 0 to 5 kg/cr.
The pressure is maintained at a pressure of rl Give back.

Exhaust gas containing carbon dioxide and carbon monoxide produced by the reaction of iron oxide and coke and the reaction of coke and oxygen is discharged from pipe 8.

Laterite particles heated to 750-950°C are transferred to tube 9.
and a cracking column 2 and a gasification column 1 through pipes 10 and 10, respectively.
Sent to 1.

Laterite containing reduced iron is sent to a gasification tower 11 via a transfer pipe 10, where the iron is oxidized by steam supplied from a pipe 12 to produce hydrogen.

Note that the inside of the gasification tower 11 is maintained at a temperature of 600 to 800°C and a pressure of 0 to 5 kg/crttG.

Since the oxidation reaction of iron mainly occurs in the gasification tower 11, the hydrogen concentration in the generated gas from the gasification tower 11 taken out from the pipe 13 is extremely high, and is usually 65% by volume or more on a dry basis.

The oxidized laterite is recycled to the cracking column 2 via pipe 14.

As described above, the present invention has the advantage that light oil and hydrogen can be advantageously produced from heavy oil by using laterite, which is available at low cost, as a catalyst for catalytic cracking of heavy oil.

Examples will now be illustrated, and the types and compositions of catalysts used in each example are shown in Table 1 below.

Example In this example, the amount of coke produced when heavy oil is catalytically cracked using laterite as a catalyst is compared with when other catalysts are used.

After calcining each of the catalysts shown in Table 2 below in an electric furnace at 1000°C for 3 hours, 10cc of each catalyst was charged into a stainless steel reaction tube with an inner diameter of 12.5mm, and heated at 500°C in a fixed bed.
Craate atmospheric residual oil was decomposed for 5 minutes at a temperature of .

The results are shown in Table 2. From the above table, it is understood that laterite, which has a high coke yield, is advantageous for producing hydrogen together with lightened oil.

Example 2 This example shows the reduction rate of laterite with coke deposited by catalytic cracking of heavy oil in comparison with other catalysts.

Each of the catalysts shown in Table 3 below was calcined at 1000° C. for 3 hours, and claate atmospheric residue oil was catalytically cracked to deposit 8 to 10% by weight of coke on the catalyst.

Approximately 31 cc of each coke deposited catalyst was filled into a stainless steel tubular reactor, nitrogen was fed from the bottom at a flow rate of 0.251/-, and the reactor was heated at 900° C. for 60 minutes in a nitrogen gas stream.

Table 3 shows the reduction rate of each catalyst after this heating.

It can be seen from the above table that laterite has a significantly higher reduction rate than other catalysts.

Note that the reduction rate is determined by the fact that Fe and Ni in the catalyst are each F
e2O3 and'? Regarding the amount of oxygen combined with Fe and Ni, as existing in the form of JNiO,
It is expressed as a percentage of the amount of oxygen released as CO or CO2 during the heating.

From the above table, it can be seen that laterite is advantageous for producing hydrogen using the oxidation-reduction of iron.

That is, as the reduction of iron progresses, the reaction formula (4) ~
This is because the oxidation reaction of iron according to (6) progresses.

Example 3 In this example, laterite on which coke has been deposited is brought into contact with steam to generate hydrogen from water while utilizing iron oxidation-reduction, and the hydrogen concentration is compared with that when other catalysts are used. .

No. 4 below, in which coke was deposited after firing at 1000°C for 3 hours.
A stainless steel reaction tube was filled with 15 cc of each of the catalysts shown in the table, and steam was supplied from the bottom at a rate of about 109/h to produce hydrogen from the steam while utilizing the redox of iron.

The reaction temperature was 800°C. The results are shown in Table 4.

It can be seen from the above table that laterite exhibits the highest gas production and hydrogen concentration.

Example 4 According to the process shown in the attached diagram, residual carbon 22% by weight,
304 nickel and 110p11 with specific gravity 1.040
When the kraate vacuum residue oil containing vanadium was catalytically cracked at a temperature of 540°C using Laterite I-A as a catalyst, a light oil with a boiling point of 560°C or less was supplied, which was 57% by weight based on the vacuum residue oil. It was obtained in a yield of .

The specific gravity of this light oil was 0.9354, and nickel and vanadium were 1- or less.

The coke deposited on the laterite was 9.52% by weight.

Approximately 40% of the coke in this coke-deposited laterite 11 was partially combusted with air at 880° C., and at the same time iron was reduced.

Then, steam was supplied to this to oxidize the iron at 800° C. for 1'5 minutes.

The amount of gas generated at this time was 11.54/h, and the gas composition was H270.5 mol% and 0.005.7 mol%.

It was C0223.8 mol%.

No methane was detected.

[Brief explanation of drawings]

The accompanying drawings are process explanatory diagrams illustrating embodiments of the present invention. In the figure, 2... decomposition tower, 6... regeneration tower, 11... gasification tower.

Claims (1)

[Claims] 1 A step of decomposing heavy oil in the presence of laterite to make it lighter and depositing coke on the laterite, a step of bringing the laterite with the coke deposited into a reduced state, and contacting the reduced laterite with steam. 1. A method for producing light oil and hydrogen from heavy oil, characterized by combining the steps of producing hydrogen-rich gas by producing hydrogen-rich gas.