JPS5951335B2 - Catalyst for treatment of heavy oil containing high sulfur content - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for catalytically cracking heavy oil, particularly heavy oil with a high sulfur content, in the absence of hydrogen to obtain a cracked fraction with a low sulfur content.

Conventionally, catalysts for the catalytic cracking of heavy oil include supported catalysts in which metals such as nickel, cobalt, and tungsten are supported on carriers such as silica, alumina, and magnesia, and various natural ores such as nickel ores with 900 to 12
Baked ¥ obtained by firing at 00℃! IJ (Unexamined Japanese Patent Publication No. 1983-
72388), etc. have been proposed.

However, with the conventional catalysts mentioned above, sulfur compounds in the cracked fraction cannot be effectively removed unless heavy oil is treated in the presence of hydrogen, and especially hydrogen sulfide in the cracked gas cannot be removed. It was extremely difficult to ensure that there were almost no

As a result of intensive studies to solve these problems, the present inventors found that when high sulfur-containing heavy oil is catalytically cracked using iron and/or iron oxide in a specific range of reduction state as a catalyst,
It was found that the sulfur compounds in the cracked distillate were reduced, the cracked gas contained almost no hydrogen sulfide, and the cracking rate of heavy oil was also increased.

The present invention was obtained based on such knowledge, and by reducing the sulfur compounds in the cracked fraction, the amount of hydrogen consumed in the subsequent desulfurization treatment process is reduced, which is extremely useful in the industrial field of vines, etc. This paper proposes a new catalyst.

That is, in the present invention, the iron content is 30% by weight as Fe.
In the above, at least one of Fe, FeO or Fe3O4
The present invention is a catalyst for the treatment of high sulfur-containing heavy oils in the absence of hydrogen, in which the average composition of iron in the catalyst is in the range of 1.4 to 0.8 atoms of oxygen per 1 atom of iron.

The present invention will be described in detail below.

In the catalyst of the present invention, if the iron content is 30% by weight or less as Fe, the function of capturing decomposed sulfur compounds as iron sulfide is insufficient, and the object of the present invention cannot be achieved.

Further, in the present invention, as long as the average composition ratio of iron and oxygen in the catalyst is within a specific range, there is no particular problem in terms of raw materials.

Therefore, natural ores containing 30% by weight or more of iron, such as laterite, magnetite, magnetite, etc., or mixtures thereof, or mixtures thereof with refractories such as silica, alumina, and magnesia, as well as iron chloride, iron oxide, and iron sulfate. Iron compounds such as these, or mixtures thereof with the above-mentioned natural ores, refractories, etc., can be used as raw materials.

Among these compounds, it is preferable to use natural ores because they are inexpensive, and laterite is particularly preferable because the catalyst can be easily adjusted.

After pulverizing, granulating and drying these catalyst raw materials, they are calcined in air at 900 to 1200°C to give them the necessary strength.

In the heating process, all of the above-mentioned various iron compounds become iron oxide in the form of Fe2O4.

Of course, it is conceivable to carry out the calcination in a reducing atmosphere, but this would reduce the decomposition activity of the catalyst due to sintering of the reduced iron and reduce the surface area, or fusion between catalyst particles. This is not very preferable because it causes staining.

Next, these fired products are mixed with carbon and burned in a reducing atmosphere, or reduced in a hydrogen or carbon monoxide gas stream.

At this time, this reduction proceeds very smoothly if carried out at a temperature of 750° to 950°C.

Thereby, the iron oxide in the fired product is reduced, and a catalyst is obtained in which the average composition of iron in the catalyst is a ratio of 1.4 to 0.8 atoms of oxygen to 1 atom of iron.

In general, the conditions for obtaining the catalyst described in section 2 cannot be determined as a single condition because they vary depending on the crystal state, particle size, iron content, etc. of the fired product.

However, the reduction state of iron is determined by the balance between oxygen atoms in the gas discharged from the reduction process and oxygen atoms introduced into the reduction process, and the reduction rate is calculated from the following equation. Atomic ratio can be calculated.

The relationship between this reduction rate and the O/Fe atomic ratio is shown as follows.

For example, Fe2O3, Fe3O4, and FeO forms of iron oxide each have a reduction rate of 0.11.1.33.3%,
0/Fe (7) Constituent atomic ratio is 1.5.1, 33°1
．． It is 0.

Generally, iron forms the above three types of stable oxides, but in the present invention, it exists as a mixture of these oxides or four types of Fe, and the composition ratio of Fed, Fe, etc. increases as the reduction rate increases. It gets expensive.

In the present invention, if the ratio of 0/Fe is 1.4 or more, it is not possible to reduce the sulfur compounds in the cracked fraction,
Furthermore, if the ratio of 0/Fe is less than 0.8, sintering of iron occurs, the specific surface area decreases, and the decomposition activity and desulfurization activity also decrease. Selected.

The catalyst prepared as described above was heated to 45% in the absence of hydrogen.
Contact with high sulfur-containing heavy oil such as atmospheric distillation residue oil, vacuum distillation residue oil, deasphalting residue oil, shale oil, tar sand, etc. at a temperature of 0-600℃ and a pressure of 0-15kg/cm□ G Disassemble.

This decomposition can be carried out in a fixed bed, fluidized bed, or gas bed by appropriately selecting the catalyst particle size.

In addition, the desulfurization activity or decomposition activity of these catalysts gradually decreases during use, but due to the combustion of coke adhering to the catalyst or the conversion of iron sulfide into iron oxide and hydrogen sulfide due to steam, etc. Although it can be regenerated by decomposition and reduction, in general, when using inexpensive natural ores, it is also possible to recover valuable metals by directly transferring them to the iron making or smelting process without regenerating them.

By using the catalyst of the present invention as described above, the content of sulfur compounds in the cracked fraction can be reduced, so that the amount of hydrogen consumed in the desulfurization equipment in the next step can be reduced.

In addition, since the cracked gas contains almost no hydrogen sulfide, it has the advantage of being able to be used as a fuel as it is, and further increases the decomposition rate, making it extremely advantageous industrially.

The effects of the present invention will be specifically described below based on Examples and Comparative Examples of the present invention.

Examples 1-4. Comparative Examples 1-2 Fe 55.1wt%, Ni' 1.26wt%,
Cr 4.09wt%.

Mg02.56wt%, 51024,69wt%, A
Laterite ore consisting of 12032.81 wt% was crushed, granulated, dried, and then calcined in air at 1200°C for 3 hours.

The average particle size of this catalyst was 1.2 mm.

This was reduced in a hydrogen stream at 850° C. to the atomic ratio of each 07F shown in Table 2.

This catalyst was filled in a stainless steel reaction vessel with a tube diameter of 43 mm, and the vacuum residue obtained from craate crude oil having the properties shown in the upper column of Table 1 was catalytically cracked under the conditions shown in the lower column of Table 1.

The results of this experiment are shown in Table 2.

Example 5 Adding and mixing silica and magnesia to Laterai I ore,
After pulverization, granulation, and drying, the mixture was calcined in air at 1200° C. for 3 hours.

The composition of this fired product is Fe 33.1wt%, N12,
5wt%, Mg019.6wt%, 5in317,
5wt% + Al2O3 1.0wt%, CaOQ, 6
It was wt%.

This was reduced at 850°C in a hydrogen stream to obtain a reduced catalyst with an 0/Fe atomic ratio of 1.0°.

Using this catalyst, the same feedstock oil as in the previous example was catalytically cracked.

The results are also shown in Table 2.

As described above, it can be seen that the higher the reduction rate, the lower the S content in the cracked fraction, and the less hydrogen sulfide is contained in the cracked gas.

In this way, the sulfur compounds in the cracked fraction and cracked gas decrease because the sulfur in the cracked sulfur compounds combines with the reduced iron in the catalyst to produce iron sulfide. It is assumed that this is because the sulfur component "51" is extracted from the sulfur, and that the decomposition rate is also improved by the extraction of sulfur.On the other hand, under the conditions where the reduced iron causes sintering as in Comparative Example 2, Considering that the decomposition activity decreases, it is clear that any catalyst other than laterite ore that contains iron in a reduced state within a specific range can be applied to the present invention.

Claims (1)

[Claims] 1 The iron content is 30% by weight or more as Fe, Fe,
Contains at least one type of Fed or Fe3O4, and the average composition of iron in the catalyst is 1.4 to 0 oxygen per 1 atom of iron.
．． A catalyst for treating heavy oil containing high sulfur in the absence of hydrogen, characterized in that the number of atoms is in the range of 8 atoms.