JPS63258985A - Hydrogenation treatment of heavy oil - Google Patents

Abstract

PURPOSE:To economically and effectively hydrogenate a heavy oil, by deasphalting a heavy oil with a solvent, mixing the treated heavy oil with a light oil at a specific ratio and hydrogenating the mixture under a specific condition. CONSTITUTION:A heavy oil is deasphalted with a solvent and the deasphalted oil is mixed with a light oil in such a manner as to keep a Conradson carbon residue to <=5wt.%. The obtain mixture is subjected to hydrogenation treatment under hydrogen partial pressure of 30-60kg/cm<2> at a reaction temperature of 350-450 deg.C and an LHSV of 0.1-3.0/hr using a heavy oil-treatment catalyst. The heavy oil can be hydrogenated by this process. The catalyst is preferably produced by supporting a group VIA metal (e.g. Mo) and/or a group VIII metal (e.g. Co) on a carrier such as alumina and silica alumina.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses an existing or newly installed reduced pressure gas oil hydrodesulfurization reactor (indirect desulfurization reactor) and its reaction conditions.
The present invention relates to a method for effectively hydrotreating heavy oils such as atmospheric distillation residues and vacuum distillation residues under reaction conditions of low hydrogen partial pressure.

[Conventional technology]

At Japanese oil refineries, in recent years, the yield of light oil such as gasoline and kerosene has been increasing, while the yield of C heavy oil has been decreasing, and heavy oil processing such as hydrocracking of heavy oil has been increasing. There is a growing need for At refineries equipped with direct desulfurization equipment, it is possible to directly hydrotreat atmospheric residual oil under reaction conditions with high hydrogen partial pressure, thereby making it lighter.
It has become possible to use the desulfurized residual oil as an FCC feedstock (fluid catalytic cracker feedstock) to reduce the weight of the oil.

However, refineries that only have indirect desulfurization equipment are unable to cope with this problem, mainly due to the low hydrogen partial pressure of the indirect desulfurization equipment.

In other words, problems when hydrotreating heavy oil in indirect desulfurization equipment include deactivation of the catalyst due to metal poisoning such as Ni and V in the heavy oil, CCR (Conradson residual carbon content), and asphaltene coke. An example of this is carbon deactivation due to oxidation. As a result, the life of the catalyst becomes extremely short, and the cost of the catalyst increases, making it uneconomical. In addition, in fixed bed type actual equipment, it is difficult to frequently replace the catalyst, making it impractical.

As a solution to this problem, hydrogenation treatment of heavy oil using a heavy oil treatment type catalyst has been proposed.

[Problem that the invention seeks to solve]

This method of hydrotreating heavy oil using a heavy oil processing catalyst is an attempt to mix some atmospheric residual oil with vacuum gas oil and perform the hydrotreating process, but there is a problem that it cannot be applied when the hydrogen partial pressure is low. There is a point. As shown in the examples below, when 1% Arabian Light atmospheric residual oil 25vo is mixed with vacuum gas oil and hydrotreated, if the hydrogen partial pressure exceeds 60 kg/-, the practical life of the catalyst is 1 year. However, if the hydrogen partial pressure is less than 60 kg/cffl, carbon will rapidly deactivate and the catalyst life will be extremely shortened. At a hydrogen partial pressure of 40 kg/cd, the catalyst life is shortened to about two months, making it impractical.

Furthermore, the ratio of atmospheric residual oil that can be mixed with vacuum gas oil is low, and there is also the problem that the lightening effect is not sufficient compared to the deasphalted oil treatment shown in the present invention.

The present invention solves the above-mentioned disadvantages, and economically and efficiently processes heavy oils such as atmospheric distillation residual oil and vacuum distillation residual oil in indirect desulfurization equipment that must be treated under reaction conditions with low hydrogen partial pressure. The purpose is to provide information on how to effectively process the process.

As a result of intensive research aimed at achieving this objective, the present inventors found that if heavy oil is once deasphalted and then this deasphalted oil is hydrotreated under certain conditions, catalyst life can be maintained while ,
The present invention was completed based on the discovery that heavy oil can be effectively treated even under reaction conditions of low hydrogen partial pressure.

In other words, we discovered that asphaltene in heavy oil has a significant negative effect on catalyst life, and through deasphalting treatment,
After removing this, CCR after mixing deasphalted oil and light oil
If the mixture is adjusted so that the hydrogen content is 5 wt% or less, and then hydrogenated using a heavy oil treatment type catalyst, it can be used even under reaction conditions with low hydrogen partial pressure, depending on LIISV (liquid standard hourly space velocity). It was discovered that a typical one-year catalyst life can be expected.

Means and operation for solving the problems [c] The present invention has been made based on the above knowledge, and it deasphalts heavy oil with a solvent and mixes the deasphalted oil and light oil so that the residual carbon content is 5 wt% or less. After mixing and preparing, using a heavy oil treatment type catalyst, the hydrogen partial pressure is 30 to 60 kg/cm2, and the reaction temperature is 350 to 350.
It is characterized in that the hydrogenation treatment is carried out under reaction conditions of 450° C. LIISV O, 1 to 3.0 h −1 .

Hereinafter, the configuration of the present invention will be explained based on the drawings.

Figure 1 is a flow sheet showing the equipment configuration for carrying out the present invention. In the figure, 1 is a solvent deasphalting equipment, and 2 is an indirect desulfurization equipment in which at least a part of the interior is filled with a heavy oil processing type catalyst. It is a device. Heavy oil, which is the raw material, is sent to solvent deasphalting equipment 1.
Descaled oil is obtained. Asphaltenes, which act as catalyst poisons, are removed as deasphalted pitch, so they are hardly present in deasphalted oil, but they still contain CCR content, which causes coke deactivation, and prevents the catalyst from being overloaded. To prevent this, the CCR content in the mixed oil is 5wt%.
Mix with light oil as follows. The mixed oil is hydrotreated in the indirect desulfurization device 2 under reaction conditions of low hydrogen partial pressure to obtain a product oil. The produced oil is fully desulfurized and refined and passed through the FCC
Used as raw materials, etc.

In particular, the catalyst is important in the present invention, which is made possible by using a heavy oil treatment type catalyst having a composition and structure suitable for treating deasphalted oil with a large molecular weight.

An example of a heavy oil processing type catalyst suitable for use in the process of the present invention includes metals from group V [A] of the periodic table, such as molybdenum, on supports such as alumina, silica-alumina, and alumina-boria. Catalysts that support metals from group 1 of the periodic table and have the following pore characteristics can be mentioned. In other words, when the pore diameter of the catalyst is measured by the mercury intrusion method, the average diameter of the pores in the range of 62 to 600 pores is 91 to 300 pores, and the average diameter is ±20 pores. The volume occupied by the pores is at least 60%, preferably 80%, of the volume occupied by the pores with a diameter of 62 to 600
The pore volume in the 0-person range is at least 0.45+d/g.

Conventionally, the pore characteristics of a hydrotreating catalyst have been selected according to the molecular weight of the oil to be treated, allowing the oil molecules to enter the pores of the hydrotreating catalyst and undergo the hydrogenation reaction. Attempts have been made to maintain high desulfurization activity by reducing the pore size within a range of size and reducing the pore diameter as much as possible and expanding the active surface area of the catalyst. For example, the pore diameter of the hydrotreating catalyst for indirect desulfurization equipment is selected to be about 60 to 80, corresponding to the molecular weight of vacuum gas oil to be treated, which is 400 to 500, and the average molecular weight is 4,000.
It is said that a pore size of 100 to 400 is required for the purpose of asphaltene treatment, which is said to be 6,000 to 6,000. 8 between vacuum gas oil and asphaltene
For deasphalted oil having a molecular weight of about 0.00, it was estimated that a pore diameter of about 70 to 90, which is close to the pore diameter of vacuum gas oil, is suitable. However, it was found that the hydrogenation reaction was insufficient under the reaction conditions of low hydrogen partial pressure, and the normally selected pore diameter was inappropriate. Under low hydrogen partial pressure, the hydrogenation reaction of oil does not proceed, and carbon components precipitate as coke, particularly at the entrances of the pores, thereby rapidly blocking the catalyst pores. In the case of asphaltene treatment, coke precipitation is particularly significant, and even if the pore size is slightly increased, a practical catalyst life cannot be expected; increasing the pore size even further may lead to a decrease in the physical pressure resistance of the catalyst and the active surface area of the catalyst. There is a problem of decrease in the amount of water, making it difficult to put it into practical use. On the other hand, it has been found that the degree of coke precipitation is considerably reduced with deasphalted oil obtained by removing asphaltenes from heavy oil, and although the normally selected 70 to 90 people is insufficient, it is possible to use deasphalted oil with a larger pore diameter. 91 to 300 people, preferably 100 to 15 people
It was found that a practical catalyst life can be ensured by selecting a catalyst with zero people. Heavy oil processing type catalysts having the above pore characteristics are available as commercial catalysts.

In the present invention, the heavy oil is not limited to atmospheric distillation residual oil or vacuum distillation residual oil, but may be any oil containing asphaltene that has an adverse effect on the catalyst, such as heavy crude oil, atmospheric distillation residual oil, vacuum distillation residual oil, etc. Residual oil, direct desulfurized residual oil, direct desulfurized vacuum residual oil,
Pyrolysis tar, rock oil, tar sand oil, coal liquefied oil, etc. can be used as feedstock oils. Hydrotreating here refers to hydrodesulfurization treatment for the purpose of desulfurization, hydrocracking treatment for the purpose of decomposition, hydrogenation treatment for the purpose of demetalization, and de-CCR, and solvent deasphalting refers to 3. This refers to the operation of removing the asphaltene content from raw oil using a solvent consisting of an aliphatic hydrocarbon having ~7 carbon atoms or a mixed solvent thereof, and recovering the resin content and/or oil content, which is mixed with deasphalted oil. As the light oil, vacuum light oil components obtained by vacuum distillation, light oil components obtained by normal pressure distillation, oil components obtained by hydrogenating these, etc. can be used.

The CCR content in the present invention is the Conradson residual carbon content according to the JIS 2270 analysis method, and is the value for deasphalted oil from which asphaltenes have been removed by solvent deasphalting, and is the value for heavy oil before deasphalting. This CC11 minute value cannot be applied to CC11 minutes below 5wt%,
The reason why it is preferably limited to 2.5 to 3.5 wt% is that if it is too high, it will lead to coke deactivation and shorten the catalyst life, making it impractical.Catalyst life and LHSV
Although the allowable CCR will vary depending on the relationship, if the LHSV of a standard indirect desulfurization equipment is 0.4 to 0.8 and the catalyst life is about 1 year, this CCR will be 2.5 to 3. 5wt%
becomes.

Conventionally, there have been proposals to hydrotreat deasphalted oil, but these are mainly limited to cases where hydrogen partial pressure is high, and the hydrotreating conditions in the examples include reaction conditions with low hydrogen partial pressure. However, there is no description regarding the catalyst life. For example, in JP-A-56-166291, deasphalted oil is treated with hydrogen under a pressure of 40 to 140 bar for 1 second to IO time at 440 to 530°C. After keeping at temperature,
Although it is proposed that hydrogenation be carried out using a catalyst at a pressure of 40 to 140 bar and a temperature of 320 to 430°C, there is no practical example under a pressure of 40 bar, and although there is a description of the composition of the catalyst, There is no description regarding its structure and lifespan, and in Japanese Patent Application Laid-Open No. 60-31594, deasphalted oil is exposed to 350 to 450 pu/- under pressure conditions of 30 to 200 pu/-.
Although it is proposed to carry out hydrogenation treatment using a commercially available catalyst at LHSV of 0.5 to 5 h-1, no description regarding the catalyst life is found. The difference between these methods and the present invention is that the reaction conditions necessary to ensure a practical catalyst life are specified.

If the hydrogen partial pressure is less than 30 + r/cJ, the desulfurization rate will decrease and the effect of hydrogenation treatment will be insufficient, and if the hydrogen partial pressure exceeds 60 kir/c + 4, the effect of heavy oil treatment will decrease. If the zero reaction point temperature is less than 350°C, the desulfurization rate will decrease and the effect of the hydrogenation treatment will be insufficient. If the reaction temperature exceeds 450°C, the design temperature should be changed for the existing indirect desulfurization equipment. Moreover, it is not economical to install a new indirect desulfurization equipment because the equipment cost will be high.

When LH3V is less than O, lh-', the effect of heavy oil treatment is reduced, and when LIISv exceeds 3h-1, a sufficient desulfurization rate cannot be obtained.

〔Effect of the invention〕

Since the present invention is configured as described above, the following effects can be achieved.

(l) The present invention makes it possible to hydrogenate heavy oil under a low hydrogen partial pressure of 30 to 60 kg/c+J, which was previously impossible.In Japanese refineries, indirect desulfurization equipment with low hydrogen partial pressure is used. Therefore, the present invention can be easily applied to existing indirect desulfurization equipment and is useful.

(2) Compared to the case where atmospheric residual oil is processed, the effect of lightening is greater, that is, when the oil type is Arabian light atmospheric residual oil and the hydrogen partial pressure is +r/- to 65, atmospheric residual oil is processed. When compared with the case where processing is attempted, the results are as shown in FIGS. 2 and 3. FIG. 2 is a flow sheet of a conventional method in which Arabian Light atmospheric residual oil is distilled under reduced pressure in a vacuum distillation device 3 to obtain a vacuum gas oil, and this vacuum gas oil and atmospheric residual oil are treated in an indirect desulfurization device 2. In addition, Figure 3 shows that Arabian Light atmospheric residual oil is distilled under reduced pressure in a vacuum distillation device 3, the vacuum residual oil is deasphalted in a solvent deasphalting device 1, the deasphalted pitch is separated, and the deasphalted oil is indirectly distilled together with vacuum gas oil. 1 is a flow sheet of the present invention processed by desulfurization device 2. Figures 2 and 3
In the figure, the numbers in parentheses represent vo1%. In the method of the present invention shown in Fig. 3, 93% of the atmospheric residual oil, excluding 7% of the deasphalted pitch, can be passed to the indirect desulfurization equipment, and in the case of Fig. 2, in which the atmospheric residual oil is mixed in as is. Compared to this, the amount of oil passed to the indirect desulfurization equipment can be increased by 20% or more.

The present invention can be suitably applied in consideration of the fact that, in recent years, there has been a surplus in the capacity of indirect desulfurization equipment due to a decrease in the throughput of crude oil.

(3) In recent years, atmospheric residual oil such as southern low-sulfur crude oil has been
These oil types are widely used as raw materials, and the composition ratio of these oil types in FCC raw materials is increasing. However, the production volumes of these oil types are not large, the production areas are limited, and problems remain in terms of stable supply in the future.According to the present invention, it is possible to use FCC feedstock even from Middle Eastern crude oil with a high sulfur content. easily,
And it can be secured in large quantities, helping to solve this problem.

〔Example〕

Examples of the present invention will be described below.

Example Using Arabian heavy vacuum residual oil as a raw material, solvent deasphalting was performed using pentane and butane solvents to obtain deasphalted oil (8) and deasphalted oil (B), respectively. Table 1 shows the properties of each deasphalted oil and the yield of deasphalted oil.

Deasphalted oil (A) and deasphalted oil (B) are mixed with vacuum light oil, and the CCR content in the mixed oil is 3.0wt each.
% and 2.8 wt% of mixed oil (MA) and (M
B) was obtained. The mixing ratio of the deasphalted oil and the properties of the mixed oil are shown in Table 2.

Next, a Co-Mo-Altos-based catalyst was added to the hydrogenation reactor, and when the pore size was measured by mercury porosimetry,
The average diameter of pores with a diameter ranging from 62 to 600 is 1
25 people, the volume occupied by pores with an average diameter of ±20 people accounts for 72% of the volume occupied by pores with a diameter of 62 to 600 people, and the pore volume in the range of 62 to 600 people is 0.47+af/
heavy oil processing type catalyst 70vol.g and Co-M.

-3i01-A1102 series catalyst, when the pore diameter is measured by mercury intrusion method, the average diameter of pores with a diameter in the range of 62 to 600 is 90, and the pores with a diameter of 20 are occupies 68% of the volume occupied by pores with a diameter of 62 to 600 pores, and the pore volume in the range of 62 to 600 pores is 0.45 m/g.
The mixed oil (MA) and mixed oil (MB) were hydrotreated under the hydrotreating conditions shown in Table 3.

During processing, the sulfur concentration in the fraction above 343°C.

0.3 wt% or less, that is, the sulfur concentration in the produced oil is 0.3 wt% or less.
The reaction temperature was changed so that the concentration was about 2 wt% or less.

The properties of each produced oil are shown in Table 3, and the relationship between time, reaction temperature, and sulfur concentration of the produced oil at that time is shown in Figures 4 to 4.
It is shown in FIG.

Table 1 Table 2 Decreased margin) Table 3 When heavy oil is hydrotreated, metals such as Ni, ■, CC11, and asphaltene in the heavy oil become catalyst poisons, and the activity of the catalyst decreases over time. decreases.

Therefore, if you want to maintain the sulfur concentration in the produced oil,
It is necessary to increase the reaction temperature. Figures 4 and 5
Regarding the mixed oil (MA) in the figure, there is no need to change the reaction temperature even after 700 hours have elapsed, and the catalyst activity can be expected to last for more than one year with almost no decrease in catalyst activity. Also, in order to increase the catalyst load, LII
In the case of the mixed oil (MB) with twice the SV, a slight decrease in catalyst activity was observed, and after 3,000 hours, the catalytic activity decreased to 9.
Although it became necessary to raise the temperature by ℃, the change in catalyst activity was stable, and it is thought that the temperature will continue to rise to the same extent in the future. The reaction temperature after one year is thought to be about 410°C, which is within a temperature range that can be adequately handled by a normal indirect desulfurization equipment.

The produced oil is desulfurized, demetalized, and de-CCR treated with F.
It has properties similar to those of CC raw materials. That is, according to the present invention,
A sufficiently purified FCC feedstock can be produced from vacuum residue, which is heavy oil.

Conventionally, it has been thought that oils having the properties shown in Table 2 cannot be treated under indirect desulfurization conditions because of their metal content and CCR content, which causes severe catalyst poisoning.

However, by combining a heavy oil processing type catalyst and the unique features of deasphalted oil, this treatment becomes possible, leading to the present invention.

Using the same catalyst used in the present invention to explain the characteristics of deasphalted oil treatment, we will take as an example the results of hydrotreating a mixed oil of atmospheric residual oil and vacuum gas oil. Using the residual oil, a mixed oil (MC) with vacuum gas oil was prepared. The mixing ratio of the atmospheric residual oil and the properties of the mixed oil (MC) are shown in Table 4, and the hydrotreating conditions of the mixed oil <nc> are shown in Table 5.

Table 4 Table 5 Mixed oil (MC) has a lighter specific gravity and lower CCR content and metal content than (MB) and is considered to be easier to process, but deasphalted oil The degree of deactivation of the catalyst is greater than that during treatment, and the life of the catalyst is significantly shortened, especially under low hydrogen partial pressure. Experiments have shown that the catalyst life is affected by hydrogen partial pressure, and the relationship between catalyst life and hydrogen partial pressure is shown in Figure 8. A partial pressure of about 65kr/- is required, and at this time approximately! It can be expected to have a lifespan of about 20 years, and is considered practical.

However, the condition of 40kg/- in a normal indirect desulfurization equipment
In this case, its lifespan is shortened to about two months, making it impractical in terms of catalyst replacement frequency and economy.

In general, metals, asphaltene, and CCR components are poisonous substances for catalysts, but especially in indirect desulfurization equipment, the main cause of deactivation is thought to be carbon deactivation due to asphaltene and CCR components turning into coke and adhering to the catalyst surface. . ? Comparing rL synthetic oil (MA), (MB) and (MC), it is metal, and the CCR content is mixed oil (MC).
There are fewer cases, only for asphaltenes (MC
), and in this case it is thought that the minute amount of asphaltene had a decisive effect on the life.As shown in Figure 8, the effect of this asphaltene becomes more pronounced when the hydrogen partial pressure is low. Therefore, the nature of deasphalting heavy oil and removing asphaltenes in advance can be said to be more effective in hydrotreating heavy oil under low hydrogen partial pressure.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet showing the configuration of an apparatus for carrying out the heavy oil hydrotreating method of the present invention, Fig. 2 is a flow sheet showing an example of the conventional atmospheric residual oil processing method, and Fig. 3 is the present invention. A flow sheet showing an example of the atmospheric residual oil treatment method according to the method of the invention, FIG. 4 is a graph showing the relationship between oil passage time and reaction temperature when mixed oil (MA) is hydrotreated, and FIG. A graph showing the relationship between the oil passing time and the sulfur concentration of the produced oil when mixed oil (MA) is hydrotreated. Figure 6 shows the oil passing time and reaction temperature when mixed oil (MB) is hydrotreated. Figure 7 is a graph showing the relationship between oil passage time and sulfur concentration of the produced oil when mixed oil (MB) is hydrotreated, Figure 8 is a graph showing the relationship between mixed oil (MC), It is a graph showing the relationship between the catalyst life, the amount of oil that can pass, and the hydrogen partial pressure. 1...Solvent deasphalt equipment, 2...Indirect desulfurization equipment, 3.
...Vacuum distillation equipment

Claims (1)

[Claims] 1. After deasphalting heavy oil with a solvent, mixing and adjusting the deasphalted oil and light oil so that the Conradson residual carbon content is 5 wt% or less, using a heavy oil processing type catalyst, hydrogen partial pressure is reduced to 30%.
~60kg/cm^2, reaction temperature 350~450℃, L
A method for hydrotreating heavy oil, which is characterized by hydrotreating under reaction conditions of HSV 0.1 to 3.0h^-^1.