JPH0398648A - Activation of sulfide precursor type hydrotreatment catalyst - Google Patents

Abstract

PURPOSE:To eliminate the lowering of initial activity due to a temp. rise speed by supplying a hydrogen sulfide/hydrogen gaseous mixture containing a specific amount of hydrogen sulfide to a sulfide precursor type hydrotreatment catalyst at specific temp. at a specific linear velocity in the flow direction of a catalyst bed. CONSTITUTION:A sulfurization agent is contained in a catalyst wherein a metal of the Group VI of the Periodic Table and a metal of the Group VIII of the Periodic Table are supported on an inorg. oxide carrier to prepare a sulfide precursor type hydrotreatment catalyst. Subsequently, a hydrogen sulfide/ hydrogen gaseous mixture containing 0.1-30vol.% of hydrogen sulfide is supplied to the aforementioned sulfide precursor type hydrotreatment catalyst at linear velocity of 20cm/hr or more in the flow direction of a catalyst bed during a time from 150 deg.C to the start point of time of hydrodesulfurization to activate the catalyst. The pref. linear velocity of the aforementioned hydrogen sulfide/ hydrogen gaseous mixture in the flow direction of the catalyst bed is about 20-200cm/hr and the pref. total pressure of the hydrogen sulfide/hydrogen gaseous mixture is about 1-30atm as absolute pressure.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for reducing the initial activity of a sulfide precursor-type hydrotreating catalyst containing an organic sulfur compound by a simple operation and due to a heating rate. The present invention relates to a method for activating a sulfide precursor-type hydrotreating catalyst that can initiate a desulfurization reaction without causing any damage.

(Prior art) In general, so-called hydrogenation treatment, in which hydrocarbon oil is subjected to hydrogenation, desulfurization, denitrification, decomposition, etc. in the presence of hydrogen, uses an inorganic oxide carrier such as alumina, silica alumina, titania, etc. Metals from group 6 of the periodic table such as molybdenum and tungsten, and metals from group 8 of the periodic table such as cobalt and nickel.
Catalysts supported on group metals are used. However, when these catalytically active metal species are prepared, metals from Group 6 of the Periodic Table are usually supported as hexavalent oxides, and metals from Group 8 of the Periodic Table are supported as divalent or trivalent oxides, and they can be used as they are. Since the metal has no activity, it is necessary to perform pre-sulfidation to activate the active metal by converting it from an oxide form to a sulfide form before being subjected to hydrogenation treatment. Moreover, the catalyst that is filled after this is used for at least one year, and whether or not the sulfurization treatment is properly performed greatly influences the desulfurization activity during this period. This pre-sulfurization treatment method involves sulfurizing hydrocarbon oil using hydrogen sulfide before the desulfurization reaction, in which organic sulfur compounds such as mercaptans, which are sulfurizing agents, are mixed with light extraction and the oil is passed through a fixed catalyst bed. This method is the most commonly used method and is used in many manufacturing facilities. However, these pre-sulfurization methods have the problem that it takes time for sulfurization to proceed completely, and furthermore, it is difficult to judge when the sulfurization process has finished.
Therefore, in many cases, the current situation is that conditions such as processing temperature and time must be selected by relying on empirical operating methods.

Recently, as a method that is even more efficient than these presulfidation methods, a catalyst with the general formula R-S is used to support an active metal.
(n)-R' (n is an integer of 3 to 20, R and R are hydrogen atoms or organic groups having 1 to 150 carbon atoms per molecule) sulfide impregnated with an organic polysulfide A precursor-type hydrotreating catalyst (hereinafter referred to as a hydrotreating catalyst) was heated at 65 to 275°C and 0 in the absence of hydrogen gas.
．． A method of heat treatment under a pressure of 5 to 70 bar (Japanese Patent Application Laid-open No.
No. 1-111144), and a hydrogenation catalyst to which an excessive amount of an organic sulfur compound as a sulfiding agent was added (JP-A No. 6
No. 3-310639 to No. 3-310642> are disclosed. According to this method, the polysulfide impregnated into the hydrotreating catalyst sulfurizes the active metal through heat treatment, making the operation easier than pre-sulfiding in the reactor for actual operation. It is said that hydrotreating operations can be started immediately by filling a reactor with a hydrotreating catalyst that has been pre-sulfurized outside.

(Problems to be Solved by the Invention) However, when a hydrogenation catalyst prepared by adding an organic sulfur compound as a sulfurizing agent is heated for pre-sulfurization, the slower the temperature rise rate, the more hydrogen A problem occurred in that the desulfurization activity was not sufficiently exhibited, and the desulfurization activity was equal to or lower than the desulfurization activity when activated by the conventional presulfurization method.

This is because the contained organic sulfur compound decomposes and desorbs before sulfiding the active metal, leaving a large amount of the active metal in the form of an unsulfurized oxide, resulting in a low initial activity. On the other hand, since active metals become passivated when exposed to a pressurized hydrogen atmosphere, prolonged exposure to a strong reducing atmosphere is unfavorable for catalyst activity.

In order to solve this problem, it is necessary to raise the temperature of the hydrotreating catalyst in as short a time as possible.
In reality, there is a limit to the heating capacity of reaction towers in refineries.
The limit value of temperature increase is set to 50°C/'hr.

Therefore, the commonly used desulfurization reaction temperature <315-350°C>
It will take more than 7 hours to complete the process, and the hydrogenation catalyst will be exposed to a reducing atmosphere for such a long time, resulting in loss of the 2-sulphur content in the hydrogenation catalyst. This is unavoidable, and the desulfurization activity that should be developed cannot be sufficiently developed, so this is not a practical solution. This is a problem that cannot be avoided even when an excessive amount of sulfurizing agent is added.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and provide a means that does not lose the simplicity of the activation operation and is not affected by the temperature increase conditions during activation. There is.

(Means for Solving the Problems) In order to solve the above problems and achieve the above objects, the present inventor has conducted intensive research on a method for activating a hydrotreating catalyst, and has found that During this period, the inventors discovered that the objective could be achieved by carrying out an activation treatment while supplying a water line-hydrogen sulfide mixed gas containing a specific amount of hydrogen sulfide at a specific speed range, leading to the completion of the present invention. . In other words, the present invention provides a sulfide precursor type hydrogenation method prepared by containing a sulfiding agent in a catalyst in which a metal of group 6 of the periodic table and a metal of group 8 of the periodic table are supported on an inorganic oxide carrier. In the method of activating a treatment catalyst, from at least 150°C to the start of hydrodesulfurization, 0.1 vol% to 30 v
This is a method for activating a sulfide precursor-type hydrotreating catalyst, in which a hydrogen sulfide-hydrogen mixed gas containing 1 ol% of hydrogen sulfide is activated while being supplied at a linear velocity in the catalyst layer flow direction of 20 cm/'hr or more.

In this way, in the present invention, the active metal oxides remaining without being sulfurized by the sulfurizing agent are sulfurized by the hydrogen sulfide supplied when the temperature is raised, and at the same time, even after sulfurization, the active metal oxides surrounding the hydrotreating catalyst are sulfurized. This is to adjust the reducing atmosphere. Therefore, even if the temperature increase rate is slow, the desulfurization reaction can be started without inhibiting the sulfidation rate of the active metal.

Further, the time for adding hydrogen sulfide in the present invention may be while the temperature of the hydrotreating catalyst is rising, that is, until the temperature of the reaction tower is rising to the reaction temperature. Suitably, the addition of hydrogen sulfide is started at a temperature of 0.degree. This is because when the hydrogen sulfide addition start temperature is below 150°C, the active metals contained will hardly interact with the added hydrogen sulfide, and once the hydrodesulfurization reaction starts, they will no longer release hydrogen sulfide. This is because there is no need to add it, and the sulfur content in the feedstock oil becomes hydrogen sulfide when desorbed and diffuses onto the surface of the hydrotreating catalyst. Here, the start time of the hydrodesulfurization reaction is approximately 30% when the temperature of the hydrotreating catalyst is raised only in the gas phase, although it varies depending on the type of feedstock oil and reaction conditions.
This refers to the point in time when the raw material port starts to flow after the temperature has been raised to a predetermined hydrodesulfurization reaction temperature of 15 to 350°C. In addition, when the temperature is increased while circulating the raw material, the hydrodesulfurization reaction begins to proceed during the temperature rise, so the temperature at which this reaction becomes noticeable (approximately 300 ° C.) is set as the starting point of the hydrodesulfurization reaction, At this point, the addition of hydrogen sulfide can be terminated.

The hydrogen sulfide concentration of the hydrogen sulfide-hydrogen mixed gas flowing during temperature rise is 0.1 vol% to 30 vol% of the total gas phase pressure.
That's fine. This means that the hydrogen sulfide concentration is 0.1 vol%
This is because in an unsulfurized groove, the unsulfurized active metal can be sulfurized and the initial activity is lowered due to the increased temperature; conversely, the higher the hydrogen sulfide concentration, the more complete the sulfidation of the active metal is. It is sufficient to have a concentration of at most 30 vol%, and adding more hydrogen sulfide is meaningless.
If the proportion of hydrogen sulfide increases too much, the hydrogen partial pressure decreases, and carbonaceous matter that should be desorbed by the decomposition of the sulfurizing agent remains on the surface of the hydrotreating catalyst, which is undesirable. It is et al.

In addition, the linear velocity of the hydrogen sulfide-hydrogen mixed gas flowing through the catalyst layer is 2
The range is 0 to 200 cyn/'Flr, and if it is less than 20■■■/'hr, it is not preferable because it will interfere with the desorption of carbonaceous matter accompanying the decomposition of the sulfurizing agent, and vice versa. The higher the linear velocity, the faster the decomposition of the sulfiding agent can be without loss of sulfidity;
This is because hr is sufficient, and it is meaningless to circulate at a faster rate than this.

In addition, the total pressure of the hydrogen sulfide-hydrogen mixed gas is preferably in the range of absolute pressure - 30 atm, and the total pressure required for activation is less than 1 atm, which means under reduced pressure and is not suitable for industrial use. It is unrealistic and inappropriate for the total pressure to exceed 30 atmospheres, and it is undesirable for the maintenance of the equipment because it exceeds the set pressure of Tsunekawa.

Further, the total pressure and flow rate of the sulfurized water line-hydrogen mixed gas can be selected depending on the conditions used at each manufacturing facility.

The method of the present invention uses metals from group 6 of the periodic table such as molybdenum, tungsten, etc. and metals from group 8 of the periodic table such as cobalt nickel on inorganic oxide supports such as alumina, silica alumina, titania, etc. The present invention can be effectively applied to the activation of a sulfide precursor-type hydrogenation catalyst in which a metal is supported as an active substance and an organic sulfur compound as a sulfurizing agent as described in the above-mentioned patent publication.

Furthermore, in the method of the present invention, it is essential to supply hydrogen sulfide, but the supply device itself is not complicated, and hydrogen sulfide only needs to be added when the temperature of the hydrotreating catalyst is raised. The activation time does not become long, and the concentration of hydrogen sulfide added does not need to be kept strictly constant as long as it is within the above range. Therefore, operations can be started without losing the advantage of the ease of activation of the hydrotreating catalyst used in the present invention.

(Example) Next, examples of the present invention will be described.

Example 1) Preparation of hydrogenation catalyst Molybdenum trioxide 29.0g, cobalt carbonate 12.5g
, 24.1 g of 85% orthophosphoric acid, 85% mercaptoacetic acid
The aqueous solution prepared by adding 2.3 g of aluminum hydroxide was kneaded with 140 g of pseudo-boehmy 1 (aluminum hydroxide), and the
After molding into a cylindrical shape, it was dried at 100'C for 18 hours, and then sized to have an average length of 3B to prepare a hydrogenation catalyst.

2) Presulfurization Activation Treatment 15 CC of the hydrogenation catalyst prepared in 1) was filled into a reaction tube with a diameter of 1.5 (7), and this was connected to a flow system reactor. Then, from room temperature to 330°C,
vol%hS-h mixed gas at a linear velocity of 150 a in the flow direction
The temperature was raised to 330'C at a heating rate of n/'hr and 30kg/'cx2-G. The time required to raise the temperature was 8 hours.

3) Hydrodesulfurization reaction conditions Tsuura time space velocity (LI1SV): 2 (hr-”)
Hydrogen pressure: 30 (kg/an2-G)
Hydrogen flow direction linear velocity: 150 ((1)/'hr) Reaction temperature, time: 48 hours, 330°C reaction raw material night
: Kuwait normal pressure light overnight (sulfur content: 1.55
%) 4) Hydrodesulfurization reaction and results In the activation treatment described in section 2), immediately after the temperature reached 330°C, Kuwait atmospheric gas oil, which is the raw material, was introduced.
At the same time, the supply of the lI23-112 mixed gas was stopped, the flow was switched to hydrogen gas, and a hydrodesulfurization reaction was carried out under the reaction conditions shown in section 3).

As a result of the reaction, the average desulfurization activity value is 10.1, with the rate measurement value kn-1.75 calculated as reaction order 1.75.
There were two. This is 10 vo1% II2s-142
This is almost equivalent to the rate constant of 10.0 for the hydrodesulfurization reaction after activation under the conditions of gas pressure 30 kg/'cm2-G, linear velocity 150 an/ilr, and temperature rise time 20 hours. This was recognized.

Example 2 Using a hydrotreating catalyst prepared in the same manner as in Example 1-(1), the temperature was raised at a constant rate (2.75°C/'min).
Example 1-(2) except that the activation treatment was carried out while raising the temperature at
), and a hydrodesulfurization reaction was carried out in the same manner as in Example 1-(4) under the conditions of Example 1-(3).

As a result of the reaction, the average desulfurization activity value is 10. It was 0.

Comparative Example 1 Using a hydrotreating catalyst prepared in the same manner as in Example 1-(1), activation treatment was carried out at 30 kg7'(1)''-G
The same procedure as in Example 1-(2) was carried out except that pressurized hydrogen of 100% was used. It took 8 hours to raise the temperature to 330°C. Thereafter, a hydrodesulfurization reaction was carried out under the conditions of Example 1-(3).

As a result of the reaction, the average desulfurization activity value was calculated using the reaction rate constant kn=1.75 as the reaction order. 75 is 8.
It was 2.

Comparative Example 2 A hydrodesulfurization reaction was carried out in the same manner as in Comparative Example 1, except that the time required to raise the temperature in the activation treatment was 20 hours.

As a result of the reaction, the average desulfurization activity value is 7.5, with the reaction rate constant kn = 1.75 calculated with the reaction order being 1.75.
It was 5.

These results show that when activated by the method of the present invention, the temperature increase rate during activation does not affect the desulfurization activity, and moreover, the activation operation performed in Examples 1 and 2 above does not affect the desulfurization activity. Comparing Comparative Examples 1 and 2, the only difference was that hydrogen sulfide was added, and it was found that the operating method was not complicated.

(Effects of the Invention) Since the present invention activates a sulfide precursor-type hydrotreating catalyst under specific conditions using a sulfide water-hydrogen mixed gas, the simplicity of the activation operation is lost. without, and
The desulfurization reaction can be started without decreasing the initial activity depending on the heating rate, and a remarkable effect is observed.

Claims (1)

[Claims] 1) Activate a sulfide precursor-type hydrogenation catalyst prepared by incorporating a sulfiding agent into a catalyst in which a group 6 metal of the periodic table and a group 8 metal of the periodic table are supported on an inorganic oxide carrier. In the method, a hydrogen sulfide/hydrogen mixed gas containing 0.1 vol% to 30 vol% hydrogen sulfide is supplied at a linear velocity in the catalyst bed flow direction of 20 cm/hr or more from at least 150°C until the start of hydrodesulfurization. A method for activating a sulfide precursor-type hydrotreating catalyst, characterized by activating a sulfide precursor-type hydrotreating catalyst.