JP7722830B2 - Information processing method, naphtha yield calculation device, naphtha yield calculation program, and non-transitory computer-readable recording medium - Google Patents

Description

The present invention relates to an information processing method, a naphtha yield calculation device, a naphtha yield calculation program, and a non-transitory computer-readable recording medium.

Diesel base stock is produced by hydrotreating atmospheric distillation diesel oil, which is obtained by atmospheric distillation of crude oil. Hydrotreating is carried out by contacting atmospheric distillation diesel oil with a hydrotreating catalyst in the presence of hydrogen.

During the hydrotreatment of atmospheric distillation gas oil, coke is produced as a by-product, and as the coke accumulates on the hydrotreatment catalyst, the activity of the hydrotreatment catalyst decreases over time. Therefore, in order to keep the sulfur content in the produced oil below a certain level, the reaction temperature must be increased to counteract the decrease in activity of the hydrotreatment catalyst.

In addition, during the hydrotreating of atmospheric distillation gas oil, light fractions such as naphtha are produced as by-products, and these light fractions must be managed. The yield of light fractions such as naphtha fluctuates over time depending on the cracking activity of the hydrotreating catalyst and changes in reaction temperature.

Atmospheric distillation diesel hydrotreating units have an upper limit to their extraction capacity for light fractions such as naphtha, and if the extraction of light fractions such as naphtha becomes a bottleneck, the throughput of diesel fractions will be limited. Therefore, a method for accurately estimating the yield of light fractions such as naphtha is desired.

In the field of crude oil refining, various methods for accurately estimating various conditions have been studied. For example, Patent Document 1 discloses a method for estimating the reaction temperature required after switching to a feedstock containing atmospheric distillation light oil with different properties in the hydroprocessing of the feedstock containing atmospheric distillation light oil, based on information about the properties of the atmospheric distillation light oil before the switch and the operating conditions, and information about the properties of the atmospheric distillation light oil after the switch and the operating conditions other than the reaction temperature.

Japanese Patent Application Publication No. 10-60455

However, there is currently no method for estimating the yield of light fractions such as naphtha, and the current method is to use actual data from past operations.

The present invention was made in consideration of the above circumstances, and aims to provide an information processing method capable of estimating naphtha yield under specified reaction conditions for the hydrotreating reaction of feedstock oil, including atmospheric distillation gas oil; a naphtha yield calculation device capable of estimating the naphtha yield; a naphtha yield calculation program for causing a computer to function as the naphtha yield calculation device; and a non-transitory computer-readable recording medium storing the program.

In order to solve the above problems, the present invention has the following aspects.
[1] An information processing method, comprising: an information acquisition step for acquiring information on the feedstock, information on the product oil, and information on operating conditions when a predetermined time has elapsed since the start of the reaction, regarding a hydrotreating reaction of a feedstock containing atmospheric distillation gas oil; a deterioration degree calculation step for calculating a deterioration level of a desulfurization reaction and a deterioration level of a cracking reaction of a catalyst using a deterioration function based on the acquired information on the feedstock, information on the product oil, and information on the operating conditions; a reaction temperature calculation step for calculating a reaction temperature necessary to satisfy the information on the feedstock, information on the product oil, and the operating conditions based on the deterioration level of the desulfurization reaction of the catalyst; and a naphtha yield calculation step for calculating a naphtha yield based on the reaction temperature and the deterioration level of the cracking reaction of the catalyst.
[2] The deterioration function is a coke deterioration function relating to catalyst deterioration due to coke deposition, and is composed of an easily deactivated active species deterioration function relating to the deterioration of easily deactivated active species of the catalyst and a hardly deactivated active species deterioration function relating to the deterioration of hardly deactivated active species of the catalyst. The information processing method described in [1].
[3] The information processing method according to [1] or [2], wherein the information about the feedstock oil includes information about the sulfur concentration in the feedstock oil, and the information about the product oil includes information about the sulfur concentration in the product oil.
[4] The information processing method according to any one of [1] to [3], wherein the information about the operating conditions includes information about hydrogen partial pressure, information about catalyst loading, information about the feedstock supply rate, and information about the hydrogen supply rate.
[5] A naphtha yield calculation device including: an acquisition unit that acquires information about the feedstock oil, information about the product oil, and information about operating conditions when a predetermined time has elapsed since the start of the hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil; and a calculation unit that calculates the degradation degree of the desulfurization reaction and the degradation degree of the cracking reaction of the catalyst using a degradation function based on the information about the feedstock oil, the information about the product oil, and the information about the operating conditions acquired by the acquisition unit, calculates the information about the feedstock oil, the information about the product oil, and the reaction temperature necessary to satisfy the operating conditions based on the calculated degradation degree of the desulfurization reaction of the catalyst, and calculates the naphtha yield based on the calculated reaction temperature and the degradation degree of the cracking reaction of the catalyst.
[6] The naphtha yield calculation device according to [5], wherein the deactivation function is a coke deactivation function relating to catalyst deactivation due to coke deposition, and is composed of an easily deactivated active species deactivation function relating to deactivation of easily deactivated active species of the catalyst, and a hardly deactivated active species deactivation function relating to deactivation of hardly deactivated active species of the catalyst.
[7] The naphtha yield calculation device according to [5] or [6], wherein the information about the feed oil includes information about the sulfur concentration in the feed oil, and the information about the product oil includes information about the sulfur concentration in the product oil.
[8] The naphtha yield calculation device according to any one of [5] to [7], wherein the information on the operating conditions includes information on hydrogen partial pressure, information on catalyst loading, information on the feedstock oil supply amount, and information on the hydrogen supply amount.
[9] A naphtha yield calculation program for causing a computer to function as the naphtha yield calculation device according to any one of [5] to [8].
[10] A non-transitory computer-readable recording medium storing the program according to [9].

The present invention provides an information processing method capable of calculating naphtha yield under specified reaction conditions for the hydrotreating reaction of feedstock oil, including atmospheric distillation gas oil, a naphtha yield calculation device capable of calculating the naphtha yield, a naphtha yield calculation program for causing a computer to function as the naphtha yield calculation device, and a non-transitory computer-readable recording medium storing the program.

1 is a flowchart of an information processing method according to an embodiment. FIG. 1 is a configuration block diagram of a naphtha yield calculation device according to an embodiment.

The following describes in detail the embodiments of the present invention. However, the following description is merely an example of an embodiment of the present invention, and the present invention is not limited to these details and can be modified and implemented within the scope of its essence.

<Information processing method>
The information processing method of this embodiment includes an information acquisition step (S1 in FIG. 1) for acquiring information about the feedstock, the product oil, and the operating conditions at a predetermined time after the start of the hydrotreating reaction of a feedstock containing atmospheric distillation gas oil; a degradation degree calculation step (S2 in FIG. 1) for calculating the degradation degree of the desulfurization reaction and the degradation degree of the cracking reaction of the catalyst using a degradation function based on the acquired information about the feedstock, the product oil, and the operating conditions; a reaction temperature calculation step (S3 in FIG. 1) for calculating the reaction temperature required to satisfy the information about the feedstock, the product oil, and the operating conditions based on the degradation degree of the desulfurization reaction of the catalyst; and a naphtha yield calculation step (S4 in FIG. 1) for calculating the naphtha yield based on the reaction temperature and the degradation degree of the cracking reaction of the catalyst. Each step will be described below. Note that each of the steps shown below is executed, for example, by the naphtha yield calculation device 1 of this embodiment. For example, S1 is executed by the acquisition unit 11, and S2, S3, and S4 are executed by the calculation unit 13 in the computer main body 12.

<Information Acquisition Steps>
The information acquisition step of this embodiment is a step of acquiring information about the feedstock oil, information about the product oil, and information about the operating conditions when a predetermined time has elapsed since the start of the reaction. The predetermined time after the start of the reaction refers to, for example, any t days having elapsed since the start of the reaction. t may be an integer or a decimal; for example, if t is 0.5, it means that 12 hours have elapsed since the start of the reaction. Furthermore, the time when t days have elapsed may be in the past, present, or future from the time when the information processing method of this embodiment is implemented. For example, if the information processing method of this embodiment is implemented two days after the start of the reaction and t is 4, the reaction temperature two days later (in the future) will be estimated.

(Information about feedstock oil)
An example of the information about the feedstock oil is information about the composition of the feedstock oil. An example of the information about the composition of the feedstock oil is information about the sulfur concentration in the feedstock oil.

Information regarding the sulfur concentration in the feedstock oil can be obtained using sulfur concentration measurement methods known in the art, such as ultraviolet fluorescence spectroscopy and wavelength-dispersive X-ray fluorescence spectroscopy. The sulfur concentration in the feedstock oil can also be controlled by changing the feedstock oil. It is preferable that the information regarding the sulfur concentration in the feedstock oil is a set value. In other words, the sulfur concentration of the feedstock oil planned for use can be used.

(Information about produced oil)
Examples of the information about the product oil include information about the composition of the product oil, and information about the sulfur concentration in the product oil.

Information regarding the sulfur concentration in the product oil can be obtained in the same manner as in the case of the feedstock oil described above. In this embodiment, the information regarding the sulfur concentration in the product oil is preferably a set value. In other words, the sulfur concentration of the target product oil can be used.

(Information about operating conditions)
Examples of information about operating conditions include information about hydrogen partial pressure, information about catalyst loading, information about the feedstock feed rate, and information about the hydrogen feed rate. For example, the information about operating conditions is at least one of information about hydrogen partial pressure, information about catalyst loading, information about the feedstock feed rate, and information about the hydrogen feed rate, and preferably all of these. The operating conditions also include time information, such as the time when any t days have elapsed since the start of the reaction. The operating conditions may also include information about the actually measured naphtha yield.

Information regarding hydrogen partial pressure, catalyst loading, feedstock feed rate, and hydrogen feed rate can be determined by methods known in the art. Information regarding hydrogen partial pressure, catalyst loading, feedstock feed rate, and hydrogen feed rate can be controlled in the hydrotreating reaction of feedstocks, including atmospheric distillation gas oil. Information regarding operating conditions is preferably a set value; that is, the planned operating conditions are used.

<Deterioration level calculation step>
The deterioration degree calculation step in this embodiment is a step of calculating the deterioration degree of the desulfurization reaction and the deterioration degree of the cracking reaction of the catalyst using a deterioration function based on the acquired information about the feedstock oil, information about the product oil, and information about the operating conditions.
The step of calculating the degradation degree of the desulfurization reaction will be described below. The step of calculating the degradation degree of the decomposition reaction will be described later.

<Deterioration of desulfurization reaction>
The deterioration degree of the desulfurization reaction is expressed by the following formula 1.
Φ=k _t /k ₀ Equation 1
In the above formula 1, _k0 is the reaction rate constant of the desulfurization reaction of the catalyst after 0 days of reaction (i.e., at the start of the reaction), and _kt is the reaction rate constant of the desulfurization reaction of the catalyst after t days of reaction. Note that _k0 and _kt are reaction rate constants of the desulfurization reaction at a temperature T _SOR described below.

In this embodiment, the degree of degradation of the catalyst's desulfurization reaction can be calculated using the desulfurization reaction degradation function based on the acquired information about the feedstock oil, information about the product oil, and information about the operating conditions.

<Degradation function 1 of desulfurization reaction>
The desulfurization reaction deterioration function is a function for calculating the degree of deterioration of the desulfurization reaction of the catalyst. In this embodiment, the desulfurization reaction deterioration function is preferably a coke deterioration function relating to deterioration of the desulfurization reaction of the catalyst due to coke deposition. The coke deterioration function is not particularly limited as long as it is a function capable of calculating the degree of deterioration relating to coke deterioration of the catalyst. For example, desulfurization reaction deterioration function 1 expressed by the following formula 2 can be mentioned as an example.

Φ=exp(-Dt) Formula 2
In the above formula 2, D is the deterioration coefficient of the active species of the desulfurization reaction of the catalyst, and t is the number of days elapsed since the reaction began (days).

D can be calculated using the following equation 3. Equation 3 below is a formula that can calculate the depletion coefficient of the active species in the desulfurization reaction of the catalyst using specific parameters. It was first discovered by the inventors of this application based on the operating results of an actual plant.

In the above formula 3, α is the catalyst constant of the desulfurization reaction (a constant representing the degradation rate of the desulfurization reaction of the catalyst), S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ^-1 ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm ³ /kL), and G is the hydrogen/feed oil ratio (Nm ³ /kL), b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), T _B is the reference reaction temperature (K), and T _SOR is the required temperature on day 0 (K).

As used herein, the term "required temperature" refers to the reaction temperature required to achieve predetermined reaction conditions. That is, the required temperature on day 0 refers to the reaction temperature required to achieve the reaction conditions S _F , S _P , LHSV, G, and P at the start of the reaction.

In this specification, "reference hydrogen partial pressure" refers to the standard pressure under actual reaction conditions. It is calculated as the average reaction pressure used when determining the hydrogen partial pressure coefficient a, which will be described later.

In this specification, the "reference reaction temperature" means the average value of T _SOR obtained over a range of standard operating conditions that may be actually encountered during operation.

In this specification, "reference hydrogen/feed oil ratio" refers to the standard hydrogen/feed oil ratio under actual reaction conditions. It is calculated as the average hydrogen/feed oil ratio used when determining the hydrogen/feed oil ratio coefficient b, which will be described later.

In Equation 3, T _SOR represents the initial activity of the desulfurization reaction of the catalyst, and α represents the deterioration rate of the desulfurization reaction of the catalyst. That is, the larger the values of T _SOR and α, the greater the deterioration of the desulfurization reaction of the catalyst, and this deterioration behavior is reflected in the value of D.

In the above equation 3, the term expressed by (1/S _P ^n-1 -1/S _F ^n-1 )LHSV is a desulfurization reaction rate constant, and as described above, is a constant when S _P , S _F , and LHSV are set values and operation is performed under constant conditions. In the above equation 3, the term expressed by (P _B /P) ^a is a term indicating hydrogen partial pressure dependency, and as described above, is a constant when P is set value and operation is performed under constant conditions. In the above equation 3, the term expressed by (G _B /G) ^b is a term indicating hydrogen/feed oil ratio dependency, and as described above, is a constant when G is set value and operation is performed under constant conditions. In the above equation 3, the term expressed by exp[Ec/R(1/T _B -1/T _SOR )] is a term indicating temperature dependency and is a constant.

In the above formula 3, S _F , S _P , LHSV, P, and G are values substituted based on the information on the feed oil, the information on the product oil, and the information on the operating conditions acquired in the above-mentioned information acquisition step. Note that LHSV can be calculated by dividing the feed oil supply rate (volume/h) by the catalyst loading rate (volume). G can be calculated by dividing the hydrogen supply rate (Nm ³ /hour) by the feed oil supply rate (kL/hour).

As described above, S _F , LHSV, P, and G are controllable parameters. Furthermore, S _P is the sulfur concentration of the target product oil. That is, the deterioration coefficient of the active species of the desulfurization reaction of the catalyst under the reaction conditions of S _F , S _P , LHSV, P, and G can be calculated using Equation 3. The method for determining n, which is the reaction order of the hydrotreating reaction of feedstock oil containing atmospheric distillation gas oil, will be described later.

(How to determine basic degradation parameters)
In the above formula 3, α, P _B , a, G _B , b, Ec, T _B , and T _SOR are constants. Hereinafter, these parameters will be collectively referred to as "basic deterioration parameter 1." The basic deterioration parameter 1 is a parameter determined depending on the catalyst used, and may be determined while performing a reaction in an actual machine, or may be determined in advance on a bench scale based on the operating conditions of the actual machine. In this embodiment, it is preferable to determine the parameter in advance on a bench scale based on the operating conditions of the actual machine.
Below, examples of how to determine the basic deterioration parameters P _B , a, G _B , b, Ec, and T _B are shown. These methods (methods for determining P B , a, G B , b, Ec, and T B) are based on the deterioration behavior of the catalyst desulfurization reaction (changes in the reaction rate constant of the desulfurization reaction) analyzed from data obtained from the above-mentioned reaction on the _{actual plant} or a bench-scale reaction under actual _plant operating conditions. Two examples of how to determine α and T _SOR are shown, but the present invention is not limited to these. The first example is a method (method 1 for determining α and T SOR) in which the parameters are determined from the deterioration behavior of the catalyst desulfurization reaction (changes in the reaction rate constant of the desulfurization reaction) analyzed from data obtained from the above-mentioned reaction on the actual plant or a bench-scale reaction under actual plant operating conditions. The second example is a method (method 2 for determining α and T _SOR ) in which the parameters are determined from the reaction temperature profile analyzed from data obtained from the above-mentioned reaction on the actual plant or a bench- _scale reaction under actual plant operating conditions.

(How to find P _B , a, G _B , b, Ec, and T _B )
The method for determining the basic deterioration parameters in this embodiment is based on the deterioration behavior of the desulfurization reaction of the catalyst analyzed from data obtained from the above-mentioned reaction in an actual plant or a bench-scale reaction under actual plant operating conditions. The deterioration behavior (degree of deterioration) of the desulfurization reaction of this catalyst can be expressed by the following equation 4, based on the same concept as equation 1 above.
Φ'=k _t '/k ₀ ' Equation 4
In the above formula 4, k ₀ ' is the reaction rate constant of the desulfurization reaction of the catalyst after 0 days of reaction (i.e., at the start of the reaction), and k _t ' is the reaction rate constant of the desulfurization reaction of the catalyst after t days of reaction. Note that k ₀ ' and k _t ' are reaction rate constants of the desulfurization reaction at a temperature T _SOR ' described below.

Like Equation 1, Equation 4 is a degradation function based on the reaction rate constant of the desulfurization reaction. The reaction rate constant is expressed by the Arrhenius equation in Equation 5 below.

In the above formula 5, k is the reaction rate constant, A is the frequency factor, E is the activation energy (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), and T is the reaction temperature (K).

The reaction rate constant k ₀ ' of the desulfurization reaction at the reaction start temperature T _SOR ' decreases to k _t ' after t days of reaction. If the reaction temperature must be set to T _t ' to obtain activity equivalent to the reaction rate constant k ₀ ' of the desulfurization reaction after t days of reaction, the following formula 6 can be derived from formulas 4 and 5. Note that since the reaction in this embodiment is a hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil, the activation energy E is set to the desulfurization activation energy Ea (kJ/mol).

In this embodiment, P _B , a, G _B , b, Ec, and T _B are calculated based on the above-mentioned formula 6.

(How to calculate Ec and T _B )
The reaction is carried out for a certain period of time under constant conditions of LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, and sulfur concentration in the feed oil so that the sulfur concentration in the product oil reaches a certain value _SPn . Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature in order to maintain the sulfur concentration in the product oil at _SPn . By plotting the reaction time on the horizontal axis and the measured reaction temperature on the vertical axis and drawing a regression line, a straight line expressed as y = a _n x + b _n (0 < a _n ) is obtained. _{a n} and b _n are values reflecting the deterioration behavior of the catalyst. b _n in this straight line is T _SOR ' in the above-mentioned formula 6. In the above-mentioned formula 6, by substituting b _n for T _SOR ' and substituting the measured reaction temperature for T _t ', the deterioration degree Φ' of the desulfurization reaction after any t days of reaction can be obtained. Note that the desulfurization activation energy Ea can be a value determined by the method described below. Plotting the logarithm of Φ' on the vertical axis against the reaction time on the horizontal axis and drawing a regression line gives a straight line expressed as y = -a _n ^' x (|-a _n ^' | = a _n ^' ), where _{a n} ^' represents the degradation rate of the catalyst desulfurization reaction.

The same reaction is carried out for n types of sulfur concentration S _Pn , and n a _n and b _n are determined in the same manner, and n a _n ^' are obtained by the same method as above. n is an integer of 3 or more. The larger the number of n, the more accurate Ec can be obtained. On the other hand, if the number of n is too large, it takes a long time to obtain Ec, which is not efficient. In this embodiment, n is preferably 3 to 20, and more preferably 3 to 10.
The n a _n ^'s and b _n values thus obtained are respectively substituted into the following formula 7. The following formula 7 is an equation that can calculate the activation energy and reference reaction temperature of coke, and was first discovered by the inventors of the present application based on the operating results of an actual machine, etc.

ln( _an ^' )=ln(A)-(Ec/ _Rbn ) Equation 7
In Equation 7, A is a frequency factor, Ec is the activation energy of coke deterioration (kJ/mol), and R is the gas constant: 0.00831 (kJ/(mol·K)).

For n combinations of a _n ^' and b _n , ln(a _n ^' ) is plotted on the vertical axis and 1/b _n on the horizontal axis, a regression line is drawn, and its slope is calculated. Since this slope is Ec/R, the activation energy of coke deterioration, Ec, can be calculated by subtracting R from the slope.

Also, T _B can be obtained by averaging n b _n values.

In determining Ec and _TB , it is preferable that the LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, and sulfur concentration in the feed oil are conditions that correspond to the operating conditions of an actual plant.
Such an LHSV is, for example, 0.3 to 2.0 h ⁻¹ , the hydrogen partial pressure is, for example, 3 to 7 MPa, the hydrogen/feed oil ratio is, for example, 100 to 700 [Nm ³ /kL], and the sulfur concentration in the feed oil is, for example, 0.5 to 2.0 mass %.
Similarly, it is preferable that the n-type sulfur concentrations S _Pn are set to conditions that correspond to the actual operating conditions of the engine. For example, S _Pn is 0.001 mass % or less.
The reaction period is, for example, 30 to 1600 days.

(How to calculate P _B and a)
The reaction is carried out for a certain period of time under conditions of constant LHSV, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil, and hydrogen partial pressure _Pm . Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature in order to maintain a constant sulfur concentration in the product oil. When the reaction time is plotted on the horizontal axis and the measured reaction temperature on the vertical axis and a regression line is drawn, a straight line expressed as y = _amx + _bm (0 < _am ) is obtained. _bm on this line is T _SOR ' in the above-mentioned formula 6. When _bm is substituted for T _SOR ' in the above-mentioned formula 6 and the measured reaction temperature is substituted for _Tt ', the degree of deterioration Φ' of the desulfurization reaction after any t days of reaction has elapsed can be obtained. When the reaction time is plotted on the horizontal axis and the logarithm of Φ' on the vertical axis and a regression line is drawn, a straight line expressed as y = -a _m ^' x (|-a _m ^' | = a _m ^' ) is obtained. a _m ^' represents the deterioration rate of the desulfurization reaction of the catalyst.

The same reaction is carried out for m types of hydrogen partial pressure P _m , m a _m and b _m are determined in the same manner, and m a _m ^' are obtained by the same method as above. m is an integer of 3 or more. The larger the number of m, the more accurate a can be obtained. On the other hand, if the number of m is too large, it takes a long time to obtain a, which is not efficient. In this embodiment, m is preferably 3 to 20, and more preferably 3 to 10.
The m a _m 's and P _m obtained in this way are respectively substituted into the following formula 8. The following formula 8 is an equation that can calculate the hydrogen partial pressure coefficient and the reference hydrogen partial pressure, and was first discovered by the inventors of the present application based on the operating results of an actual machine, etc.

ln( _am ^' )=-aln( _Pm )+B1 Equation 8
In the formula 8, B1 can be 0.

For m combinations of a _m ' and P _m , ln(a _m ^' ) is plotted on the vertical axis and ln(P _m ) on the horizontal axis, a regression line is drawn, and the slope is determined. This slope is the hydrogen partial pressure coefficient a.

In addition, P _B can be obtained by averaging the m types of hydrogen partial pressures P _m .

In determining a and P _B , the LHSV, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil are preferably set to conditions that correspond to the operating conditions of an actual plant.
Such an LHSV is, for example, 0.3 to 2.0 h ⁻¹ , the hydrogen/feed oil ratio is, for example, 100 to 700 [Nm ³ /kL], the sulfur concentration in the feed oil is, for example, 0.5 to 2.0 mass %, and the sulfur concentration in the product oil is, for example, 0.001 mass % or less.
Similarly, it is preferable that the hydrogen partial pressure _Pm of m units is set to a condition that corresponds to the operating conditions of the actual plant. Such _Pm is, for example, 3 to 7 MPa. The reaction period is, for example, 30 to 1600 days.

(How to find _GB and b)
The reaction is carried out for a certain period of time under the conditions of constant LHSV, hydrogen partial pressure, sulfur concentration in the feed oil, and sulfur concentration in the product oil, and a hydrogen/feed oil ratio of G _h . Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature in order to maintain a constant sulfur concentration in the product oil. When the reaction time is plotted on the horizontal axis and the measured reaction temperature on the vertical axis and a regression line is drawn, a straight line expressed as y = a _h x + b _h (0 < a _h ) is obtained. b _h in this line is T _SOR ' in the above-mentioned formula 6. When b _h is substituted for T _SOR ' in the above-mentioned formula 6 and the measured reaction temperature is substituted for T _t ^' , the deterioration degree Φ' of the desulfurization reaction after any t days of reaction has elapsed can be obtained. When the reaction time is plotted on the horizontal axis and the logarithm of Φ' on the vertical axis and a regression line is drawn, a straight line expressed as y = - _{a h} ^' x (|- _{a h} ^' | = a _h ^' ) is obtained. a _h ^' represents the deterioration rate of the desulfurization reaction of the catalyst.

The same reaction is carried out for h types of hydrogen/feed oil ratios _Gh , h a _h and b _h are determined in the same manner, and h a _h ^' are obtained by the same method as above. h is an integer of 3 or more. The larger the number of h, the more accurate b can be obtained. On the other hand, if the number of h is too large, it takes a long time to obtain b, which is not efficient. In this embodiment, h is preferably 3 to 20, and more preferably 3 to 10.
The h _a 's and G _h's thus obtained are respectively substituted into the following formula 9. The following formula 9 is an equation that can calculate the hydrogen/feed oil ratio coefficient and the reference hydrogen/feed oil ratio, and was first discovered by the inventors of the present application based on the operating results of an actual plant, etc.

ln( _ah ')=-bln( _Gh )+B2 Equation 9
In the formula 9, B2 can be 0.

For h combinations of a _h ' and G _h , ln(a _h ') is plotted on the vertical axis and ln(G _h ) on the horizontal axis, a regression line is drawn, and the slope is determined. This slope is the hydrogen/feed oil ratio coefficient b.

Moreover, _GB can be obtained by averaging the above h types of hydrogen/feedstock ratios _Gh .

In determining b and _GB , it is preferable that the LHSV, hydrogen partial pressure, sulfur concentration in the feed oil, and sulfur concentration in the product oil are conditions that correspond to the operating conditions of an actual plant.
Such an LHSV is, for example, 0.3 to 2.0 h ⁻¹ , the hydrogen partial pressure is, for example, 3 to 7 MPa, the sulfur concentration in the feed oil is, for example, 0.5 to 2.0 mass%, and the sulfur concentration in the product oil is, for example, 0.001 mass% or less.
Similarly, it is preferable that the hydrogen/feedstock ratio G _h of the h types is set to a condition that corresponds to the actual operating conditions. Such G _h is, for example, 100 to 700 [Nm ³ /kL]. The reaction period is, for example, 30 to 1600 days.

(Method 1 for determining α and T _SOR )
In an actual plant or on a bench scale, the reaction is carried out for a certain period of time so that the LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil are the assumed actual plant operating conditions. Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature. Examples of the assumed actual plant operating conditions include the operating conditions described in (How to determine Ec and T _B ), (How to determine P _B and a), and (How to determine G _B and b). By plotting the reaction time on the horizontal axis and the measured reaction temperature on the vertical axis and drawing a regression line, a straight line expressed as y = a _α x + b _α is obtained. In this line, a _α is a value correlated with α in Equation 3, and b _α is T _SOR in Equation 3. Substituting b _α for T _SOR ′ and the measured reaction temperature for T _t ′ in Equation 6 gives the degree of deterioration Φ′ of the desulfurization reaction after any t days of reaction have elapsed. Plotting the logarithm of Φ' on the vertical axis against the reaction time on the horizontal axis yields a regression line expressed as y = -a _α ^' x (where |-a _α ^' | = a _α ^' ), where _{a α} ^' represents the degradation rate of the desulfurization reaction of the catalyst.

D is determined by substituting the operating conditions S _P , S _F , LHSV, P, and G, as well as P _B , a, G _B , b, Ec, T _{B , and} T _SOR (i.e., b _α ) determined by the above method, into Equation 3. Φ is obtained by substituting the determined D into Equation 2. In this case, Φ is a function of α. If the reaction time is plotted on the horizontal axis and the logarithm of Φ on the vertical axis, and a regression line is drawn while changing α so that α is 0 < α, multiple straight lines expressed as y = -a _α ^" x (|-a _α ^" | = a _α ^" ) are obtained for each value of α. The _α when a _α ^" on each straight line is equal to the above-mentioned a α ^' can be defined as the α in Equation 3.

(Method 2 for determining α and T _SOR )
A reaction similar to that in (Method 1 for Determining α and T _SOR ) is carried out to obtain a straight line expressed as y = a _α x + b _α , and b _α is defined as T _SOR in the above formula 3. D is determined by substituting the operating conditions S _P , S _F , LHSV, and P, and P _B , a, G _B , b, Ec, T _{B , and} T _SOR (i.e., b _α ) determined by the above method into the above formula 3. Φ is obtained by substituting the determined D into the above formula 2. In this case, Φ is a function of α. Substituting the obtained Φ into Φ' in the above formula 6 and T _SOR (i.e., b _α ) into T _SOR ^' in the above formula 6 and rearranging for T _t ', T _t ' becomes a function of α. The α in the above formula 3 can be the α when the ratio (T _t '/T _obs ) of T _t ' to the measured reaction temperature T _obs is 1. Similarly, it is preferable to calculate N ratios (T _t '/T _obs ) of T _t ' to the reaction temperature T _obs , and use the α when the average of these is closest to 1 as the α in the above formula 3. N is an integer of 10 or more, preferably 10 to 500, and more preferably 50 to 200.

<Degradation function 2 of desulfurization reaction>
In this embodiment, the coke deterioration function relating to the deterioration of the desulfurization reaction of the catalyst due to coke deposition is preferably deterioration function 2, expressed by the following equation 10, which is composed of an easily deactivated active species deterioration function relating to the deterioration of easily deactivated active species in the desulfurization reaction of the catalyst and a hardly deactivated active species deterioration function relating to the deterioration of hardly deactivated active species in the desulfurization reaction of the catalyst.

Φ=k ₁ ×exp(-D ₁ t)+k ₂ ×exp(-D ₂ t) Equation 10
In Equation 10, _k1 is the active site coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst, _k2 is the active site coefficient of the resistant to deactivation active species in the desulfurization reaction of the catalyst, and the active site coefficients represent the relative reaction rate constants of the desulfurization reaction of both active species. _D1 is the deterioration coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst, _D2 is the deterioration coefficient of the resistant to deactivation active species in the desulfurization reaction of the catalyst, t is the number of days elapsed since the reaction began, and _k1 + _k2 = 1.

As mentioned above, in the hydrotreating reaction of atmospheric distillation gas oil, catalyst degradation occurs due to coke buildup, so operation must be carried out at elevated reaction temperatures to maintain the sulfur content of the resulting oil below a certain level. In the hydrotreating reaction of atmospheric distillation gas oil, the reaction temperature rises rapidly at the beginning of the reaction. This rapid rise in reaction temperature indicates rapid catalyst degradation at the beginning of the reaction. On the other hand, from the middle of the reaction onwards, the reaction temperature rises gradually. This gradual rise in reaction temperature indicates gradual catalyst degradation at the middle of the reaction onwards.

In other words, the profile of reaction temperature versus reaction time suggests that in the hydrotreating reaction of atmospheric distillation gas oil, rapid catalyst deterioration occurs at the beginning of the reaction, followed by gradual catalyst deterioration from the middle of the reaction onwards.

The inventors of the present application further improved Degradation Function 1 and discovered Degradation Function 2 based on the above-mentioned profile of reaction temperature versus reaction time and the assumption that the catalyst contains active species that are easily deactivated for the desulfurization reaction, which are deactivated early in the reaction, and active species that are difficult to deactivate for the desulfurization reaction, which are deactivated from the middle or later stages of the reaction. As a result, they found that Degradation Function 2 makes it possible to calculate the degree of degradation of the catalyst's desulfurization reaction more accurately than Degradation Function 1. Easily deactivated active species for the desulfurization reaction are active species that lose activity mainly in the early stages of the reaction, and difficult to deactivate active species for the desulfurization reaction are active species that lose activity from the middle or later stages of the reaction.

In the formula 10, _k1 represents the active site coefficient of the active species that is easily deactivated in the desulfurization reaction of the catalyst, and _k2 represents the active site coefficient of the active species that is difficult to deactivate in the desulfurization reaction of the catalyst. _k1 and _k2 are constants specific to the catalyst, and their determination will be described later.

_D1 can be calculated by the following formula 11, and _D2 can be calculated by the following formula 12.

In the above formulas 11 and 12, S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ⁻¹ ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm ³ /kL), G is the hydrogen/feed oil ratio (Nm ³ /kL) after t days of reaction, b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), and T _B is the reference reaction temperature (K) and T _SOR is the required temperature on day 0 (K).
In the above formula 11, _α1 is a catalytic constant of the easily deactivated active site in the desulfurization reaction (a constant representing the degradation rate of the desulfurization reaction of the catalyst), and in the above formula 12, _α2 is a catalytic constant of the hardly deactivated active site in the desulfurization reaction (a constant representing the degradation rate of the desulfurization reaction of the catalyst).

In the above-mentioned formulas 11 and 12, S _F , S _P , LHSV, P, and G are values substituted based on the information on the feed oil, the information on the product oil, and the information on the operating conditions acquired in the above-mentioned information acquisition step, as in the explanation of the above-mentioned formula 3. Note that LHSV can be calculated by dividing the feed oil supply rate (volume/h) by the catalyst loading rate (volume). G can be calculated by dividing the hydrogen supply rate (Nm ³ /hour) by the feed oil supply rate (kL/hour).

As described above, S _F , LHSV, P, and G are controllable parameters. Furthermore, S _P is the sulfur concentration of the target product oil. That is, the deterioration coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst and the deterioration coefficient of the hardly deactivated active species in the desulfurization reaction of the catalyst under the reaction conditions of S _F , S _P , LHSV, and P can be calculated using the above-mentioned Equation 11 and Equation 12. The method for determining n, which is the reaction order of the hydrotreating reaction of feedstock oil containing atmospheric distillation gas oil, will be described later.

(How to determine basic degradation parameters)
In the above formulas 11 and 12, α ₁ , α ₂ , P _B , a, G _B , b, Ec, T _B , and T _SOR are constants, as in the above formula 3, and these parameters are collectively referred to as "basic deterioration parameter 2." The basic deterioration parameter 2 is a parameter determined depending on the catalyst used, and may be determined while performing a reaction in an actual machine, or may be determined in advance on a bench scale based on the actual machine operating conditions. In this embodiment, it is preferable to determine it in advance on a bench scale based on the actual machine operating conditions. In the above formulas 11 and 12, P _B , a, G _B , b, Ec, and T _B can be determined by the same method as in the above formula 3.
On the other hand, α ₁ , α ₂ and T _SOR can be calculated, for example, by the following two methods. In addition, the active site coefficient k ₁ of the easily deactivated active species in the desulfurization reaction of the catalyst and the active site coefficient k ₂ of the hardly deactivated active species in the desulfurization reaction of the catalyst in the above formula 10 can also be calculated simultaneously as follows.

(Method 1 for determining α ₁ , α _{2 ,} T _SOR , k ₁ , and k ₂ )
In an actual plant or on a bench scale, the reaction is carried out for a certain period of time so that the LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil are the expected operating conditions of the actual plant. Because the catalyst deteriorates during the reaction, operation is carried out while increasing the reaction temperature. Reaction time is plotted on the horizontal axis and reaction temperature on the vertical axis. When drawing a regression line between these plots, as described above, two lines are obtained: one line expressed as y = a ₁ x + b ₁ , which correlates with the rapid increase in reaction temperature in the early stage of the reaction (x ₁ to x _n ), and the other line expressed as y = a ₂ x + b ₂ , which correlates with the gradual increase in reaction temperature from the middle stage of the reaction onwards (x n+ ₁ to x _m ). In the above formula, a ₁ > a ₂ > 0, b ₁ < b ₂ , and x ₁ < x _n < x _n+1 < x _m . x _n and x _m represent the reaction time relative to the n(m)th plot from the start of the reaction.

The above-mentioned _a1 is a value correlated with _α1 , _b1 is a value correlated with _k1 + _k2 , and is T _SOR . Furthermore, _a2 is a value correlated with _α2 , and _b2 is a value correlated with _k2 . Next, the intersection point (x _ip , y _ip ) at y = a ₁ x + b ₁ and y = a ₂ x + b ₂ is calculated. This intersection point represents the inflection point of y = a ₁ x + b ₁ and y = a ₂ x + b _2. In other words, up to (x _ip , y ip ), only active species that are easily deactivated in the desulfurization reaction of the catalyst are considered to exist, and from (x _ip , _{y ip} ), two active species are considered to exist: an active species that is easily deactivated in the desulfurization reaction of the catalyst and an active species that is difficult to deactivate in the desulfurization reaction of the catalyst.

In Equation 6, substituting _b1 for T _SOR ' and substituting the reaction temperature for T _t ' gives the degree of degradation Φ' of the desulfurization reaction after any t days of reaction. Plotting the reaction time on the horizontal axis and the logarithm of Φ' on the vertical axis and drawing a regression line from x ₁ to x _ip gives a line expressed as y = -a ₁ ^' x (|-a ₁ ^' | = a ₁ ^' ). Furthermore, drawing a regression line from x _ip to x _m gives a line expressed as y = -a ₂ ^' x -b ₂ ^' (|-a ₂ ^' | = a ₂ ^' and |-b ₂ ^' | = b ₂ ^' ). _{a 1} ^' is a value correlated with α ₁ , a ₂ ^' is a value correlated with α ₂ , and b ₂ ^' is a value correlated with k ₂ .

_k2 can be found by substituting _b2 ^' obtained from the regression line described above into the following formula 13. Since _k1 is _k1 + _k2 = 1, k1 can be found from _k1 = 1 - _k2 .
k ₂ =exp(-b ₂ ^' ) Equation 13

D1 and D2 are obtained by substituting the operating conditions S _P , S _F , LHSV, P, and G, as well as P _B , a, G _B , b, Ec, T _B , and T _SOR (b ₁ ) obtained by the above method, into the above equations 11 and _12. Φ is obtained by substituting _{the obtained D 1 ,} D ₂ , k ₁ , and k ₂ into the above equation 10. In this case, Φ is a function of α ₁ and α ₂ . If the reaction time is plotted on the horizontal axis and the logarithm of Φ on the vertical axis, and a regression line is drawn from x ₁ to x _ip while setting α ₂ =0 and changing α ₁ so that 0 < α ₁ , multiple lines expressed as y = -a _α1 ^'' x (|-a _α1 ^'' | = a _α1 ^'' ) will be obtained for each value of α _1. The α 1 when a _α1 ^'' on each line is equal to the above-mentioned a ₁ ^' can be taken as _{the α 1 in} the above formula 11.
Next, by substituting the obtained α1 into Φ, which is a function of _α1 and _α2 obtained by the _above method, and drawing a regression line from _xip to _xm while changing _α2 so that 0 < _α2 , multiple lines expressed as y = _-aα2 ^" x- _bα2 ^" (| _-aα2 ^" | = _aα2 ^" ) are obtained for each value of _α2 . _{The α2} when aα2 on each line is equal to the above-mentioned _a2 ^' can be taken as the _α2 in the above formula 12 _.

(Method 2 for determining α ₁ , α _{2 ,} T _SOR , k ₁ , and k ₂ )
A reaction similar to that in (Method 1 for determining _α1 , α2 _, T _SOR , _k1 , and _k2 ) is carried out to obtain T _SOR ( _b1 ). D1 and D2 are obtained by substituting the operating conditions S _P , _SF , LHSV, and P, as well as P _B , a, Ec, T _B , and T _SOR ( _b1 ) determined by the above method, into Equations 11 and _12. Φ is obtained by substituting _the determined _D1 and _D2 into Equation 10. In this case, Φ is a function of _α1 , _α2 , _k1 , and _k2 . Substituting the obtained Φ for Φ' in the above formula 6 and T _SOR (i.e., b ₁ ) for T _SOR ^' in the above formula 6 and rearranging for T _t ', T _t ' becomes a function of α ₁ , α ₂ , k ₁ , and k _2. If α ₂ is set to 0 and k ₂ = 1 - k ₁ , T _t ' becomes a function of α ₁ and k _1. The combination of α 1 and k ₁ when the ratio of T _t ' to the actually measured reaction temperature T _obs at x ₁ to x _ip (T _t '/T _obs ) is ₁ can be found, and this α ₁ can be used as α ₁ in the above formula 11. Note that k ₁ at this time is a provisional value. Similarly, it is preferable to calculate the ratio of T _t ' to M reaction temperatures T _obs (T _t '/T _obs ), and define α ₁ when the average of these is closest to 1 as α ₁ in the above formula 11. M is an integer of 10 or more, preferably 10 to 500, and more preferably 50 to 200.
Using the obtained _α1 , and setting _k1 = 1 - _k2 , _Tt ' becomes a function of _α2 and _k2 . The combination of α2 and _k2 when the ratio (Tt'/ _Tobs ) _of Tt' to the actually measured reaction temperature _Tobs at _xip to _xm is 1 is determined, and these _α2 and _k2 can be used as _{α2 and k2} in the above formula 12. By substituting the obtained _k2 into _k1 = 1 - _k2 , _k1 is determined, and this _k1 can be used as _k1 in the above formula 11. Similarly, it is preferable to calculate the ratios ( _Tt '/ _Tobs ) of _Tt ' to L reaction temperatures _Tobs , and use the _α2 and _k2 when their average is closest to 1 as the _α2 and _k2 in the above formula 12. It is also preferable to use the _k1 determined from the obtained _k2 as _k1 in the above formula 11. L is an integer of 10 or more, preferably 10 to 500, and more preferably 50 to 200.

In this way, in order to find α ₁ , α _{2 ,} T _SOR , k ₁ , and k ₂ , it is necessary to obtain y = a ₁ x + b ₁ and y = a ₂ x + b _2. For example, y = a ₁ x + b ₁ and y = a ₂ x + b ₂ can be found as follows.

Using the method described above, the reaction time is plotted on the horizontal axis and the reaction temperature on the vertical axis. By drawing a regression line from the start of the reaction to the end of the reaction, a straight line expressed as y = a'x + b' is obtained. This line does not take into account the inflection point. Plots are sequentially deleted from the end of the reaction, and the y = a'x + b' is adjusted so that the correlation coefficient approaches 1, resulting in y = _a1'x + _b1 '. Similarly, plots are sequentially deleted from the start of the reaction, and the y = a'x + b' is adjusted so that the correlation coefficient approaches ₁ , resulting in y = _a2'x + _b2 '. The lines where the average correlation coefficients _{of y = a1'x +} b1' and y = a2'x + _b2 ' are closest to 1 are y = _a1x + _b1 and _y = a2x + _b2 . All plots belong to either y=a ₁ x+b ₁ or y=a ₂ x+b ₂ .

The reaction time required to obtain y = a ₁ x + b ₁ and y = a ₂ x + b ₂ is usually 100 days or more. In general, it is sufficient to carry out the reaction until the correlation function of y = a'x + b' becomes 0.5 or more.

<Reaction temperature calculation step>
The reaction temperature calculation step of this embodiment is a step of calculating a reaction temperature necessary to satisfy the information on the feedstock oil, the information on the product oil, and the operating conditions based on the degree of deterioration of the desulfurization reaction of the catalyst. The reaction temperature is preferably calculated using a desulfurization rate equation based on the Arrhenius equation.

<Degradation rate equation for desulfurization reaction>
The deterioration rate equation for the desulfurization reaction is based on the Arrhenius equation expressed by the above-mentioned Equation 5. Similar to the calculation method for the above-mentioned Equation 6, the following Equation 14 is derived from the above-mentioned Equations 1 and 5.

In Equation 14, Φ is the degree of deterioration of the desulfurization reaction, Ea is the activation energy of desulfurization (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), _Tt is the required temperature (K) after t days of reaction, and T _SOR is the required temperature (K) on day 0.
By rearranging the above formula 14, the following formula 15 is obtained.

T _t (K) after t days of reaction can be obtained by substituting T _SOR and Φ obtained by the above-mentioned method into the above-mentioned formula 15. The activation energy of the desulfurization reaction in the above-mentioned formula 15 can be calculated as follows.

(How to calculate the activation energy of the desulfurization reaction)
The activation energy of the desulfurization reaction can be determined by a method known in the art based on the Arrhenius equation represented by the above-mentioned formula 5. An example will be described below.

First, the reaction order of the desulfurization reaction of feedstock oil containing atmospheric distillation gas oil is determined. The reaction temperature, hydrogen partial pressure, hydrogen/feedstock ratio, and sulfur concentration in the feedstock oil are constant, and the reaction is carried out under LHSV(x) conditions, and the sulfur concentration in the product oil is measured. In the desulfurization reaction rate equation expressed by the following equation 16, the sulfur concentration in the feedstock oil is substituted for _SF , the sulfur concentration in the resulting product oil for _SP , and LHSV(x) for LHSV. The result of the left-hand side obtained is plotted on the vertical axis, and 1/LHSV on the horizontal axis. In this case, the vertical axis is a function of n.

A similar reaction is carried out for x types of LHSV(x), and x of the above plots are obtained. Based on the obtained plots, a regression line is drawn passing through the origin to obtain a line expressed as y = cx. y is (1/n-1((1/S _P ^n-1 )-(1/S _F ^n-1 ))), x is 1/LHSV, and c is k. The correlation function is calculated using Excel or similar software, and n is determined for which the correlation coefficient is closest to 1. The obtained n is the reaction order. Note that n can be calculated to one decimal place.

The above x is an integer of 3 or greater. The larger the number of x, the more accurate n can be obtained. On the other hand, if the number of x is too large, it takes a long time to obtain n, which is inefficient. In this embodiment, x is preferably 3 to 20, and more preferably 3 to 10.

In determining n, the reaction temperature, hydrogen partial pressure, hydrogen/feedstock ratio, and sulfur concentration in the feedstock are preferably set to conditions that correspond to the operating conditions of an actual plant.
Such a reaction temperature is, for example, 300 to 400°C, the hydrogen partial pressure is, for example, 3 to 7 MPa, the hydrogen/feedstock ratio is, for example, 100 to 700 [Nm ³ /kL], and the sulfur concentration in the feedstock is, for example, 0.5 to 2.0 mass%.
Similarly, it is preferable that the x types of LHSV(x) are set to conditions that correspond to the actual operating conditions of the engine. Such LHSV(x) is, for example, 0.3 to 2.0 h ⁻¹ .

When the activation energy E in the Arrhenius equation expressed by the above formula 5 is set as the activation energy Ea of desulfurization and the natural logarithm of both sides is taken, the following formula 17 is obtained.

The reaction is carried out under constant conditions of hydrogen partial pressure, hydrogen/feed oil ratio, LHSV, and sulfur concentration in the feed oil at a reaction temperature T(y), and the sulfur concentration in the product oil is measured. The sulfur concentration in the feed oil is substituted for _SF , the sulfur concentration in the resulting product oil for _SP , LHSV for LHSV, and the obtained n in the desulfurization reaction rate equation expressed by Equation 16 above are substituted for LHSV, and the reaction rate constant k is calculated. The obtained reaction rate constant is substituted into Equation 17 above, and the result (lnk) on the left side of the equation obtained is plotted on the vertical axis and 1/T (1/T(y)) on the horizontal axis.

The same reaction is carried out for y different reaction temperatures T(y), and y of the above plots are obtained. A regression line is drawn from the resulting plots, and its slope is determined. Since this slope is Ea/R, the activation energy of desulfurization, Ea, can be determined by subtracting R from the slope.

The above y is an integer of 3 or greater. The larger the value of y, the more accurate Ea can be obtained. On the other hand, if the value of y is too large, it takes a long time to obtain Ea, which is inefficient. In this embodiment, y is preferably 3 to 20, and more preferably 3 to 10.

The hydrogen partial pressure, hydrogen/feed oil ratio, LHSV, and sulfur concentration in the feed oil used to determine Ea are preferably set to conditions that correspond to the operating conditions of an actual plant.
Such hydrogen partial pressure is, for example, 3 to 7 MPa, the hydrogen/feedstock ratio is 100 to 700 [Nm ³ /kL], the LHSV is 0.3 to 2.0 h ⁻¹ , and the sulfur concentration in the feedstock is 0.5 to 2.0 mass %.
Similarly, it is preferable that the reaction temperature T(y) of the y types is set to a condition that conforms to the operating conditions of the actual equipment. Such T(y) is 300 to 400°C.

By substituting each parameter thus obtained into the above-mentioned formula 15, the reaction temperature _Tt required to achieve the predetermined reaction conditions can be obtained.

The ratio of the reaction temperature _Tt determined by the information processing method of this embodiment to the actually measured reaction temperature _Tobs , _Tt / _Tobs , is preferably 0.97 to 1.03, and more preferably 0.985 to 1.015, in °C. When _Tt / _Tobs is within the above range, it can be determined that the reaction temperature has been estimated with high accuracy.

<Naphtha yield calculation step>
In the naphtha yield calculation step of this embodiment, the naphtha yield is calculated based on the reaction temperature _Tt and the deterioration degree of the cracking reaction of the catalyst. The naphtha yield is preferably calculated using a naphtha yield calculation function based on a first-order cracking reaction rate equation.

<Naphtha yield calculation function>
The naphtha yield calculation function is expressed by the following equation 18.

In the above-mentioned formula 18, C _t is the naphtha yield (mass %) after t days have passed since the reaction, k _C0(Tt) is the reaction rate constant (h −1 ) of the cracking reaction at the reaction temperature T _t calculated in the above-mentioned reaction temperature calculation step for the catalyst (fresh catalyst) after 0 days have passed since the reaction ( ^i.e. , at the start of the reaction), Φ _C is the degree of deterioration of the cracking reaction, and LHSV is the liquid hourly space velocity (h ⁻¹ ) after t days have passed since the reaction.

In the above-mentioned formula 18, LHSV is a value substituted based on the information on the operating conditions acquired in the information acquisition step described above. Note that LHSV can be calculated by dividing the feed oil supply rate (volume/h) by the catalyst loading rate (volume). How to calculate Φ _C and k _C0(Tt) will be described later.

The degradation degree of the decomposition reaction in the above formula 18 is expressed by the following formula 19.
Φ _C =k _Ct(T0) /k _C0(T0) Equation 19
In the above equation 19, k _C0(T0) is the reaction rate constant of the decomposition reaction of the catalyst (fresh catalyst) after 0 days of reaction (i.e., at the start of the reaction), and k _Ct(T0) is the reaction rate constant of the decomposition reaction of the catalyst after t days of reaction. Note that k _Ct(T0) and k _C0(T0) are the reaction rate constants of the decomposition reaction at the above-mentioned temperature T _SOR .

Equation 18 is derived based on the assumption that the cracking reaction of diesel is a first-order reaction and that naphtha is produced by the cracking reaction. The method for deriving equation 18 is explained below.

The decomposition reaction rate equation is expressed by the following equation 20.
k _Ct(Tt) = ln(C _F /C _P )×LHSV Equation 20
In the above equation 20, k _Ct(Tt) is the reaction rate constant (h ⁻¹ ) of the catalytic cracking reaction at the reaction temperature T _t calculated in the above-mentioned reaction temperature calculation step after t days of reaction, C _F is the diesel oil concentration (mass %) in the feed oil after t days of reaction, C _P is the diesel oil concentration (mass %) in the product oil after t days of reaction, and LHSV is the liquid hourly space velocity (h ⁻¹ ) after t days of reaction.

Since C _F /C _P is dimensionless, if C _F is 1, the conversion rate C _t (%) of the cracking reaction after any t days of reaction is C _t = (1 - C _P ) × 100. Therefore, C _P can be expressed as C _P = 1 - Ct/100. As mentioned above, based on the premise that naphtha is produced by the cracking reaction, the conversion rate C _t (%) also becomes the amount of naphtha obtained (mass %). Substituting these into the above formula 20, the following formula 21 is obtained.

When the above-mentioned formula 21 is summarized for _Ct , the following formula 22 is obtained.

From the above formula 19, the degradation degree of the decomposition reaction can also be expressed by the following formula 23.

Φ _C =k _Ct(Tt) /k _C0(Tt) Equation 23
In the above formula 23, k _C0(Tt) is the reaction rate constant of the decomposition reaction of the catalyst (fresh catalyst) after 0 days of reaction (i.e., at the start of the reaction), and k _Ct(Tt) is the reaction rate constant of the decomposition reaction of the catalyst after t days of reaction. Note that k _Ct(Tt) and k _C0(Tt) are the reaction rate constants of the decomposition reaction at the reaction temperature _Tt after t days of reaction calculated in the reaction temperature calculation step described above.

From the above-mentioned equation 23, k _Ct(Tt) =Φ _C ×k _C0(Tt) , and by substituting this value into the above-mentioned equation 22, the above-mentioned equation 18 is derived.

Next, how to obtain Φ _C and k _C0(Tt) will be described.

(How to calculate kC0 _(Tt) )
kC0 _(Tt) is a parameter (constant) determined depending on the catalyst used, and may be determined while performing the reaction in an actual reaction system, or may be determined in advance on a bench scale based on the operating conditions of the actual reaction system. In this embodiment, it is preferable to determine it in advance on a bench scale based on the operating conditions of the actual reaction system.
kC0 _(Tt) can be calculated by the following formula 24. The following formula 24 is based on the Arrhenius equation expressed by the above formula 5.

In the above formula 24, k _C0(T0) is the reaction rate constant (h ⁻¹ ) of the decomposition reaction of the catalyst (fresh catalyst) at the reaction temperature T _SOR after 0 days of reaction (i.e., at the start of the reaction), k _C0(Tt) is the reaction rate constant (h ⁻¹ ) of the decomposition reaction at the reaction temperature T _t after any t days of reaction calculated in the above-mentioned reaction temperature calculation step, E _D is the activation energy of the decomposition (kJ/mol), and R is the gas constant: 0.00831 (kJ/(mol·K)).

Since k _C0(T0) is the reaction rate constant of the decomposition reaction of the fresh catalyst at the reaction temperature T _SOR , it can be calculated by the following equation 25 based on the above equation 21.

In the above formula 25, C _t0 is the naphtha yield (mass %) when the desulfurization reaction of atmospheric distillation gas oil is carried out using a fresh catalyst at a reaction temperature T _SOR , and LHSV is the liquid hourly space velocity (h ⁻¹ ).

That is, k _C0(T0) can be calculated from the above-mentioned formula 25 by performing a hydrotreating reaction on a bench scale using a fresh catalyst, setting the reaction temperature to the above-mentioned T _SOR , and performing the hydrotreating reaction at LSHV, which is the operating condition of the actual plant, and measuring the amount of naphtha obtained at that time.

When determining kC0 _(T0) on the bench scale, it is preferable that the hydrogen partial pressure, hydrogen/feed oil ratio, LHSV, and sulfur concentration in the feed oil are set to conditions that correspond to the operating conditions of an actual plant.
Such hydrogen partial pressure is, for example, 3 to 7 MPa, the hydrogen/feedstock ratio is 100 to 700 [Nm ³ /kL], the LHSV is 0.3 to 2.0 h ⁻¹ , and the sulfur concentration in the feedstock is 0.5 to 2.0 mass %.

kC0 _(T0) may be determined while carrying out the reaction in an actual reactor as follows. It can be determined by substituting the amount of naphtha obtained and LHSV at the reaction temperature T _int immediately after the start of the reaction in the actual reactor (after t _int days of reaction) into the above-mentioned formula 25. T _int is preferably 20 days or less, more preferably 10 days or less. When t _int is equal to or less than the above-mentioned upper limit, a value very close to the reaction rate constant of the decomposition of a fresh catalyst can be obtained. Note that T _int is a value determined in the above-mentioned reaction temperature calculation step from the degree of deterioration of the desulfurization reaction.

The activation energy _ED of decomposition can be calculated as follows:

When the activation energy E in the Arrhenius equation expressed by the above formula 5 is set as the activation energy _ED of decomposition and the natural logarithm of both sides is taken, the following formula 26 is obtained.

The activation energy of cracking may be determined while the reaction is carried out in an actual plant, or may be determined in advance on a bench scale based on the operating conditions of the actual plant. The hydrogen partial pressure, hydrogen/feedstock ratio, LHSV, and sulfur concentration in the feedstock are constant, and the reaction is carried out at a reaction temperature T(y'), and the naphtha yield in the product oil is measured. The naphtha yield and LHSV obtained are substituted into Equation 21 to determine the reaction rate constant k. The obtained reaction rate constant is substituted into Equation 26, and the result (lnk) of the left-hand side obtained is plotted on the vertical axis and 1/T (1/T(y')) on the horizontal axis.

A similar reaction is carried out for y' types of reaction temperatures T(y'), and y' plots of the above are obtained. A regression line is drawn from the obtained plots, and its slope is determined. Since this slope is _ED /R, the activation energy of decomposition _ED can be determined by subtracting R from the slope.

The above y' is an integer of 3 or more. The larger the number of y', the more accurate _ED can be obtained. On the other hand, if the number of y' is too large, it takes a long time to obtain _ED , which is not efficient. In this embodiment, y' is preferably 3 to 20, and more preferably 3 to 10.

In determining _ED , the hydrogen partial pressure, hydrogen/feed oil ratio, LHSV, and sulfur concentration in the feed oil are preferably set to conditions that correspond to the operating conditions of an actual plant.
Such hydrogen partial pressure is, for example, 3 to 7 MPa, the hydrogen/feedstock ratio is 100 to 700 [Nm ³ /kL], the LHSV is 0.3 to 2.0 h ⁻¹ , and the sulfur concentration in the feedstock is 0.5 to 2.0 mass %.
Similarly, it is preferable that the reaction temperature T(y') of the y' types is set to a condition that conforms to the operating conditions of the actual equipment. Such T(y') is 300 to 400°C.

By substituting the thus obtained k _C0(T0) , the decomposition activation energy E _D , T _SOR , and the reaction temperature T _t calculated in the reaction temperature calculation step described above into Equation 24, k _C0(Tt) is calculated.

<How to determine the degradation level of decomposition reaction>
When the desulfurization reaction activity of a catalyst decreases, the cracking reaction activity also decreases. Therefore, it is believed that there is a correlation between the degree of degradation of the desulfurization reaction and the degree of degradation of the cracking reaction. The inventors of the present application focused on this correlation and discovered for the first time that the degree of degradation of the cracking reaction Φ _C can be calculated based on the above-mentioned degree of degradation of the desulfurization reaction Φ. Below, we will explain how to calculate the degree of degradation of the cracking reaction Φ _C based on the desulfurization reaction deterioration function 1 and the desulfurization reaction deterioration function 2.

(Method 1 for determining the degradation level of decomposition reaction)
Method 1 for determining Φ _C is a method for determining Φ _C based on the degradation function 1 of the desulfurization reaction. Φ _C can be determined by the following equation 27.

Φ _C = βΦ Equation 27
In the above formula 27, Φ _C is the degradation degree of the decomposition reaction, Φ is the degradation degree of the desulfurization reaction (degradation function 1 of the desulfurization reaction), and β is the degradation coefficient of the decomposition reaction (constant).

Since Φ can be calculated by the above-mentioned method, once β is determined, Φ _C can be calculated from Φ. In addition, in the above formula 27, Φ _C at the time when the reaction has elapsed 0 is βΦ=1.

In an actual plant or on a bench scale, the reaction is carried out for a certain period of time so that the LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil are those of the assumed actual plant operating conditions. Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature. The reaction temperature at this time may be the reaction temperature _Tt calculated in the reaction temperature calculation step described above. Examples of assumed actual plant operating conditions include the conditions used to calculate the activation energy of cracking described above. ΦC is calculated by measuring the amount of naphtha Ct _' obtained after t' days of reaction, and substituting the obtained Ct _' , kC0 _(Tt) (kC0 _(Tt') ) calculated by the above method, and LHSV into Equation 18. _ΦC is also calculated after t' days of reaction using the above method. _ΦC and Φ are calculated in the same manner for multiple reactions after t'. The combinations of _ΦC and Φ obtained after the same reaction are plotted with Φ on the x-axis and _ΦC on the y-axis. A regression line is drawn between these plots (where x=0 and y=0). The slope of this line is β. The number of plots for determining β is preferably 10 to 100, more preferably 10 to 50. Furthermore, the time t' for determining β is preferably 3 days or more after the reaction has started.

(Method 2 for determining the degradation level of decomposition reaction)
Method 2 of determining Φ _C is a method of determining Φ _C based on the degradation function 2 of the desulfurization reaction. Φ _C can be determined by the following equation 28.

Φ _C = β ₁ Φ ₁ + β ₂ Φ ₂ Equation 28
In the above formula 28, Φ _C is the degradation degree of the decomposition reaction, Φ ₁ is k ₁ × exp(−D ₁ t) in the above formula 10, Φ ₂ is k ₂ × exp(−D ₂ t) in the above formula 10, β ₁ is the decomposition degradation coefficient (constant) of the easily deactivated active species of the catalyst, and β ₂ is the decomposition degradation coefficient (constant) of the hardly deactivated active species of the catalyst.

Since Φ ₁ and Φ ₂ can be determined by the above-mentioned method, once β ₁ and β ₂ are determined, Φ _C can be determined from Φ ₁ and Φ _2. In addition, in the above formula 28, Φ _C at time 0 of reaction elapsed time is β ₁ Φ ₁ + β ₂ Φ ₂ = 1.

In an actual plant or on a bench scale, the reaction is carried out for a certain period of time so that the LHSV, hydrogen partial pressure, hydrogen/feed oil ratio, sulfur concentration in the feed oil, and sulfur concentration in the product oil are those of the assumed actual plant operating conditions. Because the catalyst deteriorates due to the reaction, operation is carried out while increasing the reaction temperature. The reaction temperature at this time may be the reaction temperature _Tt calculated in the reaction temperature calculation step described above. The naphtha yield _{Ct '} is measured after t' days of reaction have elapsed, and _ΦC is calculated by substituting the obtained Ct _{', kC0(Tt)} (kC0 _(Tt') ) calculated by the above method, and LHSV into Equation 18. Also, _Φ1 and _Φ2 after t' days of reaction are calculated by the above method. The obtained _ΦC , _Φ1 , and _Φ2 are substituted into Equation 28. Similarly, _ΦCn , _Φ1n , and _Φ2n are obtained after t' days of reaction for n numbers of times. If Equation 28 is satisfied for each combination, a simultaneous two-variable linear equation of Φ _Cn = β ₁ 'Φ _1n + β ₂ 'Φ _2n is obtained. In this equation, β ₁ ' and β ₂ ' with minimum error can be determined by two-variable linear regression with Φ _Cn as the dependent variable _{and Φ 1n} and Φ _2n as independent variables. The obtained β ₁ ' can be used as β ₁ in Equation 28, and the obtained β ₂ ' can be used as β ₂ in Equation 28. The number of combinations of Φ _C , Φ ₁ , and Φ ₂ in determining β ₁ and β ₂ is preferably 10 to 100, and more preferably 10 to 50. Furthermore, the t' in determining β ₁ and β ₂ is preferably after 3 days of reaction have elapsed.

Using β or _β1 and _β2 obtained by the above method, _ΦC can be calculated from the above formula 27 or formula 28.

By substituting k _C0(Tt) obtained by the above-mentioned method, Φ _C obtained by the above-mentioned formula 27 or the above-mentioned formula 28, and LHSV into the above-mentioned formula 18, the yield of naphtha after t days of reaction can be calculated.

The ratio of the naphtha yield _Ct calculated by the information processing method of this embodiment to the actually measured naphtha yield C _obs , C _t /C _obs , is preferably 0.80 to 1.20, and more preferably 0.85 to 1.15, in mass %. When C _t /C _obs is within the above range, it can be determined that the naphtha yield has been estimated with high accuracy.

<<Information output step>>
The method may further include an information output step (S5 in FIG. 1) of outputting information indicating the naphtha yield thus obtained. For example, S5 is executed by the output unit 14.

<Hydrotreatment reaction of feedstock oil including atmospheric distillation gas oil>
The hydrotreating reaction of feedstock oils including atmospheric distillation gas oil will be outlined below.
Atmospheric distillation gas oil is a fraction obtained by atmospheric distillation of crude oil and has a boiling point range of 150 to 380°C. The density of atmospheric distillation gas oil is 0.83 to 0.90 g/mL. The content of atmospheric distillation gas oil in the feedstock oil may be, for example, 50 to 100% by volume, or 80 to 100% by volume.
In addition, examples of oil types contained in the feedstock other than atmospheric distillation light oil and cracked light oil include light oil fractions obtained from fluid catalytic cracking units, direct desulfurization units, indirect desulfurization units, and the like.

The hydrotreating reaction of a feedstock containing atmospheric distillation gas oil can be carried out by contacting the feedstock containing atmospheric distillation gas oil with a hydrotreating catalyst in the presence of hydrogen.
The hydrotreating catalyst is not particularly limited, and any hydrotreating catalyst known in the art can be used. Various catalyst supports can be used, including, for example, silica, alumina, boria, magnesia, titania, silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania, silica-boria, alumina-zirconia, alumina-titania, alumina-boria, alumina-chromia, titania-zirconia, silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, silica-magnesia-zirconia, and the like, or mixtures of two or more of these. Among these inorganic oxides, preferred are alumina, silica-alumina, alumina-titania, alumina-boria, and alumina-zirconia, with alumina being particularly preferred, and among aluminas, γ-alumina being particularly preferred. These inorganic oxides may be used alone or in combination of two or more.

The metal contained in the support as an active component is at least one metal selected from Group 6 and Groups 8-10 of the Periodic Table, preferably molybdenum, tungsten, cobalt, and nickel. These metals are effective in the metallic state, metal oxide, or metal sulfide form. They may also be bonded to the catalyst support by ion exchange or other methods. The content of this metal component is typically within the range of approximately 10-25 mass% of the catalyst, calculated as oxide. If the metal content is less than 10 mass%, the absolute amount of metal acting as active sites is low, preventing hydrotreating activity (hereinafter simply referred to as hydrotreating activity), including desulfurization activity. Conversely, if the supported metal content is greater than 25 mass%, metal aggregation occurs, reducing the number of active sites and, as a result, reducing hydrotreating activity. Furthermore, if necessary, phosphorus, boron, zinc, zirconia, etc. can be contained in addition to the active metals consisting of Groups 6 and 8 of the Periodic Table. When applying the method of the present invention, there are no restrictions on the form of the catalyst bed, and it can be applied to catalyst bed reactors such as fixed beds, moving beds, and fluidized beds.

The conditions for the hydrotreating reaction of feedstock containing atmospheric distillation gas oil are generally a reaction temperature of 300 to 400°C, preferably 330 to 400°C, a hydrogen partial pressure of 3 to 7 MPa, preferably 4 to 7 MPa, an LHSV of 0.3 to 2.0 hr ^-1 , preferably 0.5 to 1.5 hr ^-1 , and a hydrogen/feedstock ratio of 100 to 700 (Nm ³ /kL), preferably 200 to 500 (Nm ³ /kL).

The sulfur concentration in feedstock oil, including atmospheric distillation gas oil, is typically 0.5 to 2.0 mass%. The sulfur concentration in the resulting oil is 0.001 mass% or less.

In this specification, "naphtha" refers to a component having a boiling point range of 175°C or less and having 5 to 10 carbon atoms, which is obtained by cracking in a hydrotreating reaction.
The yield of naphtha can be obtained by a method for measuring the yield of naphtha known in the art, and examples thereof include calculation from the proportion of fractions at 175°C or less in a distillation test such as ASTM D-6730.

<Naphtha yield calculation device>
The naphtha yield calculation device of this embodiment includes an acquisition unit that acquires information about the feedstock oil, information about the product oil, and information about operating conditions when a predetermined time has elapsed since the start of the reaction, regarding the hydrotreating reaction of feedstock oil containing atmospheric distillation gas oil; and a calculation unit that calculates a catalyst degradation level using a degradation function based on the information about the feedstock oil, information about the product oil, and information about the operating conditions acquired by the acquisition unit, calculates the information about the feedstock oil, information about the product oil, and a reaction temperature necessary to satisfy the operating conditions based on the calculated catalyst degradation level, and calculates the naphtha yield based on the calculated reaction temperature and the catalyst degradation level.

The naphtha yield calculation device 1 of this embodiment is configured using an information processing device such as a personal computer, a server device, or a dedicated device. The naphtha yield calculation device 1 may be configured using one or more information processing devices. For example, the naphtha yield calculation device 1 may be configured as a cluster machine, a cloud, or in any other manner. Specifically, as shown in FIG. 2, the naphtha yield calculation device 1 has an acquisition unit 11 and a computer main body 12 that processes information from the acquisition unit. The naphtha yield calculation device 1 may also have an output unit 14 that outputs information processed in the computer main body 12 to the outside. These components are implemented, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Furthermore, some or all of these components may be implemented by hardware (including circuitry) such as an LSI (Large Scale Integrated circuit), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or GPU (Graphics Processing Unit), or by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device with a non-transitory storage medium) such as an HDD (Hard Disk Drive) or flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed in the storage device by inserting the storage medium into a drive. The storage device may be configured, for example, with an HDD, flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), ROM (Read Only Memory), or RAM (Random Access Memory).

The acquisition unit 11 receives predetermined information input by a reaction operator and transmits the information acquired through this input to the computer main body 12. The information acquired by the acquisition unit 11 in this embodiment is, for a hydrotreating reaction of a feedstock containing atmospheric distillation gas oil, information on the feedstock, information on the product oil, and information on operating conditions a predetermined time after the start of the reaction. The information on the feedstock, information on the product oil, and information on operating conditions a predetermined time after the start of the reaction are as described above. For example, the acquisition unit 11 executes the information acquisition step described above. The acquisition unit 11 only needs to acquire information on the feedstock, information on the product oil, and information on operating conditions a predetermined time after the start of the reaction, and there are no particular limitations on the method of acquisition.

In this embodiment, the acquisition unit 11 is configured with a single keyboard. The specific configuration of the acquisition unit 11 is not limited, and although it is a keyboard in this embodiment, it may also be a touch panel or the like. It is also possible for acquisition units that acquire various types of information to be configured separately and each to be independently connected to the computer main body 12. The acquisition unit 11 may also be configured to directly acquire each of the above-mentioned information via wired or wireless connections from a computer or the like used for controlling the reactor, etc.

The computer main body 12 is, for example, a so-called computer capable of processing various types of information. The computer main body 12 includes an arithmetic unit 13. For example, a predetermined program is installed in the computer main body 12, and the arithmetic unit 13 is functionally configured by executing this program. Specifically, the arithmetic unit 13 calculates the catalyst deterioration level using a deterioration function based on the information on the feedstock oil, the information on the product oil, and the information on the operating conditions acquired by the acquisition unit 11 at a predetermined time after the start of the reaction. Based on the catalyst deterioration level, the arithmetic unit 13 calculates the reaction temperature required to satisfy the information on the feedstock oil, the information on the product oil, and the operating conditions. The naphtha yield is calculated based on the reaction temperature and the catalyst deterioration level. The deterioration function is as described above. As described above, the reaction temperature can be calculated, for example, from a deterioration rate equation. Furthermore, the naphtha yield can be calculated, for example, from a naphtha yield function. For example, the arithmetic unit 13 executes the deterioration level calculation step, reaction temperature calculation step, and naphtha yield calculation step described above. The calculation unit 13 may include, for example, a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and non-volatile or volatile semiconductor memory (for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory)). For example, the calculation unit 13 may be a microcontroller such as an MCU.

The calculation unit 13 may output to the output unit 14 information regarding the feedstock oil obtained as described above, information regarding the product oil, and information indicating the naphtha yield at the reaction temperature required to satisfy the operating conditions.

The output unit 14 receives the calculation results (reaction temperatures) output by the computer main body 12 (more specifically, the calculation unit 13) and outputs the received calculation results to the outside. In this embodiment, the output unit 14 is configured as a display unit such as a CRT display, LCD display, or PDP, but is not limited to this and may be configured to output to a printing unit such as a printer, or to other devices (for example, a computer used to control the hydrotreating reaction of feedstock oil including atmospheric distillation diesel). The output unit 14 may also be a combination of these. For example, the output unit 14 executes the information output step described above.

In addition, this embodiment provides a naphtha yield calculation program for causing a computer to function as a naphtha yield calculation device, and a non-transitory computer-readable recording medium storing the program. Examples of non-transitory computer-readable recording media include magnetic tape (such as digital data storage (DSS)), magnetic disks (such as hard disk drives (HDDs) and flexible disks (FDs)), optical disks (such as compact disks (CDs), digital versatile disks (DVDs), and Blu-ray disks (BDs)), magneto-optical disks (MOs), and flash memory (such as solid-state drives (SSDs), memory cards, and USB memory).

<Method of using the information processing method and naphtha yield calculation device>
The information processing method and naphtha yield calculation device of this embodiment can estimate the naphtha yield at the reaction temperature required to achieve predetermined reaction conditions for the hydrotreating reaction of feedstock oil containing atmospheric distillation gas oil.The information processing method and naphtha yield calculation device of this embodiment can obtain a plot of estimated naphtha yield over time.The relationship between the plot and the upper limit of the naphtha withdrawal capacity of the atmospheric distillation gas oil hydrotreating treatment device can be considered for the following applications.

Utilization methods include estimating reaction conditions (reaction temperature, throughput (LHSV)) for achieving a naphtha yield below the upper limit of naphtha withdrawal capacity, and formulating a production plan for a secondary treatment facility using cracked naphtha by estimating and knowing the future naphtha production volume in advance. That is, when a predetermined naphtha yield volume is set for a predetermined operating time, the above equation 18 becomes a function of KCO _(Tt) , _ΦC , and LHSV. A combination of kCO _(Tt) , _ΦC , and LHSV that satisfies the equation of the above equation 18 is found. The reaction conditions in this combination become estimated reaction conditions that achieve a naphtha yield below the upper limit of naphtha withdrawal capacity and that allow the future naphtha production volume to be known in advance.

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples.

[Example 1]
A bench-scale hydrotreating reaction was carried out by contacting a feedstock containing 99% by volume of atmospheric distillation gas oil with hydrotreating catalyst A. Based on the obtained results, the deterioration function of the desulfurization reaction was calculated. In this example, the deterioration function 2 of the desulfurization reaction represented by equation 10 was used. The parameters in equations 10 to 12 were determined by the above-mentioned method, and the following were found: k ₁ =0.45, k ₂ =0.55, α ₁ =0.01, α ₂ =0.002, P _B =3.234 (MPa), a=2, G _B =400 (Nm ³ /kL), b=1.3, _{E C} =83.1 (kJ/mol), T _B =625 (K), T _SOR =630 (K), and n=1.2.
The reaction was carried out in an actual plant using the same feedstock and hydrotreating catalyst as in the bench-scale hydrotreating reaction. The operating conditions in Equations 11 and 12 were: S _F = 1.57 (mass%), P = 4.9 (MPa), G = 250 (Nm ³ /kL), LHSV = 2.0 ^{(h −1} ), and S _P = 0.0008 (mass%).
Furthermore, the activation energy of desulfurization and the activation energy of decomposition were determined in advance by the above-mentioned method, and were found to be Ea = 120 (kJ/mol) and E _D = 120 (kJ/mol).

When k _C0(T0) was calculated from the measured value of the naphtha yield at one day and time of reaction using the formula 25, it was 0.14 [h ⁻¹ ]. The measured value of the reaction temperature at this time, _T0 , was 631 (K). Thereafter, in the initial stage of the reaction, β 1 and β 2 were calculated from Φ ₁ (k ₁ × exp(−D ₁ t)) and Φ ₂ (k ₂ × exp(−D ₂ t)) calculated using the formula 10, the measured value of the naphtha yield, the k _C0(T0) , and Φ _C calculated from the formula 18 using LHSV using the formula ₂₈ , and the results were _{β 1 =} 0.45 and β ₂ = 1.35.
Using the above parameters, (1) the required temperature _Tt was calculated from the above-mentioned formula 15, and (3) the naphtha yield _Ct was calculated from the above-mentioned formula 18. The results are shown in Table 1.

[Example 2]
A bench-scale hydrotreating reaction was carried out by contacting a feedstock containing 99% by volume of atmospheric distillation gas oil with hydrotreating catalyst B. Based on the obtained results, a degradation function was calculated. In this example, degradation function 2 represented by equation 10 was used. The basic degradation parameters in equations 10 to 12 were determined by the above-mentioned method, and the following were found: k ₁ =0.45, k ₂ =0.55, α ₁ =0.01, α ₂ =0.002, P _B =3.234 (MPa), a=2, G _B =400 (Nm ³ /kL), b=1.3, _{E C} =83.1 (kJ/mol), T _B =625 (K), T _SOR =629 (K), and n=1.2.
The reaction was carried out in an actual plant using the same feedstock and hydrotreating catalyst as in the bench-scale hydrotreating reaction. The operating conditions in Equations 11 and 12 were: S _F = 1.57 (mass%), P = 4.9 (MPa), G = 250 (Nm ³ /kL), LHSV = 2.0 ^{(h −1} ), and S _P = 0.0008 (mass%).
Furthermore, the activation energy of desulfurization and the activation energy of decomposition were determined in advance by the above-mentioned method, and were found to be Ea = 120 (kJ/mol) and E _D = 120 (kJ/mol).

When k _C0(T0) was calculated from the measured value of the naphtha yield at one day and time of reaction using Equation 25, it was 0.069 [h ⁻¹ ]. The measured value of the reaction temperature at this time, _T0 , was 629 (K). Thereafter, in the initial stage of the reaction, β 1 and β 2 were calculated from Φ ₁ (k ₁ × exp(−D ₁ t)) and Φ ₂ (k ₂ × exp(−D ₂ t)) calculated using Equation 10, the measured value of the naphtha yield, k _C0(T0) , and Φ _C calculated from Equation 18 using LHSV using Equation ₂₈ , and the results were _{β 1 =} 0.45 and β ₂ = 1.35.
Using the above parameters, (1) the required temperature _Tt was calculated from the above-mentioned formula 15, and (3) the naphtha yield _Ct was calculated from the above-mentioned formula 18. The results are shown in Table 2.

As shown in Tables 1 and 2, it was found that the naphtha yield _Ct calculated by the present invention was almost equal to the actually measured value of the naphtha yield.

1... Naphtha yield calculation device 11... Acquisition unit 12... Computer main body 13... Calculation unit 14... Output unit

Claims (6)

With respect to the hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil, an information acquisition step of acquiring information on the feedstock oil, information on the product oil, and information on operating conditions at a predetermined time after the start of the reaction;
a deterioration degree calculation step of calculating a deterioration degree of a desulfurization reaction and a deterioration degree of a cracking reaction of the catalyst using a deterioration function based on the acquired information on the feedstock oil, the information on the product oil, and the information on the operating conditions;
a reaction temperature calculation step of calculating information about the feed oil, information about the product oil, and a reaction temperature necessary to satisfy the operating conditions based on the degree of deterioration of the desulfurization reaction of the catalyst;
and a naphtha yield calculation step of calculating a naphtha yield based on the reaction temperature and a deterioration degree of the decomposition reaction of the catalyst ,
The information processing method, wherein the degradation function is a function expressed by the following equation 2 :
Φ=exp(-Dt) Formula 2
In the above formula 2, Φ is the degree of deterioration of the catalyst, D is the deterioration coefficient of the active species of the catalyst and is calculated using the following formula 3, and t is the number of days elapsed since the reaction began.
In Equation 3, α is a catalyst constant (a constant representing the rate of catalyst deterioration), S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ^-1 ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm3 ^/ kL), G is the hydrogen/feed oil ratio ( ^Nm3 /kL) after t days of reaction , b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is a gas constant: 0.00831 (kJ/(mol·K)), and T _B is the reference reaction temperature (K), and T _SOR is the required temperature (K) on day 0. α, P _B , a, G _B , b, Ec, T _B , and T _SOR are constants determined depending on the catalyst used. These constants are determined while performing the reaction in an actual reactor, or are determined in advance on a bench scale based on the operating conditions of the actual reactor. With respect to the hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil, an information acquisition step of acquiring information on the feedstock oil, information on the product oil, and information on operating conditions at a predetermined time after the start of the reaction;
a deterioration degree calculation step of calculating a deterioration degree of a desulfurization reaction and a deterioration degree of a cracking reaction of the catalyst using a deterioration function based on the acquired information on the feedstock oil, the information on the product oil, and the information on the operating conditions;
a reaction temperature calculation step of calculating information about the feed oil, information about the product oil, and a reaction temperature necessary to satisfy the operating conditions based on the degree of deterioration of the desulfurization reaction of the catalyst;
and a naphtha yield calculation step of calculating a naphtha yield based on the reaction temperature and a deterioration degree of the decomposition reaction of the catalyst,
The information processing method, wherein the degradation function is a function expressed by the following equation 10 :
Φ=k ₁ ×exp(-D ₁ t)+k ₂ ×exp(-D ₂ t) Equation 10
In Equation 10, k1 _is the active site coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst, k2 _is the active site coefficient of the resistant to deactivation active species in the desulfurization reaction of the catalyst, and the active site coefficients represent the relative reaction rate constants of the desulfurization reaction of both active species. _D1 is the deterioration coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst and is calculated from Equation 11 below, D2 is the deterioration coefficient of the resistant to deactivation _active species in the desulfurization reaction of the catalyst and is calculated from Equation 12 below, t is the number of days elapsed since the reaction began (days), k1 ₊ k2 ₌ 1, and k1 _and k2 _are determined during the reaction in an actual system or are determined in advance on a bench scale based on the operating conditions of the actual system.
In the above formulas 11 and 12, S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ⁻¹ ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm ³ /kL), G is the hydrogen/feed oil ratio (Nm ³ /kL) after t days of reaction, b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), and T _B is the reference reaction temperature (K), and T _SOR is the required temperature on day 0 (K). In equation 11, α ₁ is the catalytic constant of the easily deactivated active sites in the desulfurization reaction (a constant representing the deterioration rate of the desulfurization reaction of the catalyst), and in equation 12, α ₂ is the catalytic constant of the less easily deactivated active sites in the desulfurization reaction (a constant representing the deterioration rate of the desulfurization reaction of the catalyst). α ₁ , α ₂ , P _B , a, G _B , b, Ec, T _B , and T _SOR are constants determined depending on the catalyst used. The above constants are determined while performing the reaction in an actual plant, or are determined in advance on a bench scale based on the operating conditions of the actual plant. A naphtha yield calculation device comprising: an acquisition unit that acquires information about the feedstock oil, information about the product oil, and information about operating conditions when a predetermined time has elapsed since the start of a hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil; and a calculation unit that calculates a deterioration level of a desulfurization reaction and a deterioration level of a cracking reaction of a catalyst using a deterioration function based on the information about the feedstock oil, the information about the product oil, and the information about the operating conditions acquired by the acquisition unit, calculates a reaction temperature required to satisfy the information about the feedstock oil, the information about the product oil, and the operating conditions based on the calculated deterioration level of the desulfurization reaction of the catalyst, and calculates a naphtha yield based on the calculated reaction temperature and the deterioration level of the cracking reaction of the catalyst,
The naphtha yield calculation device, wherein the deterioration function is a function expressed by the following equation 2 .
Φ=exp(-Dt) Formula 2
In the above formula 2, Φ is the degree of deterioration of the catalyst, D is the deterioration coefficient of the active species of the catalyst and is calculated using the following formula 3, and t is the number of days elapsed since the reaction began.
In Equation 3, α is a catalyst constant (a constant representing the rate of catalyst deterioration), S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ^-1 ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm3 ^/ kL), G is the hydrogen/feed oil ratio ( ^Nm3 /kL) after t days of reaction , b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is a gas constant: 0.00831 (kJ/(mol·K)), and T _B is the reference reaction temperature (K), and T _SOR is the required temperature (K) on day 0. α, P _B , a, G _B , b, Ec, T _B , and T _SOR are constants determined depending on the catalyst used. These constants are determined while performing the reaction in an actual reactor, or are determined in advance on a bench scale based on the operating conditions of the actual reactor. A naphtha yield calculation device comprising: an acquisition unit that acquires information about the feedstock oil, information about the product oil, and information about operating conditions when a predetermined time has elapsed since the start of a hydrotreating reaction of a feedstock oil containing atmospheric distillation gas oil; and a calculation unit that calculates a deterioration level of a desulfurization reaction and a deterioration level of a cracking reaction of a catalyst using a deterioration function based on the information about the feedstock oil, the information about the product oil, and the information about the operating conditions acquired by the acquisition unit, calculates a reaction temperature required to satisfy the information about the feedstock oil, the information about the product oil, and the operating conditions based on the calculated deterioration level of the desulfurization reaction of the catalyst, and calculates a naphtha yield based on the calculated reaction temperature and the deterioration level of the cracking reaction of the catalyst,
The naphtha yield calculation device, wherein the deterioration function is a function expressed by the following equation 10 .
Φ=k ₁ ×exp(-D ₁ t)+k ₂ ×exp(-D ₂ t) Equation 10
In Equation 10, k1 _is the active site coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst, k2 _is the active site coefficient of the resistant to deactivation active species in the desulfurization reaction of the catalyst, and the active site coefficients represent the relative reaction rate constants of the desulfurization reaction of both active species. _D1 is the deterioration coefficient of the easily deactivated active species in the desulfurization reaction of the catalyst and is calculated from Equation 11 below, D2 is the deterioration coefficient of the resistant to deactivation _active species in the desulfurization reaction of the catalyst and is calculated from Equation 12 below, t is the number of days elapsed since the reaction began (days), k1 ₊ k2 ₌ 1, and k1 _and k2 _are determined during the reaction in an actual system or are determined in advance on a bench scale based on the operating conditions of the actual system.
In the above formulas 11 and 12, S _F is the sulfur concentration (mass%) in the feed oil after t days of reaction, S _P is the sulfur concentration (mass%) in the product oil after t days of reaction, n is the reaction order of the hydrotreating reaction of the feed oil containing atmospheric distillation gas oil, LHSV is the liquid hourly space velocity (h ⁻¹ ) after t days of reaction, P _B is the reference hydrogen partial pressure (MPa), P is the hydrogen partial pressure (MPa) after t days of reaction, a is the hydrogen partial pressure coefficient, G _B is the reference hydrogen/feed oil ratio (Nm ³ /kL), G is the hydrogen/feed oil ratio (Nm ³ /kL) after t days of reaction, b is the hydrogen/feed oil ratio coefficient, Ec is the activation energy of coke deterioration (kJ/mol), R is the gas constant: 0.00831 (kJ/(mol·K)), and T _B is the reference reaction temperature (K), and T _SOR is the required temperature on day 0 (K). In equation 11, α ₁ is the catalytic constant of the easily deactivated active sites in the desulfurization reaction (a constant representing the deterioration rate of the desulfurization reaction of the catalyst), and in equation 12, α ₂ is the catalytic constant of the less easily deactivated active sites in the desulfurization reaction (a constant representing the deterioration rate of the desulfurization reaction of the catalyst). α ₁ , α ₂ , P _B , a, G _B , b, Ec, T _B , and T _SOR are constants determined depending on the catalyst used. The above constants are determined while performing the reaction in an actual plant, or are determined in advance on a bench scale based on the operating conditions of the actual plant. A naphtha yield calculation program for causing a computer to function as the naphtha yield calculation device according to claim 3 or 4 . A non-transitory computer-readable recording medium storing the program according to claim 5 .