JP3464047B2 - Hydroprocessing of heavy oil - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydrotreating heavy oil, and more particularly to a heavy oil for obtaining a product oil having a low sulfur content and dry sludge content. And a method for hydrotreating. [0002] Conventionally, in heavy oil hydrotreating, heavy oil is hydrotreated at a high demetallization rate, high denitrification rate, high desulfurization rate or high cracking rate. It is effective to carry out such a hydrotreatment at a relatively high reaction temperature. However, when hydrogenation is performed at a high reaction temperature, dry sludge (carbonaceous insoluble solid) is generated, and the generated dry sludge causes clogging of heat exchangers and other parts of the device, and as a result, purification equipment Has a problem in that long-term stable operation cannot be performed and productivity is impaired. Therefore, various methods have been proposed for suppressing the production of dry sludge in the hydrotreating of heavy oil. For example, a method of performing hydrogenation treatment of heavy oil in the presence of a hydrogen-donating solvent (for example, JP-A-63-156890, JP-A-63-15479)
No. 5, Japanese Patent No. 5), or, in the order of hydrodemetallization treatment, hydrocracking treatment, hydrodesulfurization and hydrodenitrogenation treatment of heavy residue oil in the presence of a catalyst,
After the hydrocracking treatment, a treatment method of introducing hydrogen and ammonia at the stage of hydrodesulfurization and hydrodenitrogenation treatment (Japanese Patent Laid-Open No. 5-263804), a method of converting heavy hydrocarbon oil from which sludge precursor has been removed to hydrogen After hydrotreating and then hydrocracking, part of the hydrocracked oil is recycled to the heavy hydrocarbon oil and recycled, and the remainder of the hydrocracked oil is hydrodesulfurized and desulfurized. A method of performing a nitrogen treatment (Japanese Patent Application Laid-Open No. 5-117666) has been proposed. However, the conventional method of hydrotreating in the presence of a hydrogen-donating solvent requires the use of a large amount of a hydrogen-donating solvent, and thus reduces the throughput of heavy oil. Alternatively, there is a problem that a step of separating and recovering the hydrogen-donating solvent is required. In addition, the method of introducing ammonia at the stage of hydrodesulfurization and hydrodenitrogenation does not provide sufficient desulfurization activity, and the method of recycling part of the hydrocracked oil does not increase the throughput and further increases the sludge. There were problems such as an increase in processing costs due to the removal of the precursor, and this was not always satisfactory. [0003] It is an object of the present invention to provide a method for hydrotreating heavy oil, in which heavy residual oil is hydrotreated at a high demetallization rate, high denitrification rate, high desulfurization rate or high cracking rate. Even so, the problem of clogging of a heat exchanger or the like caused by dry sludge can be solved by reducing the dry sludge content of the product oil obtained in the hydrotreating, and stable operation can be performed for a long period of time. An object of the present invention is to provide a hydrotreating method. Another object of the present invention is to produce a high-grade desulfurized heavy residue (product oil) suitable as a feedstock for fluid catalytic cracking (FCC). [0004] In the conventional method for hydrotreating heavy oil, the reaction temperature is generally adjusted to achieve a desired demetallization rate, desulfurization rate or decomposition rate within a reaction temperature range of 300 ° C to 500 ° C. The method of increasing gradually is adopted. However, the reaction temperature is high, for example above 385 ° C., in particular 390
When the temperature exceeds ℃, the production of dry sludge in the spilled oil rapidly increases, so that the operation of the hydrotreating catalyst has to be stopped despite having sufficient residual activity. In the hydrotreating method of the present invention, the hydrotreating is carried out at a reaction temperature of 385 ° C. or higher by making full use of the activity of the hydrotreating catalyst. And then hydrotreating the oil at a reaction temperature of less than 385 ° C., preferably at a temperature of 380 ° C. or less to hydrogenate and reduce the amount of dry sludge produced. Wherein demetallization, desulfurization or decomposition is performed as required to produce a high-quality product oil. That is, the present invention relates to a method for hydrotreating heavy oil, comprising: (a) reacting a heavy oil containing at least 1.0 wt% of asphaltenes in the presence of a hydrotreating catalyst at a reaction temperature of 385 ° C. to 5 ° C.
00 ° C, preferably 390 ° C to 450 ° C, hydrogen partial pressure 50
^{kg / cm 2 G~250kg / cm 2} G, preferably 1
Hydrotreating under the condition of 00 kg / cm ² G to ²⁰⁰ kg / cm ² G, the dry sludge content is 0.1 wt% or more,
(B) obtaining an spilled oil having a sulfur content of 1.0 wt% or less, (b) converting the spilled oil in the step (a) in the presence of a hydrotreating catalyst,
Reaction temperature 385 below ° C., preferably 380 ° C. or less, a hydrogen partial pressure of ^{50kg / cm 2 G~250kg / cm 2} G, preferably by treatment with conditions of ^{100kg / cm 2 G~200kg / cm 2} G, the product oil 0.1w of dry sludge
(b) a step of reducing the weight of the heavy oil to less than 1%.
The difference between the reaction temperature in the step (a) and the reaction temperature in the step (b) is 10 ° C. or more, and (2) the hydrotreating catalyst in the step (b) comprises a hydrogenation active metal component and an inorganic oxide carrier. A catalyst having a pore volume of 0.40 m
1 / g or more, average pore diameter is 90 ° or more, specific surface area is 1
A catalyst having an average pore diameter of not less than 20 m ² / g and an average pore diameter larger than the average pore diameter of the hydrotreating catalyst used in the last stage of the step (a). The present invention relates to a method for hydrotreating high quality oil. In the step (a), a treatment such as hydrodemetallization treatment, hydrodesulfurization treatment, hydrodenitrification treatment, or hydrocracking may be used alone or in combination, as in the case of the conventional heavy oil hydrotreating method. Do with.
In addition, conventional hydrotreating conditions other than the reaction temperature and the hydrogen partial pressure can be adopted. That is, a hydrogen / oil ratio of 300 to 2,000 Nm ³ / kl,
The liquid hourly space velocity (LHSV) is 0.1 to 5 hr ^-1 or the like. As the hydrotreating catalyst used in the step (a), those usually used for hydrodemetallation, hydrodesulfurization, hydrodenitrogenation and hydrocracking may be used. For example, alumina, silica, zeolite, titania, boria, a mixture thereof, or a mixture of at least one metal component of a group VIA metal of the periodic table such as Mo and W and a group VIII metal of the periodic table such as Ni and Co is used. A catalyst supported on a carrier such as a substance can be used. The present invention comprises a step of performing hydrodesulfurization or the like at a high temperature in the step (a) and a step of performing a hydrogenation reaction of dry sludge at a low temperature in the step (b).
In the step (a), it is desirable to sufficiently hydrodesulfurize, and the sulfur content of the spilled oil in the step (a) is 1.0 wt% or less, preferably 0.7 wt% or less, more preferably 0.5 wt% or less. Is desirable. In the hydrogenation treatment in the step (b), conventional hydrogenation treatment conditions are adopted, except for the conditions of the reaction temperature and the hydrogen partial pressure. The reaction temperature in the step (b) is (a)
The temperature must be such that the dry sludge fraction produced in the process is sufficiently hydrogenated and does not thermally decompose to form new dry sludge fraction, but such a critical temperature is below 385 ° C, preferably Corresponds to a temperature of 380 ° C. or less. Further, in the method of the present invention, the difference between the reaction temperature in the step (a) and the reaction temperature in the step (b) is 10 ° C. or more in order to reduce the sulfur content of the produced oil as much as possible and to reduce the dry sludge content as much as possible. , Preferably 20
C. or higher, more preferably 30 ° C. or higher. However, when the sulfur content is reduced together with the dry sludge component in the step (b), the reaction temperature in the step (b) is preferably a high temperature side within the critical temperature. When the temperature difference between the steps (a) and (b) is small, and when the sulfur content is not reduced in the step (b), the reaction temperature in the step (b) may be about 200 ° C. The temperature difference between the steps (a) and (b) increases. The reaction temperature in the present invention refers to the weight average temperature (weight average temperature) of the catalyst layer.
(hereinafter abbreviated as WAT). In addition, when the catalyst layer filled with the catalyst is divided into n, the weight average temperature t is defined as t _{i where} the temperature of the i-th divided catalyst layer is filled with the catalyst of the i-th divided catalyst layer. When the weight ratio to the catalyst layer and x _i, represented by the following equation. (Equation 1) The hydrotreating catalyst used in the step (b) is a catalyst comprising a hydrogenation-active metal component and an inorganic oxide carrier, and macromolecules such as dry sludge are hydrogenated in the pores of the catalyst. In order to achieve this, a catalyst having pores having a large pore diameter is desirable, and therefore, those having an average pore diameter of 90 ° or more, preferably in the range of 100 to 200 ° are preferred. The pore volume of the catalyst is 0.40 ml / g or more, preferably 0.50 to 1.00 ml / g, and the specific surface area is 120 m ² / g or more, preferably 130 to 35 / g.
Those having a range of 0 m ² / g are preferred. The average pore diameter and pore volume of the catalyst were determined by mercury porosimetry, and the specific surface area was B
It is measured by the ET method. In the conventional heavy oil hydrotreating method, a catalyst having a large pore diameter is packed in the front stage of a reaction tower, and a catalyst having a small pore diameter is packed in a rear stage. Usually, in the method of the present invention, the hydrotreating catalyst used in the step (b) is used in the step (a) because the dry sludge component, which is a macromolecule, is hydrogenated in the pores. It is preferable that the catalyst has a larger average pore diameter than the hydrotreating catalyst used in the last stage. As the hydrogenation-active metal component, a metal component used in a normal hydrotreating catalyst such as a Group VIA or Group VIII metal of the periodic table may be used in an amount within a normal usage range, for example, 3%.
It can be used in the range of ３０30 wt%. Specifically, M
o, W, Ni, Co and the like. Examples of the inorganic oxide carrier include ordinary hydrogenation such as alumina, silica, silica-alumina, alumina-boria, phosphorus-alumina, alumina-titania, alumina-zirconia, alumina-silica-boria, and alumina-silica-titania. An inorganic oxide carrier used as a carrier for the treatment catalyst can be used. In the method of the present invention, the dry sludge content of the product oil obtained in the step (b) is desirably less than 0.1 wt%, preferably 0.05 wt% or less. When the dry sludge content of the generated oil is 0.1 wt% or more, it is not preferable because a problem of clogging of a heat exchanger or the like in a downstream device is likely to occur. The heavy oil used in the present invention is a heavy oil containing at least 1.0% by weight of asphaltene (n-pentane-insoluble) and at least 2.0% by weight of sulfur. Such heavy oils include normal pressure residue oils,
Heavy hydrocarbon oils such as heavy residual oils such as vacuum residue oils, visbreaking oils, tar sand oils and shell oils can be mentioned. The above-mentioned heavy oil usually contains at least 1.0 wt% of asphaltenes, and this asphaltenes are thermally affected when the reaction temperature becomes 385 ° C or more in the hydrogenation treatment, so that dealkylation, A dehydrocyclization reaction occurs to convert to dry sludge. 385 ° C for heavy oil with low asphaltene content
Even if the hydrogenation treatment is performed at the above temperature, the above problem does not occur because the amount of dry sludge is small. In the present invention, the dry sludge content is defined as SHF described below.
T method (Shel Hot Filtration Te
(st method).
That is, the dry sludge content is 5 to 10 g of sample oil.
After weighing the sample and maintaining the sample at a temperature of 100 ° C., the upper side of the filter paper was weighed 5 times using a quantitative filter paper (Whatman No. 50).
Kg / cm ² G, and the lower side of the filter paper is −100.
Filter under reduced pressure to mmHg. The amount of oil in the sample is adjusted in the range of 5 to 10 g so that the filtration time does not exceed 25 minutes. Next, after washing with 10 ml of n-heptane, the residue is dried at 110 ° C. for 20 minutes, and the residue is weighed and quantified. Usually, the aforementioned dry sludge component exists in a state of a solvated sludge precursor in a high-temperature reactor, but when the temperature of the oil decreases, the precursor agglomerates,
It becomes dry sludge. [0008] The process of the present invention can be carried out using a single reaction column or a plurality of reaction columns. In the case of a single reaction tower, by an optional method such as a method of cooling by supplying hydrogen gas to the inside of the reaction tower on the outlet side, or in the case of a plurality of reaction towers, by supplying hydrogen gas to a pipeline between the reaction towers. The reaction temperature in the step (b) can be lower than 385 ° C, preferably 380 ° C or lower. In the method of the present invention, the amount of the hydrotreating catalyst used in each of the steps (a) and (b) in each step is not particularly limited. For example, 50 to 90% of the total amount of the hydrotreating catalyst used in the steps (a) and (b) is used in the step (a),
A range of 10% to 10% can be used in step (b). Hereinafter, the present invention will be specifically described based on examples. Tables 1 to 4 show the results of the examples and comparative examples. COMPARATIVE EXAMPLE 1 Atmospheric pressure residual oil having a density of 0.987 g / cm ³ , a sulfur content of 3.36 wt%, a residual carbon content (Conradson residual coal) of 12.3 wt%, and an asphaltene content of 5.1 wt%, and an oil passing amount of 46 ml /
Hr, reaction pressure 145 kg / cm ² , hydrogen to oil ratio 100
Hydrotreatment was carried out with 0 ml hydrogen / l oil in the presence of a catalyst. The reaction was carried out using a two-stage reactor. The first stage reactor has a reactor upper 20vol
% Was filled with a nickel-molybdenum-supported alumina catalyst having an average pore diameter of 130 °, and the lower 80 vol% was filled with a cobalt-molybdenum-supported alumina catalyst having an average pore diameter of 105 °. Second
The stage reactor was filled with an alumina catalyst supporting cobalt molybdenum having an average pore diameter of 105 °. The catalyst loading in the first-stage reactor was 200 ml in total, and the catalyst loading in the second-stage reactor was 220 ml. Therefore, the LHSV of the first-stage reactor is 0.23 Hr ⁻¹ ,
The LHSV through the first and second stages is 0.11 Hr- ¹ . The first stage reactor has a weight average temperature of 410 ° C.,
The weight average temperature of the second-stage reactor was set to 200 ° C., and the oil at the outlet of the first-stage reactor was analyzed. As a result, the dry sludge content in the shell method (SHFT method) was 0.21 wt%,
The sulfur content was 0.025 wt%. When the second stage reactor outlet oil was analyzed, the dry sludge content of the shell method was 0.05 wt% and the sulfur content was 0.025 wt%, and a clear decrease in the dry sludge content was confirmed. Comparative Example 2 A reaction was carried out in exactly the same manner as in Comparative Example 1 except that the weight average temperature of the second stage reactor was 370 ° C. First stage reactor outlet oil is 0.2% of shell method dry sludge
1 wt%, sulfur content 0.025 wt%, the second stage reactor outlet oil was 0.07 watts of shell method dry sludge
At t% and a sulfur content of 0.020 wt%, the same decrease in dry sludge content as in Comparative Example 1 was confirmed. Comparative Example 3 A reaction was carried out in exactly the same manner as in Comparative Example 1 except that the weight average temperature of the second stage reactor was 380 ° C. First stage reactor outlet oil is 0.2% of shell method dry sludge
1 wt%, sulfur content 0.025 wt%, and the second stage reactor outlet oil was 0.09 w / dry weight of shell method dry sludge
t%, sulfur content 0.018 wt%. Comparative Example 4 A reaction was carried out in exactly the same manner as in Comparative Example 1, except that the weight average temperature of the second stage reactor was 390 ° C. First stage reactor outlet oil is 0.2% of shell method dry sludge
1 wt%, sulfur content 0.025 wt%, and the second stage reactor outlet oil was 0.50 watts of shell method dry sludge
t%, sulfur content 0.016 wt%. By setting the weight average temperature of the second stage reactor to 390 ° C,
Although the sulfur content could be reduced as compared with Comparative Example 2, the dry sludge content in the shell method greatly increased. Comparative Example 5 A reaction was carried out in exactly the same manner as in Comparative Example 1, except that the weight average temperature of the second stage reactor was 410 ° C. First stage reactor outlet oil is 0.2% of shell method dry sludge
1 wt%, sulfur content 0.025 wt%, and the second stage reactor outlet oil was 1.1 wt.
% And a sulfur content of 0.011 wt%. By setting the weight average temperature of the second-stage reactor to 410 ° C., although the sulfur content was significantly reduced, the dry sludge content in the shell method was greatly increased. Example 1 The same procedure as in Comparative Example 1 was carried out except that a cobalt molybdenum-supported alumina catalyst having an average pore diameter of 135 ° and having an average pore diameter of 30 ° larger than that of the lower catalyst in the first stage was filled in the second stage reactor. The reaction was performed in the manner described. Shell method dry sludge content of the first stage reactor outlet oil is 0.2
1 wt%, sulfur content 0.025 wt%, shell method dry sludge content of second stage reactor outlet oil 0.04 wt%
% And the sulfur content were 0.025 wt%. Example 2 A method completely the same as that of Comparative Example 1 except that the second stage reactor was filled with an alumina catalyst supporting cobalt molybdenum having an average pore diameter of 135 ° and the weight average temperature of the second stage reactor was set at 370 ° C. The reaction was carried out. The first stage reactor outlet oil has a shell method dry sludge content of 0.21 wt% and a sulfur content of 0.025 wt%, and the second stage reactor outlet oil has a shell method dry sludge content of 0.06 wt% and a sulfur content of 0%. It was 0.018 wt%. Comparative Example 6 An average pore diameter of 13 was added to 25 vol% of the upper part of the first stage reactor.
0% nickel-molybdenum-supported alumina catalyst, 75% by volume of the lower part of the first-stage reactor were filled with a cobalt-molybdenum-supported alumina catalyst having an average pore diameter of 105 °, and the second-stage reactor was filled with a cobalt-molybdenum-supported alumina catalyst having an average pore diameter of 105 °. The catalyst loading in the second stage reactor was 336 ml, and the catalyst loading in the second stage reactor was 84 m.
l. The weight average temperature of the first stage reactor is 400
The reaction was carried out under the same feedstock oil and reaction conditions as in Comparative Example 1 except that the temperature was 340 ° C, the weight average temperature of the second stage reactor was 340 ° C, and the oil flow rate was 84 ml / Hr. The LHSV of the first stage reactor is 0.25 Hr ^-1 , the LHSV through the first stage and the second stage is 0.20 Hr ^-1 , and the weight average temperature is 388 ° C. The first stage reactor outlet oil has a shell method dry sludge content of 0.12 wt% and a sulfur content of 0.036 wt%, and the second stage reactor outlet oil has a shell method dry sludge content of 0.06 wt% and a sulfur content of 0. .0
It was 35 wt%. Comparative Example 7 A reaction was carried out in the same manner as in Comparative Example 6, except that the weight average temperature of the first stage reactor was 380 ° C. and the weight average temperature of the second stage reactor was 420 ° C. The weight average temperature through the first and second stages is 388 ° C., which is the same as Comparative Example 6. Shell method dry sludge content of first stage reactor outlet oil is 0.05wt%, sulfur content is 0.058wt%
The shell-stage dry sludge content of the second stage reactor outlet oil is 0.18 wt%, and the sulfur content is 0.036 wt%.
Met. Reference Example 1 The product oils obtained in Comparative Examples 6 and 7 were distilled to obtain fraction oils having a boiling point of 343 ° C. or higher. This oil is
The catalytic cracking reaction was carried out at a SV of 40 Hr ^-1 , a Cat / Oil ratio of 3.0 and a reaction temperature of 530 ° C. using a commercially available FCC catalyst. The device used for the reaction is a micro-activity test device (MAT). The reaction results are shown in Table 5. The product oil of Comparative Example 6 showed higher conversion and gasoline yield than the product oil of Comparative Example 7. [Table 1] [Table 2] [Table 3] [Table 4] note. * First stage reactor packed catalyst upper part 20vol% Nickel molybdenum supported alumina catalyst lower part 80vol% Cobalt molybdenum supported alumina catalyst Second stage reactor packed catalyst cobalt molybdenum supported alumina catalyst ** First stage reactor packed catalyst upper part 25vol% nickel molybdenum Supported alumina catalyst Lower part 75 vol% Cobalt molybdenum supported alumina catalyst Second stage reactor filling catalyst Cobalt molybdenum supported alumina catalyst According to the present invention, in the step (a), the activity of the hydrotreating catalyst is sufficiently utilized to convert heavy oil with a high demetallation rate, a high denitrification rate, a high desulfurization rate or a high cracking rate. It is possible to carry out the hydrotreating and to reduce the dry sludge content of the oil obtained by the hydrotreating in the step (a) in the step (b), so that the oil can be stably operated for a long period of time. A method for hydrotreating heavy oils is provided. Further, the product oil obtained by the method for hydrotreating heavy oil of the present invention is suitable as a raw material oil for FCC because it has a low content of metals and sulfur and a low content of dry sludge.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-243196 (JP, A) JP-A-61-130394 (JP, A) JP-A-5-93190 (JP, A) JP-A-1- 224049 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C10G 65/04-65/12 C10G 45/04-45/08

Claims (1)

(57) [Claim 1] A method for hydrotreating heavy oil, comprising: (a) reacting a heavy oil containing asphaltene content of 1.0 wt% or more in the presence of a hydrotreating catalyst; Temperature 385 ℃ ～ 5
00 ° C, hydrogen partial pressure 50 kg / cm ² G-250 kg / c
a step of obtaining a spilled oil having a dry sludge content of 0.1 wt% or more and a sulfur content of 1.0 wt% or less by hydrotreating under the condition of m ² G, (b) hydrogenating the spilled oil in the step (a) In the presence of the treatment catalyst,
Reaction temperature less than 385 ° C., hydrogen partial pressure 50 kg / cm ² G ~
A step of treating under a condition of 250 kg / cm ² G to reduce the dry sludge content of the produced oil to less than 0.1 wt%.
The difference between the reaction temperature in the step (a) and the reaction temperature in the step (b) is 10 ° C. or more, and (2) the hydrotreating catalyst in the step (b) comprises a hydrogenation active metal component and an inorganic oxide carrier. A catalyst having a pore volume of 0.40 m
1 / g or more, average pore diameter is 90 ° or more, specific surface area is 1
A catalyst having an average pore diameter of not less than 20 m ² / g and an average pore diameter larger than the average pore diameter of the hydrotreating catalyst used in the last stage of the step (a). Hydroprocessing of high quality oil.