A method for reducing the acid value of hydrocarbon raw materials

Abstract

The application relates to a method for reducing the acid value of a hydrocarbon feedstock, wherein the hydrocarbon feedstock is introduced into an optional dephosphorization and de-ironing reaction zone, and sequentially reacts with a hydrogenation protective agent and a hydrogenation dephosphorization and de-ironing catalyst in the absence of hydrogen, and the reaction effluent is introduced into a deacidification reaction zone, and reacts with a hydrogenation deacidification catalyst in the absence of hydrogen to obtain a reaction product oil with an acid value lower than 0.5 mgKOH / g. The method provided by the application is simple in process flow, convenient in operation and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrocarbon raw material processing, and in particular to a method for reducing the acid value, iron content and phosphorus element of hydrocarbon raw materials. Background Art

[0002] Crude oil contains organic acidic substances, and is generally considered to have an acid value higher than 0.5 mgKOH / g, which is called acidic crude oil. The output of acidic crude oil in the world crude oil market accounts for about 5% of the world's total crude oil production each year, and is still increasing every year.

[0003] The most challenging issue to address with acidic crude oil, especially those high in naphthenic acid, is equipment corrosion. Crude oil with an acid value greater than 0.5 mgKOH / g can corrode metals during transportation and processing. For example, severe equipment corrosion can occur during atmospheric and vacuum distillation, primarily through the formation of iron naphthenate. The distillates produced from this type of crude oil also often have high acid values, impacting the quality of petroleum products. Therefore, reducing the acid value of crude oil or distillates has long been a pressing issue for refineries.

[0004] Prior art approaches to preventing cyclohexane acid corrosion in crude oil primarily involve upgrading refining equipment or adding high-temperature corrosion inhibitors to atmospheric and vacuum units. However, upgrading materials is expensive, and adding high-temperature corrosion inhibitors can introduce impurities. For example, some high-temperature inhibitors contain phosphorus, which can negatively impact downstream raw material processing equipment. Therefore, processing acidic crude oil often requires the removal of iron and phosphorus impurities.

[0005] It is important to note that the presence of iron and phosphorus can accumulate in the upper reactor during downstream processing, particularly in fixed-bed hydrogenation processes, forming fouling. This can cause a rapid increase in reactor pressure drop and can lead to forced plant shutdowns. Therefore, removing iron and phosphorus from hydrocarbons is a pressing issue for refineries.

[0006] In summary, in the process of processing acid-containing hydrocarbon raw materials, how to reduce the acid value of crude oil or distillate oil and remove iron and phosphorus elements, these three problems often appear separately or in combination during the hydrocarbon processing process. Therefore, how to reduce the acid value, iron and phosphorus in crude oil or distillate oil is a relatively comprehensive issue.

[0007] CN1847366A discloses a method for removing cyclohexane acids from crude oil or distillate oils. The method comprises adding at least one ionic liquid and / or an auxiliary compound to the crude oil or distillate oil, subjecting the mixture to a mixing reaction at 20-80°C, allowing the mixture to stand, and separating to obtain the deacidified crude oil or distillate oil. The present invention utilizes ionic liquids to remove acidic compounds from crude oil or distillate oils. The ionic liquids are less likely to emulsify and readily form complexes with acids to form corresponding ionic liquid-acid complexes. These complexes, upon standing, separate from the crude oil or distillate oil, thereby achieving separation. The method achieves a high cyclohexane acid removal rate of approximately 90% from the crude oil or distillate oils.

[0008] CN102051200A discloses a method for deacidifying crude oil and / or petroleum distillates. The method comprises contacting an alcohol with the crude oil and / or petroleum distillate in the presence of a catalyst under esterification reaction conditions. The catalyst comprises a Y-type molecular sieve and an inorganic oxide support. The method for deacidifying crude oil and / or petroleum distillates provided by the present invention can rapidly remove acid from the crude oil and / or petroleum distillate at a relatively low temperature of no more than 150°C and normal pressure, achieving a deacidification rate of up to 80-95%.

[0009] CN1164867A discloses a method for removing cyclohexane acids from hydrocarbon oils, wherein the hydrocarbon oil is hydrogenated at high temperature over a catalyst similar to that used for hydrogenating atmospheric residual oils. The catalyst preferably contains nickel-molybdenum or cobalt-molybdenum and is deposited on an alumina support material. The hydrocarbon oil used is either a) crude oil that has not been distilled into fractions or b) crude oil from which the naphtha fraction has been removed. The hydrogenation is carried out at 1 to 50 bar and 100 to 300°C, thereby achieving the goal of removing cyclohexane acids.

[0010] The above-mentioned deacidification methods, whether using ionic liquids, esterification reactions or hydrogenation reactions, all have the problem of high processing costs. Summary of the Invention

[0011] The present invention aims to solve the problem of high cost in processing acid-containing hydrocarbon oil in the prior art and the problem of how to simultaneously reduce the acid value, iron and phosphorus impurities in the hydrocarbon oil.

[0012] The present invention provides a method for reducing the acid value of a hydrocarbon feedstock, comprising: the hydrocarbon feedstock enters an optional dephosphorization and deferrification reaction zone, and in the absence of hydrogen, sequentially contacts with a hydrogenation protective agent and a hydrodephosphorization and deferrification catalyst for reaction; the reaction effluent enters a deacidification reaction zone, and in the absence of hydrogen, contacts with a hydrodeacidification catalyst for deacidification reaction; the reaction conditions of the deacidification reaction are: a reaction temperature in the range of 320°C to 420°C, a liquid hourly volume space velocity of 1h -1 ~ 10 hours -1The reaction oil obtained has an acid value of less than or equal to 0.5 mgKOH / g, and the hydrocarbon material has an acid value of 1-10 mgKOH / g.

[0013] In one embodiment of the present application, the hydrocarbon material is reacted in a full liquid phase in the absence of any gas with a hydrogenation protective agent and a hydrodeoxygenation catalyst.

[0014] In one embodiment of the present application, the hydrocarbon material is reacted in a full liquid phase in the absence of any gas with a hydrodeoxygenation catalyst.

[0015] In the present application, "optional" means that the corresponding step, unit, component or ingredient is optional, not necessary, i.e. the step, unit, component or ingredient can exist or not.

[0016] In the present application, the hydrocarbon material is any oil having an acid value of at least 1 mgKOH / g, such as one or more selected from diesel oil, wax oil, atmospheric residue, vacuum residue, deasphalted oil, crude oil, coal tar, and coal liquefaction heavy oil.

[0017] In one embodiment of the present application, the hydrocarbon material directly enters a deacidification reaction zone, and is contacted with a hydrodeoxygenation catalyst in the absence of hydrogen to perform a deacidification reaction, and the hydrocarbon material has an acid value of 1-10 mgKOH / g.

[0018] In one embodiment of the present application, the reaction conditions of the deacidification reaction are as follows: the reaction temperature is in the range of 340-400°C, and the liquid hourly space velocity is in the range of 3-6 h -1 -1

[0019] In one embodiment of the present application, the hydrodeoxygenation catalyst is a supported catalyst, and the active metal component includes nickel, and the hydrodeoxygenation catalyst is in a sulfided state.

[0020] In one embodiment of the present application, the active metal component of the hydrodeoxygenation catalyst is nickel, and molybdenum and / or tungsten, and the content of molybdenum and / or tungsten is 15-30 wt%, and the content of nickel is 0.5-15 wt%, based on the total amount of the hydrodeoxygenation catalyst.

[0021] The inventors of the present application have found that the use of a hydrodeoxygenation catalyst in a sulfided state can achieve a high deacidification rate at a relatively mild temperature in the absence of any gas atmosphere, and in addition, increasing the active metal content of the hydrodeoxygenation catalyst in a sulfided state can effectively improve the deacidification rate or reduce the reaction temperature in the deacidification reaction zone.

[0022] ​​Due to factors such as corrosion and the addition of high-temperature slow-release agents, acidic hydrocarbons also contain relatively high levels of iron and phosphorus. These elements are easily released preferentially during the deacidification reaction, causing fouling of the sulfided hydrodeacidification catalyst and creating a pressure differential, making it difficult for the deacidification process to operate stably over a long period of time. Therefore, after in-depth research on the reaction processes of phosphorus and iron, the inventors combined the dephosphorization and deironization processes with the deacidification reaction process.

[0023] In one embodiment of the present invention, when the iron content in the hydrocarbon feedstock is greater than 0.5 μg / g and / or the phosphorus content is greater than 1 μg / g, the hydrocarbon feedstock first enters the dephosphorization and deferrification reaction zone, and in the absence of hydrogen, sequentially contacts with a hydrogenation protective agent and a hydrodephosphorization and deferrification catalyst for reaction. The reaction conditions for dephosphorization and deferrification are: a reaction temperature in the range of 220°C to 400°C, a liquid hourly volume space velocity of 1h -1 ~10h -1 The preferred reaction temperature is in the range of 250 ℃ to 320 ℃, and the preferred liquid hourly volume space velocity is 4h -1 ~8h -1 The reaction effluent enters the deacidification reaction zone and undergoes deacidification reaction to obtain reaction product oil, wherein the acid value of the reaction product oil is less than or equal to 0.5 mgKOH / g, the iron content is less than or equal to 0.5 μg / g, and the phosphorus content is less than or equal to 1 μg / g.

[0024] In one embodiment of the present invention, the hydrogenation protective agent is a supported catalyst, the active metal component is one or more selected from nickel, cobalt, molybdenum, and tungsten, and the hydrogenation protective agent is a sulfided catalyst.

[0025] In one embodiment of the present invention, the active metal component content is 0.1 to 15 wt % in terms of oxide, based on the weight of the hydrogenation protective agent.

[0026] In one embodiment of the present invention, the particle size of the hydrogenation protective agent is 2.0 to 50.0 mm, and the bulk density is 0.3 to 1.2 g / cm 3 , with a specific surface area of ​​50 to 300 m 2 / g.

[0027] In one embodiment of the present invention, the hydrodephosphorization and deferrification catalyst is a supported catalyst, the active metal component includes nickel, and the hydrodephosphorization and deferrification catalyst is a sulfided catalyst.

[0028] In one embodiment of the present invention, the active metal components of the hydrodephosphorization and deferrification catalyst are nickel, and molybdenum and / or tungsten. Calculated as oxides and based on the total amount of the hydrodephosphorization and deferrification catalyst, the content of molybdenum and / or tungsten is 0.5 to 15 weight percent, and the content of nickel is 0.5 to 15 weight percent.

[0029] The particle size of the hydrodephosphorization and deferrification agent is 0.2-2.0 mm, and the bulk density is 0.3-0.8 g / cm 3 , with a specific surface area of ​​100 to 250 m 2 / g.

[0030] In one embodiment of the present invention, at least one fixed bed reactor is provided in the dephosphorization and deferrification reaction zone, and at least one hydrogenation protective agent and at least one hydrogenation dephosphorization and deferrification agent are graded in sequence along the flow direction in the fixed bed reactor.

[0031] In one embodiment of the present invention, the first reactor is a dephosphorization and deironization reactor; its main purpose is to remove the iron and phosphorus elements that are more easily reacted to prevent pressure difference in the entire reaction system; the second reactor is a deacidification reactor; its main purpose is to be used for deacidification.

[0032] In one embodiment of the present invention, the particle sizes of the hydrogenation protective agent and the hydrodephosphorization and deironification catalyst gradually decrease in the direction of the flow of the logistics;

[0033] According to the direction of the flow of the material flow, the active metal content of the hydrogenation protective agent, the hydrodephosphorization and deironification catalyst, and the hydrodeacidification catalyst gradually increases.

[0034] In one embodiment of the present invention, in the dephosphorization and deferrification reaction zone, the hydrodephosphorization and deferrification catalyst is a graded packing of two or more hydrodephosphorization and deferrification catalysts.

[0035] In one embodiment of the present invention, according to the direction of flow of the logistics, the hydrogenation protective agent and the two or more hydrogenation dephosphorization and deferrification catalysts in the dephosphorization and deferrification reaction zone are arranged from large to small according to the particle size;

[0036] According to the direction of the flow of the material flow, the active metal content of the hydrogenation protective agent and two or more hydrogenation dephosphorization and deferrification catalysts in the dephosphorization and deferrification reaction zone gradually increases.

[0037] In one embodiment of the present invention, according to the flow direction of the logistics, the particle size of the hydrodephosphorization and deferrification catalyst loaded at the end of the dephosphorization and deferrification reaction zone is the same as the particle size of the deacidification catalyst in the deacidification reaction zone.

[0038] The particle size mentioned in the present invention refers to the maximum value of the distance between any two points on the cross section of the catalyst.

[0039] The grading scheme of the hydrogenation protective agent and the hydrogenation dephosphorization and deferrification agent in the present invention can be optimized according to the particle size and activity of the catalyst, the properties of the raw materials, the operating conditions and the like.

[0040] In one embodiment of the present application, the reaction temperature of the dephosphorization and de-ironing reaction zone is lower than the reaction temperature of the de-acidification reaction zone, preferably 120-20℃ lower. The reaction product of the dephosphorization and de-ironing reaction zone enters the de-acidification reaction zone after heat exchange and / or heating.

[0041] In one embodiment of the present application, the volume ratio of the loading of the hydrogenation dephosphorization and de-ironing catalyst to the loading of the hydrogenation de-acidification catalyst is in the range of 0.2-1.0:1.0-2.0.

[0042] Features of the present application:

[0043] The present application provides a method for reducing the acid value of a hydrocarbon feedstock and simultaneously removing iron and phosphorus elements from the hydrocarbon feedstock. The present application can achieve the goal of reducing the acid value of the hydrocarbon feedstock and removing the iron and phosphorus element content in a gas-free atmosphere. The reactor is simplified in the gas-free environment, and the investment cost is greatly reduced. In addition, the method provided by the present application is simple to operate, has low operating cost, and has no environmental problems.

[0044] By using the method provided by the present application, partial acidic components in the hydrocarbon feedstock can be removed at low cost, and the adaptability of enterprises to acid-containing feedstocks is increased. Not only is low-acid-value feedstock provided for subsequent devices, reducing the corrosion of high-acid-value feedstock on equipment and improving economic efficiency, but the present application also reduces the iron and phosphorus content of the hydrocarbon feedstock, which is beneficial to reducing the impurity content in the raw oil for downstream fixed-bed hydrogenation devices and prolonging the operation period of subsequent devices. DETAILED DESCRIPTION

[0045] The present application will be further described below in conjunction with examples, but the present application is not limited in any way by the examples.

[0046] The catalysts used in the examples and comparative examples are hydrogenation catalysts developed by SINOPEC Research Institute of Petroleum Processing and produced by SINOPEC Catalyst Changling Branch. In the present application, the commercial grade RG series is a hydrogenation guard catalyst, the commercial grade RDM series is a hydrogenation dephosphorization and de-ironing catalyst I, the commercial grade RCS series is a hydrogenation dephosphorization and de-ironing catalyst II, and the commercial grade RN series is a hydrogenation de-acidification catalyst. The suffix of the catalyst name indicates the particle size of the catalyst. For example, RG-30B-3.0 represents that the hydrogenation guard catalyst has a grade of RG-30B and a particle size of 3.0 mm, RDM-202-1.3 represents that the hydrogenation dephosphorization and de-ironing catalyst has a grade of RDM-202 and a particle size of 1.3 mm, and RN-410-1.3 represents that the hydrogenation de-acidification catalyst has a grade of RN-410 and a particle size of 1.3 mm.

[0047] The properties of the several feedstocks used in each example and comparative example are shown in Table 1. The active metal content of the catalysts used in each example and comparative example is shown in Table 2.

[0048] Example 1

[0049] Raw material 1 directly enters the deacidification reactor and, in the presence of gas, contacts with the hydrodeacidification catalyst RN-410-1.3 in the full liquid phase for deacidification reaction. The hydrodeacidification catalyst is a sulfurized catalyst. The reaction conditions of the deacidification reaction are: reaction temperature 340°C, liquid hourly volume space velocity 4h -1 The catalyst loading scheme is shown in Table 3, and the reaction process conditions and reaction results are shown in Table 4.

[0050] From the results in Table 4, it can be seen that the acid value of the reaction oil is reduced from 2.9 mgKOH / g of raw material 1 to 0.4 mgKOH / g.

[0051] Comparative Example 1, Comparative Example 3

[0052] Feedstock 1 was directly fed into the deacidification reactor. In the absence of gas, the entire liquid phase came into contact with a sulfurized hydrogenation catalyst for a deacidification reaction. The deacidification reaction conditions were the same as those in Example 1, yielding a product oil with a reduced acid value. The catalyst loading scheme is shown in Table 3, and the reaction process conditions and results are shown in Table 4.

[0053] Comparative Examples 1 and 3 are different from Example 1 in that the hydrogenation catalysts are different. Comparative Example 1 is loaded with the RG-30B catalyst with the lowest active metal content, while Comparative Example 3 is loaded with the RCS-31-1.3 catalyst with a higher active metal content.

[0054] From the results in Table 4, it can be seen that under the same reaction conditions, the acid value of the oil generated by the reaction in Comparative Example 1 is 1.7 mgKOH / g, and the acid value of the oil generated by the reaction in Comparative Example 3 is 1.2 mgKOH / g, both of which are higher than 0.5 mgKOH / g and do not meet the requirements of low-acid hydrocarbon raw materials.

[0055] Comparative Example 2

[0056] Raw material 1 directly enters the deacidification reactor and, in the absence of gas, contacts with the hydrodeacidification catalyst RN-410-1.3 in the full liquid phase for deacidification reaction. The hydrodeacidification catalyst is an oxidized catalyst. The reaction conditions of the deacidification reaction are: reaction temperature 340°C, liquid hourly volume space velocity 4h -1 The catalyst loading scheme is shown in Table 3, and the reaction process conditions and reaction results are shown in Table 4.

[0057] From the results in Table 4, it can be seen that compared with Example 1, under the same reaction conditions, using an oxidized catalyst, the acid value of the reaction product oil is 2.5 mgKOH / g, which is higher than 0.5 mgKOH / g and does not meet the requirements of low-acid hydrocarbon feedstock.

[0058] Table 1

[0059] Crude oil number Raw material 1 Raw material 2 Raw material 3 <![CDATA[密度(20℃) / (g / cm 3 )]]> 0.9257 0.9275 0.9277 Distillation range / (℃) 270～538 275～545 275～547 Total acid value / (mgKOH / g) 2.9 2.9 3.0 Fe / (μg / g) <0.5 9 8 P / (μg / g) <1 <1 19

[0060] Table 2

[0061] catalyst <![CDATA[MoO3,重%]]> NiO, weight % Total active metal content / weight% RG-30B-3.0 5.7 1.1 Base RDM-202-1.8 / 1.3 7.7 1.5 Basic+2.4 RCS-31-1.3 14.5 3.5 Base+11.2 RN-410-1.3 26.5 4.4 Base +24.1

[0062] Table 3

[0063]

[0064] Table 4

[0065] project Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reaction conditions Reaction temperature / ℃ 340 340 340 340 <![CDATA[液时体积空速 / h -1 ]]> 4 4 4 4 Total acid value of the reaction oil / (mgKOH / g) 0.4 1.7 2.5 1.2

[0066] Examples 2, 3 and 4

[0067] Hydrocarbon feedstock 2 enters the dephosphorization and deferrification reaction zone, where it sequentially contacts a hydrodephosphorization and deferrification catalyst in the absence of gas, all in a liquid phase, and reacts at a relatively low reaction temperature. The reaction effluent, after undergoing heat exchange and temperature increase, enters the deacidification reaction zone. In the absence of gas, it contacts a hydrodeacidification catalyst in the liquid phase for a deacidification reaction, yielding a product oil with a reduced acid value and metallic impurity content. The hydrodephosphorization and deferrification catalyst, and the hydrodeacidification catalyst are all sulfurized catalysts. The graded loading volume ratio of the three catalysts is 0.2:0.3:1.0. The specific catalyst loading scheme is shown in Table 5, and the reaction process conditions and results are shown in Table 6.

[0068] From the results in Table 6, we can see that in Examples 2, 3, and 4, the reaction temperature in the deironing and dephosphorization reaction zone is gradually increased from 220°C to 320°C, and the liquid hourly volume space velocity is gradually increased from 4h -1 Increase to 8 hours -1 The iron contents of the effluents from the deironification and dephosphorization reactors were 0.7 μg / g, 0.5 μg / g and 0.2 μg / g, respectively, and the corresponding deironization rates were 92.2%, 94.4% and 97.8%, respectively.

[0069] It can also be seen from the results in Table 6 that the acid values ​​of the oils produced by the final reactions of Examples 2, 3, and 4 are 0.4 mgKOH / g, 0.3 mgKOH / g, and 0.2 mgKOH / g, respectively.

[0070] Comparative Example 4

[0071] The same hydrocarbon feedstock and catalyst loading scheme as in Example 4 were used, and the same all-liquid-phase reaction conditions were employed, with the exception that the reaction temperature in the deironization and dephosphorization reaction zones was 200°C, and the reaction temperature in the deacidification reaction zone was 300°C. The specific catalyst loading scheme is shown in Table 5, and the reaction process conditions and reaction results are shown in Table 6.

[0072] From the results in Table 6, it can be seen that the iron content of the effluent from the deironing and dephosphorization reactor in Comparative Example 4 is 1.5 μg / g, corresponding to an iron removal rate of 83.3%.

[0073] The acid value of the oil finally produced by the reaction was 1.0 mgKOH / g, and the deacidification effect was worse than that of Examples 2, 3 and 4.

[0074] Table 5

[0075]

[0076] Table 6

[0077]

[0078]

[0079] Examples 5, 6 and 7

[0080] Hydrocarbon feedstock 3 enters the dephosphorization and deferrification reaction zone, where it sequentially contacts a hydrogenation protective agent, hydrodephosphorization and deferrification catalyst I, and hydrodephosphorization and deferrification catalyst II in the absence of gas, reacting at a relatively low reaction temperature. The reaction effluent, after heat exchange and temperature increase, enters the deacidification reaction zone. In the absence of gas, it contacts the hydrodeacidification catalyst in the liquid phase for a deacidification reaction, producing a product oil with a reduced acid value and reduced metallic impurity content. The hydrogenation protective agent, hydrodephosphorization and deferrification catalyst I, hydrodephosphorization and deferrification catalyst II, and hydrodeacidification catalyst are all sulfided catalysts. The four catalysts are graded and loaded in a volume ratio of 0.2:0.2:0.1:1.5. The specific catalyst loading scheme is shown in Table 7. The reaction process conditions and reaction results are shown in Table 8. To examine the long-term effects of catalyst grading, each test condition was tested continuously for approximately 500 hours. The test results represent the reaction results after 500 hours.

[0081] As can be seen from the results in Table 8, the iron contents of the effluents from the deironification and dephosphorization reactors of Examples 5, 6, and 7 were 0.4 μg / g, 0.3 μg / g, and 0.1 μg / g, respectively, corresponding to iron removal rates of 95.0%, 96.3%, and 98.8%, respectively. Furthermore, the phosphorus contents of the effluents from the deironification and dephosphorization reactors were 1.6 μg / g, 1.2 μg / g, and 0.5 μg / g, respectively, corresponding to dephosphorization rates of 91.6%, 93.7%, and 97.4%, respectively.

[0082] It can also be seen from the results in Table 8 that in Examples 5, 6, and 7, the acid values ​​of the oils produced by the final reactions are 0.5 mgKOH / g, 0.4 mgKOH / g, and 0.4 mgKOH / g, respectively.

[0083] Comparative Example 5

[0084] The same hydrocarbon feedstock and all-liquid-phase reaction conditions were used as in Example 5. This comparative example differed in that the de-ironization and dephosphorization reaction zones were loaded with RG-30B-3.0, RDM-202-1.8, and RCS-31-1.8 catalysts, respectively, and the reaction temperature in the deacidification reaction zone was 310°C. The specific catalyst loading scheme is shown in Table 7, and the reaction conditions and results are shown in Table 8. To examine the long-term effects of the catalyst grading, the test was conducted continuously for approximately 500 hours. The test results represent the reaction effects after 500 hours.

[0085] From the results in Table 7, it can be seen that in Comparative Example 5, the iron content of the deferrification and dephosphorization reactor effluent was 1.0 μg / g, corresponding to an iron removal rate of 87.5%. In addition, the phosphorus content of the deferrification and dephosphorization reactor effluent was 3.5 μg / g, and the dephosphorization rate was 81.6%.

[0086] From the comparative data in Table 8, it can be seen that Comparative Example 5 does not adopt the grading scheme of the present invention, and the iron removal rate and dephosphorization rate are both lower than those of Example 5.

[0087] It can also be seen from the results in Table 8 that the acid value of the oil produced by the final reaction is 0.8 mgKOH / g, and the deacidification effect is worse than that of Example 5.

[0088] Table 7

[0089]

[0090] Table 8

[0091]

[0092]

Claims

1. A method for reducing the acid value of a hydrocarbon feedstock, comprising: The hydrocarbon feedstock enters the dephosphorization and deferrification reaction zone and contacts with the hydrogenation protective agent and the hydrodephosphorization and deferrification catalyst in the absence of hydrogen to react. The reaction effluent enters the deacidification reaction zone and contacts with the hydrodeacidification catalyst in the absence of hydrogen to carry out the deacidification reaction. The reaction conditions of the deacidification reaction are: the reaction temperature is in the range of 320℃~420℃, the liquid hourly volume space velocity is in the range of 1h -1 ~10h -1 A reaction product oil having an acid value of less than or equal to 0.5 mgKOH / g is obtained, the acid value of the hydrocarbon feedstock is in the range of 1 to 10 mgKOH / g, the hydrodeacidification catalyst is a supported catalyst, the hydrodeacidification catalyst is a sulfided catalyst, the active metal components of the hydrodeacidification catalyst are nickel, and molybdenum and / or tungsten, the content of molybdenum and / or tungsten is 15 to 30% by weight, and the content of nickel is 0.5 to 15% by weight, calculated as oxides and based on the total amount of the hydrodeacidification catalyst; The reaction temperature of the dephosphorization and deferrification reaction zone is lower than that of the deacidification reaction zone, and is 20 to 120°C lower.

2. The method according to claim 1, characterized in that The reaction conditions of the deacidification reaction are: reaction temperature in the range of 340℃~400℃, liquid hourly volume space velocity in 3h -1 ~6h -1 within the range.

3. The method according to claim 1, characterized in that When the iron content in the hydrocarbon feedstock is greater than 0.5 μg / g and / or the phosphorus content is greater than 1 μg / g, the hydrocarbon feedstock first enters the dephosphorization and deferrification reaction zone, and in the absence of hydrogen, sequentially contacts with the hydrogenation protective agent and the hydrodephosphorization and deferrification catalyst for reaction. The reaction conditions for dephosphorization and deferrification are: reaction temperature within the range of 220℃~400℃, liquid hourly volume space velocity within 1h -1 ~10h -1 The reaction effluent enters the deacidification reaction zone, undergoes deacidification reaction, and obtains reaction product oil, wherein the acid value of the reaction product oil is less than or equal to 0.5 mgKOH / g, the iron content is less than or equal to 0.5 μg / g, and the phosphorus content is less than or equal to 1 μg / g.

4. The method according to claim 3, characterized in that The reaction conditions for dephosphorization and deironification are: the reaction temperature is in the range of 250℃ to 320℃.

5. The method according to claim 3, characterized in that The reaction conditions for dephosphorization and deferrification are: liquid volume space velocity at 4h -1 ~8h -1 within the range.

6. The method according to claim 1 or 3, characterized in that The hydrogenation protective agent is a supported catalyst, the active metal component is one or more selected from nickel, cobalt, molybdenum and tungsten, and the hydrogenation protective agent is a sulfided catalyst.

7. The method according to claim 1, characterized in that The hydrodephosphorization and deironification catalyst is a supported catalyst, the active metal component of which includes nickel, and the hydrodephosphorization and deironification catalyst is a sulfided catalyst.

8. The method according to claim 7, characterized in that The active metal components of the hydrodephosphorization and deferrification catalyst are nickel, molybdenum and / or tungsten. Calculated as oxides and based on the total amount of the hydrodephosphorization and deferrification catalyst, the content of molybdenum and / or tungsten is 0.5-15% by weight, and the content of nickel is 0.5-15% by weight.

9. The method according to claim 1, characterized in that According to the direction of the flow of the material flow, the particle size of the hydrogenation protective agent and the hydrodephosphorization and deironification catalyst gradually decreases; According to the direction of the flow of the material flow, the active metal content of the hydrogenation protective agent, the hydrodephosphorization and deironification catalyst, and the hydrodeacidification catalyst gradually increases.

10. The method according to claim 1, characterized in that In the dephosphorization and deferrification reaction zone, the hydrodephosphorization and deferrification catalyst is a graded packing of two or more hydrodephosphorization and deferrification catalysts; According to the direction of the flow of the material flow, the hydrogenation protective agent and the two or more hydrogenation dephosphorization and deferrification catalysts in the dephosphorization and deferrification reaction zone are arranged in descending order of particle size; According to the direction of the flow of the material flow, the active metal content of the hydrogenation protective agent and two or more hydrogenation dephosphorization and deferrification catalysts in the dephosphorization and deferrification reaction zone gradually increases.

11. The method according to claim 1 or 9, characterized in that According to the flow direction of the logistics, the particle size of the hydrodephosphorization and deferrification catalyst loaded at the end of the dephosphorization and deferrification reaction zone is the same as the particle size of the deacidification catalyst in the deacidification reaction zone.

12. The method according to claim 1, characterized in that The loading volume ratio of the hydrodephosphorization and deironification catalyst to the hydrodeacidification catalyst is in the range of 0.2-1.0:1.0-2.0.

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