Methods for Hydrorefining Inferior Aromatic Distillate Oils

Abstract

This invention relates to the field of hydrotreating rich aromatic distillate oils, and discloses a method for hydrorefining inferior rich aromatic distillate oils. The method includes: S1, in the presence of a hydrorefining catalyst, the inferior rich aromatic distillate oil is contacted with hydrogen to undergo hydrorefining to obtain a hydrotreated product; S2, the stream containing the hydrotreated product undergoes a first separation to obtain a gaseous stream and a hydrorefined stream; S3, all or part of the gaseous stream is recycled back to step S1 as a circulating hydrogen stream for further hydrorefining; wherein the NH3 content in the circulating hydrogen stream is controlled to be 20-400 ppm. Using the method of this invention, the final liquid product has high desulfurization and denitrification rates, as well as high aromatic hydrocarbon retention, which can meet the requirements of subsequent hydrocracking.

Description

Technical Field

[0001] This invention relates to the field of hydrotreating technology, specifically to a method for hydrorefining inferior aromatic-rich distillate oils. Background Technology

[0002] Due to the finite nature of global oil resources and the increasing severity and deterioration of oil products, the deep transformation of inferior oil products and the production of high-value-added light oil products have become a major development strategy for the refining industry. Inferior aromatic-rich distillate oils, such as catalytic cracking diesel (LCO), account for a relatively high proportion (approximately 30%) in my country's diesel fuel pool, and are a major component of secondary processed diesel. Ethylene tar is also a heavy distillate oil (>205℃) rich in aromatics (aromatic content greater than 90%), a product of high-temperature condensation of feedstock and products during the steam cracking process of ethylene cracking. In the field of aromatic-rich distillate oil hydrotreating, mature catalytic cracking feedstock pretreatment technologies are now available to improve denitrification, residual carbon, and polycyclic aromatic hydrocarbon saturation capabilities.

[0003] With increasingly stringent environmental regulations, the quality requirements for gasoline and diesel products are becoming higher, mainly in terms of sulfur content, density, cetane number, and polycyclic aromatic hydrocarbon (PAH) content. Hydrotreating technology for low-quality distillate oils can significantly reduce the sulfur and PAH content in diesel products, while also reducing density and increasing cetane number.

[0004] During the implementation of hydrotreating technology, sulfur-containing species in the feedstock produce hydrogen sulfide after the hydrodesulfurization reaction. The concentration of hydrogen sulfide in the reaction system has varying degrees of impact on catalyst activity, selectivity, and stability. For active metals existing in the sulfide state, a certain concentration of hydrogen sulfide in the system is essential for maintaining the sulfide state. Some studies indicate that hydrogen sulfide in the reaction system can promote reactions such as hydrodenitrification, while others suggest that excessively high hydrogen sulfide concentrations can inhibit the hydrotreating reaction, possibly due to competitive adsorption of hydrogen sulfide with other reactants. Therefore, controlling the hydrogen sulfide concentration is crucial for the reaction.

[0005] CN1171430A discloses a medium-pressure hydrocracking method for heavy distillate oils. This method uses heavy distillate oils such as atmospheric wax oil, vacuum wax oil, and coking wax oil as raw materials and adopts a single-pass process with a hydrorefining catalyst and a hydrocracking catalyst connected in series in a single stage. It can achieve a conversion rate of up to 80%. Although diesel fractions have a high cetane number and low sulfur and nitrogen content, their yield is low, generally below 50% by weight.

[0006] USP3622267 discloses a method for removing hydrogen sulfide from a mixed gas using methyldiethanolamine with added monoethanolamine as the absorbent. The method employs a two-stage absorption-two-stage regeneration process, where the hydrogen sulfide-rich solution is fed to a regeneration tower, where the gas is regenerated by steam heating. The disadvantages of this invention are poor hydrogen sulfide removal efficiency, high hydrogen sulfide content in the regenerated tail gas, requiring the conversion of hydrogen sulfide into sulfur, and significantly increased operating costs. Summary of the Invention

[0007] The purpose of this invention is to provide a method for hydrorefining inferior aromatic-rich distillate oil with a high aromatic retention rate. This method has a high aromatic retention rate and can achieve good denitrification and desulfurization rates.

[0008] The first aspect of the present invention provides a method for hydrorefining inferior aromatic-rich distillate oil, the method comprising: S1, in the presence of a hydrorefining catalyst, contacting the inferior aromatic-rich distillate oil with hydrogen to perform hydrorefining to obtain a hydrorefining product; S2, the stream containing the hydrorefining product undergoes a first separation to obtain a gaseous stream and a hydrorefined stream; S3, all or part of the gaseous stream is recycled back to step S1 as a circulating hydrogen stream for further hydrorefining; wherein, the NH3 content in the circulating hydrogen stream is controlled to be 20-400 ppm.

[0009] The above technical solution achieves high desulfurization and denitrification rates, as well as high aromatics retention rates, and the hydrorefined distillate oil can meet the needs of subsequent hydrocracking. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a method for hydrorefining inferior aromatic-rich distillate oil according to one embodiment of the present invention.

[0011] Explanation of reference numerals in the attached figures

[0012] 1. Inferior aromatic distillate feedstock; 2. Hydrogen supplementation.

[0013] 3. Hydrorefining reactor 4. High-pressure separator

[0014] 5. Circulating hydrogen stream; 6. Liquid-liquid separator

[0015] 7. Oily wastewater 8. Hydrogenated refining products

[0016] 9. Low-pressure separator 10. Gas phase products

[0017] 11. Liquid phase products Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of the present invention provides a method for hydrorefining inferior aromatic-rich distillate oil, the method comprising: S1, in the presence of a hydrorefining catalyst, contacting the inferior aromatic-rich distillate oil with hydrogen to perform hydrorefining to obtain a hydrorefining product; S2, the stream containing the hydrorefining product undergoes a first separation to obtain a gaseous stream and a hydrorefined stream; S3, all or part of the gaseous stream is recycled back to step S1 as a circulating hydrogen stream for further hydrorefining; wherein, the NH3 content in the circulating hydrogen stream is controlled to be 20-400 ppm.

[0020] In this invention, the method of this invention can selectively hydrogenate the rich aromatic heavy distillate oil from inferior rich aromatic distillate oil, selectively hydrogenating the polycyclic aromatic hydrocarbons therein to prepare solvent oil or use it as an aromatic feedstock for the production of benzene, toluene and xylene, with a high aromatic hydrocarbon retention rate; the method of this invention can also deeply hydrogenate to remove impurities such as sulfur and nitrogen, reduce hydrogen consumption and increase its added value.

[0021] According to the present invention, the inferior aromatic-rich distillate oil and hydrogen can be introduced separately into a hydrogenation reactor filled with a hydrogenation refining catalyst for contacting with the hydrogenation refining catalyst for hydrogenation refining, or the inferior aromatic-rich distillate oil and hydrogen can be mixed and then introduced into a hydrogenation reactor filled with a hydrogenation refining catalyst for contacting with the hydrogenation refining catalyst for hydrogenation refining.

[0022] According to some preferred embodiments of the present invention, the NH3 content in the circulating hydrogen stream is controlled to be 50-350 ppm, for example, 50 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, 280 ppm, 350 ppm, or any combination of two of the above values. Using the aforementioned preferred embodiments results in higher aromatic hydrocarbon retention, desulfurization, and denitrification rates.

[0023] According to some preferred embodiments of the present invention, the H2S content in the circulating hydrogen stream is controlled to be 500-5000 ppm, for example, 500 ppm, 600 ppm, 500 ppm, 800 ppm, 1000 ppm, 1300 ppm, 1500 ppm, 2000 ppm, 2300 ppm, 3000 ppm, 3500 ppm, 4000 ppm, 4500 ppm, 5000 ppm, or a range of any two of the above values, preferably 600-4000 ppm. Using the aforementioned embodiments, the final modified diesel fuel exhibits higher aromatic hydrocarbon retention, desulfurization rate, and denitrification rate.

[0024] According to some preferred embodiments of the present invention, the Ne content in the circulating hydrogen stream is controlled to be 1-200 ppm, for example, 1 ppm, 5 ppm, 10 ppm, 20 ppm, 40 ppm, 50 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, or any combination of two of the above values, preferably 10-100 ppm. Using the aforementioned embodiments, high aromatic hydrocarbon retention rates, desulfurization rates, and denitrification rates can be achieved.

[0025] According to the present invention, in some embodiments, the recycling ratio of the circulating hydrogen stream is 0.5-8:1, for example, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or any range of two of the above ratios, preferably 1-6:1. By employing the aforementioned embodiments, not only can the consumption of fresh hydrogen be reduced, but also high aromatic hydrocarbon retention rates, desulfurization rates, and denitrification rates can be achieved.

[0026] According to the present invention, the circulation ratio of the circulating hydrogen stream refers to the volumetric flow rate ratio of the circulating hydrogen stream to the replenished hydrogen (fresh hydrogen).

[0027] According to the present invention, the method for controlling the content of materials beneficial to the effects of the present invention in the circulating hydrogen stream can be any method known in the art. Specifically, the method for controlling the content of NH3, H2S and Ne gas can be a conventional method in the art. For example, the amount of NH3 and H2S can be controlled by controlling the amount of circulating hydrogen stream and / or the amount of water injected, or by loading materials capable of absorbing NH3 and / or H2S into the pipeline through which the circulating hydrogen stream flows (circulating hydrogen pipeline) (e.g., a drying bottle containing sodium hydroxide or a drying bottle containing phosphorus pentoxide into the circulating hydrogen pipeline); or by injecting Ne gas into the circulating hydrogen pipeline to control the content of Ne gas in the circulating hydrogen stream.

[0028] According to the present invention, to prevent equipment blockage, in some embodiments, the stream containing the hydrogenated product is obtained by injecting water into the hydrogenated product; that is, hydrogenation refining can be performed by contacting inferior aromatic-rich distillate oil with hydrogen to obtain the hydrogenated product, and injecting water into the hydrogenated product can obtain the stream containing the hydrogenated product. By adopting the aforementioned embodiments, not only can equipment blockage be prevented, but the content of NH3 and / or H2S in the final gaseous stream can also be controlled.

[0029] According to the present invention, in some preferred embodiments, the flow ratio of hydrogenation product to water injection is 1-80:1, for example 1:1, 2:1, 10:1, 13:1, 22:1, 30:1, 40:1, 60:1, 80:1, or any two of the above values, preferably 1-50:1, and more preferably 2-40:1. Using the aforementioned embodiments, high aromatic hydrocarbon retention, desulfurization, and denitrification rates can be achieved.

[0030] According to the present invention, as long as the purpose of the present invention can be achieved, there are no special restrictions on the conditions for hydrorefining, specifically involving the volume hourly space velocity of the inferior aromatic oil, the total hydrogen-to-oil volume ratio, the reaction temperature, and the reaction pressure; wherein, the total hydrogen-to-oil volume ratio H2 / Oil (V / V) refers to the volume ratio of hydrogen to the inferior aromatic oil feed; when a circulating hydrogen stream is circulated back for hydrorefining, it refers to the total volume of the supplementary hydrogen and the circulating hydrogen stream, and the volume ratio of the inferior aromatic oil feed.

[0031] According to the present invention, in some embodiments, the conditions for hydrorefining include: a volume hourly space velocity (VHSV) of 0.5-2 h⁻¹ for the low-quality aromatic-rich distillate oil. -1 .

[0032] According to the present invention, in some embodiments, the conditions for hydrorefining include a total hydrogen-to-oil volume ratio of 1000-4000:1.

[0033] According to the present invention, in some embodiments, the conditions for hydrorefining include: a reaction temperature of 200-400°C; wherein the reaction temperature refers to the inlet temperature of the hydrorefining reactor.

[0034] According to the present invention, in some embodiments, the conditions for hydrorefining include a reaction pressure of 4-7.5 MPa.

[0035] According to the present invention, the purpose of the first separation is to separate the gaseous stream and the hydrorefined stream. As long as the separation purpose and the purpose of the present invention can be achieved, the method of the first separation is not particularly limited. In some embodiments, the first separation is high-pressure separation.

[0036] According to some preferred embodiments of the present invention, the conditions for high-pressure separation include: temperature 0-100°C and / or pressure 4-7.5 MPa.

[0037] According to the present invention, high-pressure separation can be performed in a conventional high-pressure separator in the art, and the structure of the high-pressure separator is not particularly limited.

[0038] According to the present invention, the hydrorefining stream also contains other materials such as water. In order to obtain the final desired liquid product (i.e., the modified aromatic-rich distillate oil), in some embodiments, the method of the present invention further includes: S4 the hydrorefining stream undergoes a second separation to obtain a gaseous product and a liquid product.

[0039] According to the present invention, steps S3 and S4 only represent the corresponding operation methods and do not represent the order of operations.

[0040] According to the present invention, in some embodiments, the second separation method includes liquid-liquid separation and low-pressure separation.

[0041] According to the present invention, liquid-liquid separation is for separating water from the hydrorefining stream. In some preferred embodiments, the conditions for liquid-liquid separation include a temperature of 0-80°C and / or a pressure of 4-7.5 MPa. The equipment for liquid-liquid separation is not particularly limited and can be a conventional liquid-liquid separator in the art.

[0042] According to the present invention, water in the hydrogen refining stream can be separated by liquid-liquid separation to obtain a hydrogenated product. The hydrogenated product is then subjected to low-pressure separation. In some preferred embodiments, the conditions for low-pressure separation include a temperature of 0-80°C and / or a pressure of 0-1 MPa. The equipment for low-pressure separation is not particularly limited and can be a conventional low-pressure separator in the art.

[0043] According to the present invention, as long as the purpose of the present invention can be achieved, the hydrorefining catalyst can be any catalyst in the art that can be used in hydrorefining. In some embodiments, the hydrorefining catalyst includes a support and a metal oxide supported on the support; wherein, as long as the purpose of the present invention can be achieved, the support can be a conventional support in the art, such as alumina.

[0044] According to some preferred embodiments of the present invention, the metal oxide comprises oxides of group VIB and / or group VIII metals.

[0045] According to some preferred embodiments of the present invention, the metal oxide is an oxide of molybdenum and / or tungsten.

[0046] According to some preferred embodiments of the present invention, the metal oxide is an oxide of nickel and / or cobalt.

[0047] According to some preferred embodiments of the present invention, the content of metal oxide in the hydrorefining catalyst is 1-30% based on the total weight of the hydrorefining catalyst. For example, when the metal oxide is an oxide of nickel and / or cobalt, the content of metal oxide is 1-10%; when the metal oxide is an oxide of molybdenum and / or tungsten, the content of metal oxide is 10-30%.

[0048] According to the present invention, in order to maintain good activity and stability of the hydrorefining catalyst during use, in some embodiments, the hydrorefining catalyst is used after pre-sulfurization treatment.

[0049] According to the present invention, the pre-vulcanization treatment can be carried out using methods conventional in the art, such as dry vulcanization or wet vulcanization, preferably wet vulcanization. In some embodiments, the pre-vulcanization treatment method includes: wet vulcanization with sulfide-containing hydrocarbons or distillate oils in the presence of hydrogen in a liquid or semi-liquid phase; wherein the sulfide content in the sulfide-containing hydrocarbons or distillate oils can be 500-5000 ppm; there are no special restrictions on the selection of sulfides, such as carbon disulfide and / or dimethyl disulfide.

[0050] According to the present invention, in some embodiments, the conditions for wet vulcanization include: preheating to 130-200°C to begin vulcanization, followed by a programmed temperature increase.

[0051] According to some embodiments of the present invention, the hydrogen-to-oil volume ratio is 300-2000:1 during wet vulcanization.

[0052] According to the present invention, in some preferred embodiments, the conditions for wet vulcanization include: wet vulcanization in a cyclohexane solution containing 500-5000 ppm CS2, preferably preheating to 130-200°C to start vulcanization, followed by programmed temperature increase for vulcanization.

[0053] According to some preferred embodiments of the present invention, the temperature program includes: a heating rate of 5-30℃ / h, and a constant temperature of 280-380℃ for 4-30h.

[0054] According to the present invention, in some embodiments, the inferior aromatic-rich distillate oil has an initial boiling point of 150-250°C and a final boiling point of 300-380°C.

[0055] According to some embodiments of the present invention, the inferior aromatic-rich distillate feedstock contains: aromatic hydrocarbon content >70wt%, sulfur content of 1000-5000ug / mL, and nitrogen content of 300-600ug / mL.

[0056] According to some embodiments of the present invention, the inferior aromatic-rich distillate feedstock is selected from at least one of catalytic cracking diesel, coking diesel, hydrotreated diesel, straight-run diesel, coal tar, direct coal liquefaction oil, and indirect coal liquefaction oil.

[0057] According to the present invention, in some embodiments, combined with Figure 1 The method of the present invention is as follows:

[0058] S1 inferior aromatic distillate feedstock 1 is mixed with hydrogen (or supplementary hydrogen 2) and then enters the hydrorefining reactor 3, which is filled with hydrorefining catalyst, to be hydrorefined in contact with the hydrorefining catalyst to obtain the hydrorefined product.

[0059] S2 hydrogenation product flows out of the hydrogenation refining reactor 3, and water is injected into the outflowing hydrogenation product to obtain a stream containing hydrogenation product. The stream containing hydrogenation product is introduced into the high-pressure separator 4 for high-pressure separation to obtain a gaseous stream and a hydrogenated refining stream.

[0060] After S3 partially or completely injects water and Ne gas, it is returned to step S1 as a circulating hydrogen stream 5 times via the circulating hydrogen pipeline. After mixing with supplementary hydrogen 1, it continues to undergo hydrogenation refining.

[0061] The S4 hydrorefining stream is introduced into the liquid-liquid separator 6 for separation to obtain oily wastewater 7 and hydrorefining product 8. The hydrorefining product 8 is introduced into the low-pressure separator 9 for low-pressure separation to obtain gaseous product 10 and liquid product 11 (i.e., the modified aromatic-rich distillate oil).

[0062] The present invention will be described in detail below through embodiments.

[0063] In the following examples and comparative examples:

[0064] like Figure 1 As shown, the method for hydrorefining inferior aromatic-rich distillate oil includes:

[0065] S1 inferior aromatic distillate feedstock 1 is mixed with hydrogen (or supplementary hydrogen 2) and then enters the hydrorefining reactor 3, which is filled with hydrorefining catalyst, to be hydrorefined in contact with the hydrorefining catalyst to obtain the hydrorefined product.

[0066] S2 hydrogenation product flows out of the hydrogenation refining reactor 3, and water is injected into the outflowing hydrogenation product to obtain a stream containing hydrogenation product. The stream containing hydrogenation product is introduced into the high-pressure separator 4 for high-pressure separation to obtain a gaseous stream and a hydrogenated refining stream.

[0067] After S3 partially or completely injects water and Ne gas, it is returned to step S1 as a circulating hydrogen stream 5 times via the circulating hydrogen pipeline. After mixing with supplementary hydrogen 1, it continues to undergo hydrogenation refining.

[0068] The S4 hydrorefined stream is introduced into the liquid-liquid separator 6 for liquid-liquid separation to obtain oily wastewater 7 and hydrorefined product 8. The hydrorefined product 8 is introduced into the low-pressure separator 9 for low-pressure separation to obtain gaseous product 10 and liquid product 11 (i.e., modified diesel).

[0069] Inferior aromatic-rich distillate feedstock 1 (inferior hydrotreated diesel): distillation range 203-340℃, total aromatics 84wt%, S content 2800ppm, N content 400ppm.

[0070] The hydrorefining reactor is filled with 60 mL of hydrorefining catalyst, the specific properties of which are as follows: the hydrorefining catalyst support is alumina, and the active components, by total catalyst weight, are NiO 4.5 wt% and MoO 3 12.5 wt%.

[0071] Before performing hydrorefining in step S1, the hydrorefining catalyst is pre-sulfurized. The pretreatment conditions are as follows: wet sulfidation is carried out in a cyclohexane solution containing 3000 ppm CS2 in the presence of hydrogen, with a hydrogen-to-oil volume ratio of 1000:1. Sulfidation begins at 170°C, and then the temperature is increased to 350°C at a rate of 15°C / h and held at that temperature for 10h.

[0072] Aromatic hydrocarbon retention rate:

[0073]

[0074] Desulfurization rate:

[0075]

[0076] Denitrification rate:

[0077] In the formula,

[0078] R A Aromatics retention rate %

[0079] X S The percentage of sulfur conversion rate;

[0080] X N Nitrogen conversion rate (%);

[0081] C A in The mass percentage of total aromatics in low-quality aromatic-rich distillate feedstock

[0082] C A out The mass percentage of total aromatics in the liquid phase product

[0083] C S inThe mass percentage of sulfur in low-quality aromatic distillate feedstock;

[0084] C S out This represents the mass percentage of sulfur in the liquid phase product.

[0085] C N in The mass percentage of nitrogen in low-quality aromatic-rich distillate feedstock;

[0086] C N out This represents the mass percentage of nitrogen in the liquid phase product.

[0087] Example 1

[0088] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0089] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.05 ml / min.

[0090] The conditions for high-pressure separation are: 50℃, 5.8MPa.

[0091] The content of H2S in circulating hydrogen stream 5 is 1000 ppm, the content of NH3 is 50 ppm, and the content of Ne is 20 ppm.

[0092] The recycling ratio of circulating hydrogen stream 5 is 1:1;

[0093] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0094] The conditions for low-pressure separation are: 36℃, 0.1MPa.

[0095] After stabilization, the desulfurization rate of liquid product 11 was 97.96%, the denitrification rate was 96.25%, and the aromatic hydrocarbon retention rate was 93.1%.

[0096] Example 2

[0097] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 6.1 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0098] The flow rate of the hydrogenation product stream was 1.6 ml / min; the water injection rate was 0.07 ml / min.

[0099] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0100] The content of H2S in circulating hydrogen stream 5 is 2000 ppm, the content of NH3 is 70 ppm, and the content of Ne is 80 ppm.

[0101] The recycling ratio of circulating hydrogen stream 5 is 2:1;

[0102] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0103] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0104] After stabilization, the desulfurization rate of liquid product 11 was 98.04%, the denitrification rate was 96.75%, and the aromatic hydrocarbon retention rate was 94.17%.

[0105] Example 3

[0106] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 6.1 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0107] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0108] The conditions for high-pressure separation are: 50℃, 5.8MPa.

[0109] The content of H2S in circulating hydrogen stream 5 is 3000 ppm, the content of NH3 is 100 ppm, and the content of Ne is 50 ppm.

[0110] The recycling ratio of circulating hydrogen stream 5 is 3:1;

[0111] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0112] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0113] After stabilization, the desulfurization rate of liquid product 11 was 98.21%, the denitrification rate was 97.75%, and the aromatic hydrocarbon retention rate was 94.05%.

[0114] Example 4

[0115] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0116] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.15 ml / min.

[0117] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0118] The content of H2S in circulating hydrogen stream 5 is 4000 ppm, the content of NH3 is 200 ppm, and the content of Ne is 40 ppm.

[0119] The recycling ratio of circulating hydrogen stream 5 is 4:1;

[0120] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0121] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0122] After stabilization, the desulfurization rate of liquid product 11 was 98.07%, the denitrification rate was 97%, and the aromatic hydrocarbon retention rate was 94.29%.

[0123] Example 5

[0124] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0125] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.2 ml / min.

[0126] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0127] The content of H2S in circulating hydrogen stream 5 is 4000 ppm, the content of NH3 is 300 ppm, and the content of Ne is 40 ppm.

[0128] The recycling ratio of circulating hydrogen stream 5 is 5:1;

[0129] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0130] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0131] After stabilization, the desulfurization rate of liquid product 11 was 97.93%, the denitrification rate was 96%, and the aromatic hydrocarbon retention rate was 94.4%.

[0132] Example 6

[0133] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0134] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0135] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0136] The content of H2S in circulating hydrogen stream 5 is 2300 ppm, the content of NH3 is 350 ppm, and the content of Ne is 30 ppm.

[0137] The recycling ratio of circulating hydrogen stream 5 is 6:1;

[0138] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0139] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0140] After stabilization, the desulfurization rate of liquid product 11 was 97.68%, the denitrification rate was 95.5%, and the aromatic hydrocarbon retention rate was 94.64%.

[0141] Example 7

[0142] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0143] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0144] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0145] The H2S content in circulating hydrogen stream 5 is 3000ppm, the NH3 content is 100ppm, and no Ne gas is injected into the circulating hydrogen pipeline, so the Ne content is 0ppm.

[0146] The recycling ratio of circulating hydrogen stream 5 is 3:1;

[0147] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0148] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0149] After stabilization, the desulfurization rate of liquid product 11 was 97.2%, the denitrification rate was 93.3%, and the aromatic hydrocarbon retention rate was 92.4%.

[0150] Example 8

[0151] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0152] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0153] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0154] The content of H2S in circulating hydrogen stream 5 is 3500 ppm, the content of NH3 is 380 ppm, and the content of Ne is 50 ppm.

[0155] The recycling ratio of circulating hydrogen stream 5 is 8:1;

[0156] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0157] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0158] After stabilization, the desulfurization rate of liquid product 11 was 97.11%, the denitrification rate was 91.25%, and the aromatic hydrocarbon retention rate was 91.9%.

[0159] Example 9

[0160] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 5.8 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0161] The flow rate of the hydrogenation product stream was 1.6 ml / min; the water injection rate was 0.04 ml / min.

[0162] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0163] The content of H2S in circulating hydrogen stream 5 is 1300 ppm, the content of NH3 is 50 ppm, and the content of Ne is 50 ppm.

[0164] The recycling ratio of circulating hydrogen stream 5 is 0.5:1;

[0165] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0166] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0167] After stabilization, the desulfurization rate of liquid product 11 was 96.43%, the denitrification rate was 92.5%, and the aromatic hydrocarbon retention rate was 91.67%.

[0168] Comparative Example 1

[0169] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 6.1 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0170] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0171] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0172] The H2S content in circulating hydrogen stream 5 is 3000ppm. The circulating hydrogen pipeline is equipped with a drying bottle containing phosphorus pentoxide to make the NH3 content 0ppm and the Ne content 0ppm.

[0173] The recycling ratio of circulating hydrogen stream 5 is 3:1;

[0174] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0175] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0176] After stabilization, the desulfurization rate of liquid product 11 was 50%, the denitrification rate was 40%, and the aromatic hydrocarbon retention rate was 71.43%.

[0177] Comparative Example 2

[0178] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 6.1 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0179] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0180] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0181] In the circulating hydrogen stream 5, the circulating hydrogen pipeline is equipped with a drying bottle containing sodium hydroxide to ensure that the content of H2S is 0 ppm, the content of NH3 is 100 ppm, and the content of Ne is 0 ppm.

[0182] The recycling ratio of circulating hydrogen stream 5 is 3:1;

[0183] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0184] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0185] After stabilization, the desulfurization rate of liquid product 11 was 46.43%, the denitrification rate was 37.5%, and the aromatic hydrocarbon retention rate was 67.26%.

[0186] Comparative Example 3

[0187] Hydrorefining conditions: The inlet temperature of hydrorefining reactor 3 is 290℃, and the volume hourly space velocity (VHSV) of the low-quality aromatic-rich oil feedstock 1 is 1.0 h⁻¹. -1 The reaction pressure is 6.1 MPa, and the total hydrogen-to-oil volume ratio H2 / Oil (V / V) = 1500.

[0188] The flow rate of the hydrogenation product stream is 1.6 ml / min; the water injection rate is 0.12 ml / min.

[0189] The conditions for high-pressure separation are: 50℃, 5.8MPa;

[0190] In the circulating hydrogen pipeline 5, the circulating hydrogen pipeline is equipped with a drying bottle containing sodium hydroxide to make the H2S content 0 ppm, and the circulating hydrogen pipeline is equipped with a drying bottle containing phosphorus pentoxide to make the NH3 content 0 ppm and the Ne content 50 ppm.

[0191] The recycling ratio of circulating hydrogen stream 5 is 3:1;

[0192] The conditions for liquid-liquid separation are: 35℃, 5.8MPa;

[0193] The conditions for low-pressure separation are: 36℃, 0.08MPa.

[0194] After stabilization, the desulfurization rate of liquid product 11 was 10.71%, the denitrification rate was 6.25%, and the aromatic hydrocarbon retention rate was 64.64%.

[0195] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for hydrorefining inferior aromatic-rich distillate oil, characterized in that, The method includes: S1 In the presence of a hydrorefining catalyst, inferior aromatic-rich distillate oil is contacted with hydrogen to undergo hydrorefining to obtain hydrorefined products. S2 The hydrogenated product stream is separated into a gaseous stream and a hydrogenated purified stream by the first separation. S3 The gaseous stream is recycled back to step S1 as a circulating hydrogen stream for further hydrogenation purification. The NH3 content in the circulating hydrogen stream is controlled at 20-400 ppm, and the circulation ratio of the circulating hydrogen stream refers to the volumetric flow rate ratio of the circulating hydrogen stream to the supplementary hydrogen stream; the H2S content in the circulating hydrogen stream is controlled at 500-5000 ppm, the Ne content in the circulating hydrogen stream is controlled at 1-200 ppm, and the circulation ratio of the circulating hydrogen stream is 0.5-8:

1. Inferior aromatic-rich distillate feedstocks contain: aromatic hydrocarbon content >70wt%, sulfur content 1000-5000ug / mL, and nitrogen content 300-600ug / mL.

2. The method according to claim 1, wherein, The NH3 content in the circulating hydrogen stream is controlled to be 50-350 ppm; and / or The H2S content in the circulating hydrogen stream is controlled to be 600-4000 ppm; and / or The Ne content in the circulating hydrogen stream is controlled to be 10-100 ppm; and / or The recycling ratio of the circulating hydrogen stream is 1-6:

1.

3. The method according to claim 1 or 2, wherein, The hydrogenated product-containing stream is obtained by injecting water into the hydrogenated product.

4. The method according to claim 3, wherein, The flow rate ratio of hydrogenation product to water injection is 1-80:

1.

5. The method according to claim 4, wherein, The flow rate ratio of hydrogenation product to water injection volume is 2-40:

1.

6. The method according to claim 1 or 2, wherein, The conditions for the hydrorefining include: The volume hourly space velocity (VHSV) of the inferior aromatic-rich distillate oil is 0.5-2 h⁻¹. -1 ; and / or The total hydrogen-to-oil volume ratio is 1000-4000:1; and / or The reaction temperature is 200-400℃; and / or The reaction pressure is 4-7.5 MPa.

7. The method according to claim 1 or 2, wherein, The first separation is a high-pressure separation, and the conditions for the high-pressure separation include: temperature 0-100℃ and / or pressure 4-7.5MPa.

8. The method according to claim 1 or 2, wherein, The method also includes: S4 hydrorefining the stream for a second separation to obtain gaseous and liquid products.

9. The method according to claim 8, wherein, The second separation method includes liquid-liquid separation and low-pressure separation; The conditions for low-pressure separation include a temperature of 0-80℃ and / or a pressure of 0-1MPa.

10. The method according to claim 9, wherein, The conditions for liquid-liquid separation include: a temperature of 0-80℃ and / or a pressure of 4-7.5MPa.

11. The method according to claim 1 or 2, wherein, The hydrorefining catalyst comprises a support and a metal oxide supported on the support; and / or The content of metal oxides in the hydrorefining catalyst is 1-30% based on the total weight of the hydrorefining catalyst.

12. The method according to claim 11, wherein, The metal oxides include oxides of group VIB and / or group VIII metals.

13. The method according to claim 12, wherein, The metal oxides include oxides of molybdenum and / or tungsten, or oxides of nickel and / or cobalt.

14. The method according to claim 1 or 2, wherein, The hydrorefining catalyst is used after pre-sulfurization treatment.

15. The method according to claim 14, wherein, The pre-sulfurization treatment method includes: wet sulfidation with sulfide-containing hydrocarbons in the presence of hydrogen in a liquid or semi-liquid state.

16. The method according to claim 15, wherein, In sulfide-containing hydrocarbons, the sulfide content is 500-5000 ppm; and / or The sulfide includes carbon disulfide and / or dimethyl disulfide; and / or The conditions for wet vulcanization include: preheating to 130-200°C to begin vulcanization, followed by a programmed temperature increase; and / or The hydrogen-to-oil volume ratio is 300-2000:

1.

17. The method according to claim 16, wherein, The conditions for wet vulcanization include: wet vulcanization in a cyclohexane solution containing 500-5000 ppm CS2, preheating to 130-200°C to begin vulcanization, followed by programmed temperature increase for vulcanization.

18. The method according to claim 17, wherein, The programmed temperature rise includes: a heating rate of 5-30℃ / h, and a constant temperature of 280-380℃ for 4-30h.

19. The method according to claim 1 or 2, wherein, Inferior aromatic-rich distillate oils have an initial boiling point of 150-250℃ and a final boiling point of 300-380℃; and / or The sources of the inferior aromatic-rich distillate feedstock include at least one of catalytic cracking diesel, coking diesel, hydrotreated diesel, straight-run diesel, coal tar, direct coal liquefaction oil, and indirect coal liquefaction oil.

20. The method according to claim 15 or 16, wherein, Hydrocarbons are distillate oils.

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