Method for directly preparing chemicals from feedstock oil

Abstract

The present invention relates to the technical field of catalytic refining and chemical engineering, and discloses a method for directly producing chemicals from feedstock oil: (1) contacting the feedstock oil with a DPC-1 catalyst to carry out a first reaction, obtaining a first reaction product containing the spent DPC-1 catalyst; (2) contacting the first reaction product, recycle oil with a DPC-2 catalyst to carry out a second reaction, obtaining a second reaction product; (3) fractionating the second reaction product to obtain chemicals; (4) recycling at least one of gasoline, diesel and wax oil to step (2) as the recycle oil; wherein, the alkalinity of the DPC-1 catalyst is stronger than that of the DPC-2 catalyst, and the DPC-2 catalyst contains a zeolite ZEO-1 of the silicoaluminate type. The method provided by the present invention has strong adaptability to feedstock, can be used to process both high-quality crude oil and low-quality crude oil and various types of heavy oil, can improve the distribution of chemicals, increase the chemical yield and quality, and reduce the coke yield.

Description

Technical Field

[0001] The invention relates to the technical field of oil refining and chemical catalysis, and in particular to a method for directly preparing chemicals from crude oil. Background Art

[0002] The catalytic technology route of direct production of chemicals from crude oil refers to a method of directly converting crude oil into light olefins and aromatics under the action of a catalyst to maximize the production of olefin and aromatic chemicals. Direct production of chemicals from crude oil can maximize the conversion of crude oil resources into the production of basic organic chemical raw materials, and is an effective way to fully utilize crude oil, a primary fossil resource; it can "skip" the traditional refining processes of atmospheric and vacuum distillation and raw material refining, which can reduce equipment investment, resource waste, processing energy consumption, and greenhouse gas emissions.

[0003] Reliance Industries of India has developed a multi-zone catalytic cracking (MCC) process for direct cracking of crude oil, which does not require the use of atmospheric and vacuum units, and can also be used in combination with the cracking of condensate oil, shale oil and tight oil. Sinopec Petrochemical Research Institute has proposed two methods for direct production of chemicals from crude oil, one of which is used to process paraffin-based high-quality light crude oil: first, the paraffin-based high-quality light crude oil is cut into light and heavy fractions, and then the light fraction and the heavy fraction are catalytically cracked in a double riser reactor to maximize the production of low-carbon olefins; the other is used to process cyclopentane intermediate crude oil: first, the cyclopentane intermediate crude oil is hydrotreated and then catalytically cracked.

[0004] Other research institutions, such as China University of Petroleum (East China) and Institute of Process Engineering of Chinese Academy of Sciences, have also conducted research on direct production of chemicals from crude oil, but they all use high-quality light paraffin-based crude oil as raw materials and consider dividing the raw materials into light and heavy fractions to enter two risers for catalytic cracking. The above-mentioned technologies also emphasize the need for very high reaction temperatures (such as 670-730°C) and very high catalyst-oil ratios (such as more than 25). Tsinghua University emphasizes its descending bed reactor technology, which has the advantage of increasing propylene production compared to traditional catalytic cracking technology.

[0005] However, the current crude oil direct chemical production technology route generally has poor adaptability to raw materials and can only be used to process high-quality raw oils, such as paraffin-based light crude oil, and cannot be directly used to process non-paraffin-based low-quality raw oils. Even if high-quality raw oils are used to dilute or hydrogenate low-quality raw oils, it is difficult to obtain high-yield and high-quality chemicals.

[0006] Therefore, there is an urgent need to provide a method for directly preparing chemicals from crude oil, which has strong raw material adaptability, can improve chemical distribution, and increase chemical yield. Summary of the invention

[0007] The object of the present invention is to solve the problems existing in the prior art, such as poor adaptability of raw materials in the technology of directly producing chemicals from crude oil, poor distribution of chemicals, low yield, and high coke yield, and to provide a method for directly producing chemicals from feedstock oil.

[0008] To achieve the above object, the present invention provides a method for directly producing chemicals from feedstock oil, and the method comprises the following steps:

[0009] (1) Contacting the feedstock oil with the DPC-1 catalyst to carry out a first reaction to obtain a first reaction product containing the spent DPC-1 catalyst;

[0010] (2) Contacting the first reaction product containing the spent DPC-1 catalyst and recycle oil with the DPC-2 catalyst to carry out a second reaction to obtain a second reaction product;

[0011] (3) Fractionating the second reaction product to obtain chemicals;

[0012] (4) Recycling at least one of gasoline, diesel and wax oil in the chemicals to step (2) as the recycle oil;

[0013] Wherein, the basicity of the DPC-1 catalyst is stronger than that of the DPC-2 catalyst, and the DPC-2 catalyst contains a zeolite molecular sieve ZEO-1 of the aluminosilicate type.

[0014] Through the above technical solution, the beneficial technical effects obtained by the present invention are as follows:

[0015] 1) In the method for directly producing chemicals from feedstock oil provided by the present invention, the DPC-1 catalyst is first used to carry out a first reaction with the feedstock oil, and then the first reaction product containing the spent DPC-1 catalyst is contacted with the recycle oil and the DPC-2 catalyst containing the zeolite molecular sieve ZEO-1 of the aluminosilicate type to carry out a second reaction. Under the combined action of the DPC-1 catalyst and the DPC-2 catalyst, not only the adaptability of the method for directly producing chemicals from feedstock oil to raw materials is improved, so that it can be used to process high-quality crude oil, but also to process inferior crude oil and various types of heavy oil. At the same time, the yields of wax oil and coke can be further reduced, and the content of light olefins in the obtained chemicals can be further increased, especially the content of ethylene in dry gas; for example, when using the method in the present invention to process intermediate-cycloalkyl feedstock oil, the dry gas yield is between 2.2-3 wt%, and the content of ethylene in the dry gas ≥ 50%;

[0016] 2) In the method for directly producing chemicals from feedstock oil provided by the present invention, there is no need to separate the catalyst from the reaction product for the first reaction product, the process flow is simple, the investment is low, and it is suitable for industrial promotion. Detailed Embodiments

[0017] The endpoints and any values in the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0018] In the present invention, the basicity of the catalyst can be tested by temperature-programmed carbon dioxide adsorption method (CO 2 -TPD) on a Quantachrome ChemBet 3000 chemisorption instrument. Take 150 mg of the catalyst sample and pretreat it at 600 °C for 1 h in a He gas atmosphere, and then cool it to 100 °C for CO 2 adsorption. Use a CO 2 / He mixed gas with a volume ratio of 1:9 as the adsorption gas, adsorb at 100 °C for 30 min, and then purge with He gas for 30 min to remove physically adsorbed CO 2 . Finally, desorb at a rate of 16 °C min -1 in a He gas atmosphere, and the desorption temperature rises from 100 °C to 600 °C to obtain a CO 2 -TPD spectrum. Read the CO 2 desorption peak temperature from the CO 2 -TPD spectrum, and calculate the number of basic centers at the position of the CO 2 desorption peak. Among them, the higher the CO 2 desorption peak temperature, the more the number of basic centers at the position of the CO 2 desorption peak, and the stronger the basicity of the catalyst.

[0019] The present invention provides a method for directly producing chemicals from feedstock oil, and the method includes the following steps:

[0020] (1) Contact the feedstock oil with a DPC-1 catalyst to carry out a first reaction to obtain a first reaction product containing the spent DPC-1 catalyst;

[0021] (2) Contact the first reaction product containing the spent DPC-1 catalyst and recycle oil with a DPC-2 catalyst to carry out a second reaction to obtain a second reaction product;

[0022] (3) Fractionate the second reaction product to obtain chemicals;

[0023] (4) Recycle at least one of gasoline, diesel, and wax oil in the chemicals to step (2) as the recycle oil;

[0024] Among them, the alkalinity of the DPC-1 catalyst is stronger than that of the DPC-2 catalyst, and the DPC-2 catalyst contains a zeolite ZEO-1 of the aluminosilicate type.

[0025] In step (1):

[0026] Among them, in the present invention, the first reaction that occurs when the feedstock oil contacts the DPC-1 catalyst includes a cracking "shearing" reaction and a refining reaction, which are used to remove substances such as sulfur, nitrogen, metals, and coke residue in the feedstock oil, so as to improve the catalytic cracking effect of the subsequent feedstock oil, improve the distribution of chemicals, and increase the chemical yield and quality.

[0027] In a preferred embodiment, the feedstock oil is selected from crude oil and / or heavy oil; among them, the crude oil refers to the unrefined petroleum extracted, and the heavy oil refers to the residue remaining after the light components are extracted from the crude oil, and can be selected from various types of intermediate-base, intermediate-naphthenic-base, and naphthenic-base heavy distillate oils such as straight-run wax oil, coker wax oil, hydrotreated wax oil, atmospheric residue, and vacuum residue.

[0028] In the present invention, for the method for directly producing chemicals from the feedstock oil provided by the present invention, the feedstock adaptability is strong, and there is no special limitation on the crude oil. Specifically, when classified according to the basic properties of the crude oil, the crude oil can be divided into paraffinic crude oil, intermediate-base crude oil, intermediate-naphthenic crude oil, and naphthenic crude oil. The method for directly producing chemicals from the feedstock oil provided by the present invention can be used to process paraffinic crude oil, and can also be used to process intermediate-base crude oil, intermediate-naphthenic crude oil, and naphthenic crude oil. When classified according to the density of the crude oil, the crude oil can be divided into light crude oil, medium crude oil, heavy crude oil, and extra-heavy crude oil. The method for directly producing chemicals from the feedstock oil provided by the present invention can be used to process light crude oil and medium crude oil, and can also be used to process heavy crude oil and extra-heavy crude oil such as oil sand asphalt and Venezuelan extra-heavy oil. The feedstock oil in the present invention can be either a single crude oil, or a single heavy oil, or a mixture of multiple crude oils, multiple heavy oils, or a mixture of crude oil and heavy oil. That is, the feedstock oil is selected from one or more of oil sand asphalt, Venezuelan extra-heavy oil, straight-run wax oil, coker wax oil, hydrotreated wax oil, atmospheric residue, and vacuum residue.

[0029] In a preferred embodiment, the DPC-1 catalyst comprises 85-99 parts by weight of carrier I and 1-15 parts by weight of active metal oxide I; among them, the carrier I is selected from at least one of alumina, silica, titanium oxide, and zirconium oxide; the active metal oxide I is selected from alkali metal oxides and / or alkaline earth metal oxides.

[0030] In a preferred embodiment, the DPC-1 catalyst comprises 90-98 parts by weight, preferably 94-97 parts by weight of carrier I and 2-10 parts by weight, preferably 3-6 parts by weight of active metal oxide I.

[0031] In a preferred embodiment, the carrier I is selected from alumina and / or silica, preferably silica.

[0032] In a preferred embodiment, the active metal oxide I is selected from at least one of calcium oxide, magnesium oxide, barium oxide, and strontium oxide, preferably magnesium oxide and / or barium oxide.

[0033] In a preferred embodiment, the CO 2 desorption peak temperature of the DPC-1 catalyst is 185-195 °C, preferably 187-192 °C; the number of basic sites at the CO 2 desorption peak position is 16-22 mmol / g, preferably 18-21 mmol / g.

[0034] In a preferred embodiment, the bulk density of the DPC-1 catalyst is 0.5-0.65 g / mL, preferably 0.55-0.6 g / mL; the average particle size is 30-110 μm, preferably 40-80 μm.

[0035] In a preferred embodiment, the reaction conditions of the first reaction include: the mass ratio of the DPC-1 catalyst to the feedstock oil is 5-20:1, preferably 8-15:1.

[0036] In a preferred embodiment, the reaction conditions of the first reaction further include: the temperature of the first reaction is 380-550 °C, preferably 410-535 °C; the pressure of the first reaction is 0.1-1 MPa, preferably 0.1-0.4 MPa; the time of the first reaction is 0.1-4 s, preferably 0.5-3 s.

[0037] In step (2):

[0038] In a preferred embodiment, the recycle oil is selected from at least one of gasoline, diesel, and wax oil in the chemicals, preferably wax oil.

[0039] Among them, in the present invention, the second reaction is carried out under the combined action of the DPC-1 catalyst and the DPC-2 catalyst. Using wax oil as the recycle oil can further increase the yield of light olefins in the second reaction product and reduce the yields of wax oil and coke.

[0040] In a preferred embodiment, the DPC-2 catalyst comprises 75-95 parts by weight of support II, 3.5-8 parts by weight of active metal oxide II, and 5-20 parts by weight of a silicoaluminate molecular sieve ZEO-1; wherein the support II is selected from at least one of alumina, silica, titanium oxide, and zirconium oxide; and the active metal oxide II is selected from alkali metal oxides and / or alkaline earth metal oxides.

[0041] In a preferred embodiment, the DPC-2 catalyst preferably comprises 80-90 parts by weight of support II, 4-5 parts by weight of active metal oxide II, and 10-15 parts by weight of a silicoaluminate molecular sieve ZEO-1.

[0042] In a preferred embodiment, the support II is selected from alumina and / or silica, preferably silica.

[0043] In a preferred embodiment, the active metal oxide II is selected from at least one of calcium oxide, magnesium oxide, barium oxide, and strontium oxide, preferably calcium oxide and / or magnesium oxide.

[0044] In a preferred embodiment, the support I and the metal active component I in the DPC-1 catalyst are the same as the support II and the metal active component II in the DPC-2 catalyst.

[0045] In a preferred embodiment, the silicoaluminate molecular sieve ZEO-1 is a silicoaluminate molecular sieve having a multi-dimensional super-large pore structure, and its synthesis method includes using tricyclohexylmethylphosphonium (tCyMp) as an organic template agent, aluminum hydroxide as an aluminum source, and tetraethyl orthosilicate as a silicon source, and performing synthesis under hydrothermal conditions. Among them, the inventors of the present invention have found through research that introducing the silicoaluminate molecular sieve ZEO-1 into the DPC-2 catalyst can increase the content of light olefins in the obtained second reaction product.

[0046] In a preferred embodiment, the CO of the DPC-2 catalyst 2 desorption peak temperature is 165-184 °C, preferably 169-182 °C; the number of basic centers at the CO 2 desorption peak position is 2-13 mmol / g, preferably 3-11 mmol / g.

[0047] In a preferred embodiment, the bulk density of the DPC-2 catalyst is at least 0.2 g / mL greater than that of the DPC-1 catalyst, preferably 0.75 - 0.9 g / mL; the difference in the average particle size between the DPC-2 catalyst and the DPC-1 catalyst is at least ≥20 μm, preferably a difference of 20 - 40 μm.

[0048] In a preferred embodiment, the mass ratio of the DPC-2 catalyst to the feedstock oil is 5 - 20:1, preferably 7 - 13:1; the mass ratio of the recycle oil to the feedstock oil (i.e., the recycle ratio) is 0.1 - 0.5:1, preferably 0.2 - 0.4:1.

[0049] In a preferred embodiment, the DPC-2 catalyst contacts the recycle oil under the entrainment of the first reaction product.

[0050] In a preferred embodiment, the reaction conditions of the second reaction further include: the reaction temperature of the second reaction is 495 - 515 °C, preferably 500 - 510 °C; the pressure of the second reaction is 0.1 - 1 MPa, preferably 0.1 - 0.4 MPa; the time of the second reaction is at least 1.5 s longer than the time of the first reaction, preferably 2 - 3 s longer.

[0051] In a preferred embodiment, the first reaction and the second reaction are carried out in a riser reactor; wherein, the riser reactor includes a first reaction zone, a second reaction zone and a settler. Under the action of a pre-lift medium, the feedstock oil contacts the DPC-1 catalyst in the first reaction zone to carry out the first reaction, obtaining a first reaction product containing the spent DPC-1 catalyst; the first reaction product containing the spent DPC-1 catalyst, the recycle oil and the DPC-2 catalyst enter the second reaction zone, and contact in the second reaction zone to carry out the second reaction, obtaining a mixture containing the spent DPC-1 catalyst, the spent DPC-2 catalyst and the second reaction product; the mixture contacts with stripping steam in the settler for stripping, separating the second reaction product from the spent DPC-1 catalyst and the spent DPC-2 catalyst, and obtaining the second reaction product.

[0052] In a preferred embodiment, the pre-lift medium is selected from at least one of steam, dry gas, natural gas and liquefied gas, preferably steam.

[0053] In a preferred embodiment, the mass ratio of the feedstock oil to the pre-lift medium is 100:1 - 10, preferably 100:1 - 5.

[0054] In a preferred embodiment, the stripping steam is selected from at least one of steam, dry gas, natural gas, and liquefied gas, preferably steam.

[0055] In a preferred embodiment, the mass ratio of the feedstock oil to the stripping steam is 100:1 - 8, preferably 100:2 - 5.

[0056] In a preferred embodiment, the spent DPC-1 catalyst and the spent DPC-2 catalyst are analyzed, and the coke yield is 3 - 7%, preferably 4.5 - 6%.

[0057] In step (3):

[0058] In a preferred embodiment, the present invention does not specifically limit the fractionation operation of the second reaction product. The fractionation can be carried out according to the specific distribution of chemicals in the second reaction product according to the conventional fractionation operations in the art, and the present invention will not elaborate further.

[0059] In a preferred embodiment, the chemicals include dry gas, liquefied gas, gasoline, diesel, and wax oil. Among them, the boiling range of gasoline is 35 - 200 °C, the boiling range of diesel is 200 - 380 °C, and wax oil is the fraction oil with a boiling point above 380 °C.

[0060] In a preferred embodiment, the yield of the dry gas is 0.3 - 6%, preferably 0.6 - 4.5%; the yield of the liquefied gas is 15 - 50%, preferably 22 - 40%; the yield of the gasoline is 25 - 47%, preferably 28 - 40%; the yield of the diesel is 12 - 32%, preferably 15 - 26%; the yield of the wax oil is 5 - 20%, preferably 4 - 18%.

[0061] In a preferred embodiment, in the dry gas, the content of ethylene is ≥ 50 wt%, preferably 55 - 70 wt%, and more preferably 60 - 65 wt%. Among them, in the method for directly preparing chemicals from the feedstock oil provided in the present invention, the second reaction is catalyzed by the DPC-2 catalyst containing the aluminosilicate-type molecular sieve ZEO-1, which can increase the content of ethylene in the dry gas to more than 50 wt%, and can maximize the added value of the dry gas.

[0062] In a preferred embodiment, in the liquefied gas, the total content of C3 olefins and C4 olefins is 60 - 98 wt%, preferably 70 - 95 wt%; in the gasoline, the content of olefins with more than C 5 is 30 - 60 wt%, preferably 40 - 55 wt%.

[0063] In a preferred embodiment, the content of aromatics in the diesel is 70 - 95 wt%, preferably 75 - 90 wt%.

[0064] The method for directly preparing chemicals from feedstock oil provided by the present invention has strong feedstock adaptability. It can not only be used to process light crude oil, but also be used to process heavy crude oil and heavy oil. Moreover, it can further reduce the yield of wax oil and increase the content of dry gas and liquefied gas in the obtained chemicals, which is suitable for industrial promotion.

[0065] The following will describe the present invention in detail through examples. Among them, the DPC-1 catalyst used in the examples contains 95 wt% of silica and 5 wt% of magnesium oxide. The CO 2 desorption peak temperature of the DPC-1 catalyst is 189 °C, and the number of basic centers at the position of the CO 2 desorption peak is 20.27 mmol / g, the bulk density is 0.55 g / mL, and the average particle size is 60 μm;

[0066] The DPC-2 catalyst contains 80 wt% of silica, 2.5 wt% of calcium oxide, 2.5 wt% of magnesium oxide and 15 wt% of silicoaluminate molecular sieve ZEO-1; the CO 2 desorption peak temperature of the DPC-2 catalyst is 172 °C, and the number of basic centers at the position of the CO 2 desorption peak is 8.85 mmol / g, the bulk density is 0.85 g / mL, and the average particle size is 80 μm.

[0067] Among them, the preparation method of the silicoaluminate molecular sieve ZEO-1 in the DPC-2 catalyst includes:

[0068] (1) Synthesis of organic structure directing agent OSDA: Add 24.6 g of tricyclohexylphosphine to 250 mL of acetonitrile, dropwise add 48.20 g of methyl iodide (MeI) under ice bath conditions. After the addition is completed, stir at room temperature for 2 days, and remove the solvent with a rotary evaporator to obtain 36.30 g of tricyclohexylmethylphosphonium iodide (TCyMP);

[0069] Add 24.10 g of TCyMP iodide to a mixture of 200 mL of water and 200 mL of anion exchange resin (type: Dowex Monosphere 550A; exchange capacity: 1.2 mmol / mL wet resin), stir for 12 h and then filter to collect the OSDAOH solution; concentrate the OSDAOH solution to obtain the organic structure directing agent OSDA;

[0070] (2) Synthesis of silicoaluminate molecular sieve ZEO-1: Add 43.61 mg of Al(OH) 3 (Al(OH) 3(with a water content of 14.4 wt%) was added to 49.04 g of OSDA with a concentration of 0.1935 mmol / g, and the mixture was stirred until all the Al(OH) 3 was completely hydrolyzed, then 3.984 g of Si(OEt) 4 was added, and stirring was continued for 12 h. Then it was transferred to an oven at 85 °C for drying to remove excess water, obtaining a gel. After that, the gel was transferred to an autoclave and crystallized at 200 °C for 20 days. Then it was filtered, washed, and dried in sequence, and then calcined at 600 °C for 6 h to obtain ZEO-1 zeolite molecular sieve.

[0071] The intermediate-cycloalkyl marine heavy crude oil PL19-3 and the intermediate-base atmospheric residue in the examples are all from CNOOC Huizhou Petrochemical Co., Ltd.

[0072] Example 1

[0073] (1) Under the action of pre-lifting steam (steam), the DPC-1 catalyst is in countercurrent contact with the intermediate-cycloalkyl marine heavy crude oil PL19-3 in the first reaction zone of the riser reactor to carry out the first reaction. The temperature of the first reaction is 480 °C, the pressure of the first reaction is 0.23 MPa, and the time of the first reaction is 2 s, obtaining the first reaction product containing the spent DPC-1 catalyst; among them, the mass ratio of the DPC-1 catalyst to the intermediate-cycloalkyl marine heavy crude oil PL19-3 is 8:1, and the mass ratio of the intermediate-cycloalkyl marine heavy crude oil PL19-3 to the pre-lifting medium is 100:3.3;

[0074] (2) The above first reaction product carries the DPC-2 catalyst into the second reaction zone of the riser reactor and is in countercurrent contact with the recycle oil in the second reaction zone to carry out the second reaction. The temperature of the second reaction is 505 °C, the pressure of the second reaction is 0.22 MPa, and the time of the second reaction is 4 s, obtaining a mixture containing the spent DPC-1 catalyst, the spent DPC-2 catalyst, and the second reaction product; among them, the recycle oil is wax oil, the recycle ratio is 0.3, and the mass ratio of the DPC-2 catalyst to the intermediate-cycloalkyl marine heavy crude oil PL19-3 is 10:1;

[0075] The above mixture is in contact with stripping steam (steam) in the settler for stripping to separate the second reaction product from the spent DPC-1 catalyst and the spent DPC-2 catalyst, obtaining the second reaction product; among them, the mass ratio of the intermediate-cycloalkyl marine heavy crude oil PL19-3 to the stripping steam is 100:5;

[0076] The separated spent DPC-1 catalyst and spent DPC-2 catalyst were analyzed, and the coke yield was obtained as 5.2%;

[0077] (3) Fractionate the above second reaction product to obtain dry gas with an ethylene content of 61.1 wt%, liquefied gas with a total content of C3 olefins and C4 olefins of 95.2 wt%, gasoline with an olefin content of 52.2 wt%, diesel with an aromatic content of 80 wt%, and wax oil; among them, the yield of dry gas is 2.3%, the yield of liquefied gas is 28.3%, the yield of gasoline is 32.3%, the yield of diesel is 23.4%, and the yield of wax oil is 8.5%; 5 The above-mentioned olefin content is 52.2 wt% gasoline, diesel with an aromatic content of 80 wt%, and wax oil;

[0078] (4) Recycle the wax oil obtained by fractionation to step (2) as recycle oil.

[0079] Example 2

[0080] (1) Under the action of pre-lifting steam (steam), the DPC-1 catalyst contacts the intermediate-base atmospheric residue in a countercurrent manner in the first reaction zone of the riser reactor to carry out the first reaction. The temperature of the first reaction is 520 °C, the pressure of the first reaction is 0.27 MPa, and the time of the first reaction is 2.5 s to obtain the first reaction product containing the spent DPC-1 catalyst; among them, the mass ratio of the DPC-1 catalyst to the intermediate-base atmospheric residue is 15:1, and the mass ratio of the intermediate-base atmospheric residue to the pre-lifting medium is 100:4.5;

[0081] (2) The above first reaction product carries the DPC-2 catalyst into the second reaction zone of the riser reactor and contacts the recycle oil in a countercurrent manner in the second reaction zone to carry out the second reaction. The temperature of the second reaction is 515 °C, the pressure of the second reaction is 0.26 MPa, and the time of the second reaction is 5 s to obtain a mixture containing the spent DPC-1 catalyst, the spent DPC-2 catalyst and the second reaction product; among them, the recycle oil is wax oil, the recycle ratio is 0.35, and the mass ratio of the DPC-2 catalyst to the intermediate-base atmospheric residue is 10:2;

[0082] The above mixture contacts with stripping steam (steam) in the settler for stripping to separate the second reaction product from the spent DPC-1 catalyst and the spent DPC-2 catalyst to obtain the second reaction product; among them, the mass ratio of the intermediate-base atmospheric residue to the stripping steam is 100:5;

[0083] Analyze the separated spent DPC-1 catalyst and spent DPC-2 catalyst to obtain a coke yield of 5.5 wt%;

[0084] (3) Fractionate the above second reaction product to obtain dry gas with an ethylene content of 55.5 wt%, liquefied gas with a total content of C3 olefins and C4 olefins of 96.1 wt%, C 5Gasoline with an olefin content of 53.0 wt%, diesel with an aromatic content of 81.0 wt%, and wax oil; among them, the dry gas yield is 2.8%, the liquefied gas yield is 23.4%, the gasoline yield is 36.2%, the diesel yield is 27.2%, and the wax oil yield is 4.9%;

[0085] (4) Recycle the wax oil obtained by fractionation to step (2) as recycle oil.

[0086] Comparative Example 1

[0087] Same as Example 1, the difference is that: the DPC-2 catalyst contains 67 wt% silica, 0.5 wt% calcium oxide, 1.0 wt% magnesium oxide, 26.0 wt% ZSM-5 molecular sieve (silica / alumina molar ratio is 30:1), 2.0 wt% ZSM-48 molecular sieve (silica / alumina molar ratio is 100:1), and 3.5 wt% Y-type molecular sieve (silica / alumina molar ratio is 5:1); the CO 2 desorption peak temperature of the DPC-2 catalyst is 172 °C, and the number of basic centers at the CO 2 desorption peak position is 8.85 mmol / g, the bulk density is 0.75 g / mL, and the particle size is 50 μm.

[0088] Among them, the yield of dry gas with an ethylene content of 42.3 wt% is 2.1%, the yield of liquefied gas with a total content of C3 and C4 olefins of 91.5 wt% is 25.5%, and the C 5 yield of gasoline with an olefin content of 45.7 wt% or more is 32.9%, the yield of diesel with an aromatic content of 77.2 wt% is 25.4%, the yield of wax oil is 9.3%, and the coke yield is 4.8%.

[0089] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for directly producing chemicals from a feedstock oil, characterized in that, the method comprises the following steps: (1) contacting the feedstock oil with a DPC-1 catalyst to carry out a first reaction to obtain a first reaction product containing the spent DPC-1 catalyst; (2) contacting the first reaction product containing the spent DPC-1 catalyst and recycle oil with a DPC-2 catalyst to carry out a second reaction to obtain a second reaction product; (3) fractionating the second reaction product to obtain chemicals; (4) recycling at least one of gasoline, diesel and wax oil in the chemicals to step (2) as the recycle oil; wherein, the feedstock oil is selected from crude oil and / or heavy oil; wherein, the DPC-1 catalyst comprises 85-99 parts by weight of carrier I and 1-15 parts by weight of active metal oxide I; wherein, the carrier I is selected from at least one of alumina, silica, titanium oxide, zirconium oxide; the active metal oxide I is selected from alkali metal oxides and / or alkaline earth metal oxides; wherein, the DPC-2 catalyst comprises 75-95 parts by weight of carrier II, 3.5-8 parts by weight of active metal oxide II and 5-20 parts by weight of a silicoaluminate molecular sieve ZEO-1; wherein, the carrier II is selected from at least one of alumina, silica, titanium oxide, zirconium oxide; the active metal oxide II is selected from alkali metal oxides and / or alkaline earth metal oxides; wherein, the basicity of the DPC-1 catalyst is stronger than that of the DPC-2 catalyst, and the DPC-2 catalyst contains a silicoaluminate molecular sieve ZEO-1.

2. The method according to claim 1, wherein, the crude oil includes light crude oil, medium crude oil, heavy crude oil and extra-heavy crude oil; the heavy oil is selected from one or more of straight-run wax oil, coker wax oil, hydrocracked wax oil, atmospheric residue, vacuum residue.

3. The method according to claim 1, wherein, the feedstock oil is selected from one or more of oil sand asphalt, Venezuelan extra-heavy oil, straight-run wax oil, coker wax oil, hydrocracked wax oil, atmospheric residue, vacuum residue.

4. The method according to claim 1, wherein, the carrier I is selected from alumina and / or silica; and / or, the active metal oxide I is selected from at least one of calcium oxide, magnesium oxide, barium oxide, strontium oxide; and / or, the CO of the DPC-1 catalyst 2 desorption peak temperature is 185 - 195 °C, and the CO 2 number of basic sites at the desorption peak position is 16 - 22 mmol / g; and / or, the bulk density of the DPC-1 catalyst is 0.5-0.65 g / mL, and the average particle size is 30-110 μm.

5. The method according to claim 4, wherein, the carrier I is silica; and / or, the active metal oxide I is magnesium oxide and / or barium oxide; and / or, the CO of the DPC-1 catalyst 2 desorption peak temperature is 187 - 192 °C, and the CO 2 number of basic centers at the desorption peak position is 18 - 21 mmol / g; and / or, the bulk density of the DPC-1 catalyst is 0.55-0.6 g / mL; the average particle size is 40-80 μm.

6. The method according to claim 1, wherein, the reaction conditions of the first reaction include: the mass ratio of the DPC-1 catalyst to the feedstock oil is 5-20:11; And / or, the reaction conditions of the first reaction further include: the temperature of the first reaction is 380 - 550°C, the pressure of the first reaction is 0.1 - 1 MPa, and the time of the first reaction is 0.1 - 4 s.

7. According to the method described in claim 6, wherein, the reaction conditions of the first reaction include: the mass ratio of the DPC-1 catalyst to the feedstock oil is 8 - 15:1; and / or, the reaction conditions of the first reaction further include: the temperature of the first reaction is 410 - 535°C, the pressure of the first reaction is 0.1 - 0.4 MPa, and the time of the first reaction is 0.5 - 3 s.

8. According to the method described in claim 1, wherein, the carrier II is selected from alumina and / or silica; and / or, the active metal oxide II is selected from at least one of calcium oxide, magnesium oxide, barium oxide, and strontium oxide; and / or, the CO of the DPC-2 catalyst 2 desorption peak temperature is 165-184 °C, CO 2 the number of basic centers at the desorption peak position is 2-13 mmol / g; and / or, the bulk density of the DPC-2 catalyst is at least 0.2 g / mL greater than that of the DPC-1 catalyst, and the difference in particle size between the DPC-2 catalyst and the DPC-1 catalyst is at least ≥20 μm.

9. According to the method described in claim 8, wherein, the carrier II is silica; and / or, the active metal oxide II is calcium oxide and / or magnesium oxide; and / or, the CO of the DPC-2 catalyst 2 desorption peak temperature is 169-182 °C, CO 2 the number of basic sites at the desorption peak position is 3-11 mmol / g; and / or, the bulk density of the DPC-2 catalyst is at least 0.75 - 0.9 g / mL greater than that of the DPC-1 catalyst, and the difference in particle size between the DPC-2 catalyst and the DPC-1 catalyst is 20 - 40 μm.

10. According to the method described in claim 1, wherein, the mass ratio of the DPC-2 catalyst to the feedstock oil is 5 - 20:1, and the mass ratio of the recycle oil to the feedstock oil is 0.1 - 0.5:1; and / or, the reaction conditions of the second reaction further include: the DPC-2 catalyst is contacted with the recycle oil under the entrainment of the first reaction product; and / or, the reaction temperature of the second reaction is 495 - 515°C, the pressure of the second reaction is 0.1 - 1 MPa, and the time of the second reaction is at least 1.5 s longer than the time of the first reaction.

11. According to the method described in claim 10, wherein, the mass ratio of the DPC-2 catalyst to the feedstock oil is 7 - 13:1, and the mass ratio of the recycle oil to the feedstock oil is 0.2 - 0.4:1; and / or, the reaction temperature of the second reaction is 500 - 510°C, the pressure of the second reaction is 0.1 - 0.4 MPa, and the time of the second reaction is at least 2 - 3 s longer than the time of the first reaction.

12. According to the method described in claim 1, wherein, The first reaction and the second reaction are carried out in a riser reactor; wherein, the riser reactor includes a first reaction zone, a second reaction zone and a settler. Under the action of a pre-lift medium, the feedstock oil contacts with the DPC-1 catalyst in the first reaction zone to carry out the first reaction, obtaining a first reaction product containing the spent DPC-1 catalyst; the first reaction product containing the spent DPC-1 catalyst, recycle oil and DPC-2 catalyst enter the second reaction zone, and contact and react in the second reaction zone to carry out the second reaction, obtaining a mixture containing the spent DPC-1 catalyst, the spent DPC-2 catalyst and a second reaction product; the mixture contacts with stripping steam in the settler for stripping to separate the second reaction product from the spent DPC-1 catalyst and the spent DPC-2 catalyst, obtaining the second reaction product.

13. According to the method described in claim 12, wherein, the pre-lift medium is selected from at least one of steam, dry gas, natural gas and liquefied gas; and / or, the mass ratio of the feedstock oil to the pre-lift medium is 100:1 - 10.

14. According to the method described in claim 13, wherein, the pre-lift medium is steam; and / or, the mass ratio of the feedstock oil to the pre-lift medium is 100:1 - 5.

15. According to the method described in claim 12 or 13, wherein, the stripping steam is selected from at least one of steam, dry gas, natural gas and liquefied gas; and / or, the mass ratio of the feedstock oil to the stripping steam is 100:1 - 8.

16. According to the method described in claim 15, wherein, the stripping steam is steam; and / or, the mass ratio of the feedstock oil to the stripping steam is 100:2 - 5.

17. According to the method described in claim 1, wherein, the chemicals include dry gas, liquefied gas, gasoline, diesel oil and wax oil.