Method and system for producing ethylene and propylene

Abstract

The present disclosure provides a method and system for producing ethylene and propylene, the method comprising: contacting and reacting a heavy raw material with a catalytic cracking catalyst in a catalytic cracking reaction unit; contacting and reacting a light raw material with a dehydrogenation cracking catalyst in a dehydrogenation cracking reaction unit; wherein the dehydrogenation cracking catalyst to be regenerated obtained after the dehydrogenation catalytic cracking reaction is introduced into a catalytic cracking regeneration unit for heat exchange treatment, and after reaching the initial regeneration temperature, enters the dehydrogenation cracking regeneration unit for regeneration reaction to obtain a dehydrogenation cracking regeneration catalyst. The method organically combines the catalytic cracking of the heavy raw material with the dehydrogenation cracking of the light raw material, which can promote the effective conversion of the heavy raw material and the light raw material into ethylene and propylene. In addition, the heat generated during the regeneration of the catalytic cracking catalyst can be further utilized to provide heat for the regeneration process of the dehydrogenation cracking catalyst, thereby greatly reducing energy consumption, and has important industrial application value.

Description

Technical Field

[0001] The present disclosure relates to the technical field of petrochemical industry, and in particular to a method and system for producing ethylene and propylene. Background Art

[0002] With the continuous development of the chemical industry, the demand for ethylene and propylene has shown a rapid growth trend, and there is a large gap in the market for ethylene and propylene. At present, the main methods for producing ethylene and propylene include steam cracking technology, catalytic cracking technology, propane dehydrogenation technology and methanol to olefins technology. Among them, steam cracking technology is the main source of ethylene and propylene, and the ethylene produced by it accounts for more than 95% of the total ethylene production, and the propylene accounts for about 61% of the total propylene production, while the propylene produced by catalytic cracking technology accounts for about 34% of the total propylene production. Steam cracking technology, propane dehydrogenation technology and methanol to olefins technology all use light raw materials, while catalytic cracking technology can process heavy raw materials and can produce more ethylene and propylene. In addition, while producing ethylene and propylene, catalytic cracking technology will also produce more C4~C8 hydrocarbons, among which C4~C8 olefins can be partially converted into ethylene and propylene through recycling, but the conversion rate is low, and C4~C8 alkanes are difficult to convert. In recent years, great progress has been made in the dehydrogenation and cracking technology of light alkanes. By using catalysts with dual activities of catalytic dehydrogenation and catalytic cracking, the dehydrogenation reaction and cracking reaction of light alkanes can be coupled, so that the dehydrogenation reaction and cracking reaction can be carried out in the same reactor, shortening the process of the device and increasing the yield of ethylene and propylene.

[0003] CN1031834A discloses a catalytic conversion method for producing low-carbon olefins. The method uses petroleum fractions, residual oil or crude oil with different boiling ranges as raw materials, a mixture containing Y zeolite and five-membered ring high-silicon zeolite as catalyst, and a fluidized bed or moving bed as a reactor. The reaction conditions are: temperature 500-650°C, pressure 0.15-0.30MPa, weight hourly space velocity 0.2-20h -1 The catalyst-oil ratio is 2 to 12. The catalyst after the reaction is burned and regenerated and then returned to the reactor for recycling. Compared with conventional catalytic cracking and steam cracking, this method can produce more propylene and butene.

[0004] CN104560149A discloses a catalytic conversion method for producing butene. The method has four reactors in total. In addition to adopting a reactor configuration of a double riser plus a fluidized bed, a fluidized bed reactor is also arranged outside the settler for cracking the gasoline fraction, and the reaction product enters the riser reactor to continue the cracking reaction. The catalyst after the reaction is charred and regenerated and then returned to the reactor for recycling. The method uses a mixture containing Y zeolite and β zeolite as a catalyst, and can obtain a higher yield of propylene and butene.

[0005] CN102206509A discloses a hydrocarbon catalytic conversion method for producing propylene and light aromatics. The method adopts a combined reactor form of a double riser and a fluidized bed reactor, wherein heavy hydrocarbons and a cracking catalyst containing modified beta zeolite are contacted and reacted in a first reactor, and a C4 hydrocarbon fraction and / or a light gasoline fraction and a cracking catalyst containing modified beta zeolite are contacted and reacted in a second reactor and then introduced into a third reactor for further reaction, and the third reactor is a fluidized bed reactor, which creates conditions for the secondary cracking reaction of the gasoline fraction, thereby increasing the yield of propylene and light aromatics.

[0006] CN1506342A discloses a method for producing propylene by catalytic cracking of C4 or higher olefins. The method uses a ZSM molecular sieve loaded with at least one alkaline earth metal selected from Mg, Ca or Ba as a catalyst, and the reaction temperature of the C4 or higher olefins is 400°C to 600°C, the reaction pressure is 0MPa to 0.15MPa, and the liquid phase space velocity is 10h -1 ~50h -1 The cracking reaction occurs under the above conditions. The method can significantly improve the selectivity and yield of propylene.

[0007] CN105085143A discloses a method for producing ethylene and propylene by mixing C5 and C6 alkanes. The raw materials rich in C5 and C6 alkanes first enter a reactor equipped with a dehydrogenation catalyst at a temperature of 480°C to 700°C, a pressure of 0.01MPa to 3MPa, and a volume space velocity of 0.1h -1 ~10h -1 The alkane dehydrogenation reaction is carried out under the following conditions. The dehydrogenation product is mixed with C4 hydrocarbons and then enters a reactor equipped with a catalytic cracking catalyst at a temperature of 450°C to 650°C, a pressure of 0.1MPa to 0.3MPa, and a volume space velocity of 0.1h -1 ~10h -1 The catalytic cracking reaction is carried out under the following conditions. The method can improve the yield of ethylene and propylene and reduce energy consumption.

[0008] The above technologies use catalytic cracking technology to process heavy raw materials and use dehydrogenation cracking technology to process light raw materials, but the two are not effectively combined, and the ethylene and propylene yields of light hydrocarbon raw materials are low.

[0009] It should be noted that the information disclosed in the aforementioned background technology section is only used to enhance the background understanding of the present disclosure, and therefore it may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0010] A main purpose of the present disclosure is to overcome at least one defect of the above-mentioned prior art and provide a method and system for producing ethylene and propylene to solve the problems of low yield and high energy consumption when producing ethylene and propylene in the existing systems or methods.

[0011] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0012] The present disclosure provides a method for producing ethylene and propylene, comprising: contacting and reacting a heavy raw material with a catalytic cracking catalyst in a catalytic cracking reaction unit to obtain a catalytic cracking oil agent mixture, and separating to obtain a catalytic cracking oil and gas product and a catalytic cracking catalyst to be regenerated; contacting and reacting a light raw material with a dehydrogenation cracking catalyst in a dehydrogenation cracking reaction unit to obtain a dehydrogenation cracking oil agent mixture, and separating to obtain a dehydrogenation cracking oil and gas product and a dehydrogenation cracking catalyst to be regenerated; wherein the catalytic cracking oil and gas product and the dehydrogenation cracking oil and gas product are separated to obtain ethylene and propylene; introducing the catalytic cracking catalyst to be regenerated into a catalytic cracking regeneration unit for regeneration reaction to obtain a catalytic cracking regenerated catalyst; introducing the dehydrogenation cracking catalyst to be regenerated into the catalytic cracking regeneration unit for heat exchange treatment, and after reaching the initial regeneration temperature, entering the dehydrogenation cracking regeneration unit for regeneration reaction to obtain a dehydrogenation cracking regenerated catalyst.

[0013] According to one embodiment of the present disclosure, the catalytic cracking catalyst includes a catalytic cracking active component, clay and a binder, wherein the catalytic cracking active component includes a molecular sieve having an MFI structure and a Y molecular sieve, and the mass ratio of the Y molecular sieve to the molecular sieve having an MFI structure is 1:0 to 2, preferably 1:0.1 to 0.8.

[0014] According to one embodiment of the present disclosure, the dehydrogenation cracking catalyst includes a dehydrogenation cracking active component, clay and a binder, wherein the dehydrogenation cracking active component includes a molecular sieve having an MFI structure and a metal active component, and the metal active component is selected from one or more of the metal elements and their oxides of the following elements: iron, chromium, and vanadium; based on the total weight of the molecular sieve having the MFI structure, the iron content is 0% to 5%, preferably 0 to 1%, the chromium content is 0% to 8%, preferably 0 to 2%, and the vanadium content is 0% to 15%, preferably 0 to 8%.

[0015] According to one embodiment of the present disclosure, the catalytic cracking regenerated catalyst is introduced into the catalytic cracking reaction unit for cyclic use, and the dehydrogenation cracking regenerated catalyst is introduced into the dehydrogenation cracking reaction unit for cyclic use.

[0016] According to one embodiment of the present disclosure, in the catalytic cracking reaction unit, the heavy feedstock is introduced into the first riser reactor, and reacts in contact with the catalytic cracking regeneration catalyst from the catalytic cracking regeneration unit, and the resulting product is introduced into the first fluidized bed reactor for further reaction to obtain a catalytic cracking oil agent mixture.

[0017] According to one embodiment of the present disclosure, the reaction temperature of the first riser reactor is 540°C to 640°C, preferably 560°C to 620°C; the catalyst-oil ratio is 3 to 25, preferably 5 to 20; the reaction time is 1s to 20s, preferably 2s to 10s; the reaction temperature of the first fluidized bed reactor is 520°C to 620°C, preferably 540°C to 600°C; the weight hourly space velocity is 1 hour -1 ~25 hours -1 , preferably 2 hours -1 ~10 hours -1 ; Catalytic cracking catalyst density is 50kg / m 3 ~400kg / m 3 , preferably 100kg / m 3 ~250kg / m 3 ; The bed height is 1 / 2 to 4 / 5 of the bed reactor height, preferably 1 / 2 to 3 / 4; The pressure in the first fluidized bed reactor is 0.1 MPa to 0.4 MPa; preferably 0.15 MPa to 0.3 MPa.

[0018] According to one embodiment of the present disclosure, the method further includes introducing cracked heavy oil into the middle or upper part of the first riser reactor, wherein the mass ratio of the cracked heavy oil to the heavy feedstock is 0.01 to 0.1:1.

[0019] According to one embodiment of the present disclosure, in the dehydrogenation cracking reaction unit, the light feedstock is introduced into the second fluidized bed reactor, and the dehydrogenation cracking regenerated catalyst is introduced into the second fluidized bed reactor through the second riser to contact and react with the light feedstock to obtain a dehydrogenation cracking oil agent mixture.

[0020] According to one embodiment of the present disclosure, the reaction temperature of the second fluidized bed reactor is 560°C to 660°C, preferably 580°C to 640°C; the weight hourly space velocity is 1 hour -1 ~20 hours -1 , preferably 2 to 8 hours -1 ; Catalyst density is 50kg / m 3 ~450kg / m 3 , preferably 100kg / m 3 ~350kg / m 3 ; The bed height is 1 / 2 to 4 / 5 of the bed reactor height, preferably 1 / 2 to 3 / 4; The pressure in the second fluidized bed reactor is 0.1 MPa to 0.4 MPa, preferably 0.15 to 0.3 MPa.

[0021] According to one embodiment of the present disclosure, the heavy feedstock is selected from one or more of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sand oil, shale oil, distillate oil obtained by FT synthesis, animal oil and vegetable oil; the light feedstock is selected from C4~C8 hydrocarbons.

[0022] According to one embodiment of the present disclosure, based on the total weight of the light raw material, the content of C4-C8 alkanes is not less than 20%.

[0023] According to one embodiment of the present disclosure, the light feedstock is selected from catalytic cracking oil and gas products and dehydrogenation cracking oil and gas products, and the products are separated to obtain C4-C8 hydrocarbons.

[0024] The present invention also provides a production system of ethylene and propylene, comprising: a catalytic cracking reaction unit, a catalytic cracking regeneration unit, a dehydrogenation cracking reaction unit and a dehydrogenation cracking regeneration unit, wherein the catalytic cracking reaction unit is configured to perform a catalytic cracking reaction of a heavy raw material; the catalytic cracking regeneration unit is configured to regenerate a catalytic cracking catalyst to be regenerated after separation of the catalytic cracking reaction to obtain a catalytic cracking regenerated catalyst; the dehydrogenation cracking reaction unit is configured to perform a dehydrogenation cracking reaction of a light raw material; the dehydrogenation cracking regeneration unit is configured to regenerate a dehydrogenation cracking catalyst to be regenerated after separation of the dehydrogenation cracking reaction to obtain a dehydrogenation cracking regenerated catalyst; wherein the catalytic cracking regeneration unit also includes a heat exchange device, which is configured to utilize the heat generated when the catalytic cracking catalyst to be regenerated to heat the dehydrogenation cracking catalyst to be regenerated generated by the dehydrogenation cracking reaction unit, so that the dehydrogenation cracking catalyst to be regenerated reaches the initial regeneration temperature before entering the dehydrogenation cracking regeneration unit.

[0025] According to one embodiment of the present disclosure, the catalytic cracking reaction unit includes a first riser reactor, a first stripper, a first fluidized bed reactor and a first settler, a heavy raw material inlet is provided at the bottom of the first riser reactor, the outlet of the first riser reactor is connected to the inlet of the first fluidized bed reactor, the first stripper is located below the first fluidized bed reactor and wraps a portion of the first riser reactor, and the first settler is located above the first fluidized bed reactor and is connected to the first fluidized bed reactor.

[0026] According to one embodiment of the present disclosure, a cracked heavy oil inlet is further provided in the middle or upper portion of the first riser reactor.

[0027] According to one embodiment of the present disclosure, the catalytic cracking regeneration unit includes a catalytic cracking regenerator and a heat exchange device, the heat exchange device is placed in the catalytic cracking regenerator, the catalytic cracking regenerator is connected to the first stripper, and the catalytic cracking regenerator is connected to the first riser reactor through a catalytic cracking regeneration catalyst delivery pipeline.

[0028] According to one embodiment of the present disclosure, the heat exchange device is a heat exchange tube, and the ratio of the cross-sectional area of ​​the heat exchange tube to the cross-sectional area of ​​the catalytic cracking regenerator is 1:2-10, preferably 1:3-6; the ratio of the length of the heat exchange tube to the length of the catalytic cracking regenerator is 1:1.5-5, preferably 1:2-3.

[0029] According to one embodiment of the present disclosure, the dehydrogenation cracking reaction unit includes a second riser, a second stripper, a second fluidized bed reactor and a second settler. A light raw material inlet is provided at the bottom of the second fluidized bed reactor. The second riser is connected in series below the second fluidized bed reactor. The second stripper is located below the second fluidized bed reactor and wraps a portion of the second riser. The second settler is located above the second fluidized bed reactor and is connected to the second fluidized bed reactor.

[0030] According to one embodiment of the present disclosure, the dehydrogenation cracking regeneration unit includes a dehydrogenation cracking regenerator, wherein the inlet of the heat exchange device is connected to the second stripper, the outlet of the heat exchange device is connected to the dehydrogenation cracking regenerator, and the dehydrogenation cracking regenerator is connected to the second riser through a dehydrogenation cracking regeneration catalyst transport pipeline.

[0031] The beneficial effects of the present disclosure are:

[0032] The present disclosure proposes a production method and system for producing ethylene and propylene, which can realize the organic combination of catalytic cracking of heavy raw materials and dehydrogenation cracking of light raw materials, and can promote the conversion of heavy raw materials and light raw materials into ethylene and propylene, effectively improving the conversion rate; the method can further utilize the heat generated during the regeneration of the catalytic cracking catalyst to provide heat for the regeneration process of the dehydrogenation cracking catalyst, thereby greatly reducing energy consumption. In short, the production method and system can achieve a higher hydrocarbon conversion capacity, achieve a higher ethylene and propylene yield while reducing production costs, and have important industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following drawings are used to provide further understanding of the present disclosure and constitute a part of the specification. They are used to explain the present disclosure together with the following specific embodiments, but do not constitute a limitation of the present disclosure.

[0034] Figure 1 It is a schematic diagram of the connection relationship of the production system of ethylene and propylene according to one embodiment of the present disclosure;

[0035] Figure 2 This is a schematic diagram of the structure of an ethylene and propylene production system according to an embodiment of the present disclosure;

[0036] Figure 3 This is a schematic diagram of the structure of a heat exchange device in an ethylene and propylene production system according to an embodiment of the present disclosure;

[0037] Figure 4 It is a schematic diagram of the AA cross-sectional structure of a heat exchange device in an ethylene and propylene production system according to an embodiment of the present disclosure.

[0038] The reference numerals are described as follows:

[0039] 1: Catalytic cracking reaction unit

[0040] 1-1: First riser reactor

[0041] 1-2: First stripper

[0042] 1-3: First fluidized bed reactor

[0043] 1-4: First settler

[0044] 11: Heavy raw materials

[0045] 12: Pre-lift gas pipeline

[0046] 13: Cracking heavy oil

[0047] 14: Stripping gas

[0048] 15: Catalytic cracking catalyst pipeline

[0049] 16: Catalytic cracking oil and gas product pipeline

[0050] 2: Catalytic cracking regeneration unit

[0051] 2-1: Catalytic cracking regenerator

[0052] 2-2: Heat exchange device

[0053] 21: Main air inlet pipeline

[0054] 22: Catalytic cracking regeneration catalyst delivery pipeline

[0055] 23: Regeneration flue gas outlet pipeline

[0056] 24: Catalyst delivery pipeline

[0057] 3: Dehydrogenation cracking reaction unit

[0058] 3-1: Second riser

[0059] 3-2: Second stripper

[0060] 3-3: Second fluidized bed reactor

[0061] 3-4: Second settler

[0062] 31: Lightweight raw materials

[0063] 32: Pre-lift gas pipeline

[0064] 33: Stripping gas

[0065] 34: Catalyst delivery pipeline

[0066] 35: Dehydrogenation cracking oil and gas product pipeline

[0067] 4: Dehydrogenation cracking regeneration unit

[0068] 4-1: Dehydrogenation Cracking Regenerator

[0069] 41: Main air inlet pipeline

[0070] 42: Dehydrogenation cracking regeneration catalyst pipeline

[0071] 43: Regeneration flue gas outlet pipeline DETAILED DESCRIPTION

[0072] Typical embodiments that embody the features and advantages of the present disclosure will be described in detail in the following description. It should be understood that the present disclosure can have various changes in different embodiments without departing from the scope of the present disclosure, and the descriptions and drawings therein are essentially for illustrative purposes rather than for limiting the present disclosure.

[0073] In the following description of different exemplary embodiments of the present disclosure, reference is made to the accompanying drawings, which form a part of the present disclosure and in which different exemplary structures, systems and steps that can implement multiple aspects of the present disclosure are shown by way of example. It should be understood that other specific schemes of components, structures, exemplary devices, systems and steps can be used, and structural and functional modifications can be made without departing from the scope of the present disclosure. Moreover, although the terms "above", "between", "within", etc. may be used in this specification to describe different exemplary features and elements of the present disclosure, these terms are used herein only for convenience, such as according to the direction of the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of the present disclosure.

[0074] See also Figure 1 , which representatively shows a schematic diagram of the connection relationship of the ethylene and propylene production system of an exemplary embodiment proposed in the present disclosure. The ethylene and propylene production system proposed in the present disclosure is described by taking the application to the production of ethylene and propylene as an example. It is easy for those skilled in the art to understand that in order to apply the relevant design of the present disclosure to the production of other oil and gas products, various modifications, additions, substitutions, deletions or other changes are made to the specific embodiments described below, and these changes are still within the scope of the principles of the ethylene and propylene production system proposed in the present disclosure.

[0075] like Figure 1As shown, in this embodiment, the ethylene and propylene production system proposed in the present disclosure mainly includes a catalytic cracking reaction unit 1, a catalytic cracking regeneration unit 2, a dehydrogenation cracking reaction unit 3 and a dehydrogenation cracking regeneration unit 4. It should be noted that, Figure 1 This is only a partial schematic diagram of the ethylene and propylene production system. Figure 2 As shown, Figure 2 The present invention is a schematic diagram of the structure of an ethylene and propylene production system according to an embodiment of the present invention. Figure 3 This is a schematic structural diagram of a heat exchange device in an ethylene and propylene production system according to an embodiment of the present disclosure; Figure 4 The AA cross-sectional structure diagram of the heat exchange device in the ethylene and propylene production system according to one embodiment of the present disclosure is shown in FIG. The structure, connection mode and functional relationship of each main component of an exemplary embodiment of the ethylene and propylene production system according to the present disclosure will be described in detail below in conjunction with the above-mentioned drawings.

[0076] like Figure 1 As shown, the present disclosure provides a production system of ethylene and propylene, comprising: a catalytic cracking reaction unit 1, a catalytic cracking regeneration unit 2, a dehydrogenation cracking reaction unit 3 and a dehydrogenation cracking regeneration unit 4.

[0077] The catalytic cracking reaction unit 1 is configured to perform a catalytic cracking reaction of a heavy feedstock to obtain a catalytic cracking oil and gas product. Figure 1 and Figure 2 As shown, the catalytic cracking reaction unit 1 includes a first riser reactor 1-1, a first stripper 1-2, a first fluidized bed reactor 1-3 and a first settler 1-4.

[0078] Specifically, the first riser reactor 1-1 of the catalytic cracking reaction unit 1 is selected from one or more combinations of a constant diameter riser reactor, a constant linear velocity riser reactor and a variable diameter riser reactor, and is mainly used for the cracking reaction of heavy raw materials. The heavy raw material 11 is fed from the heavy raw material inlet provided at the bottom of the first riser reactor 1-1 of the catalytic cracking reaction unit. In some embodiments, the pyrolysis heavy oil 13 is introduced as a raw material, wherein, Figure 2 As shown, the cracked heavy oil 13 is fed from the middle and upper part of the first riser reactor 1-1. By introducing the cracked heavy oil 13, it is preferentially contacted with the catalytic cracking regeneration catalyst, which can cover part of the strong acid centers on the catalytic cracking regeneration catalyst and improve the cracking performance of the catalyst.

[0079] The first fluidized bed reactor 1-3 of the catalytic cracking reaction unit 1 is located at the upper part of the first riser reactor 1-1, and the two are connected in series, wherein the first fluidized bed reactor 1-3 is selected from one or more combinations of a fixed fluidized bed reactor, a dispersed fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor and a dense phase fluidized bed reactor. The first fluidized bed reactor 1-3 can prolong the reaction time of the heavy raw material therein, thereby making the conversion more thorough.

[0080] The catalytic cracking reaction unit 1 is also provided with a pre-lift gas pipeline 12, through which lift gas is introduced into the riser reactor 1-1 of the catalytic cracking reaction unit. The lift gas used is well known to those skilled in the art, and can be selected from one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0081] The first stripper 1-2 is located below the first fluidized bed reactor 1-3 of the catalytic cracking reaction unit 1 and is connected to the first fluidized bed reactor 1-3, and wraps a portion of the first riser reactor 1-1.

[0082] The first stripper 1-2 is provided with a stripping baffle and a stripping gas distribution ring for reducing the falling speed of the catalytic cracking catalyst to be regenerated and making the stripping gas 14 more evenly distributed, so that the residual reaction oil and gas on the catalytic cracking catalyst to be regenerated can be fully removed from the catalytic cracking catalyst to be regenerated.

[0083] The oil mixture obtained after the reaction in the first fluidized bed reactor 1-3 is separated by a cyclone separator to obtain oil and gas products and catalytic cracking catalyst to be regenerated, wherein the oil and gas products are led out of the reactor through the catalytic cracking oil and gas product pipeline 16 to enter the subsequent product separation system, and the catalytic cracking catalyst to be regenerated is introduced into the first stripper 1-2 for stripping.

[0084] The first settler 1-4 is connected to the first fluidized bed reactor 1-3 and the first riser reactor 1-1. The stripping gas in the first stripper 1-2 can directly enter the first settler 1-4, and enter the gas collecting chamber after being separated by the cyclone separator together with other oil and gas, and then lead out of the catalytic cracking reaction unit 1 through the catalytic cracking oil and gas product pipeline 16.

[0085] Combination Figure 1 and Figure 2 As shown, the catalytic cracking regeneration unit 2 is connected to the catalytic cracking reaction unit 1. The catalytic cracking regeneration unit 2 is configured to perform a regeneration reaction on the catalytic cracking catalyst to be generated by the catalytic cracking reaction unit 1 to obtain a catalytic cracking regenerated catalyst. The catalytic cracking regenerated catalyst enters the catalytic cracking reaction unit through the catalytic cracking regenerated catalyst delivery pipeline 22 for recycling.

[0086] Specifically, the catalytic cracking regeneration unit 2 includes a catalytic cracking regenerator 2-1 and a heat exchange device 2-2, wherein the catalytic cracking regenerator 2-1 is connected to the first stripper 1-2, and is connected to the first riser reactor 1-1 through a catalytic cracking regenerated catalyst pipeline 22. The catalytic cracking catalyst to be regenerated from the first stripper 1-2 enters the catalytic cracking regenerator 2-1 through the catalytic cracking catalyst to be regenerated delivery pipeline 15 for charring and regeneration, thereby converting the catalytic cracking catalyst to be regenerated into a catalytic cracking regenerated catalyst. The catalytic cracking regenerated catalyst in the catalytic cracking regenerator 2-1 is returned to the first riser reactor 1-1 for recycling through the catalytic cracking regenerated catalyst pipeline 22, wherein valves can be provided on the catalytic cracking catalyst to be regenerated delivery pipeline 15 and the catalytic cracking regenerated catalyst delivery pipeline 22, and the delivery speed of the catalyst can be adjusted by controlling the valves thereon.

[0087] A main air inlet pipeline 21 is provided at the bottom of the catalytic cracking regenerator 2-1, which can introduce regeneration gas into the catalytic cracking regenerator 2-1. The regeneration gas is a gas well known to those skilled in the art, including but not limited to a mixture of one or more of air, oxygen and other oxidizing gases. The flue gas generated after regeneration passes through a cyclone separator and enters a gas collecting chamber, and is discharged through a regeneration flue gas outlet pipeline 23 after treatment.

[0088] The catalytic cracking regenerator 2-1 is also provided with a heat exchange device 2-2, such as Figure 3 and Figure 4 As shown, in this embodiment, the heat exchange device 2-2 is a heat exchange tube, and the ratio of the cross-sectional area of ​​the heat exchange tube to the cross-sectional area of ​​the catalytic cracking regenerator 2-1 is 1:2 to 10, preferably 1:3 to 6, for example, 1:3, 1:4, 1:5, 1:5.5, 1:6, etc.; the ratio of the length of the heat exchange tube to the length of the catalytic cracking regenerator is 1:1.5 to 5, preferably 1:2 to 3. The heat exchange device 2-2 is configured to heat the dehydrogenation cracking catalyst produced by the dehydrogenation cracking reaction unit 3 using the heat generated when the catalytic cracking catalyst is regenerated, so that the dehydrogenation cracking catalyst reaches the initial regeneration temperature before entering the dehydrogenation cracking regeneration unit 4.

[0089] According to the present disclosure, since the coke produced by the dehydrogenation cracking reaction is relatively low, sufficient heat cannot be generated during regeneration to maintain the regeneration efficiency. Therefore, supplementary heat is required. The present disclosure provides a heat exchange device 2-2 in the catalytic cracking regenerator 2-1, and can use the excess heat of the catalytic cracking regenerator 2-1 for preheating, thereby improving the regeneration efficiency of the dehydrogenation cracking catalyst to be regenerated and reducing energy consumption.

[0090] The structures of the dehydrogenation cracking reaction unit 3 and the dehydrogenation cracking regeneration unit 4 and their connection relationship and function with the heat exchange device 2 - 2 are described in detail below.

[0091] The dehydrogenation cracking reaction unit 3 is configured to perform a dehydrogenation cracking reaction on the light feedstock 31 to obtain a dehydrogenation cracking oil and gas product. Figure 1 and Figure 2 As shown, the dehydrogenation cracking reaction unit 3 includes a second riser 3-1, a second stripper 3-2, a second fluidized bed reactor 3-3 and a second settler 3-4.

[0092] Specifically, the second riser 3-1 is selected from one or a combination of a constant diameter riser, a constant linear speed riser and a variable diameter riser, and is mainly used for transporting a dehydrogenation cracking catalyst.

[0093] The second fluidized bed reactor 3-3 is located at the upper part of the second riser 3-1, and the two are connected in series. The second fluidized bed reactor 3-3 is selected from one or a combination of fixed fluidized bed reactor, dispersed fluidized bed reactor, bubbling bed reactor, turbulent bed reactor, fast bed reactor, transport bed reactor and dense phase fluidized bed reactor, and is mainly used for cracking reaction of light raw materials. The light raw material 31 is fed from the bottom of the second fluidized bed reactor 3-3.

[0094] The lifting gas is introduced into the second lifting pipe 3-1 through the pre-lift gas pipeline 32. The lifting gas used is well known to those skilled in the art and can be selected from one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0095] The second stripper 3-2 is located below the second fluidized bed reactor 3-3 and is connected to the second fluidized bed reactor 3-3, and wraps a portion of the second riser 3-1.

[0096] The second stripper 3-2 is provided with a stripping baffle and a stripping gas distribution ring for reducing the falling speed of the dehydrogenation cracking catalyst and making the stripping gas 33 more evenly distributed, so that the residual reaction oil and gas on the dehydrogenation cracking catalyst can be fully removed from the dehydrogenation cracking catalyst.

[0097] The oil mixture after the reaction in the second fluidized bed reactor 3-3 is separated by a cyclone separator to obtain oil and gas products and dehydrogenation cracking catalyst to be regenerated. The oil and gas products are led out through the dehydrogenation cracking oil and gas product pipeline 35 for subsequent product separation, and the dehydrogenation cracking catalyst to be regenerated is introduced into the second stripper 3-2 for stripping.

[0098] The second settler 3-4 is connected to the second fluidized bed reactor 3-3 and the second riser 3-1. The stripping gas in the second stripper 3-2 can directly enter the second settler 3-4, and enter the gas collecting chamber after being separated by the cyclone separator together with other oil and gas, and then lead out of the dehydrogenation cracking reaction unit 3 through the dehydrogenation cracking oil and gas product pipeline 35.

[0099] Combination Figure 1 and Figure 2 As shown, the dehydrogenation cracking regeneration unit 4 is connected to the dehydrogenation cracking reaction unit 3. The dehydrogenation cracking regeneration unit 4 is configured to perform a regeneration reaction on the dehydrogenation cracking catalyst to be produced by the dehydrogenation cracking reaction unit 3 to obtain a dehydrogenation cracking regenerated catalyst. The dehydrogenation cracking regenerated catalyst enters the dehydrogenation cracking reaction unit through the dehydrogenation cracking regenerated catalyst delivery pipeline 42 for recycling.

[0100] Specifically, the dehydrogenation cracking regeneration unit 4 includes a dehydrogenation cracking regenerator 4-1, which is connected to the heat exchange device 2-2 and is connected to the second riser 3-1 through a dehydrogenation cracking regeneration catalyst delivery pipeline 42. The inlet of the heat exchange device 2-2 is connected to the second stripper 3-2 through a delivery pipeline 34, and the outlet of the heat exchange device 2-2 is connected to the dehydrogenation cracking regenerator 4-1 through a catalyst delivery pipeline 24.

[0101] The dehydrogenation cracking catalyst to be regenerated from the second stripper 3-2 enters the heat exchange device 2-2 in the catalytic cracking regenerator 2-1 through the dehydrogenation cracking catalyst to be regenerated delivery pipeline 34, and after the dehydrogenation cracking catalyst to be regenerated is heated to the initial regeneration temperature by the heat in the catalytic cracking regenerator 2-1, it enters the dehydrogenation cracking regenerator 4-1 for charring regeneration, thereby converting the dehydrogenation cracking catalyst to be regenerated into a dehydrogenation cracking regenerated catalyst. The dehydrogenation cracking regenerated catalyst in the dehydrogenation cracking regenerator 4-1 is returned to the second riser 3-1 for recycling through the dehydrogenation cracking regenerated catalyst delivery pipeline 42, wherein valves are provided on the catalyst delivery pipelines 34, 24 and 42, and the delivery speed of the catalyst can be adjusted by the valves thereon.

[0102] A main air inlet pipeline 41 is provided at the bottom of the dehydrogenation cracking regenerator 4-1, which can introduce regeneration gas into the dehydrogenation cracking regenerator 4-1. The regeneration gas is a gas well known to those skilled in the art, including but not limited to a mixture of one or more of air, oxygen and other oxidizing gases. The flue gas generated after regeneration passes through a cyclone separator and enters a gas collecting chamber, and is discharged through a regeneration flue gas outlet pipeline 43 after treatment.

[0103] The present disclosure also provides a method for producing ethylene and propylene using the above system, comprising:

[0104] A heavy feedstock 11 and a catalytic cracking catalyst are brought into a catalytic cracking reaction unit 1 for contact reaction to obtain a catalytic cracking oil agent mixture, which is separated to obtain a catalytic cracking oil and gas product and a catalytic cracking catalyst to be regenerated; a light feedstock 31 and a dehydrogenation cracking catalyst are brought into a dehydrogenation cracking reaction unit 3 for contact reaction to obtain a dehydrogenation cracking oil agent mixture, which is separated to obtain a dehydrogenation cracking oil and gas product and a dehydrogenation cracking catalyst to be regenerated; the catalytic cracking oil and gas product and the dehydrogenation cracking oil and gas product are separated to obtain ethylene and propylene; the catalytic cracking catalyst to be regenerated is introduced into a catalytic cracking regeneration unit 2 for regeneration reaction to obtain a catalytic cracking regenerated catalyst, which is introduced into a catalytic cracking reaction unit 1 for recycling; and the dehydrogenation cracking catalyst to be regenerated is introduced into a heat exchange device 2-2 of the catalytic cracking regeneration unit 2 for heat exchange, and after reaching the initial regeneration temperature, it enters a dehydrogenation cracking regeneration unit 4 for regeneration reaction to obtain a dehydrogenation cracking regenerated catalyst, which is introduced into a dehydrogenation cracking reaction unit 3 for recycling.

[0105] According to the present disclosure, the existing methods generally use catalytic cracking technology to process heavy raw materials and use dehydrogenation cracking technology to process light raw materials, but the two are not effectively combined, and the ethylene and propylene yields of light hydrocarbon raw materials are low. To this end, the present disclosure organically combines the catalytic cracking of heavy raw materials with the dehydrogenation cracking of light raw materials by designing the above-mentioned system, which can promote the effective conversion of heavy raw materials and light raw materials into ethylene and propylene. In addition, the system of the present disclosure can further utilize the heat generated during the regeneration process of the catalytic cracking catalyst to provide heat for the regeneration process of the dehydrogenation cracking catalyst, thereby greatly reducing energy consumption.

[0106] The method for producing ethylene and propylene disclosed in the present invention is specifically described below.

[0107] The heavy feedstock 11 and the catalytic cracking catalyst enter the catalytic cracking reaction unit 1 for contact reaction to obtain a catalytic cracking oil agent mixture, which is separated to obtain a catalytic cracking oil and gas product and a catalytic cracking catalyst to be regenerated. Among them, the catalytic cracking catalyst to be regenerated is introduced into the catalytic cracking regeneration unit 2 for regeneration reaction to obtain a catalytic cracking regenerated catalyst, and the catalytic cracking regenerated catalyst is introduced into the catalytic cracking reaction unit 1 for recycling.

[0108] Specifically, the heavy feedstock is usually preheated to 180°C to 300°C and then introduced into the bottom of the first riser reactor 1-1 of the catalytic cracking reaction unit 1, and is contacted and reacted with the catalytic cracking regeneration catalyst from the catalytic cracking regeneration unit 2 under the conditions of a reaction temperature of 540°C to 640°C, preferably 560°C to 620°C; a catalyst-oil ratio of 3 to 25, preferably 5 to 20; and a reaction time of 1 to 20 seconds, preferably 2 to 10 seconds. The resulting oil-agent mixture is introduced into the first fluidized bed reactor 1-3, and is reacted at a reaction temperature of 520°C to 620°C, preferably 540°C to 600°C, and a weight hourly space velocity of 1 to 25 hours. -1 , preferably 2 to 10 hours -1 , catalyst density is 50kg / m 3 ~400kg / m 3 , preferably 100kg / m 3 ~250kg / m 3 The bed height is 1 / 2 to 4 / 5 of the bed reactor height, preferably 1 / 2 to 3 / 4 of the bed reactor height, and the reaction continues under the condition of the pressure in the reactor being 0.1 MPa to 0.4 MPa, preferably 0.15 MPa to 0.3 MPa. The oil mixture after the reaction is separated by a cyclone separator, and the catalytic cracking catalyst to be produced is introduced into the first stripper 1-2 for stripping, and the obtained catalytic cracking oil and gas products are introduced into a product separation system (not shown) for further separation.

[0109] In some embodiments, the heavy feedstock 11 is selected from one or more of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sand oil, shale oil, distillate oil obtained by FT synthesis, animal oil and vegetable oil; the heavy feedstock mainly undergoes cracking reaction in the riser reactor and fluidized bed reactor of the catalytic cracking reaction unit, and is converted from large molecular reactants into small molecular products.

[0110] In some embodiments, the process further includes introducing cracked heavy oil into the middle or upper portion of the first riser reactor, wherein the mass ratio of the cracked heavy oil to the heavy feedstock is 0.01 to 0.1:1, for example, 0.01:1, 0.03:1, 0.05:1, 0.08:1, 0.1:1, etc.

[0111] The light feedstock 31 and the dehydrogenation cracking catalyst enter the dehydrogenation cracking reaction unit 3 for contact reaction to obtain a dehydrogenation cracking oil agent mixture, which is separated to obtain a dehydrogenation cracking oil and gas product and a dehydrogenation cracking catalyst to be regenerated; wherein, the dehydrogenation cracking catalyst to be regenerated is introduced into the heat exchange device 2-2 of the catalytic cracking regeneration unit 2 for heat exchange, and after reaching the initial regeneration temperature, enters the dehydrogenation cracking regeneration unit 4 for regeneration reaction to obtain a dehydrogenation cracking regenerated catalyst, and the dehydrogenation cracking regenerated catalyst is introduced into the dehydrogenation cracking reaction unit 3 for recycling.

[0112] Specifically, the light feedstock 31 is usually preheated to 100°C to 150°C and then introduced into the second fluidized bed reactor 3-3 of the dehydrogenation cracking reaction unit 3, and the dehydrogenation cracking regeneration catalyst introduced into the second fluidized bed reactor 3-3 through the second riser 3-1 is heated at a reaction temperature of 560°C to 660°C, preferably 580°C to 640°C; the weight hourly space velocity is 1 hour -1 ~20 hours -1 , preferably 2 to 8 hours -1 ; Catalyst density is 50kg / m 3 ~450kg / m 3 , preferably 100kg / m 3 ~350kg / m 3 ; The bed height is 1 / 2 to 4 / 5 of the bed reactor height, preferably 1 / 2 to 3 / 4; the pressure in the second fluidized bed reactor is 0.1 MPa to 0.4 MPa, preferably 0.15 to 0.3 MPa, and the oil mixture after the reaction is separated by a cyclone separator, and the dehydrogenation cracking catalyst is introduced into the stripper 3-2 of the dehydrogenation cracking reaction unit for stripping, and the dehydrogenation cracking oil and gas products are led out through the separation system pipeline into the subsequent product separation system (not shown) for separation.

[0113] In some embodiments, the aforementioned catalytic cracking oil and gas products and dehydrogenation cracking oil and gas products can be subsequently introduced into their respective product separation systems, or introduced into the same product separation system for further separation. Among them, these oil and gas products are separated into products such as dry gas, cracked gas, gasoline, light oil and oil slurry. The dry gas can be separated by a separation method well known to those skilled in the art to obtain ethylene. The separation method can use deep cold separation to recover ethylene, introduce ethylbenzene-styrene device for reaction to recover ethylene, etc.; cracked gas can obtain polymerization grade propylene products and olefin-rich C4 hydrocarbons after subsequent product separation and refining, and gasoline can obtain C5-C8 hydrocarbons and heavy gasoline after subsequent product separation and refining. The separation device in the dehydrogenation cracking reaction unit can quickly separate the oil and gas from the carbon deposited catalyst after the reaction, which can reduce the dry gas yield and inhibit the conversion of propylene after generation.

[0114] In some embodiments, the light raw material 31 is selected from C4-C8 hydrocarbons. Preferably, based on the total weight of the light raw material, the content of C4-C8 alkanes is not less than 20%. C4-C8 hydrocarbons can come from the separation products of the present disclosure or from other sources, preferably from C4-C8 hydrocarbons obtained in the present disclosure. For the present disclosure, since a dedicated dehydrogenation cracking catalyst can be used in the dehydrogenation cracking reactor, the range of light raw materials that can be used is relatively wider, which can provide a suitable reaction environment for the light raw materials and improve the yield of ethylene and propylene.

[0115] In the method of the present disclosure, cracked heavy oil 13 can also be introduced into the middle and upper part of the first riser reactor 1-1 of the catalytic cracking reaction unit 1, and reacted after mixing with the heavy feedstock 11 and the catalytic cracking catalyst. The cracked heavy oil can be the cracked heavy oil produced by the present disclosure or the cracked heavy oil produced by other devices, preferably the cracked heavy oil produced by the present disclosure.

[0116] According to the present disclosure, the catalytic cracking catalyst used in the first riser reactor 1-1 of the catalytic cracking reaction unit 1 is a regenerated catalyst obtained by a catalytic cracking regenerator 2-1, and the catalyst includes a cracking active component, clay and a binder, wherein the cracking active component includes a molecular sieve with an MFI structure and a Y molecular sieve. The molecular sieve with an MFI structure is selected from one or more of ZRP zeolite, phosphorus-containing ZRP zeolite, rare earth-containing ZRP zeolite, phosphorus- and rare earth-containing ZRP zeolite, phosphorus- and alkaline earth metal-containing ZRP zeolite, and phosphorus- and transition metal-containing ZRP zeolite, preferably phosphorus- and rare earth-containing ZRP zeolite; the Y molecular sieve can be selected from one or more of HY, USY, REUSY, REY, REHY, DASY, REDASY, or a Y-type molecular sieve obtained by treatment with various metal oxides. Clay is selected from various clays that can be used as catalyst components, such as kaolin, montmorillonite, bentonite, etc. The binder is selected from one or a mixture of two or three of silica sol, aluminum sol and pseudo-boehmite, wherein the preferred binder is a double aluminum binder of aluminum sol and pseudo-boehmite. Based on the dry weight of the catalytic cracking catalyst, the content of clay is 10-70% by weight, preferably 15-45% by weight; the content of the binder is 10-40% by weight, preferably 20-35% by weight; the content of the cracking active component is 10-80% by weight, preferably 15-60% by weight, wherein the mass ratio of the Y molecular sieve to the molecular sieve with the MFI structure is 1:0-2, that is, the molecular sieve with the MFI structure may not be contained, and the mass ratio of the two is preferably 1:0.1-0.8.

[0117] According to the present disclosure, the dehydrogenation cracking catalyst used in the second fluidized bed reactor 3-3 of the dehydrogenation cracking reaction unit 3 is a dehydrogenation cracking regeneration catalyst obtained by the dehydrogenation cracking regenerator 4-1, and the catalyst includes a dehydrogenation cracking active component, clay and a binder, wherein the dehydrogenation cracking active component includes a molecular sieve with an MFI structure and a metal active component. The molecular sieve with an MFI structure is selected from one or more of ZRP zeolite, phosphorus-containing ZRP zeolite, rare earth-containing ZRP zeolite, phosphorus- and rare earth-containing ZRP zeolite, phosphorus- and alkaline earth metal-containing ZRP zeolite, and phosphorus- and transition metal-containing ZRP zeolite, preferably phosphorus- and rare earth-containing ZRP zeolite. The metal active component is selected from one or more metals or oxides of iron (Fe), chromium (Cr) and vanadium (V) elements, and the content of Fe is 0% to 5%, preferably 0% to 1%, the content of Cr is 0% to 8%, preferably 0% to 2%, and the content of V is 0% to 15%, preferably 0% to 8%. That is, in the molecular sieve with MFI structure, it is also possible to contain no metal active component, or contain 1 to 3 metal elements of active component. Clay is selected from various clays that can be used as catalyst components, such as kaolin, montmorillonite, bentonite, etc. The binder is selected from one or a mixture of two or three of silica sol, aluminum sol and pseudo-boehmite, wherein the preferred binder is a double aluminum binder of aluminum sol and pseudo-boehmite.

[0118] In summary, the present disclosure realizes the organic combination of catalytic cracking of heavy raw materials and dehydrogenation cracking of light raw materials by adopting the above-mentioned system and method, which can promote the effective conversion of heavy raw materials and light raw materials into ethylene and propylene. At the same time, the light raw materials used can further utilize the products after separation of heavy raw materials, effectively improving the raw material conversion rate. In addition, the method can further utilize the heat generated during the regeneration of the catalytic cracking catalyst to provide heat for the regeneration process of the dehydrogenation cracking catalyst, thereby greatly reducing energy consumption; the catalytic cracking regenerated catalyst and the dehydrogenation cracking regenerated catalyst can be recycled to the corresponding reactor for reuse, effectively reducing production costs. In short, the application of this system and method can achieve a higher hydrocarbon conversion capacity, achieve a higher ethylene and propylene yield, and can greatly reduce energy consumption, which has important industrial application value.

[0119] The present disclosure will be further described below by way of examples, but the present disclosure is not limited thereto. Unless otherwise specified, the reagents or materials used in the present disclosure can be purchased from commercial sources.

[0120] Reagents, Instruments and Tests

[0121] In the embodiments and comparative examples of the present invention, the gas product was tested by the petrochemical analysis method RIPP 77-90, the coke content was determined by the petrochemical analysis method RIPP 107-90, the composition of the organic liquid product was determined by the SH / T0558-1993 method, the fraction cut points of gasoline and diesel were 221° C. and 343° C., respectively, and the light aromatics in gasoline were determined by the petrochemical analysis method RIPP 82-90.

[0122] In the following examples, the conversion rate of the feedstock oil and the yield of the cracked product are calculated according to the following formula:

[0123]

[0124]

[0125] The RIPP petrochemical analysis method used in the present invention is selected from "Petrochemical Analysis Methods (RIPP Test Methods)", edited by Yang Cuiding et al., Science Press, 1990.

[0126] Unless otherwise specified, all reagents used below are chemically pure.

[0127] The MFI structure molecular sieve used is produced by Qilu Catalyst Factory, and its industrial grade is:

[0128] ZRP-1: wherein SiO2 / Al2O3=30, the content of Na2O is 0.17 wt%, the content of rare earth oxide RE2O3 is 1.4 wt%, the content of lanthanum oxide is 0.84 wt%, the content of cerium oxide is 0.18 wt%, and the content of other rare earth oxides is 0.38 wt%.

[0129] The Y-type molecular sieve used was produced by Qilu Catalyst Factory, and its industrial grade is:

[0130] DASY, the physical property parameters are: unit cell constant is 2.443nm, Na2O content is 0.85 wt%;

[0131] The precursors of the metal active components used are all metal salt solutions, including Fe(NO3)3·9H2O, Cr(NO3)3·9H2O and NH4VO3.

[0132] The clay used is kaolin and the binder used is diaspore.

[0133] The heavy raw materials used in the examples and comparative examples were taken from Daqing wax oil. The specific properties of Daqing wax oil and light raw materials are shown in Tables 1 and 2.

[0134] The catalysts used in the embodiments and comparative examples are homemade catalysts, wherein the catalytic cracking catalyst is denoted as CCAT, and the preparation method thereof is as follows: DASY molecular sieve, ZRP-1 molecular sieve and water are mixed in a mass ratio of 2:1:5 to obtain a first slurry, kaolin, pseudo-boehmite and water are mixed in a mass ratio of 2:0.2:5 to obtain a second slurry, the first slurry and the second slurry are mixed in a mass ratio of 1:2, and then the catalytic cracking catalyst CCAT is obtained after washing, filtering, drying and calcining. The dehydrogenation cracking catalyst is denoted as DHC, and its preparation method is as follows: Fe(NO3)3·9H2O, Cr(NO3)3·9H2O, NH4VO3, ZRP-1 molecular sieve and water are mixed in a mass ratio of 2:3:1:10:25 to obtain a first slurry, and kaolin, pseudo-boehmite and water are mixed in a mass ratio of 2:0.2:5 to obtain a second slurry; the first slurry and the second slurry are mixed in a mass ratio of 1:1, and then washed, filtered, dried and calcined to obtain a dehydrogenation cracking catalyst DHC. The specific properties of the two catalysts are shown in Table 3.

[0135] Table 1 Properties of Daqing wax oil

[0136]

[0137]

[0138] Table 2 Properties of light raw materials

[0139]

[0140]

[0141] Table 3 Composition and properties of catalysts

[0142]

[0143] Examples 1 to 4 and Comparative Examples 1 to 4 are used to illustrate that the system and method of the present disclosure can improve the hydrocarbon conversion capacity and obtain higher ethylene and propylene yields.

[0144] Example 1

[0145] Test in Figure 1 and Figure 2The test was carried out on the medium-sized test device shown in the figure. The device includes a catalytic cracking reaction unit 1, a catalytic cracking regeneration unit 2, a dehydrogenation cracking reaction unit 3 and a dehydrogenation cracking regeneration unit 4. The inner diameter of the first riser reactor of the catalytic cracking reaction unit 1 is 16 mm and the length is 3200 mm, the inner diameter of the first fluidized bed reactor is 80 mm and the length is 500 mm; the inner diameter of the second fluidized bed reactor of the dehydrogenation cracking reaction unit 2 is 60 mm and the length is 400 mm. The cross-sectional area of ​​the heat exchange tube is 1600 mm 2 , length is 300mm.

[0146] The heavy feedstock is introduced into the first riser reactor 1-1, and is contacted and reacted with the regenerated catalyst CCAT from the catalytic cracking regenerator 2-1. The oil-agent mixture after the reaction is introduced into the first fluidized bed reactor 1-3 for further reaction, and the oil-agent mixture after the reaction is separated by a cyclone separator. The catalytic cracking catalyst to be regenerated is introduced into the first stripper 1-2 and then introduced into the catalytic cracking regenerator 2-1 for regeneration. The regenerated catalyst is returned to the first riser reactor 1-1 for recycling, and the oil and gas are introduced into the catalytic cracking product separation system 5 for separation.

[0147] The light raw material is introduced into the bottom of the second fluidized bed reactor 3-3, and is contacted and reacted with the regenerated catalyst DHC from the dehydrogenation cracking regenerator 4-1. The oil mixture after the reaction is separated by a cyclone separator. The dehydrogenation cracking catalyst to be regenerated is introduced into the second stripper 3-2 and then introduced into the heat exchange tubes for heat exchange and then introduced into the dehydrogenation cracking regenerator 4-1 for regeneration. The regenerated catalyst returns to the fluidized bed reactor 3-3 of the dehydrogenation cracking reaction unit 4 for recycling, and the oil and gas are introduced into the dehydrogenation cracking product separation system 6 for separation. The mass ratio of light raw material to heavy raw material is 0.2:1. The reaction conditions and results are shown in Table 4.

[0148] Example 2

[0149] The method of Example 1 is the same except that cracked heavy oil is also introduced into the middle and upper part of the first riser reactor 1-1 at a position 300 mm from the top, and the mass ratio of cracked heavy oil to heavy raw material is 0.05:1. The reaction conditions and results are shown in Table 4.

[0150] Example 3

[0151] The method of Example 1 was followed, except that the mass ratio of the light raw material to the heavy raw material was 0.3:1. The reaction conditions and results are shown in Table 4.

[0152] Example 4

[0153] The method of Example 2 was followed, except that the mass ratio of the cracked heavy oil to the heavy feedstock was 0.1:1. The reaction conditions and results are shown in Table 4.

[0154] Table 4

[0155]

[0156]

[0157] Comparative Example 1

[0158] A conventional medium-scale test device is provided, wherein the device comprises a cracking reactor and a regenerator connected thereto, wherein the cracking reactor comprises a riser reactor (a first riser reactor) and a fluidized bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 3200 mm, and the fluidized bed reactor has an inner diameter of 64 mm and a height of 500 mm.

[0159] The heavy feedstock is introduced into the bottom of the riser reactor, where it contacts and reacts with the regenerated catalyst CCAT from the regenerator. The resulting oil-agent mixture is introduced into the fluidized bed reactor. The reacted oil-agent mixture is separated by a quick separation device, and the reaction oil and gas pass through a cyclone separator. The catalyst is introduced into the stripper for stripping. After entering the stripper, the catalyst enters the catalytic cracking regenerator for regeneration. The regenerated catalyst returns to the riser reactor for recycling, and the oil and gas are introduced into the separation system for separation. The reaction conditions and results are shown in Table 5.

[0160] Comparative Example 2

[0161] A conventional pilot plant is provided, wherein the plant comprises a cracking reactor and a regenerator connected thereto, wherein the cracking reactor comprises a riser reactor (a first riser reactor) and a fluidized bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 3200 mm, and the fluidized bed reactor has an inner diameter of 64 mm and a height of 500 mm.

[0162] The light raw material is introduced into the bottom of the riser reactor, and contacts and reacts with the regenerated catalyst CCAT from the regenerator. The resulting oil-agent mixture is introduced into the fluidized bed reactor. The reacted oil-agent mixture is separated by a quick separation device, and the reaction oil and gas pass through a cyclone separator. The catalyst is introduced into the stripper for stripping. After entering the stripper, the catalyst enters the regenerator for regeneration. The regenerated catalyst returns to the riser reactor for recycling, and the oil and gas are introduced into the fractionation system for separation. The reaction conditions and results are shown in Table 5.

[0163] Comparative Example 3

[0164] A conventional pilot plant is provided, which comprises two riser reactors and a fluidized bed reactor. The first riser reactor has an inner diameter of 16 mm and a length of 3200 mm, the second riser reactor has an inner diameter of 16 mm and a height of 3000 mm, and the fluidized bed reactor has an inner diameter of 64 mm and a height of 500 mm.

[0165] The heavy raw material is introduced into the bottom of the first riser reactor, contacts and reacts with the regenerated catalyst CCAT from the regenerator, and the oil-agent mixture after the reaction is introduced into the fluidized bed reactor; the light raw material is introduced into the bottom of the second riser reactor, contacts and reacts with the regenerated catalyst CCAT from the regenerator, and the resulting oil-agent mixture is introduced into the fluidized bed reactor. The oil-agent mixture after the reaction is separated by a quick separation device, the reaction oil and gas pass through a cyclone separator, and the catalyst is introduced into a stripper for stripping. After entering the stripper, the catalyst enters the regenerator for regeneration, and the regenerated catalyst returns to the riser reactor for recycling, and the oil and gas are introduced into the fractionation system for separation. The mass ratio of the light raw material to the heavy raw material is 0.2:1. The reaction conditions and results are shown in Table 5.

[0166] Comparative Example 4

[0167] The method of Comparative Example 3 was followed, except that the cracked heavy oil was also introduced into the middle and upper part of the first riser reactor at a position 300 mm from the top, and the mass ratio of the cracked heavy oil to the heavy raw material was 0.05:1. The reaction conditions and results are shown in Table 5.

[0168] Table 5

[0169] project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 First riser reactor raw material Heavy raw materials Lightweight raw materials Heavy raw materials Heavy raw materials Outlet temperature / ℃ 570.8 620.1 570.6 571.2 Agent to oil ratio 8 10 8 8 Weight ratio of atomized water vapor to crude oil 0.25 0.25 0.25 0.25 Mass ratio of cracking heavy oil to heavy raw material 0.05 Second riser reactor raw material Lightweight raw materials Lightweight raw materials Mass ratio of light raw materials to heavy raw materials 0.2 0.2 Reaction temperature / ℃ 620.8 619.6 <![CDATA[WHSV / h -1 > 6 6 Mass ratio of atomized water vapor to light raw material Fluidized bed reactor Reaction temperature / ℃ 561.2 613.6 580.9 581.2 <![CDATA[WHSV / h -1 > 6 8 8 8 Material balance / weight % Dry gas 8.53 11.38 9.21 9.51 Liquefied gas 36.75 30.69 39.77 39.96 gasoline 27.88 48.56 23.18 23.85 diesel fuel 13.69 3.89 13.15 13.14 Oil slurry 5.46 1.57 5.68 4.09 Coke 7.69 3.91 9.01 9.45 Ethylene yield / weight% 4.31 4.62 5.01 5.12 Propylene yield / weight% 17.98 19.58 19.89 20.01

[0170] It can be seen from Table 4 and Table 5 that, compared with Comparative Examples 1 to 4, the method and system provided by the present disclosure can achieve a higher hydrocarbon conversion capacity and obtain a higher ethylene and propylene yield.

[0171] Example 2 and Comparative Example 5 are used to illustrate that a heat exchange device is provided in the catalytic cracking regenerator in the present disclosure, and the heat generated when the catalytic cracking catalyst to be regenerated is used to heat the dehydrogenation cracking catalyst to be regenerated produced by the dehydrogenation cracking reaction unit, so that the dehydrogenation cracking catalyst to be regenerated reaches the initial regeneration temperature, thereby improving the regeneration efficiency of the dehydrogenation cracking catalyst to be regenerated and reducing energy consumption.

[0172] Comparative Example 5

[0173] The method of Example 2 is the same, except that the dehydrogenation cracking catalyst to be regenerated is directly introduced into the dehydrogenation cracking regenerator 4-1 for regeneration without being preheated by the heat exchange device. The reaction conditions and results are shown in Table 6.

[0174] Table 6

[0175] project Example 2 Comparative Example 5 Catalytic cracking regeneration unit Regeneration temperature / ℃ 690.5 705.8 Regeneration pressure / MPa 0.12 0.13 Dehydrogenation cracking regeneration unit Regeneration temperature / ℃ 612.3 665.6 Regeneration pressure / MPa 0.13 0.12 Carbon content of dehydrogenation cracking catalyst to be spent / % 0.531 0.525 Dehydrogenation cracking regeneration catalyst carbon content / % 0.025 0.183

[0176] It can be seen from Table 6 that, compared with Comparative Example 5, the method and system provided by the present disclosure can increase the regeneration temperature of the dehydrogenation cracking regeneration unit, reduce the carbon content of the dehydrogenation cracking regeneration catalyst, improve the regeneration efficiency of the dehydrogenation cracking catalyst to be regenerated, and reduce energy consumption.

[0177] It should be noted by those skilled in the art that the embodiments described in the present disclosure are merely exemplary, and various other substitutions, changes and improvements may be made within the scope of the present disclosure. Therefore, the present disclosure is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A method for producing ethylene and propylene, characterized in that: include: The heavy raw material is contacted with the catalytic cracking catalyst in a catalytic cracking reaction unit to react, thereby obtaining a catalytic cracking oil agent mixture, and then the catalytic cracking oil and gas product and the catalytic cracking spent catalyst are obtained through separation; The light raw material is contacted and reacted with the dehydrogenation cracking catalyst in a dehydrogenation cracking reaction unit to obtain a dehydrogenation cracking oil agent mixture, and the dehydrogenation cracking oil and gas product and the dehydrogenation cracking catalyst to be spent are obtained through separation; The catalytic cracking oil and gas products and the dehydrogenation cracking oil and gas products are separated to obtain the ethylene and propylene; the catalytic cracking catalyst to be regenerated is introduced into the catalytic cracking regeneration unit for regeneration reaction to obtain the catalytic cracking regenerated catalyst; the dehydrogenation cracking catalyst to be regenerated is introduced into the catalytic cracking regeneration unit for heat exchange treatment, and after reaching the initial regeneration temperature, it enters the dehydrogenation cracking regeneration unit for regeneration reaction to obtain the dehydrogenation cracking regenerated catalyst; In the catalytic cracking reaction unit, the heavy feedstock is introduced into the first riser reactor, and is contacted and reacted with the catalytic cracking regeneration catalyst from the catalytic cracking regeneration unit, and the obtained product is introduced into the first fluidized bed reactor for further reaction to obtain the catalytic cracking oil agent mixture; In the dehydrogenation cracking reaction unit, the light feedstock is introduced into a second fluidized bed reactor, and the dehydrogenation cracking regeneration catalyst is introduced into the second fluidized bed reactor through a second riser to contact and react with the light feedstock to obtain the dehydrogenation cracking oil agent mixture; The first riser reactor is selected from one or more of a constant diameter riser reactor, a constant linear velocity riser reactor and a variable diameter riser reactor; The first fluidized bed reactor is selected from one or more of a fixed fluidized bed reactor, a bulk fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor, and a dense phase fluidized bed reactor; The second fluidized bed reactor is selected from one or more of a fixed fluidized bed reactor, a dispersed fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor, and a dense phase fluidized bed reactor; The reaction temperature of the first riser reactor is 540°C to 640°C; the catalyst-oil ratio is 3 to 25; the reaction time is 1s to 20s; the reaction temperature of the first fluidized bed reactor is 520°C to 620°C; the weight hourly space velocity is 1 hour -1 ~25 hours -1 ; Catalytic cracking catalyst density is 50kg / m 3 ~400kg / m 3 ; The bed height is 1 / 2 to 4 / 5 of the bed reactor height; The pressure in the first fluidized bed reactor is 0.1 MPa to 0.4 MPa; The reaction temperature of the second fluidized bed reactor is 560°C to 660°C; the weight hourly space velocity is 1 hour -1 ~20 hours -1 ; Catalyst density is 50kg / m 3 ~450kg / m 3 ; The bed height is 1 / 2 to 4 / 5 of the bed reactor height; The pressure in the second fluidized bed reactor is 0.1 MPa to 0.4 MPa; The dehydrogenation cracking catalyst comprises a dehydrogenation cracking active component, clay and a binder, wherein the dehydrogenation cracking active component comprises a molecular sieve with an MFI structure and a metal active component.

2. The production method according to claim 1, characterized in that The catalytic cracking catalyst comprises catalytic cracking active components, clay and a binder, wherein the catalytic cracking active components comprise a molecular sieve with an MFI structure and a Y molecular sieve, and the mass ratio of the Y molecular sieve to the molecular sieve with an MFI structure is 1:0-2.

3. The production method according to claim 2, characterized in that: The mass ratio of the Y molecular sieve to the molecular sieve having an MFI structure is 1:0.1-0.

8.

4. The production method according to claim 1, characterized in that The metal active component is selected from one or more of the following metal elements and their oxides: iron, chromium, and vanadium; based on the total weight of the molecular sieve with the MFI structure, the iron content is 0% to 5%, the chromium content is 0% to 8%, and the vanadium content is 0% to 15%.

5. The production method according to claim 4, characterized in that: Based on the total weight of the molecular sieve with the MFI structure, the iron content is 0-1%, the chromium content is 0-2%, and the vanadium content is 0-8%.

6. The production method according to claim 1, characterized in that: The catalytic cracking regeneration catalyst is introduced into the catalytic cracking reaction unit for cyclic use, and the dehydrogenation cracking regeneration catalyst is introduced into the dehydrogenation cracking reaction unit for cyclic use.

7. The production method according to claim 1, characterized in that: The reaction temperature of the first riser reactor is 560-620°C; the catalyst-oil ratio is 5-20; the reaction time is 2s-10s; the reaction temperature of the first fluidized bed reactor is 540-600°C; the weight hourly space velocity is 2 hours -1 ~10 hours -1 ; Catalytic cracking catalyst density is 100kg / m 3 ~250kg / m 3 ; The bed height is 1 / 2 to 3 / 4 of the bed reactor height; The pressure in the first fluidized bed reactor is 0.15 MPa to 0.3 MPa.

8. The production method according to claim 1, characterized in that: The method further comprises introducing cracked heavy oil into the middle or upper part of the first riser reactor, wherein the mass ratio of the cracked heavy oil to the heavy feedstock is 0.01 to 0.1:

1.

9. The production method according to claim 1, characterized in that: The reaction temperature of the second fluidized bed reactor is 580°C to 640°C; the weight hourly space velocity is 2 to 8 hours -1 ; Catalyst density is 100kg / m 3 ~350kg / m 3 ; The bed height is 1 / 2 to 3 / 4 of the bed reactor height; The pressure in the second fluidized bed reactor is 0.15 to 0.3 MPa.

10. The production method according to claim 1, characterized in that: The heavy raw material is selected from one or more of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sand oil, shale oil, distillate oil obtained by FT synthesis, animal oil and vegetable oil; the light raw material is selected from C4-C8 hydrocarbons.

11. The production method according to claim 1, characterized in that: Based on the total weight of the light raw material, the content of C4-C8 alkanes is not less than 20%.

12. The method according to claim 1, characterized in that The light raw material is selected from the catalytic cracking oil and gas products which are separated to obtain C4-C8 hydrocarbons and / or the dehydrogenation cracking oil and gas products which are separated to obtain C4-C8 hydrocarbons.

13. A system for producing ethylene and propylene, characterized in that: include: A catalytic cracking reaction unit configured to perform a catalytic cracking reaction of a heavy feedstock; A catalytic cracking regeneration unit is configured to regenerate the catalytic cracking spent catalyst separated after the catalytic cracking reaction to obtain a catalytic cracking regenerated catalyst; A dehydrogenation cracking reaction unit configured to perform a dehydrogenation cracking reaction of a light feedstock; A dehydrogenation cracking regeneration unit is configured to regenerate the dehydrogenation cracking spent catalyst separated after the dehydrogenation cracking reaction to obtain a dehydrogenation cracking regenerated catalyst; The catalytic cracking regeneration unit further comprises a heat exchange device, which is configured to utilize the heat generated when the catalytic cracking catalyst to be regenerated is regenerated to heat the dehydrogenation cracking catalyst to be regenerated produced by the dehydrogenation cracking reaction unit, so that the dehydrogenation cracking catalyst to be regenerated reaches the initial regeneration temperature before entering the dehydrogenation cracking regeneration unit; The catalytic cracking reaction unit comprises a first riser reactor, a first stripper, a first fluidized bed reactor and a first settler, wherein a heavy feedstock inlet is provided at the bottom of the first riser reactor, an outlet of the first riser reactor is connected to an inlet of the first fluidized bed reactor, the first stripper is located below the first fluidized bed reactor and wraps a portion of the first riser reactor, and the first settler is located above the first fluidized bed reactor and is connected to the first fluidized bed reactor; The dehydrogenation cracking reaction unit comprises a second riser, a second stripper, a second fluidized bed reactor and a second settler, wherein a light raw material inlet is provided at the bottom of the second fluidized bed reactor, the second riser is connected in series below the second fluidized bed reactor, the second stripper is located below the second fluidized bed reactor and wraps a portion of the second riser; the second settler is located above the second fluidized bed reactor and is connected to the second fluidized bed reactor; The first riser reactor is selected from one or more of a constant diameter riser reactor, a constant linear velocity riser reactor and a variable diameter riser reactor; The first fluidized bed reactor is selected from one or more of a fixed fluidized bed reactor, a bulk fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor, and a dense phase fluidized bed reactor; The second fluidized bed reactor is selected from one or more of a fixed fluidized bed reactor, a dispersed fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor, and a dense phase fluidized bed reactor; The dehydrogenation cracking catalyst comprises a dehydrogenation cracking active component, clay and a binder, wherein the dehydrogenation cracking active component comprises a molecular sieve with an MFI structure and a metal active component.

14. The production system according to claim 13, characterized in that: A cracking heavy oil inlet is also provided in the middle or upper part of the first riser reactor.

15. The production system according to claim 13, characterized in that: The catalytic cracking regeneration unit includes a catalytic cracking regenerator and a heat exchange device, wherein the heat exchange device is disposed in the catalytic cracking regenerator, the catalytic cracking regenerator is communicated with the first stripper, and the catalytic cracking regenerator is connected to the first riser reactor through the catalytic cracking regeneration catalyst delivery pipeline.

16. The production system according to claim 15, characterized in that The heat exchange device is a heat exchange tube, and the ratio of the cross-sectional area of ​​the heat exchange tube to the cross-sectional area of ​​the catalytic cracking regenerator is 1:2-10; the ratio of the length of the heat exchange tube to the length of the catalytic cracking regenerator is 1:1.5-5.

17. The production system according to claim 16, characterized in that The ratio of the cross-sectional area of ​​the heat exchange tubes to the cross-sectional area of ​​the catalytic cracking regenerator is 1:3-6; the ratio of the length of the heat exchange tubes to the length of the catalytic cracking regenerator is 1:2-3.

18. The production system according to claim 13, characterized in that: The dehydrogenation cracking regeneration unit comprises a dehydrogenation cracking regenerator, wherein the inlet of the heat exchange device is connected to the second stripper, the outlet of the heat exchange device is connected to the dehydrogenation cracking regenerator, and the dehydrogenation cracking regenerator is connected to the second riser through the dehydrogenation cracking regeneration catalyst delivery pipeline.

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