Method for increasing yield of low-carbon olefins

Abstract

The invention relates to a method for increasing the yield of low-carbon olefins, which comprises the following steps: contacting an olefin-rich raw material with a first thermal regeneration catalyst, and carrying out a first catalytic conversion reaction in a dense-phase fluidized bed layer of a first catalytic conversion reactor, the reacted material flow is subjected to rapid cooling treatment through a cooling area, close to the upper part, in the first catalytic conversion reactor, so that the reacted material flow is cooled to a target temperature of 450-530 DEG C and then is sent out of the first catalytic conversion reactor. According to the present invention, the olefin-rich raw material and the first thermal regeneration catalyst contact and react, and the reacted material flow is rapidly cooled in the cooling zone through the cooling medium, such that the control on the catalytic cracking reaction and the thermal cracking reaction is optimized, the deep reaction during the reaction process is effectively inhibited, and the yield and the selectivity of the low-carbon olefin are improved.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry, and in particular, relates to a method for increasing the production of light olefins. Background Art

[0002] As an important organic chemical raw material, the consumption of low-carbon olefins has maintained a strong growth trend. The technologies for producing low-carbon olefins using petroleum as raw materials include steam cracking, refinery fluid catalytic cracking, catalytic cracking, alkane dehydrogenation and olefin disproportionation. The typical process for producing low-carbon olefins is steam cracking to produce ethylene and propylene, which requires the consumption of a large amount of light hydrocarbons or chemical light hydrocarbons such as naphtha. However, the quality of domestic crude oil is heavy, and the production capacity of chemical light oil is insufficient to meet the demand for the production of low-carbon olefin raw materials. Moreover, with the increase in demand, the traditional steam cracking process has been difficult to meet the market demand for low-carbon olefins. In order to meet the needs of the petrochemical industry while taking into account the goal of improving the quality and efficiency of enterprises, the field has currently developed a process route for cracking and producing low-carbon olefins using high-carbon olefins with a carbon number greater than or equal to 4 in the refinery process.

[0003] CN115108876A discloses a catalytic conversion method for producing light olefins using organic oxygen-containing compounds as part of the raw materials. The method comprises performing catalytic conversion reactions on olefin-rich raw materials, heavy raw materials and organic oxygen-containing compound raw materials in different reaction zones of a catalytic conversion reactor, thereby giving full play to the advantages of different process routes and improving the yield and selectivity of light olefins, especially the yield and selectivity of ethylene and propylene.

[0004] CN114763483A discloses a catalytic conversion method for producing ethylene and propylene, which effectively improves the yield of ethylene and propylene and reduces the selectivity of methane in the product by replacing the alkane feedstock with a feedstock rich in olefins.

[0005] However, the selectivity and yield of light olefins in the existing olefin cracking process still need to be improved. Summary of the invention

[0006] The purpose of the present invention is to further improve the selectivity and yield of light olefins in the olefin cracking process and reduce the generation of dry gas.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a method for increasing the production of low-carbon olefins, which method comprises the following steps: contacting an olefin-rich raw material with a first thermally regenerated catalyst and carrying out a first catalytic conversion reaction in a dense phase fluidized bed of a first catalytic conversion reactor, and rapidly cooling the post-reaction logistics in a cooling zone near the upper part of the first catalytic conversion reactor, so that the post-reaction logistics is cooled to a target temperature of 450-530°C and then sent out of the first catalytic conversion reactor.

[0008] Optionally, the first catalytic conversion reactor includes, from bottom to top, a first lifting section, an expansion section, a dense phase fluidization section, a reduction section and a second lifting section; the angle between the side wall of the expansion section and the axis is 5-60 degrees; the ratio of the diameter to the height of the dense phase fluidization section is (0.1-10): 1; the angle between the side wall of the reduction section and the axis is 5-60 degrees; the head of the first lifting section is provided with a first heat regeneration catalyst inlet and a lifting medium inlet; the middle of the first lifting section is provided with a raw material inlet; the tail of the first lifting section is also provided with a gas-solid mixed fluid distributor; the cooling zone is provided at the tail of the dense phase fluidization section.

[0009] Optionally, the cooling zone is provided with a plurality of fluid distributors for introducing the cooling medium, and the fluid distributors are arranged in a ring shape along the circumference of the first catalytic conversion reactor; preferably, the cooling medium is a coolant and / or a cooled regenerated catalyst; the coolant is selected from at least one of liquefied gas, crude gasoline, stabilized gasoline, diesel, heavy diesel, water and olefins with eight or more carbon atoms.

[0010] Optionally, the reacted logistics is cooled to the target temperature within 0.5-2 seconds, preferably within 0.5-1 second.

[0011] Optionally, the catalyst density of the first thermally regenerated catalyst in the dense phase fluidized bed of the first catalytic conversion reactor is 100-700 kg / m 3 , preferably 300-600kg / m 3 , more preferably 400-500kg / m 3 .

[0012] Optionally, the conditions of the first catalytic conversion reaction include: reaction temperature of 500-800°C, preferably 600-700°C, further preferably 650-700°C; reaction time of 0.1-20s, preferably 0.1-10s, further preferably 0.2-0.5s; reaction pressure of 0.05-2MPa, preferably 0.1-0.6MPa; weight ratio of the first thermally regenerated catalyst to the olefin-rich feedstock is (1-200):1, preferably (10-100):1.

[0013] Optionally, based on the total weight of the first thermally regenerated catalyst, the first thermally regenerated catalyst comprises 1-50 wt% of molecular sieves, 5-99 wt% of inorganic oxides and 0-70 wt% of clay; the molecular sieve is selected from at least one of a ZSM-5 series molecular sieve and a SAPO series molecular sieve; the inorganic oxide is selected from at least one of silica and alumina; and the clay is selected from at least one of kaolin and halloysite.

[0014] Optionally, the olefin-rich feedstock is a gaseous feed; the content of C4-C8 olefins in the olefin-rich feedstock is 50-100wt%, preferably 80-100wt%, and further preferably 90-100wt%; preferably, the olefin-rich feedstock is selected from at least one of the C4 and above fractions produced by an alkane dehydrogenation unit, the C4 and above fractions produced by a catalytic cracking unit of an oil refinery, the C4 and above fractions produced by a steam cracking unit of an ethylene plant, the C4 and above olefin-rich fraction produced as a by-product of MTO, and the C4 and above olefin-rich fraction produced as a by-product of MTP.

[0015] Optionally, the method further comprises the steps of: subjecting the post-reaction logistics to gas-solid separation to obtain a first reaction oil gas and a first catalyst to be regenerated, and then subjecting the first catalyst to be regenerated to a charring treatment and returning it to the first catalytic conversion reactor; or comprising the steps of: contacting the heavy hydrocarbon oil with a second thermally regenerated catalyst in a second catalytic conversion reactor to perform a second catalytic conversion reaction to obtain a reaction oil gas containing light oil and a second catalyst to be regenerated, and when the temperature of the reaction oil gas containing light oil and the second catalyst to be regenerated in the middle and upper region of the reaction zone of the second catalytic conversion reactor exceeds 530° C., a cooling zone is provided downstream of the reaction zone, and the reaction oil gas containing light oil and the second catalyst to be regenerated are cooled to below 530° C.;

[0016] Then, the cooled reaction oil gas containing light oil, the second catalyst to be regenerated and the post-reaction logistics are mixed, and the mixed logistics are subjected to a first separation to obtain a reaction logistics containing light olefins and a catalyst to be regenerated; the reaction logistics containing light olefins is distilled to separate dry gas, light olefins and C4 and above fractions, and the C4 and above fractions are subjected to a second separation and the separated olefin-rich components are returned to the first catalytic conversion reactor; and the catalyst to be regenerated is charred and the regenerated catalyst is returned to the first catalytic conversion reactor and the second catalytic conversion reactor.

[0017] Optionally, the heavy hydrocarbon oil is selected from at least one of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil, heavy aromatic raffinate oil, coal liquefaction oil, oil sands oil and shale oil; the conditions of the second catalytic conversion reaction include: the reaction temperature is 500-600°C, preferably 530-580°C; the reaction pressure is 0.01-1MPa, preferably 0.05-1MPa; the reaction time is 0.01-80s, preferably 0.1-60s; the weight ratio of the second thermal regeneration catalyst to the heavy hydrocarbon oil is (1-100):1, preferably (3-50):1.

[0018] Through the above technical scheme, the present invention optimizes the control of catalytic cracking reaction and thermal cracking reaction by allowing the olefin-rich raw material to contact with the hot regenerated catalyst for reaction, and then quickly cools the post-reaction logistics in the cooling zone through a cooling medium, thereby effectively inhibiting the deep reaction in the reaction process and improving the yield and selectivity of light olefins.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 A schematic diagram of an embodiment of the first catalytic conversion reactor provided by the present invention.

[0022] Figure 2 A schematic diagram of another embodiment of the first catalytic conversion reactor provided by the present invention.

[0023] Figure 3 A schematic diagram of an embodiment of the method provided by the present invention.

[0024] Figure 4 A schematic diagram of another embodiment of the method provided by the present invention.

[0025] Description of Reference Numerals

[0026] 1 pipeline 2 first lifting section 3 regeneration inclined pipe

[0027] 4 Feed pipeline 5 Gas-solid mixed fluid distributor 6 Feed fluid distributor

[0028] 7 first catalytic conversion reaction zone 8 pipeline 9 fluid distributor

[0029] 10 Cooling zone 11 Second lifting section 12 Horizontal pipe

[0030] 13 pipeline 14 pipeline 15 pipeline

[0031] 16 Riser 17 Second catalytic conversion reaction zone 18 Pipeline

[0032] 19 stripping section 20 pipeline 21 outlet pipe

[0033] 22 settler 23 gas collecting chamber 24 pipeline

[0034] 25 regenerator 26 pipeline 27 fractionation tower

[0035] 28 pipeline 29 pipeline 30 pipeline

[0036] 31 pipeline 32 pipeline 33 pipeline

[0037] 34 Alkane-Olefin Separation Unit 35 Pipeline 36 Pipeline

[0038] 37 pipeline 38 pipeline DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0040] The inventors have found that in the cracking reaction of hydrocarbon raw materials, the catalytic cracking process and the thermal cracking process are competitive reactions. By inhibiting the thermal cracking reaction, the generation of dry gas (mainly methane) in the product can be effectively inhibited, and the proportion of light olefins in the product can be increased. In view of this, the scheme of the present invention is proposed.

[0041] The present invention provides a method for increasing the production of low-carbon olefins, which comprises the following steps: contacting an olefin-rich raw material with a first thermally regenerated catalyst and performing a first catalytic conversion reaction in a dense phase fluidized bed of a first catalytic conversion reactor; rapidly cooling the post-reaction logistics in a cooling zone near the top of the first catalytic conversion reactor, cooling the post-reaction logistics to a target temperature of 450-530°C and then sending the first catalytic conversion reactor out.

[0042] The present invention allows the olefin-rich raw material to contact and react with the hot regenerated catalyst, and then quickly cools the post-reaction logistics in a cooling zone via a cooling medium, thereby optimizing the control of the catalytic cracking reaction and the thermal cracking reaction, effectively inhibiting the deep reaction in the reaction process, and improving the yield and selectivity of light olefins.

[0043] in, Figure 1 A schematic diagram of an embodiment of the first catalytic conversion reactor provided by the present invention is shown as follows: Figure 1 As shown, the first catalytic conversion reactor includes, from bottom to top, a first lifting section, an expansion section, a dense phase fluidization section, a reduction section, and a second lifting section; the angle between the side wall of the expansion section and the axis is 5-60 degrees; the ratio of the diameter to the height of the dense phase fluidization section is (0.1-10): 1; the angle between the side wall of the reduction section and the axis is 5-60 degrees. For example, it can be 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, or other values ​​within the above range.

[0044] Among them, the head of the first lifting section is provided with a first heat regeneration catalyst inlet and a lifting medium inlet; the middle of the first lifting section is provided with a raw material inlet; the tail of the first lifting section is also provided with a gas-solid mixed fluid distributor; the cooling zone is provided at the tail of the dense phase fluidization section.

[0045] Specifically, the gas-solid mixed fluid distributor includes a transverse distribution plate having a plurality of openings and a distribution pipe connected to the orifices of the openings.

[0046] Preferably, the cooling zone is provided with a plurality of fluid distributors for introducing the cooling medium, and the fluid distributors are arranged in a ring shape along the circumference of the first catalytic conversion reactor. Preferably, the cooling medium is a coolant and / or a cooled regenerated catalyst; the coolant is selected from at least one of liquefied gas, crude gasoline, stabilized gasoline, diesel, heavy diesel, water and olefins with eight or more carbon atoms.

[0047] The above coolant can also be used as the second raw material to undergo cracking reaction in the cooling zone, absorbing heat to rapidly cool the reaction materials in the reaction zone. The cooled regenerated catalyst is obtained by cooling the regenerated catalyst.

[0048] In some preferred embodiments, the end of the second lifting section is connected to a horizontal pipe for connecting to a subsequent separation system. The catalyst to be produced and the reaction products are transported to the separation system for gas-solid separation via the horizontal pipe, and the diameter of the horizontal pipe can be determined according to the specific situation.

[0049] The post-reaction logistics is cooled to the target temperature within 0.5-2 seconds, preferably within 0.5-1 second.

[0050] The catalyst density of the first thermally regenerated catalyst in the dense phase fluidized bed of the first catalytic conversion reactor is 100-700 kg / m 3 , preferably 300-600kg / m 3 , more preferably 400-500kg / m 3 .

[0051] Among them, the conditions of the first catalytic conversion reaction include: reaction temperature of 500-800°C, preferably 600-700°C, and more preferably 650-700°C; reaction time of 0.1-20s, preferably 0.1-10s, and more preferably 0.2-0.5s; reaction pressure of 0.05-2MPa, preferably 0.1-0.6MPa; the weight ratio of the first thermal regeneration catalyst to the olefin-rich feedstock is (1-200):1, preferably (10-100):1.

[0052] Wherein, based on the total weight of the first thermally regenerated catalyst, the first thermally regenerated catalyst comprises 1-50 wt% of molecular sieve, 5-99 wt% of inorganic oxide and 0-70 wt% of clay; the molecular sieve is selected from at least one of ZSM-5 series molecular sieves and SAPO series molecular sieves; the inorganic oxide is selected from at least one of silica and alumina; the clay is selected from at least one of kaolin and halloysite.

[0053] Wherein, the olefin-rich raw material is a gaseous feedstock. For example, in one embodiment of the present invention, the olefin-rich raw material is preheated and then enters the reaction zone in a gaseous state for catalytic conversion reaction.

[0054] Wherein, the content of C4-C8 olefins in the olefin-rich raw material is 50-100wt%, preferably 80-100wt%, and more preferably 90-100wt%. Particularly preferably, the olefin-rich raw material is a pure olefin raw material. In some specific embodiments of the present invention, the olefin-rich raw material is a pure olefin raw material, for example, it can be any one or a mixed raw material of 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene.

[0055] Preferably, the olefin-rich raw material is selected from at least one of the C4 and above fractions produced by an alkane dehydrogenation unit, the C4 and above fractions produced by a catalytic cracking unit of an oil refinery, the C4 and above fractions produced by a steam cracking unit of an ethylene plant, the C4 and above olefin-rich fractions produced as a by-product of MTO (methanol to olefins) and the C4 and above olefin-rich fractions produced as a by-product of MTP (methanol to propylene).

[0056] The alkane raw material used in the dehydrogenation of alkanes to produce olefin-rich raw materials comes from at least one of naphtha, aromatic raffinate or other light hydrocarbons. Of course, alkane products produced by other different petrochemical plants can also be used as raw materials.

[0057] The method further comprises the steps of: subjecting the post-reaction logistics to gas-solid separation to obtain a first reaction oil gas and a first catalyst to be regenerated, and then subjecting the first catalyst to be regenerated to charring treatment and returning it to the first catalytic conversion reactor; or comprising the steps of: contacting the heavy hydrocarbon oil with a second thermally regenerated catalyst in a second catalytic conversion reactor to perform a second catalytic conversion reaction to obtain a reaction oil gas containing light oil and a second catalyst to be regenerated,

[0058] When the temperature of the reaction oil gas containing light oil and the second catalyst to be regenerated in the upper area of ​​the reaction zone of the second catalytic conversion reactor exceeds 530°C, a cooling zone is set downstream of the reaction zone to cool the reaction oil gas containing light oil and the second catalyst to be regenerated to below 530°C; then the cooled reaction oil gas containing light oil and the second catalyst to be regenerated are mixed with the post-reaction logistics, and the mixed logistics are subjected to a first separation to obtain a reaction logistics containing light olefins and a catalyst to be regenerated; the reaction logistics containing light olefins is distilled to separate dry gas, light olefins and C4 and above distillates, the C4 and above distillates are subjected to a second separation and the separated olefin-rich components are returned to the first catalytic conversion reactor; and the catalyst to be regenerated is charred and regenerated and the regenerated catalyst is returned to the first catalytic conversion reactor and the second catalytic conversion reactor.

[0059] In the present invention, the catalytic cracking process of olefin-rich raw materials and the catalytic cracking process of heavy oil are coupled to produce a variety of target products, which can give full play to the advantages of the process of producing light olefins from different raw materials, improve the yield and selectivity of light olefins, and improve the utilization rate of petroleum resources.

[0060] The heavy hydrocarbon oil is selected from at least one of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil, heavy aromatic raffinate oil, coal liquefaction oil, oil sand oil and shale oil.

[0061] The conditions of the second catalytic conversion reaction include: reaction temperature of 500-600°C, preferably 530-580°C; reaction pressure of 0.01-1MPa, preferably 0.05-1MPa; reaction time of 0.01-80s, preferably 0.1-60s; weight ratio of the second thermally regenerated catalyst to the heavy hydrocarbon oil is (1-100):1, preferably (3-50):1. It should be noted that, unless otherwise specified in the present invention, the pressure referred to in the reaction pressure is absolute pressure.

[0062] Figure 1 The first catalytic conversion reactor of a specific embodiment of the present invention is shown below. Figure 1The first catalytic conversion reactor of the present invention is specifically described. The pre-lifting medium enters the first lifting section 2 through the pipeline 1. The first hot regenerated catalyst from the regeneration inclined tube 3 goes up under the action of the pre-lifting medium. The preheated olefin-rich raw material is introduced from the first lifting section through the feed pipeline 4 and enters the first catalytic conversion reaction zone 7 after being distributed by the gas-solid mixed fluid distributor 5. The olefin-rich raw material contacts the first hot regenerated catalyst in the first catalytic conversion reaction zone 7 to perform the first catalytic conversion reaction. The cooling medium from other sections is introduced through the pipeline 8 and enters the cooling zone 10 through the annular fluid distributor 9. The reacted logistics after the cooling medium takes away part of the heat is accelerated through the second lifting section 11 and enters the subsequent catalyst separation device through the horizontal pipe 12.

[0063] like Figure 2 As shown, in another specific embodiment of the present invention, it is Figure 1 The difference between the processes shown is that the feed position of the olefin-rich raw material is different. The olefin-rich raw material is introduced through the feed pipeline 4 on the side of the first catalytic conversion reaction zone. Under the distribution effect of the feed fluid distributor 6, the olefin-rich raw material is fully contacted with the first thermal regeneration catalyst to carry out the first catalytic conversion reaction.

[0064] Figure 3 A specific implementation of the method of the present invention is shown. Figure 3 In the process, the pre-lifting medium passes through the first lifting section 2 via pipeline 1, and the first hot regenerated catalyst from the regeneration inclined tube 3 goes up under the lifting effect of the pre-lifting medium. The preheated olefin-rich raw material is introduced from the first lifting section of the first catalytic conversion reactor via the feed pipeline 4, and then enters the first catalytic conversion reaction zone 7 through the action of the feed fluid distributor, and contacts with the first hot regenerated catalyst in the first catalytic conversion reaction zone 7 to catalyze the first catalytic conversion reaction. The cooling medium from other sections enters the cooling zone 10 via pipeline 8 and mixes with the reacted logistics to quickly reduce the temperature of the reacted logistics. The reacted logistics, which has taken away part of the heat through the cooling medium, is accelerated through the second lifting section and enters the catalyst separation device.

[0065] In the catalyst separation device, the post-reaction logistics enters the cyclone separator of the settler 22 for separation, and the separated first spent catalyst enters the stripping section 19, contacts with the stripping steam from the pipeline 18 to strip out the remaining reaction oil and gas on the spent catalyst, and the first spent catalyst after stripping enters the regenerator 25 through the pipeline 20 for regeneration treatment, and the charred regenerated first thermally regenerated catalyst returns to the first catalytic conversion reactor through the pipeline 3.

[0066] The separated first reaction oil and gas containing low-carbon olefins enters the distillation tower 27 through pipeline 24 for the first separation, the separated hydrogen, methane and ethane are led out through pipeline 28, ethylene is led out through pipeline 29, propylene is led out through pipeline 30, butene is led out through pipeline 31, propane and butane are led out through pipeline 32, and the other components enter the alkane-olefin separation device 34 through pipeline 33 for the second separation, the separated olefin-free logistics leaves the reaction system through pipeline 35, and the separated olefin product is returned to the first catalytic conversion reactor through pipeline 36 and the olefin-rich feedstock from pipeline 37 for further reaction.

[0067] Figure 4 Another specific embodiment of the present invention is shown. Figure 4 In the process, the pre-lifting medium enters the first lifting section 2 of the first catalytic conversion reactor through pipeline 1, the first hot regenerated catalyst from the regeneration inclined tube 3 goes up under the action of the pre-lifting medium, the olefin-rich feedstock enters the first catalytic conversion reaction zone 7 through pipeline 4 and contacts with the first hot regenerated catalyst to carry out the first catalytic conversion reaction, and the post-reaction logistics is cooled by contact with the cooling medium from pipeline 8 in the cooling zone 10, and then enters the catalyst separation device through the second lifting section 11.

[0068] The pre-lifting medium enters the lifting pipe 16 through the pipeline 14, and goes up to the second catalytic conversion reaction zone 17 together with the second thermally regenerated catalyst from the pipeline 26. The heavy hydrocarbon oil feedstock enters the second catalytic conversion reaction zone 17 through the pipeline 15, contacts with the second thermally regenerated catalyst, and undergoes a second catalytic conversion reaction. When the temperature of the reaction oil gas containing light oil and the second catalyst to be regenerated obtained by the second catalytic conversion reactor is higher than 530°C, they are cooled by the cooling medium from the pipeline 38 and enter the catalyst separation device through the outlet pipe 21. In the catalyst separation device, the reacted flow from the first catalytic conversion reactor is mixed with the reaction oil gas containing light oil and the second catalyst to be regenerated from the second catalytic conversion reactor, and then enters the cyclone separator of the settler 22 for separation, so as to separate the catalyst to be regenerated from the reaction product. The separated regenerated catalyst enters the stripping section 19 and contacts with the stripping steam from the pipeline 18 to strip out the remaining reaction oil and gas on the catalyst. The regenerated catalyst after stripping enters the regenerator 25 for charring regeneration. The regenerated catalyst after charring treatment returns to the first catalytic conversion reactor and the second catalytic conversion reactor via the pipeline 3 and the pipeline 26 respectively.

[0069] The separated olefin-containing reaction stream enters the distillation tower 27 via pipeline 24 for the first separation, the separated hydrogen, methane and ethane are led out via pipeline 28, ethylene is led out via pipeline 29, propylene is led out via pipeline 30, butene is led out via pipeline 31, propane and butane are led out via pipeline 32, and the other components enter the alkane-olefin separation device 34 via pipeline 33 to enter the second separation, the olefin-free stream leaves the reaction system via pipeline 35, and the separated olefin-rich component is mixed with the olefin-rich feedstock from pipeline 37 via pipeline 36 and returned to the first catalytic conversion reactor to continue the reaction.

[0070] The present invention is further described in detail by the following examples, but the present invention is not limited thereto. The raw materials used in the examples can be obtained through commercial channels. Among them, the commercial brand of the catalyst used is TCC-1, which is produced by the Qilu Branch of Sinopec Catalyst Co., Ltd. The heavy hydrocarbon oil raw material used is heavy oil I, and the properties of heavy oil I are shown in Table 1.

[0071] Table 1

[0072]

[0073]

[0074] Example 1

[0075] The experiment of this example was Figure 1 The reaction was carried out on the fluidized bed catalytic converter shown in the figure, wherein the reaction raw material is 1-pentene and the catalyst is TCC-1. The specific parameters of the fluidized bed catalytic converter include: the total height of the first lifting section, the expansion section, the dense phase fluidization section, the reduction section and the second lifting section is 11.5 meters, wherein the diameter of the first lifting section is 0.5 meters and the height is 1.5 meters; the angle between the side wall of the expansion section and the axis is 45 degrees, and the height of the expansion section is 1 meter; the diameter of the dense phase fluidization section is 2.5 meters and the height is 5 meters; the angle between the side wall of the reduction section and the axis is 45 degrees, and the height is 1.0 meter; the diameter of the second lifting section is 0.5 meters and its height is 3 meters.

[0076] The raw material 1-pentene enters the fluidized bed catalytic converter from the feed pipeline at the bottom of the reaction zone, and then enters the reaction zone through the gas-solid mixed fluid distributor, and contacts with the TCC-1 catalyst at a temperature of about 650°C for the first catalytic conversion reaction. The catalyst density in the reaction zone is 400kg / m 3 The reaction conditions and product distribution are shown in Table 2.

[0077] Example 2

[0078] The test of this embodiment is carried out according to Figure 3The process shown in the figure is carried out, wherein the reaction raw material is 1-hexene and the catalyst is TCC-1. The specific parameters of the fluidized bed catalytic converter include: the total height of the first lifting section, the expansion section, the dense phase fluidization section, the reduction section and the second lifting section is 11.5 meters, wherein the diameter of the first lifting section is 0.5 meters and the height is 1.5 meters; the angle between the side wall of the expansion section and the axis is 45 degrees, and the height of the expansion section is 1 meter; the diameter of the dense phase fluidization section is 2.5 meters and the height is 5 meters; the angle between the side wall of the reduction section and the axis is 45 degrees, and the height is 1.0 meter; the diameter of the second lifting section is 0.5 meters and the height is 3 meters.

[0079] The raw material 1-hexene enters the fluidized bed catalytic converter through the feed pipeline on the side of the reaction zone, and then enters the reaction zone through the annular gas-solid mixed fluid distributor, and contacts with the TCC-1 catalyst at a temperature of about 650°C for the first catalytic conversion reaction. The catalyst density in the reaction zone is 400kg / m 3 The reaction mixture was rapidly cooled using water as a cooling medium. The weight ratio of catalyst TCC-1 to raw material 1-hexene was 30:1. The operating conditions and product distribution are shown in Table 2.

[0080] Comparative Example 1

[0081] The test of this comparative example was Figure 1 The embodiment 1 is carried out on the fluidized bed catalytic conversion device shown in the figure, wherein the reaction raw material is 1-pentene and the catalyst is TCC-1. The difference between the embodiment 1 and the embodiment 1 is that the structure of the fluidized bed catalytic conversion reaction device is different: the total height of the first lifting section, the expansion section, the dense phase fluidization section, the reduction section and the second lifting section of the fluidized bed catalytic conversion device is 15.5 meters, wherein the diameter of the first lifting section is 0.5 meters and the height is 1.5 meters; the angle between the side wall of the expansion section and the axis is 45 degrees, and the height of the expansion section is 0.5 meters; the diameter of the dense phase fluidization section is 1.5 meters and the height is 10 meters; the angle between the side wall of the reduction section and the axis is 45 degrees, and the height of the reduction section is 0.5 meters; the diameter of the second lifting section is 0.5 meters and the height is 3 meters.

[0082] The raw material 1-pentene enters the fluidized bed catalytic converter from the feed pipeline at the bottom of the reaction zone, and then enters the reaction zone through the gas-solid mixed fluid distributor, and contacts with the TCC-1 catalyst at a temperature of about 650°C for the first catalytic conversion reaction. The catalyst density in the reaction zone is 90kg / m 3 , and no cooling medium was injected at the outlet, and the weight ratio of catalyst TCC-1 to raw material 1-pentene was 20:1. The operating conditions and product distribution are shown in Table 2.

[0083] Comparative Example 2

[0084] The test of this comparative example was carried out according to Figure 3The process shown in the figure is carried out, wherein the reaction raw material is 1-hexene and the catalyst is TCC-1. The difference between it and Example 1 is that the structure of the fluidized bed catalytic conversion reaction device is different: the total height of the first lifting section, the expansion section, the dense phase fluidization section, the reduction section and the second lifting section of the fluidized bed catalytic conversion device is 15.5 meters, wherein the diameter of the first lifting section is 0.5 meters and the height is 1.5 meters; the angle between the side wall of the expansion section and the axis is 45 degrees, and the height of the expansion section is 0.5 meters; the diameter of the dense phase fluidization section is 1.5 meters and the height is 10 meters; the height of the reduction section is 0.5 meters, and the angle between the side wall of the reduction section and the axis is 45 degrees; the diameter of the second lifting section is 0.5 meters and its height is 3 meters.

[0085] The raw material 1-hexene enters the fluidized bed catalytic converter from the feed pipeline at the bottom of the reaction zone, and then enters the reaction zone through the gas-solid mixed fluid distributor, and contacts with the TCC-1 catalyst at a temperature of about 650°C for the first catalytic conversion reaction. The catalyst density in the reaction zone is 90kg / m 3 , and no cooling medium was injected at the outlet, and the weight ratio of catalyst TCC-1 to raw material 1-pentene was 20:1. The operating conditions and product distribution are shown in Table 2.

[0086] Table 2

[0087]

[0088]

[0089] Example 3

[0090] The test of Example 3 was carried out according to Figure 4 The process shown in the figure is carried out, wherein the reaction raw material of the first catalytic conversion reactor is 1-pentene, and the reaction raw material of the second catalytic conversion reactor is heavy oil I. The catalyst is TCC-1. The parameters of the fluidized bed catalytic conversion device in this embodiment are the same as those of the fluidized bed catalytic conversion device in Example 1.

[0091] The raw material 1-pentene enters the first catalytic conversion reactor through the feed pipeline on the side of the reaction zone, and then enters the reaction zone of the first catalytic conversion reactor through the annular gas-solid mixed fluid distributor, and contacts with the TCC-1 catalyst to carry out the first catalytic conversion reaction. The catalyst density in the reaction zone is 400 kg / m 3 The reaction temperature is 650°C, the reaction pressure is 0.2MPa, the reaction time is 0.5s, the weight ratio of catalyst TCC-1 and raw material 1-hexene is 30:1, and water is used as the cooling medium to quickly cool the post-reaction logistics.

[0092] Heavy oil I contacts the TCC-1 catalyst in the reaction zone of the second catalytic conversion reactor to undergo a catalytic conversion reaction to obtain a second reactant stream. The reaction temperature is 550° C., the reaction pressure is 0.2 MPa, the reaction time is 5 s, and the weight ratio of the catalytic conversion catalyst TCC-1 to the heavy oil I is 10:1.

[0093] The reaction conditions and product distribution are shown in Table 3.

[0094] Comparative Example 3

[0095] The test of Example 3 was carried out according to the method of Example 3, wherein the reaction raw material of the first catalytic conversion reactor was 1-pentene, and the catalyst density in the reaction zone was 90 kg / m 3 The reaction raw material of the second catalytic conversion reactor is heavy oil I, and the catalyst is TCC-1. The difference between it and Example 3 is that no cooling medium is introduced into the first catalytic conversion reactor.

[0096] The reaction conditions and product distribution are shown in Table 3.

[0097] Table 3

[0098]

[0099] It can be seen from the data in Table 2 and Table 3 that the method provided by the present invention can significantly increase the content of light olefins in the product by increasing the density of the catalyst bed and shortening the residence time of the reactants in the reaction zone; at the same time, by introducing a cooling medium in the cooling zone to quickly reduce the temperature of the reaction materials, the occurrence of side reactions such as thermal cracking and secondary reactions can be significantly inhibited, thereby improving the yield and selectivity of light olefins in the product.

[0100] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0102] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for increasing the production of light olefins, characterized in that: The method comprises the following steps: The olefin-rich feedstock is brought into contact with the first thermally regenerated catalyst and undergoes a first catalytic conversion reaction in the dense fluidized bed of the first catalytic conversion reactor. The post-reaction logistics is rapidly cooled in a cooling zone near the top of the first catalytic conversion reactor, and the post-reaction logistics is cooled to a target temperature of 450-530°C before being sent out of the first catalytic conversion reactor.

2. The method according to claim 1, wherein: The first catalytic conversion reactor includes, from bottom to top, a first lifting section, an expansion section, a dense phase fluidization section, a reduction section, and a second lifting section; the angle between the side wall of the expansion section and the axis is 5-60 degrees; the ratio of the diameter to the height of the dense phase fluidization section is (0.1-10): 1; the angle between the side wall of the reduction section and the axis is 5-60 degrees; The head of the first lifting section is provided with a first heat regeneration catalyst inlet and a lifting medium inlet; A raw material inlet is provided in the middle of the first lifting section; A gas-solid mixed fluid distributor is also provided at the tail of the first lifting section; The cooling zone is arranged at the tail of the dense phase fluidization section.

3. The method according to claim 1, wherein: The cooling zone is provided with a plurality of fluid distributors for introducing the cooling medium, and the fluid distributors are arranged in a ring shape along the circumference of the first catalytic conversion reactor; The cooling medium is a coolant and / or a cooled regenerated catalyst; the coolant is selected from at least one of liquefied gas, crude gasoline, stabilized gasoline, diesel, heavy diesel, water and olefins with eight or more carbon atoms.

4. The method according to claim 1, wherein: The reacted logistics is cooled to the target temperature within 0.5-2 seconds, preferably within 0.5-1 second.

5. The method according to claim 1, wherein: The catalyst density of the first thermally regenerated catalyst in the dense phase fluidized bed of the first catalytic conversion reactor is 100-700 kg / m 3 , preferably 300-600kg / m 3 , more preferably 400-500kg / m 3 .

6. The method according to claim 1, wherein: The conditions of the first catalytic conversion reaction include: reaction temperature of 500-800°C, preferably 600-700°C, more preferably 650-700°C; reaction time of 0.1-20s, preferably 0.1-10s, more preferably 0.2-0.5s; reaction pressure of 0.05-2MPa, preferably 0.1-0.6MPa; The weight ratio of the first thermally regenerated catalyst to the olefin-rich feedstock is (1-200):1, preferably (10-100):

1.

7. The method according to claim 1, wherein: Based on the total weight of the first thermally regenerated catalyst, the first thermally regenerated catalyst comprises 1-50 wt% of molecular sieve, 5-99 wt% of inorganic oxide and 0-70 wt% of clay; The molecular sieve is selected from at least one of a ZSM-5 series molecular sieve and a SAPO series molecular sieve; The inorganic oxide is selected from at least one of silicon dioxide and aluminum oxide; The clay is selected from at least one of kaolin and halloysite.

8. The method according to claim 1, wherein: The olefin-rich raw material is a gas phase feed; The content of C4-C8 olefins in the olefin-rich raw material is 50-100wt%, preferably 80-100wt%, and more preferably 90-100wt%; Preferably, the olefin-rich feedstock is selected from at least one of the C4 and above fractions produced by an alkane dehydrogenation unit, the C4 and above fractions produced by a catalytic cracking unit in a refinery, the C4 and above fractions produced by a steam cracking unit in an ethylene plant, the C4 and above olefin-rich fractions produced as a by-product of MTO, and the C4 and above olefin-rich fractions produced as a by-product of MTP.

9. The method according to claim 1, wherein: The method further comprises the steps of: performing gas-solid separation on the post-reaction logistics to obtain a first reaction oil gas and a first spent catalyst, and then performing a charring regeneration treatment on the first spent catalyst and returning it to the first catalytic conversion reactor; Or include the following steps: The heavy hydrocarbon oil is brought into contact with the second thermally regenerated catalyst in the second catalytic conversion reactor to perform a second catalytic conversion reaction, thereby obtaining a reaction oil gas containing light oil and a second catalyst to be regenerated; when the temperature of the reaction oil gas containing light oil and the second catalyst to be regenerated in the upper region of the reaction zone of the second catalytic conversion reactor exceeds 530° C., a cooling zone is provided downstream of the reaction zone, and the reaction oil gas containing light oil and the second catalyst to be regenerated are cooled to below 530° C.; Then, the cooled reaction oil gas containing light oil, the second catalyst to be regenerated and the post-reaction stream are mixed, and the mixed stream is subjected to a first separation to obtain a reaction stream containing light olefins and a catalyst to be regenerated; The reaction flow containing light olefins is distilled to separate dry gas, light olefins and C4 and above distillates, the C4 and above distillates are subjected to a second separation and the separated olefin-rich components are returned to the first catalytic conversion reactor; and the spent catalyst is charred and regenerated and the regenerated catalyst is returned to the first catalytic conversion reactor and the second catalytic conversion reactor.

10. The method according to claim 9, wherein: The heavy hydrocarbon oil is selected from at least one of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil, heavy aromatic raffinate oil, coal liquefaction oil, oil sand oil and shale oil; The conditions of the second catalytic conversion reaction include: reaction temperature of 500-600°C, preferably 530-580°C; reaction pressure of 0.01-1MPa, preferably 0.05-1MPa; reaction time of 0.01-80s, preferably 0.1-60s; The weight ratio of the second thermally regenerated catalyst to the heavy hydrocarbon oil is (1-100):1, preferably (3-50):1.

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