A catalytic cracking method and device

Abstract

The present disclosure relates to a catalytic cracking method and device. The method firstly performs heat exchange treatment on a high-temperature regenerated catalyst and a low-temperature cooling medium to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium; then, the obtained low-temperature regenerated catalyst is contacted with a catalytic cracking feedstock to reduce the contact temperature of the oil agent, inhibit the thermal cracking reaction of the catalytic cracking feedstock, and reduce the dry gas and coke yields; at the same time, the obtained high-temperature cooling medium is divided into multiple streams and sent to different parts of a reactor, which can, on the one hand, recycle the heat of the regenerated catalyst, on the other hand, reduce the hydrocarbon partial pressure in the reactor, and on the other hand, improve the temperature distribution in the reactor, so that the temperature distribution of each part in the reactor is more uniform, optimize the reaction conditions at different positions, and thus improve the product distribution.

Description

Technical Field

[0001] The present disclosure relates to the technical field of petrochemical industry, and in particular, to a catalytic cracking method and device. Background Art

[0002] The catalytic cracking process is a very important secondary processing method for petroleum. Through the catalytic cracking method, more than 70% of gasoline blending components and more than 30% of propylene are produced. Therefore, the catalytic cracking process plays a pivotal role in the refinery. In recent years, with the continuous deepening of the heaviness and inferiority of crude oil, the heaviness of the raw materials processed by the catalytic cracking unit has become higher and higher. In the catalytic cracking process, the temperature of the regenerated catalyst is close to 700℃. When the heavy catalytic cracking raw material contacts the regenerated catalyst at this temperature, thermal cracking reaction is prone to occur, producing more dry gas and coke, resulting in excessive coking of the catalyst. The over-coked catalyst will affect the conversion of the raw material, increase the yield of low-value products in the product, and bring adverse effects on the long-term operation of the catalytic cracking unit.

[0003] CN101161786A discloses a method for converting petroleum hydrocarbons. In this method, the hot regenerated catalyst is returned to the bottom of the reactor after cooling, and is contacted with the preheated raw oil to carry out cracking reaction. The resulting catalyst to be regenerated is transported to the regenerator for charring and regeneration after stripping, and then recycled or part of it is directly fed into the mixer at the bottom of the reactor, thereby reducing the oil contact temperature, improving the contact state between the raw oil and the catalyst, and thus increasing the yield and selectivity of the target product and improving the properties of the target product.

[0004] The above technology improves product distribution by lowering the oil-agent contact temperature, thereby increasing the yield of the target product and effectively reducing the yield of dry gas and coke. However, while lowering the oil-agent contact temperature, the heat of the regenerated catalyst is not effectively utilized. Summary of the invention

[0005] The purpose of the present disclosure is to solve the problem of insufficient heat utilization of regenerated catalyst while reducing the oil agent contact temperature in the prior art, and to provide a catalytic cracking method and device.

[0006] In order to achieve the above object, the present disclosure provides a catalytic cracking method, which comprises the following operations:

[0007] S01. The high temperature regenerated catalyst is subjected to heat exchange treatment with a low temperature cooling medium to obtain a low temperature regenerated catalyst and a high temperature cooling medium;

[0008] S02. The low-temperature regenerated catalyst is fed to the bottom of the reactor and contacted with the preheated catalytic cracking feedstock, so that the preheated catalytic cracking feedstock undergoes a catalytic cracking reaction to obtain a reaction oil gas and a catalyst to be regenerated;

[0009] wherein, at any time before the catalytic cracking reaction is completed, multiple streams of the high-temperature cooling medium are fed into the reactor from different locations of the reactor;

[0010] S03. Send the reaction oil gas to a subsequent treatment device for subsequent treatment; and send the catalyst to be regenerated into a regenerator for regeneration treatment after stripping to obtain a high-temperature regenerated catalyst, and return the high-temperature regenerated catalyst to the operation S01 for the heat exchange treatment.

[0011] Optionally, in operation S01, the heat exchange treatment is performed in a heat exchange section, and the heat exchange section is provided with a heat exchanger, and the heat exchanger includes at least one of a coil heat exchanger, a sleeve heat exchanger and a shell and tube heat exchanger, preferably a coil heat exchanger.

[0012] Optionally, the temperature of the high-temperature regeneration catalyst is 680-730°C, preferably 690-720°C; the temperature of the low-temperature cooling medium is 150-300°C, preferably 200-250°C;

[0013] The temperature of the low-temperature regeneration catalyst is 640-700°C, preferably 650-690°C; the temperature of the high-temperature cooling medium is 400-600°C, preferably 450-550°C.

[0014] Optionally, the cooling medium includes at least one of water, low-pressure steam, medium-pressure steam, high-pressure steam and dry gas, preferably water and / or low-pressure steam, more preferably low-pressure steam.

[0015] Optionally, in operation S02, the weight of the high-temperature cooling medium entering the reactor is 0.05 to 0.35 parts by weight, preferably 0.10 to 0.30 parts by weight, relative to 1 part by weight of the catalytic cracking feedstock.

[0016] Optionally, the catalytic cracking feedstock includes at least one 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, and animal and vegetable oils;

[0017] The temperature of the preheated catalytic cracking feedstock is 250-450°C, preferably 300-380°C.

[0018] Optionally, the conditions of the catalytic cracking reaction include: a reaction temperature of 480 to 620°C, a reaction pressure of 0 to 0.2 MPa (gauge pressure), and a weight hourly space velocity of 2 to 25 h -1 , the mass ratio of agent to oil is (4~20):1.

[0019] Optionally, the reactor comprises at least one of a riser reactor, a fluidized bed reactor and a fixed bed reactor, and the riser reactor comprises a constant diameter riser reactor and / or a variable diameter riser reactor.

[0020] Optionally, the catalyst is a catalytic cracking catalyst, and based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst contains 35 to 60 weight percent of Al 2 O 3 and 40-65 wt% SiO 2 The specific surface area of ​​the catalytic cracking catalyst is 150 to 250 m 2 / g, the pore volume is 0.02~0.55ml / g, and the particle size is 15~140μm.

[0021] Optionally, in operation S02, 1 to 10 streams of the high-temperature cooling medium are fed into the reactor from different locations of the reactor along the flow direction of the reactant stream, wherein the distance between any two adjacent locations on the reactor for the high-temperature cooling medium to enter is 0.5 to 8 m;

[0022] Preferably, the number of strands of the high-temperature cooling medium is 2 to 6, and the distance between any two adjacent parts is 1 to 5 m.

[0023] Optionally, the flow ratio of any two streams of the high-temperature cooling medium is (0.2-3):1, preferably (0.5-1.5):1.

[0024] The present disclosure also provides a catalytic cracking device, which includes a pre-lifting section, a heat exchange section, a reactor and a regenerator;

[0025] The heat exchange section is provided with a heat exchanger, the heat exchanger has a regeneration catalyst chamber and a cooling medium chamber, the inlet of the regeneration catalyst chamber is connected to the outlet of the pre-lift section, and the outlet of the regeneration catalyst chamber is connected to the catalyst inlet of the reactor;

[0026] A plurality of cooling medium inlets are provided on the side wall of the reactor, and the plurality of cooling medium inlets are respectively connected to the outlets of the cooling medium cavity of the heat exchanger;

[0027] The regenerator is used to regenerate the catalyst to be regenerated from the reactor, and the regenerated catalyst outlet is communicated with the inlet of the pre-lifting section.

[0028] Through the above technical scheme, in the catalytic cracking method provided by the present disclosure, the high-temperature regenerated catalyst and the low-temperature cooling medium are first subjected to heat exchange treatment to obtain the low-temperature regenerated catalyst and the high-temperature cooling medium; then, the obtained low-temperature regenerated catalyst is contacted with the catalytic cracking raw material to reduce the contact temperature of the oil agent, inhibit the thermal cracking reaction of the catalytic cracking raw material, and reduce the dry gas and coke yields; at the same time, the obtained high-temperature cooling medium is divided into multiple strands and sent to different parts of the reactor, which can recycle the heat of the regenerated catalyst on the one hand, reduce the hydrocarbon partial pressure in the reactor on the other hand, and improve the temperature distribution in the reactor on the other hand, so that the temperature distribution of each part in the reactor is more uniform, optimize the reaction conditions at different positions, and thus improve the product distribution. Therefore, this method can not only fully utilize the heat of the regenerated catalyst while reducing the contact temperature of the oil agent, but also effectively improve the product distribution of the catalytic cracking reaction and reduce the dry gas and coke yields.

[0029] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0031] Figure 1 The schematic diagram of the structure of a catalytic cracking unit disclosed in the present invention is shown;

[0032] Figure 2 The structural diagram of another catalytic cracking unit disclosed in the present invention is schematically shown;

[0033] Figure 3 The structural diagram of another catalytic cracking unit disclosed in the present invention is schematically shown;

[0034] Figure 4 A schematic diagram of a coil heat exchanger disclosed in the present invention is schematically shown.

[0035] Description of Reference Numerals

[0036] 1-1 Pre-lift section 1-2 Heat exchange section

[0037] 1-3 Regeneration catalyst delivery pipeline 1-4 First reaction zone

[0038] 1-5 Second reaction zone 1-6 Third reaction zone

[0039] 101 Pre-lifting medium 102 Low temperature cooling medium

[0040] 103 Catalytic cracking feedstock 104 High temperature cooling medium DETAILED DESCRIPTION

[0041] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0042] The first aspect of the present disclosure provides a catalytic cracking method, which includes the following operations: S01. subjecting a high-temperature regenerated catalyst to heat exchange treatment with a low-temperature cooling medium to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium; S02. sending the low-temperature regenerated catalyst to the bottom of a reactor and contacting it with a preheated catalytic cracking feedstock, so that the preheated catalytic cracking feedstock undergoes a catalytic cracking reaction to obtain reaction oil gas and a catalyst to be regenerated; wherein, at any time before the completion of the catalytic cracking reaction, multiple streams of the high-temperature cooling medium are sent into the reactor from different parts of the reactor; S03. sending the reaction oil gas to a subsequent treatment device for subsequent treatment; and sending the catalyst to be regenerated into a regenerator after stripping for regeneration treatment to obtain a high-temperature regenerated catalyst, and returning the high-temperature regenerated catalyst to operation S01 for the heat exchange treatment.

[0043] In the present disclosure, specifically, the high-temperature cooling medium obtained by heat exchange treatment can be first divided into multiple streams, and then each stream of high-temperature cooling medium can be sent into the reactor. Further, each stream of high-temperature cooling medium can be sent to multiple preset locations in the reactor respectively, or each stream of high-temperature cooling medium can be evenly sent to different locations in the reactor.

[0044] In the present disclosure, a high-temperature regenerated catalyst is first subjected to heat exchange treatment with a low-temperature cooling medium to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium; then, the obtained low-temperature regenerated catalyst is contacted with a catalytic cracking feedstock to reduce the contact temperature of the oil agent, inhibit the thermal cracking reaction of the catalytic cracking feedstock, and reduce the dry gas and coke yields; at the same time, the obtained high-temperature cooling medium is divided into multiple strands and sent to different parts of the reactor, which can, on the one hand, recycle the heat of the regenerated catalyst, on the other hand, reduce the hydrocarbon partial pressure in the reactor, and on the other hand, improve the temperature distribution in the reactor, so that the temperature distribution of each part in the reactor is more uniform, optimize the reaction conditions at different positions, and thus improve the product distribution. Therefore, this method can not only fully utilize the heat of the regenerated catalyst while reducing the contact temperature of the oil agent, but also effectively improve the product distribution of the catalytic cracking reaction and reduce the dry gas and coke yields.

[0045] According to the present disclosure, in operation S01, the heat exchange treatment may be performed in a heat exchange section, and the heat exchange section may be provided with a heat exchanger, and the heat exchanger may include at least one of a coil heat exchanger, a sleeve heat exchanger, and a shell and tube heat exchanger, preferably a coil heat exchanger.

[0046] According to the present disclosure, before the heat exchange treatment, the temperature of the high-temperature regeneration catalyst and the low-temperature cooling medium can vary within a certain range. For example, the temperature of the high-temperature regeneration catalyst can be 680-730°C, preferably 690-720°C; the temperature of the low-temperature cooling medium can be 150-300°C, preferably 200-250°C.

[0047] After the heat exchange treatment, the temperature of the low-temperature regeneration catalyst and the high-temperature cooling medium can vary within a certain range. For example, the temperature of the low-temperature regeneration catalyst can be 640-700°C, preferably 650-690°C; the temperature of the high-temperature cooling medium can be 400-600°C, preferably 450-550°C.

[0048] In the present disclosure, specifically, after the high-temperature cooling medium is fed into the reactor, the temperature at the reactor outlet can be increased by 2 to 10°C, preferably 4 to 8°C.

[0049] According to the present disclosure, the cooling medium can be selected within a certain range, for example, the cooling medium can include at least one of water, low-pressure steam, medium-pressure steam, high-pressure steam and dry gas, preferably water and / or low-pressure steam, more preferably low-pressure steam. Selecting water and / or low-pressure steam as the cooling medium can significantly reduce the energy consumption and operating cost of the device.

[0050] According to the present disclosure, in operation S02, when the high-temperature cooling medium is fed into the reactor, the relative amount of the catalytic cracking feedstock and the high-temperature cooling medium can vary within a certain range. For example, relative to 1 part by weight of the catalytic cracking feedstock, the weight of the high-temperature cooling medium entering the reactor can be 0.05 to 0.35 parts by weight, preferably 0.10 to 0.30 parts by weight.

[0051] According to the present disclosure, the catalytic cracking feedstock can be selected within a certain range. For example, the catalytic cracking feedstock can include at least one 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, and animal and vegetable oils; the temperature of the preheated catalytic cracking feedstock can be 250-450°C, preferably 300-380°C.

[0052] According to the present disclosure, the conditions of the catalytic cracking reaction can be varied within a certain range. For example, the conditions of the catalytic cracking reaction may include: a reaction temperature of 480 to 620°C, a reaction pressure of 0 to 0.2 MPa (gauge pressure), and a weight hourly space velocity of 2 to 25 h -1 , the mass ratio of agent to oil is (4~20):1.

[0053] According to the present disclosure, the reactor can be selected within a certain range. For example, the reactor may include at least one of a riser reactor, a fluidized bed reactor and a fixed bed reactor. The riser reactor may include a constant diameter riser reactor and / or a variable diameter riser reactor.

[0054] According to the present disclosure, the catalyst is a catalytic cracking catalyst. Based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst may contain 35 to 60 weight percent of Al 2 O 3 and 40-65 wt% SiO 2 The specific surface area of ​​the catalytic cracking catalyst can be 150 to 250 m 2 / g, the pore volume can be 0.02-0.55 ml / g, and the particle size can be 15-140 μm.

[0055] According to the present disclosure, in operation S02, 1 to 10 streams of the high-temperature cooling medium are delivered into the reactor from different parts of the reactor along the flow direction of the reactant flow, wherein the distance between any two adjacent parts of the reactor for the high-temperature cooling medium to enter is 0.5 to 8 m; preferably, the number of streams of the high-temperature cooling medium may be 2 to 6, and the distance between any two adjacent parts may be 1 to 5 m.

[0056] According to the present disclosure, the flow ratio of any two streams of the high-temperature cooling medium may be (0.2-3):1, preferably (0.5-1.5):1.

[0057] The second aspect of the present disclosure provides a catalytic cracking device, which may include a pre-lifting section, a heat exchange section, a reactor and a regenerator; the heat exchange section is provided with a heat exchanger, and the heat exchanger has a regenerated catalyst chamber and a cooling medium chamber, the inlet of the regenerated catalyst chamber is connected to the outlet of the pre-lifting section, and the outlet of the regenerated catalyst chamber is connected to the catalyst inlet of the reactor; a plurality of cooling medium inlets are provided on the side wall of the reactor, and the plurality of cooling medium inlets are respectively connected to the outlet of the cooling medium chamber of the heat exchanger; the regenerator is used to regenerate the catalyst to be regenerated from the reactor, and its regenerated catalyst outlet is connected to the inlet of the pre-lifting section.

[0058] Figure 1 The schematic diagram of the structure of a catalytic cracking device according to an embodiment of the present disclosure is shown schematically. Figure 1In the catalytic cracking unit shown, the reactor is a riser reactor of equal diameter, having one reaction zone: the first reaction zone 1-4. In the catalytic cracking unit, the high-temperature regenerated catalyst enters the pre-lifting section 1-1 through the regenerated catalyst delivery pipeline 1-3, and then enters the regenerated catalyst cavity of the heat exchange section 1-2 under the action of the pre-lifting medium 101, and exchanges heat with the low-temperature cooling medium 102 in the cooling medium cavity of the heat exchange section 1-2 to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium; the low-temperature regenerated catalyst enters the bottom of the first reaction zone 1-4 of the reactor under the action of the lifting medium and contacts with the catalytic cracking feedstock 103, so that the catalytic cracking feedstock 103 undergoes a catalytic cracking reaction, and at the same time, the high-temperature cooling medium flowing out of the heat exchange section 1-2 is divided into multiple high-temperature cooling media 104, which are respectively introduced into different positions of the reactor.

[0059] Figure 2 The schematic diagram of the structure of another catalytic cracking unit according to an embodiment of the present disclosure is shown schematically. Figure 2 In the catalytic cracking unit shown, the reactor is a variable diameter riser reactor having three reaction zones: a first reaction zone 1-4, a second reaction zone 1-5 and a third reaction zone 1-6. In the catalytic cracking unit, the low temperature regenerated catalyst enters the bottom of the first reaction zone 1-4 of the reactor under the action of the lifting medium and contacts with the catalytic cracking feedstock 103, so that the catalytic cracking feedstock 103 undergoes catalytic cracking reaction in the first reaction zone 1-4, the second reaction zone 1-5 and the third reaction zone 1-6 in sequence.

[0060] Figure 3 The schematic diagram of the structure of another catalytic cracking unit according to an embodiment of the present disclosure is shown schematically. Figure 3 In the catalytic cracking unit shown, the reactor is obtained by combining a riser reactor and a fluidized bed reactor, and has two reaction zones: a first reaction zone 1-4 (riser reactor) and a second reaction zone 1-5 (fluidized bed reactor). In the catalytic cracking unit, the low-temperature regenerated catalyst enters the bottom of the first reaction zone 1-4 of the reactor under the action of the lifting medium and contacts with the catalytic cracking feedstock 103, so that the catalytic cracking feedstock 103 undergoes catalytic cracking reaction in the first reaction zone 1-4 (riser reactor) and the second reaction zone 1-5 (fluidized bed reactor) in turn.

[0061] In the present disclosure, specifically, the heat exchange section 1-2 may be provided with a heat exchanger, and the heat exchanger may include at least one of a coil heat exchanger, a sleeve heat exchanger and a shell and tube heat exchanger, preferably a coil heat exchanger. Figure 4 A schematic diagram of a coil heat exchanger according to an embodiment of the present disclosure is schematically shown. Figure 4 As shown, after the low-temperature cooling medium 102 flows through the coil heat exchanger, it exchanges heat with the high-temperature regenerated catalyst and is heated to obtain the high-temperature cooling medium 104 .

[0062] The present disclosure is further described below by way of examples, but the present disclosure is not limited thereby. The raw materials, reagents, instruments and equipment involved in the examples of the present disclosure can all be purchased unless otherwise specified.

[0063] In the embodiments and comparative examples of the present disclosure, the gas product can be tested by petrochemical analysis method RIPP 77-90; the coke content can be measured by petrochemical analysis method RIPP 107-90; the composition of the organic liquid product can be measured by SH / T 0558-1993 method; the light aromatics in gasoline can be measured by petrochemical analysis method RIPP82-90; the cut points of gasoline and diesel are 221°C and 331°C, respectively. Among them, the RIPP petrochemical analysis method is selected from "Petrochemical Analysis Method (RIPP Test Method)", edited by Yang Cuiding et al., Science Press, 1990".

[0064] The conversion rate of catalytic cracking feedstock and the yield of each product can be calculated according to the following formula:

[0065]

[0066]

[0067] The specific properties of the catalytic cracking feedstock oil used in the examples and comparative examples of the present disclosure are shown in Table 1; the catalytic cracking catalyst used is produced by the Qilu Branch of Sinopec Catalyst Company, and its composition and properties are shown in Table 2.

[0068] Table 1 Properties of catalytic cracking feedstock oil

[0069]

[0070] Table 2 Composition and properties of catalytic cracking catalyst CAT

[0071]

[0072] Example 1

[0073] use Figure 1 The catalytic cracking unit shown in Table 1 is used to catalytically crack the catalytic cracking feedstock oil shown in Table 1 according to the reaction conditions shown in Table 3 using the following method:

[0074] (1) exchanging heat between the high-temperature regenerated catalyst from the pre-elevation section and a low-temperature cooling medium (low-pressure steam) in a heat exchange section to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium;

[0075] (2) The low-temperature regenerated catalyst obtained in step (1) is fed into the bottom of the reactor and brought into contact with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes a catalytic cracking reaction to obtain reaction oil gas and a regenerated catalyst; at the same time, the high-temperature cooling medium flowing out of the heat exchange section is evenly divided into three streams, and the streams are evenly introduced into the reactor in a manner such that the spacing between any two adjacent streams is 5 m;

[0076] (3) The reaction oil and gas obtained in step (2) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0077] (4) The catalyst to be regenerated obtained in step (2) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0078] Comparative Example 1

[0079] The catalytic cracking feedstock oil shown in Table 1 was catalytically cracked according to the reaction conditions shown in Table 3 using the following method:

[0080] (1) sending the high-temperature regenerated catalyst from the pre-elevation section into the bottom of the reactor and contacting it with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes a catalytic cracking reaction to obtain reaction oil gas and a catalyst to be regenerated;

[0081] (2) The reaction oil and gas obtained in step (1) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0082] (3) The catalyst to be regenerated obtained in step (1) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0083] Example 2

[0084] use Figure 2 The catalytic cracking unit shown in Table 1 is used to catalytically crack the catalytic cracking feedstock oil shown in Table 1 according to the reaction conditions shown in Table 3 using the following method:

[0085] (1) exchanging heat between the high-temperature regenerated catalyst from the pre-elevation section and a low-temperature cooling medium (low-pressure steam) in a heat exchange section to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium;

[0086] (2) The low-temperature regenerated catalyst obtained in step (1) is fed into the bottom of the first reaction zone of the reactor and brought into contact with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes catalytic cracking reaction in the first reaction zone, the second reaction zone and the third reaction zone in sequence to obtain reaction oil gas and a regenerated catalyst; at the same time, the high-temperature cooling medium flowing out of the heat exchange section is evenly divided into four streams, and the streams are evenly introduced into the reactor in a manner that the interval between any two adjacent streams is 4 m;

[0087] (3) The reaction oil and gas obtained in step (2) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0088] (4) The catalyst to be regenerated obtained in step (2) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0089] Comparative Example 2

[0090] The catalytic cracking feedstock oil shown in Table 1 was catalytically cracked according to the reaction conditions shown in Table 3 using the following method:

[0091] (1) sending the high-temperature regenerated catalyst from the pre-elevation section to the bottom of the first reaction zone of the reactor and contacting it with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes catalytic cracking reaction in the first reaction zone, the second reaction zone and the third reaction zone in sequence, to obtain reaction oil gas and a catalyst to be regenerated;

[0092] (2) The reaction oil and gas obtained in step (1) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0093] (3) The catalyst to be regenerated obtained in step (1) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0094] Example 3

[0095] use Figure 3 The catalytic cracking unit shown in Table 1 is used to catalytically crack the catalytic cracking feedstock oil shown in Table 1 according to the reaction conditions shown in Table 3 using the following method:

[0096] (1) exchanging heat between the high-temperature regenerated catalyst from the pre-elevation section and a low-temperature cooling medium (low-pressure steam) in a heat exchange section to obtain a low-temperature regenerated catalyst and a high-temperature cooling medium;

[0097] (2) The low-temperature regenerated catalyst obtained in step (1) is fed into the bottom of the riser reactor and brought into contact with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes catalytic cracking reaction in the first reaction zone (riser reactor) and the second reaction zone (fluidized bed reactor) in sequence to obtain reaction oil gas and a regenerated catalyst; at the same time, the high-temperature cooling medium flowing out of the heat exchange section is evenly divided into 5 streams, and the streams are evenly introduced into the reactor in a manner such that the spacing between any two adjacent streams is 3 m;

[0098] (3) The reaction oil and gas obtained in step (2) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0099] (4) The catalyst to be regenerated obtained in step (2) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0100] Comparative Example 3

[0101] The catalytic cracking feedstock oil shown in Table 1 was catalytically cracked according to the reaction conditions shown in Table 3 using the following method:

[0102] (1) The high-temperature regenerated catalyst from the pre-lifting section is fed into the bottom of the riser reactor and brought into contact with the preheated catalytic cracking feedstock oil, so that the preheated catalytic cracking feedstock oil undergoes catalytic cracking reaction in the first reaction zone (riser reactor) and the second reaction zone (fluidized bed reactor) in sequence, to obtain reaction oil gas and a catalyst to be regenerated;

[0103] (2) The reaction oil and gas obtained in step (1) is sent to a subsequent separation device for separation to separate dry gas, liquefied gas, gasoline, diesel, slurry oil and coke therein, and the ethylene yield and propylene yield therein are calculated. The results are shown in Table 3;

[0104] (3) The catalyst to be regenerated obtained in step (1) is sent to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and the high-temperature regenerated catalyst is returned to the pre-lifting section of step (1) for recycling.

[0105] Table 3 Reaction conditions and reaction results of the embodiments and comparative examples

[0106]

[0107] It can be seen from Table 3 that the method disclosed in the present invention can effectively increase the yields of ethylene, propylene and gasoline, reduce the yields of dry gas and coke, and effectively utilize low-quality low-pressure steam.

[0108] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0109] 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 disclosure will not further describe various possible combinations.

[0110] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A catalytic cracking method, characterized in that: The method includes the following operations: S01. Perform heat exchange treatment on the high-temperature regenerated catalyst and the low-temperature cooling medium to obtain the low-temperature regenerated catalyst and the high-temperature cooling medium; the temperature of the low-temperature regenerated catalyst is 640-700°C; the temperature of the high-temperature regenerated catalyst is 680-730°C; S02. sending the low-temperature regenerated catalyst into the bottom of the reactor and contacting it with the preheated catalytic cracking feedstock, so that the preheated catalytic cracking feedstock undergoes a catalytic cracking reaction to obtain reaction oil gas and a catalyst to be regenerated; Wherein, at any time before the catalytic cracking reaction is completed, multiple streams of the high-temperature cooling medium are fed into the reactor from different locations of the reactor; the temperature of the high-temperature cooling medium is 400-600°C; S03. Send the reaction oil gas to a subsequent treatment device for subsequent treatment; and send the regenerated catalyst to a regenerator for regeneration after stripping to obtain a high-temperature regenerated catalyst, and return the high-temperature regenerated catalyst to the operation S01 for the heat exchange treatment.

2. The catalytic cracking method according to claim 1, characterized in that: In operation S01, the heat exchange treatment is performed in a heat exchange section, and the heat exchange section is provided with a heat exchanger, and the heat exchanger includes at least one of a coil heat exchanger, a sleeve heat exchanger, and a shell and tube heat exchanger.

3. The catalytic cracking method according to claim 2, characterized in that: The heat exchanger is a coil heat exchanger.

4. The catalytic cracking method according to claim 1, characterized in that: The temperature of the high-temperature regeneration catalyst is 690-720°C; the temperature of the low-temperature cooling medium is 150-300°C; The temperature of the high-temperature cooling medium is 450-550°C.

5. The catalytic cracking method according to claim 4, characterized in that: The temperature of the low temperature cooling medium is 200-250°C; The temperature of the low-temperature regeneration catalyst is 650-690°C.

6. The catalytic cracking method according to claim 1, characterized in that: The cooling medium includes at least one of water, low-pressure steam, medium-pressure steam, high-pressure steam and dry gas.

7. The catalytic cracking method according to claim 6, characterized in that: The cooling medium is water and / or low-pressure steam.

8. The catalytic cracking method according to claim 7, characterized in that: The cooling medium is low-pressure steam.

9. The catalytic cracking method according to claim 1, characterized in that: In operation S02, the weight of the high-temperature cooling medium entering the reactor is 0.05 to 0.35 parts by weight relative to 1 part by weight of the catalytic cracking feedstock.

10. The catalytic cracking method according to claim 9, characterized in that: In operation S02, the weight of the high-temperature cooling medium entering the reactor is 0.10 to 0.30 parts by weight relative to 1 part by weight of the catalytic cracking feedstock.

11. The catalytic cracking method according to any one of claims 1 to 10, characterized in that: The catalytic cracking feedstock includes at least one 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, and animal and vegetable oil; The temperature of the preheated catalytic cracking feedstock is 250-450°C.

12. The catalytic cracking method according to claim 11, characterized in that: The temperature of the preheated catalytic cracking feedstock is 300-380°C.

13. The catalytic cracking method according to any one of claims 1 to 10, characterized in that: The conditions of the catalytic cracking reaction include: reaction temperature of 480-620°C, reaction pressure of 0-0.2MPa (gauge pressure), weight hourly space velocity of 2-25h -1 , the mass ratio of agent to oil is (4~20):

1.

14. The catalytic cracking method according to any one of claims 1 to 10, characterized in that: The reactor comprises at least one of a riser reactor, a fluidized bed reactor and a fixed bed reactor, and the riser reactor comprises a constant diameter riser reactor and / or a variable diameter riser reactor.

15. The catalytic cracking method according to any one of claims 1 to 10, characterized in that: The catalyst is a catalytic cracking catalyst. Based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst contains 35-60 wt% of Al2O3 and 40-65 wt% of SiO2. The specific surface area of ​​the catalytic cracking catalyst is 150-250 m 2 / g, the pore volume is 0.02~0.55ml / g, and the particle size is 15~140μm.

16. The catalytic cracking method according to claim 1, characterized in that: In operation S02, 1 to 10 streams of the high-temperature cooling medium are fed into the reactor from different locations of the reactor along the flow direction of the reactant flow, wherein the distance between any two adjacent locations on the reactor for the high-temperature cooling medium to enter is 0.5 to 8 m.

17. The catalytic cracking method according to claim 16, characterized in that: The number of strands of the high-temperature cooling medium is 2 to 6, and the distance between any two adjacent parts is 1 to 5 m.

18. The catalytic cracking method according to claim 16 or 17, characterized in that: The flow ratio of any two streams of the high-temperature cooling medium is (0.2-3):

1.

19. The catalytic cracking method according to claim 18, characterized in that: The flow ratio of any two streams of the high-temperature cooling medium is (0.5-1.5):1.

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