Device and method for preparing olefin through combination of petroleum hydrocarbon catalytic cracking and methanol-to-olefin

Abstract

The invention provides a device and a method for preparing olefin through combination of petroleum hydrocarbon catalytic cracking and methanol-to-olefin preparation. The invention provides a device for preparing olefin through combination of petroleum hydrocarbon catalytic cracking and methanol-to-olefin, which is characterized in that a methanol-to-olefin unit, a catalyst mixing unit and a catalyst separating unit are additionally arranged on the basis of the existing catalytic cracking device; according to the invention, petroleum hydrocarbon catalytic cracking reaction and methanol-to-olefin reaction are simultaneously carried out in the same set of device, the contents of ethylene, propylene and butylene in catalytic cracking gas products are increased, the equipment cost for independently constructing a methanol-to-olefin device is reduced, and the possibility for preparing olefin by using methanol as alternative energy is provided; meanwhile, the reacted catalyst can be recycled respectively; petroleum hydrocarbon catalytic cracking and methanol-to-olefin reaction can be carried out under respective proper process conditions and under the action of the catalyst, so that the selectivity of a target product is improved to the maximum extent.

Description

An apparatus and method for the combined production of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins. Technical Field

[0001] This invention relates to the field of catalytic cracking, and specifically to an apparatus and method for the combined preparation of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins. Background Technology

[0002] Low-carbon olefins are a synthesis of small-molecule olefins such as ethylene, propylene, and butene, playing a crucial role in the modern petroleum and chemical industries. With the rapid development of my country's economy and the improvement of people's living standards, the demand for low-carbon olefins has also increased rapidly, with an annual growth rate exceeding the world average.

[0003] There are various methods for producing low-carbon olefins, with petroleum hydrocarbons being the primary feedstock used in both domestic and international processes, employing steam cracking. However, the continuous rise in oil prices has led to a tight supply of feedstocks and increased production costs for low-carbon olefins. Methanol, as an alternative energy source, is widely available and can be produced from coal, natural gas, and biomass. Its total production capacity is continuously increasing worldwide, with supply consistently exceeding demand. Currently, the methanol-to-olefins (MTO) technology has matured and is considered the most promising alternative to the naphtha route for olefin production.

[0004] Most enterprises producing low-carbon olefins are equipped with facilities that use petroleum hydrocarbons as raw materials to produce low-carbon olefins. Under existing technology, it is possible to combine petroleum hydrocarbon catalytic cracking with methanol-to-olefins (MTO) to produce olefins. However, since the reaction mechanisms of petroleum hydrocarbon catalytic cracking and MTO are different, the optimal catalysts and process conditions required for the two reactions are also different. How to achieve the reaction of petroleum hydrocarbons and methanol under their respective suitable catalysts and process conditions on the basis of existing facilities, so as to maximize the selectivity of the target product, is a problem that needs to be solved. Summary of the Invention

[0005] This invention provides an apparatus for the combined production of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins (MTO). Based on existing catalytic cracking units, this apparatus combines petroleum hydrocarbon catalytic cracking and MTO reactions, enabling petroleum hydrocarbons and methanol to react under their respective suitable catalysts and process conditions. This maximizes the selectivity of the target product, increases the content of ethylene, propylene, and butene in the catalytic cracking gas products, and reduces the equipment cost of building a separate MTO unit.

[0006] The present invention also provides a method for preparing olefins by combining petroleum hydrocarbon catalytic cracking and methanol-to-olefins using the above-described apparatus.

[0007] The first aspect of the present invention provides an apparatus for the combined preparation of olefins by petroleum hydrocarbon catalytic cracking and methanol-to-olefins, comprising a petroleum hydrocarbon catalytic cracking unit, a first gas-solid separation unit, a stripping unit, a catalyst mixing unit, a methanol-to-olefins unit, a catalyst separation unit, a first catalyst regeneration unit, a second gas-solid separation unit, a second catalyst regeneration unit, and a third gas-solid separation unit.

[0008] The product outlet of the petroleum hydrocarbon catalytic cracking unit is connected to the first inlet of the first gas-solid separation unit. The solid phase outlet of the first gas-solid separation unit is connected to the stripping material inlet of the stripping unit. The first stripping material outlet of the stripping unit is connected to the first catalyst inlet of the catalyst mixing unit. The catalyst outlet of the catalyst mixing unit is connected to the catalyst inlet of the methanol-to-olefins unit. The gas phase outlet of the catalyst mixing unit is connected to the second inlet of the first gas-solid separation unit. The catalyst outlet of the methanol-to-olefins unit is connected to the inlet of the catalyst separation unit. The first outlet of the catalyst separation unit is connected to the first catalyst inlet of the first catalyst regeneration unit. The catalyst outlet of the first catalyst regeneration unit is connected to the catalyst inlet of the second gas-solid separation unit. The catalyst outlet of the second gas-solid separation unit is connected to the catalyst inlet of the petroleum hydrocarbon catalytic cracking unit. The second outlet of the catalyst separation unit is connected to the catalyst inlet of the second catalyst regeneration unit. The catalyst outlet of the second catalyst regeneration unit is connected to the catalyst inlet of the third gas-solid separation unit. The catalyst outlet of the third gas-solid separation unit is connected to the second catalyst inlet of the catalyst mixing unit.

[0009] As described above, the stripping unit further includes a second stripped product outlet, which is connected to the second catalyst inlet of the first catalyst regeneration unit.

[0010] As described above, the petroleum hydrocarbon catalytic cracking unit is a riser reactor, the first gas-solid separation unit, the second gas-solid separation unit, and the third gas-solid separation unit are settling tanks, the stripping unit is a stripper, the methanol-to-olefins unit is a fluidized bed reactor, the first catalyst regeneration unit and the second catalyst regeneration unit are catalytic cracking regenerators, the catalyst mixing unit is a catalyst mixer, and the catalyst separation unit is a solid catalyst separator.

[0011] In the apparatus described above, the fluidized bed reactor is one of a fast fluidized bed, a turbulent fluidized bed, a dispersed fluidized bed, or a dense phase fluidized bed; the catalyst separation unit is one or a combination of several of a cyclone separator, a centrifugal separator, a sieve separator, a filtration separator, a gravity separator, or a magnetic separator.

[0012] A second aspect of the present invention provides a method for preparing olefins by a combination of petroleum hydrocarbon catalytic cracking and methanol-to-olefins, which is performed by the apparatus described above;

[0013] Includes the following steps:

[0014] The feedstock, including petroleum hydrocarbons and catalytic cracking catalyst, is introduced into the petroleum hydrocarbon catalytic cracking unit through the feedstock inlet of the petroleum hydrocarbon catalytic cracking unit to carry out a first reaction, and a first product including a first catalyst to be regenerated and a first olefin gas is obtained.

[0015] The first product is fed into the first gas-solid separation unit through the product outlet of the petroleum hydrocarbon catalytic cracking unit to perform first gas-solid separation, resulting in a first catalyst to be regenerated and a first olefin gas. The first olefin gas rises and is output through the gas phase outlet of the first gas-solid separation unit, while the first catalyst to be regenerated descends and enters the stripping unit for stripping treatment to obtain a stripped catalyst to be regenerated.

[0016] The stripping catalyst to be regenerated enters the catalyst mixing unit through the first catalyst inlet of the catalyst mixing unit, and is mixed with the regenerated methanol-to-olefins catalyst that is fed into the second catalyst inlet of the catalyst mixing unit through the catalyst outlet of the third gas-solid separation unit. The mixture then enters the methanol-to-olefins unit and undergoes a second reaction with the methanol in the methanol-to-olefins unit to obtain the second catalyst to be regenerated and the second olefin gas.

[0017] The second olefin gas enters the first gas-solid separation unit through the outlet of the catalyst mixing unit and is output from the gas phase outlet of the first gas-solid separation unit;

[0018] The second catalyst to be regenerated enters the catalyst separation unit through the catalyst inlet of the catalyst separation unit. After separation in the catalyst separation unit, it yields a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated is then transported through the catalyst first outlet of the catalyst separation unit to the catalyst first inlet of the first catalyst regeneration unit for catalyst regeneration treatment, yielding a second product including regenerated flue gas and regenerated catalytic cracking catalyst. The second product enters the second gas-solid separation unit through the outlet of the first catalyst regeneration unit for second gas-solid separation, yielding a first regenerated flue gas and regenerated catalytic cracking catalyst. The first regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit. The regenerated catalytic cracking catalyst is fed into the petroleum hydrocarbon catalytic cracking unit via the catalyst outlet of the second gas-solid separation unit; the methanol-to-olefins catalyst to be regenerated is transported to the catalyst inlet of the second catalyst regeneration unit via the second catalyst outlet of the catalyst separation unit, and enters the second catalyst regeneration unit for catalyst regeneration treatment to obtain a third product including regenerated flue gas and regenerated methanol-to-olefins catalyst; the third product enters the third gas-solid separation unit via the outlet of the second catalyst regeneration unit for third gas-solid separation to obtain second regenerated flue gas and regenerated methanol-to-olefins catalyst; the second regenerated flue gas is output via the gas phase outlet of the third gas-solid separation unit, and the regenerated methanol-to-olefins catalyst is fed into the catalyst mixing unit via the catalyst outlet of the third gas-solid separation unit.

[0019] In the method described above, in the stripping unit, a portion of the stripped catalyst to be regenerated enters the first catalyst regeneration unit through the second stripped product outlet of the stripping unit, and the remaining portion of the stripped catalyst to be regenerated enters the catalyst mixing unit through the first stripped product outlet of the stripping unit.

[0020] In the method described above, the mass ratio of methanol feedstock entering the methanol-to-olefins unit to petroleum hydrocarbon feedstock entering the petroleum hydrocarbon catalytic cracking unit is 0.01 to 5.

[0021] In the method described above, the reaction conditions for the first reaction are: a reaction temperature of 480–600°C, a mass ratio of the catalytic cracking catalyst to the petroleum hydrocarbon feedstock of 4–20, a reaction time of 0.5–8 s, and a mass ratio of the atomized steam to the petroleum hydrocarbon feedstock of 0.02–0.2.

[0022] The reaction conditions for the second reaction are as follows: the reaction temperature is 420-560℃, the mass ratio of the mixed catalyst to the methanol feedstock is 5-100, the reaction time is 0.5-20s, and the mass ratio of water to methanol in the methanol feedstock is 0-1.

[0023] In the method described above, the mass ratio of the stripping catalyst to be regenerated entering from the catalyst mixing unit to the regenerated methanol-to-olefins catalyst entering from the catalyst mixing unit is 0.01 to 50.

[0024] In the method described above, the mass ratio of the stripped catalyst to be regenerated entering the catalyst mixing unit from the stripping unit to the stripped catalytic cracking catalyst to be regenerated entering the first catalyst regeneration unit from the stripping unit is 0.01 to 20.

[0025] The apparatus for combined petroleum hydrocarbon catalytic cracking and methanol-to-olefins (MTO) to olefins provided by this invention, by adding a MTO unit, a catalyst mixing unit, and a catalyst separation unit to the existing catalytic cracking unit, not only realizes the simultaneous occurrence of petroleum hydrocarbon catalytic cracking and MTO reactions in the same unit, but also increases the content of ethylene, propylene, and butene in the catalytic cracking gas products, reduces the equipment cost of building a separate MTO unit, and makes it possible to use methanol as an alternative energy source for olefin production. Simultaneously, it allows for the separate recovery and treatment of the catalysts after the reaction. The catalyst generated by the catalytic cracking reaction of petroleum hydrocarbon feedstock provides a rich "carbon pool" for the MTO reaction, initiating and promoting the rapid conversion of methanol into low-carbon olefins. Furthermore, the petroleum hydrocarbon catalytic cracking and MTO reactions occur under their respective suitable process conditions and catalysts, avoiding the limitations of using the same catalyst or the same process conditions. The petroleum hydrocarbon catalytic cracking and MTO reactions can simultaneously maximize the selectivity of their respective target products. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 is a schematic diagram of an apparatus for preparing olefins by combining petroleum hydrocarbon catalytic cracking and methanol-to-olefins in one embodiment of the present invention.

[0028] Figure 2 is a schematic diagram of an apparatus for preparing olefins by combining petroleum hydrocarbon catalytic cracking and methanol-to-olefins in one embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of the apparatus for preparing olefins by catalytic cracking of petroleum hydrocarbons provided in the comparative example of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1- Petroleum hydrocarbon feedstocks;

[0032] 2-Pre-lift air;

[0033] 3-Petroleum hydrocarbon catalytic cracking unit;

[0034] 4-First gas-solid separation unit;

[0035] 5-Stripping unit;

[0036] 6-Methanol to Olefins Unit;

[0037] 7-Methanol feedstock;

[0038] 8-Stripping steam;

[0039] 9-First connecting pipe;

[0040] 10 - First catalyst regeneration unit;

[0041] 11-Second gas-solid separation unit;

[0042] 12-Second connecting pipe;

[0043] 13-First regeneration prevailing wind;

[0044] 14 - First Regenerated Flue Gas;

[0045] 15-olefin gases;

[0046] 16 - Sixth connecting pipe;

[0047] 17 - Fifth connecting pipe;

[0048] 18-Third connecting pipe;

[0049] 19-Fourth connecting pipe;

[0050] 20-Catalyst Mixing Unit;

[0051] 21-Catalyst separation unit;

[0052] 22 - Second catalyst regeneration unit;

[0053] 23-Third gas-solid separation unit;

[0054] 24 - Seventh connecting pipe;

[0055] 25 - Eighth connecting pipe;

[0056] 26 - Second regenerated prevailing wind;

[0057] 27 - Second regenerated flue gas. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0059] The first aspect of the present invention provides an apparatus for the combined preparation of olefins by petroleum hydrocarbon catalytic cracking and methanol-to-olefins, as shown in FIG1, including a petroleum hydrocarbon catalytic cracking unit 3, a first gas-solid separation unit 4, a stripping unit 5, a catalyst mixing unit 20, a methanol-to-olefins unit 6, a catalyst separation unit 21, a first catalyst regeneration unit 10, a second gas-solid separation unit 11, a second catalyst regeneration unit 22, and a third gas-solid separation unit 23.

[0060] The product outlet of the petroleum hydrocarbon catalytic cracking unit 3 is connected to the first inlet of the first gas-solid separation unit 4. The solid phase outlet of the first gas-solid separation unit 4 is connected to the stripping material inlet of the stripping unit 5. The first stripping material outlet of the stripping unit 5 is connected to the first catalyst inlet of the catalyst mixing unit 20. The catalyst outlet of the catalyst mixing unit 20 is connected to the catalyst inlet of the methanol-to-olefins unit 6. The gas phase outlet of the catalyst mixing unit 20 is connected to the second inlet of the first gas-solid separation unit 4. The catalyst outlet of the methanol-to-olefins unit 6 is connected to the inlet of the catalyst separation unit 21. The first outlet of the catalyst separation unit 21... The catalyst outlet of the catalyst separation unit 21 is connected to the first catalyst inlet of the first catalyst regeneration unit 10, the catalyst outlet of the first catalyst regeneration unit 10 is connected to the catalyst inlet of the second gas-solid separation unit 11, the catalyst outlet of the second gas-solid separation unit 11 is connected to the catalyst inlet of the petroleum hydrocarbon catalytic cracking unit 3, the second outlet of the catalyst separation unit 21 is connected to the catalyst inlet of the second catalyst regeneration unit 22, the catalyst outlet of the second catalyst regeneration unit 22 is connected to the catalyst inlet of the third gas-solid separation unit 23, and the catalyst outlet of the third gas-solid separation unit 23 is connected to the second catalyst inlet of the catalyst mixing unit 20.

[0061] In this invention, the petroleum hydrocarbon catalytic cracking unit 3, the first gas-solid separation unit 4, the stripping unit 5, the methanol-to-olefins unit 6, the first catalyst regeneration unit 10, the second gas-solid separation unit 11, the second catalyst regeneration unit 22, the third gas-solid separation unit 23, the catalyst mixing unit 20, and the catalyst separation unit 21 are all conventional equipment in the art. For example, the petroleum hydrocarbon catalytic cracking unit 3 is a riser reactor; the first gas-solid separation unit 4, the second gas-solid separation unit 11, and the third gas-solid separation unit 23 are settling tanks; the stripping unit 5 is a stripper; the methanol-to-olefins unit 6 is a fluidized bed reactor, specifically one of a fast fluidized bed, a turbulent fluidized bed, a dispersed fluidized bed, or a dense phase fluidized bed; the first catalyst regeneration unit 10 and the second catalyst regeneration unit 22 are catalytic cracking regenerators; the catalyst mixing unit 20 is a catalyst mixer; and the catalyst separation unit 21 is a solid catalyst separator, specifically one or a combination of several separation methods such as cyclone separation, centrifugal separation, sieving separation, filtration separation, gravity separation, and magnetic separation.

[0062] The apparatus for the combined production of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins (MTO) of the present invention, based on an existing catalytic cracking apparatus, adds a MTO unit 6 and a catalyst mixing unit 20, enabling simultaneous petroleum hydrocarbon catalytic cracking and MTO reactions within the same apparatus. By separately configuring the MTO unit 6 and the petroleum hydrocarbon catalytic cracking unit 3, independent control of the petroleum hydrocarbon reaction and the methanol reaction is achieved. The third gas-solid separation unit 23 is connected to the catalyst mixing unit 20 via a fourth connecting pipe 19. By adding the catalyst mixing unit 20, the regenerated MTO catalyst can be returned to the reactor. In methanol-to-olefins unit 6, the catalytic cracking catalyst to be regenerated in stripping unit 5 enters catalyst mixing unit 20 through third connecting pipe 18, and after mixing with the regenerated methanol-to-olefins catalyst, it enters methanol-to-olefins unit 6. The catalytic cracking catalyst to be regenerated can quickly initiate and promote the methanol-to-olefins reaction, while the methanol-to-olefins catalyst can improve the selectivity of methanol to target products such as ethylene and propylene. Under the combined action of the two catalysts, methanol can be quickly and efficiently converted into target products such as ethylene and propylene, avoiding the limitation that the selectivity of target products such as ethylene and propylene is difficult to improve when using only one catalyst.

[0063] The apparatus for the combined production of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins (MTO) of the present invention, based on the existing catalytic cracking apparatus, further includes a catalyst separation unit 21. The second catalyst to be regenerated enters the catalyst separation unit 21 through a seventh connecting pipe 24. The second catalyst to be regenerated is separated by one or more of the following separation methods: cyclone separation, centrifugal separation, sieving separation, filtration separation, gravity separation, and magnetic separation, to obtain a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated enters zone A at the bottom of the catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through a first connecting pipe 9. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of the catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through an eighth connecting pipe 25.

[0064] In one specific embodiment, the first gas-solid separation unit 4 and the stripping unit 5 are integrated in the direction of gravity and coaxially connected in sequence; the catalyst mixing unit 20 and the methanol-to-olefins unit 6 are integrated in the direction of gravity and coaxially connected in sequence; the above devices are coaxially connected, which can ensure efficient and rapid separation of gas and solid phases, reduce secondary reactions, and at the same time, the catalyst descends by its own gravity, which can reduce the energy consumption of catalyst transportation.

[0065] As shown in Figure 2, in one specific embodiment, the stripping unit 5 further includes a second stripped material outlet, which is connected to the second catalyst inlet of the first catalyst regeneration unit 10.

[0066] The stripping unit 5 is connected to the first catalyst regeneration unit 10 via a sixth connecting pipe 16. The stripping catalyst to be regenerated in the stripping unit 5 can be directly input into the first catalyst regeneration unit 10 through the sixth connecting pipe 16, thereby enhancing the adjustability of the catalyst throughout the entire unit. When the methanol-to-olefins unit 6 has a small methanol throughput or requires high catalyst activity, a portion of the stripping catalyst to be regenerated can be directly input into the first catalyst regeneration unit 10 for regeneration.

[0067] The present invention does not impose too many restrictions on the first connecting pipe 9, the second connecting pipe 12, the sixth connecting pipe 16, the fourth connecting pipe 19, the seventh connecting pipe 24, and the eighth connecting pipe 25, as long as they can achieve the connection between different reaction units.

[0068] A second aspect of the present invention provides a method for preparing olefins by a combination of petroleum hydrocarbon catalytic cracking and methanol-to-olefins, which is performed by the apparatus described above;

[0069] Includes the following steps:

[0070] The feedstock, including petroleum hydrocarbons 1, is introduced into the petroleum hydrocarbon catalytic cracking unit 3 through the feedstock inlet of the petroleum hydrocarbon catalytic cracking unit 3 to carry out the first reaction, and a first product including a first catalyst to be regenerated and a first olefin gas is obtained.

[0071] The first product is fed into the first gas-solid separation unit 4 through the product outlet of the petroleum hydrocarbon catalytic cracking unit 3 for first gas-solid separation to obtain the first catalyst to be regenerated and the first olefin gas. The first olefin gas is output through the gas phase outlet of the first gas-solid separation unit 4, and the first catalyst to be regenerated is fed into the stripping unit 5 for stripping treatment to obtain the stripped catalyst to be regenerated.

[0072] The stripping catalyst to be regenerated enters the catalyst mixing unit 20 through the first catalyst inlet of the catalyst mixing unit 20, and mixes with the regenerated methanol-to-olefins catalyst that is fed into the second catalyst inlet of the catalyst mixing unit 20 through the catalyst outlet of the third gas-solid separation unit 23. The mixture then enters the methanol-to-olefins unit 6 and undergoes a second reaction with the methanol in the methanol-to-olefins unit 6 to obtain the second catalyst to be regenerated and the second olefin gas. The second olefin gas enters the first gas-solid separation unit 4 through the outlet of the catalyst mixing unit and is output from the gas phase outlet of the first gas-solid separation unit 4.

[0073] The second catalyst to be regenerated enters the catalyst separation unit 21 through the catalyst outlet of the methanol-to-olefins unit 6. After separation, the second catalyst to be regenerated yields a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated enters zone A at the bottom of the catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through the first outlet of the catalyst separation unit 21 for catalyst regeneration treatment, resulting in a second product including regenerated flue gas and regenerated catalyst. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of the catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through the second outlet of the catalyst separation unit 21 for catalyst regeneration treatment, resulting in a third product including regenerated flue gas and regenerated methanol-to-olefins catalyst.

[0074] The second product is passed through the outlet of the first catalyst regeneration unit 10 and enters the second gas-solid separation unit 11 for second gas-solid separation to obtain the first regenerated flue gas and the regenerated catalytic cracking catalyst. The first regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit 11, and the regenerated catalytic cracking catalyst is input into the petroleum hydrocarbon catalytic cracking unit 3 through the catalyst outlet of the second gas-solid separation unit 11.

[0075] The third product is introduced into the third gas-solid separation unit 23 through the outlet of the second catalyst regeneration unit 22 for third gas-solid separation to obtain the second regenerated flue gas and the regenerated methanol-to-olefins catalyst. The second regenerated flue gas is output through the gas phase outlet of the third gas-solid separation unit 23, and the regenerated methanol-to-olefins catalyst is input into the catalyst mixing unit 20 through the catalyst outlet of the third gas-solid separation unit 23.

[0076] In one specific embodiment, the above method includes the following steps:

[0077] Step 1: The feedstock including petroleum hydrocarbons 1 is introduced into the petroleum hydrocarbon catalytic cracking unit 3 through the feedstock inlet of the petroleum hydrocarbon catalytic cracking unit 3 and reacted with the catalytic cracking catalyst to obtain a first product including a first catalyst to be regenerated and a first olefin gas.

[0078] The first reaction, catalytic cracking, refers to the process by which hydrocarbons with relatively large molecular weights and high boiling points (petroleum hydrocarbon feedstocks) are broken down into hydrocarbons with relatively small molecular weights and lower boiling points (such as ethylene, propylene, and butene) under the action of heat and a catalyst. During the reaction, non-volatile carbonaceous substances deposit on the catalyst and condense into coke, causing a decrease in catalyst activity. To enable the catalyst to be recycled, it needs to be regenerated to restore its activity.

[0079] Petroleum hydrocarbon feedstock 1 includes at least one of naphtha, gasoline, diesel, distillate oil, and crude oil.

[0080] Furthermore, in petroleum hydrocarbon feedstock 1, the mass percentage of the 0–370℃ fraction is 0–100%, and the mass percentage of the fraction above 370℃ is 0–100%.

[0081] The raw materials for catalytic cracking catalysts include molecular sieves, supports, and binders. The molecular sieves include at least one of rare earth-containing USY molecular sieves, rare earth-free USY molecular sieves, β molecular sieves, ZSM molecular sieves, or Sapo molecular sieves. The support is at least one of silica, alumina, kaolin, and montmorillonite. The binder is at least one of silica sol, alumina sol, and boehmite. The catalytic cracking catalyst can be a microsphere or small sphere catalyst with an average particle size of 10 μm-10 mm. Preferably, the average particle size of the catalytic cracking catalyst is 20 μm-100 μm.

[0082] The reaction conditions for the first reaction are as follows: reaction temperature is 480–600℃, mass ratio of catalyst to petroleum hydrocarbon feedstock is 4–20, reaction time is 0.5–8s, and mass ratio of atomized steam to petroleum hydrocarbon feedstock is 0.02–0.2.

[0083] Preferably, the reaction conditions for the first reaction are: a reaction temperature of 520°C, a mass ratio of catalyst to petroleum hydrocarbon feedstock of 7, a reaction time of 2 seconds, and a mass ratio of atomized steam to petroleum hydrocarbon feedstock of 0.1.

[0084] Step 2: The first product is fed into the first gas-solid separation unit 4 through the product outlet of the petroleum hydrocarbon catalytic cracking unit 3 for first gas-solid separation to obtain the first catalyst to be regenerated and the first olefin gas. The first olefin gas is output through the gas phase outlet of the first gas-solid separation unit 4, and the first catalyst to be regenerated is fed into the stripping unit 5 for stripping treatment to obtain the stripped catalyst to be regenerated.

[0085] The first product in step 1 is a mixture of gaseous and solid phases containing a first olefin gas and a first catalyst to be regenerated. After entering the first gas-solid separation unit 4, it undergoes first gas-solid separation to obtain the first catalyst to be regenerated and the first olefin gas. The first olefin gas is output through the gas phase outlet of the first gas-solid separation unit 4, as shown in Figure 1 as olefin gas 15. Some of the first olefin gas is adsorbed on the surface of the first catalyst to be regenerated. The first catalyst to be regenerated then enters the stripping unit 5 for stripping treatment, separating the adsorbed first olefin gas from the catalyst to obtain a stripped catalyst to be regenerated.

[0086] Step 3: The stripping catalyst to be regenerated enters the catalyst mixing unit 20 and is mixed with the regenerated methanol-to-olefins catalyst that is fed into the catalyst mixing unit 20 through the catalyst outlet of the third gas-solid separation unit 23. The mixture then enters the methanol-to-olefins unit 6 and undergoes a second reaction with the methanol in the methanol-to-olefins unit 6 to obtain the second catalyst to be regenerated and the second olefin gas. The second olefin gas enters the first gas-solid separation unit 4 through the outlet of the catalyst mixing unit and is output from the gas phase outlet of the first gas-solid separation unit 4.

[0087] The second reaction, namely the methanol-to-olefins reaction, refers to the conversion of methanol into olefins (ethylene, propylene, and butene, etc.) using methanol as a raw material through the action of a catalyst. The reaction process is as follows:

[0088] 2CH3OH→C2H4+2H2O

[0089] 3CH3OH→C3H6+3H2O

[0090] 4CH3OH→C4H8+4H2O

[0091] According to the above reaction formula, the reaction products are only olefins and water, and no other toxic or harmful substances are generated.

[0092] The reaction mechanism of methanol to olefins is very complex. The "carbon pool" mechanism is currently the most widely accepted. The "carbon pool" mechanism suggests that methanol first forms some hydrocarbons with relatively large molecular weights in the catalyst channels and adsorbs them in the catalyst channels. On the one hand, these substances act as active centers and continuously react with methanol to introduce methoxy groups. On the other hand, these active centers continuously carry out dehydrogenation, hydrogen transfer, alkylation and other reactions to generate low-carbon olefins such as ethylene, propylene, and butene.

[0093] The first catalyst to be regenerated, produced from the catalytic cracking reaction of petroleum hydrocarbon feedstock, is stripped to obtain a stripped catalyst to be regenerated. This stripped catalyst then enters the methanol-to-olefins (MTO) unit 6 to participate in the MTO reaction. The first catalyst to be regenerated has polycyclic components attached to it, which can provide an abundant "carbon pool" for the MTO reaction, initiating and promoting the rapid conversion of methanol into low-carbon olefins.

[0094] In one specific embodiment, the mass ratio of the stripping catalyst to be regenerated entering from the catalyst mixing unit 20 to the regenerated methanol-to-olefins catalyst entering from the catalyst mixing unit 6 in the methanol-to-olefins unit 6 is 0.01 to 50.

[0095] By controlling the mass ratio of the regenerated methanol-to-olefins catalyst entering the catalyst mixing unit 20 to the stripping catalyst to be regenerated, the amount and density of the catalyst entering the methanol-to-olefins unit 6 can be controlled, allowing the methanol-to-olefins process to be adjusted within a wide range of catalyst-to-methanol ratios; the activity of the catalyst entering the methanol-to-olefins unit 6 can also be adjusted within a wide range, increasing the flexibility of the unit's processing.

[0096] Furthermore, the mass ratio of the stripping catalyst to be regenerated entering the methanol-to-olefins unit 6 from the catalyst mixing unit 20 to the regenerated methanol-to-olefins catalyst entering from the catalyst mixing unit is 0.01-20.

[0097] The raw materials for methanol-to-olefins catalysts include molecular sieves, supports, and binders. The molecular sieves include at least one of Sapo molecular sieves, ZSM molecular sieves, rare-earth-containing Y or USY molecular sieves, rare-earth-free Y or USY molecular sieves, or β molecular sieves. The support is at least one of silica, alumina, kaolin, and montmorillonite. The binder is at least one of silica sol, alumina sol, and boehmite. The methanol-to-olefins catalyst can be a microsphere or small sphere catalyst with an average particle size of 10 μm-10 mm, preferably 20 μm-500 μm.

[0098] The reaction conditions for the second reaction are as follows: reaction temperature is 420–560℃, mass ratio of mixed catalyst to methanol feedstock is 5–100, reaction time is 0.5–20s, and mass ratio of water to methanol in the methanol feedstock is 0–1.

[0099] Preferably, the reaction conditions for the second reaction are: a reaction temperature of 500°C, a mass ratio of the mixed catalyst to the methanol feedstock of 40, a reaction time of 5 seconds, and a mass ratio of water to methanol in the methanol feedstock of 0.2.

[0100] Step 4: The second catalyst to be regenerated enters the catalyst separation unit 21 through the catalyst outlet of the methanol-to-olefins unit 6. After separation, the second catalyst to be regenerated yields a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated enters zone A at the bottom of the catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through the first outlet of the catalyst separation unit 21 for catalyst regeneration treatment, yielding a second product including regenerated flue gas and regenerated catalyst. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of the catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through the second outlet of the catalyst separation unit 21 for catalyst regeneration treatment, yielding a third product including regenerated flue gas and regenerated catalyst.

[0101] The second product is passed through the outlet of the first catalyst regeneration unit 10 and enters the second gas-solid separation unit 11 for second gas-solid separation to obtain the first regenerated flue gas and the regenerated catalytic cracking catalyst. The first regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit 11, and the regenerated catalytic cracking catalyst is input into the petroleum hydrocarbon catalytic cracking unit 3 through the catalyst outlet of the second gas-solid separation unit 11.

[0102] The third product is introduced into the third gas-solid separation unit 23 through the outlet of the second catalyst regeneration unit 22 for third gas-solid separation to obtain the second regenerated flue gas and the regenerated methanol-to-olefins catalyst. The second regenerated flue gas is output through the gas phase outlet of the third gas-solid separation unit 23, and the regenerated methanol-to-olefins catalyst is input into the catalyst mixing unit 20 through the catalyst outlet of the third gas-solid separation unit 23.

[0103] The catalytic cracking catalyst participates in the catalytic cracking reaction of petroleum hydrocarbons and the methanol-to-olefins reaction in sequence, and becomes the second catalyst to be regenerated. The methanol-to-olefins catalyst becomes the second catalyst to be regenerated after participating in the methanol-to-olefins reaction. In order to realize the recycling of the catalyst in the reaction process, the second catalyst to be regenerated needs to be regenerated.

[0104] A commonly used catalyst regeneration method is thermal oxidation regeneration, which involves placing the spent catalyst in a high-temperature regenerator for treatment. Oxygen from the air is used to remove impurities such as coke adhering to the catalyst particles under high-temperature oxidation. In one specific embodiment, as shown in Figure 1, after the second catalyst to be regenerated is separated by catalyst separation unit 21, the catalytic cracking catalyst to be regenerated enters zone A at the bottom of catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through the first outlet of catalyst separation unit 21 for catalyst regeneration treatment, yielding a second product including regenerated flue gas and regenerated catalyst. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through the second outlet of catalyst separation unit 21 for catalyst regeneration treatment, yielding a third product including regenerated flue gas and regenerated catalyst.

[0105] Similar to the first product, the second and third products are mixtures of gaseous and solid phases containing regenerated flue gas and regenerated catalyst. The second product enters the second gas-solid separation unit 11 through the outlet of the first catalyst regeneration unit 10 for second gas-solid separation, yielding first regenerated flue gas and regenerated catalytic cracking catalyst. The first regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit 11, as shown in Figure 1 as first regenerated flue gas 14. The regenerated catalytic cracking catalyst is input into the petroleum hydrocarbon catalytic cracking unit 3 through the second connecting pipe 12 through the solid phase outlet of the second gas-solid separation unit, thereby realizing the recycling of the catalyst in the reaction process. The third product enters the third gas-solid separation unit 23 through the outlet of the second catalyst regeneration unit 22 for third gas-solid separation, yielding second regenerated flue gas and regenerated methanol-to-olefins catalyst. The second regenerated flue gas is output through the gas phase outlet of the third gas-solid separation unit 23, as shown in Figure 1 as second regenerated flue gas 27. The regenerated methanol-to-olefins catalyst is input into the catalyst mixing unit 20 through the fourth connecting pipe 19 through the solid phase outlet of the second gas-solid separation unit, thereby realizing the recycling of the catalyst in the reaction process.

[0106] In one specific embodiment, the mass ratio of methanol feedstock entering the methanol-to-olefins unit to petroleum hydrocarbon feedstock entering the petroleum hydrocarbon catalytic cracking unit is 0.01 to 5.

[0107] In one specific embodiment, as shown in Figure 2, in the stripping unit 5, part of the stripped catalyst to be regenerated enters the first catalyst regeneration unit 10 through the second stripped material outlet of the stripping unit 5, and the remaining part of the stripped catalyst to be regenerated enters the catalyst mixing unit 20 through the first stripped material outlet of the stripping unit 5.

[0108] Furthermore, the mass ratio of the stripped catalyst to be regenerated entering the catalyst mixing unit 20 from the stripping unit 5 to the stripped catalyst to be regenerated entering the catalyst regeneration unit 10 from the stripping unit 5 is 0.01 to 20.

[0109] Furthermore, the mass ratio of the stripped catalyst to be regenerated entering the catalyst mixing unit 20 to the stripped catalyst to be regenerated entering the catalyst regeneration unit 10 from the stripping unit 5 is 0.05 to 10.

[0110] In the methanol-to-olefins reaction, the mass ratio of catalyst to methanol feedstock needs to be appropriate. By controlling the input and output ratio of catalyst in each reaction unit, the content and activity of catalyst in each reaction unit can be flexibly adjusted. In particular, the catalyst density and the ratio of the two catalysts in methanol-to-olefins unit 6 can be increased as needed, thereby increasing the feedstock ratio of methanol feedstock, improving the selectivity of the target product of the methanol-to-olefins reaction, and increasing the content of ethylene and propylene in the final gaseous products.

[0111] The solution provided by the present invention will be further described below with reference to specific embodiments.

[0112] Example 1

[0113] The apparatus used is shown in Figure 1.

[0114] Preheated diesel feedstock 1 is injected into the riser reactor, where it comes into contact with the regenerated catalyst from the second connecting pipeline 12, which has been boosted by pre-lifted gas 2, and undergoes a catalytic cracking reaction to obtain a first product including the first catalyst to be regenerated and the first olefin gas.

[0115] The first product enters the settling tank through the product outlet of the riser reactor for the first gas-solid separation, resulting in the first catalyst to be regenerated and the first olefin gas. The first olefin gas is output through the gas phase outlet of the settling tank (see label 15). The first catalyst to be regenerated enters the stripper and is treated with stripping steam 8 to obtain the stripped catalyst to be regenerated.

[0116] The stripping catalyst to be regenerated is entirely fed into the catalyst mixer via the third connecting pipe 18, where it is mixed with the regenerated methanol-to-olefins catalyst from the third gas-solid separation unit 23. The mixture then enters the fluidized bed reactor. Preheated methanol feedstock 7 is injected from the bottom of the fluidized bed reactor and reacts with the mixed catalyst to produce a second catalyst to be regenerated and a second olefin gas. The second olefin gas enters the settler via the fifth connecting pipe 17 and is output from the gas phase outlet of the settler.

[0117] The second catalyst to be regenerated enters the catalyst separation unit 21 through the seventh connecting pipe 24, where it is separated into a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated enters area A at the bottom of the catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through the first connecting pipe 9 for catalyst regeneration treatment, resulting in a second product including regenerated flue gas and regenerated catalyst. The regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit 11, and the second product enters the second gas-solid separation unit 11 through the outlet of the first catalyst regeneration unit 10 for second gas-solid separation, resulting in first regenerated flue gas 14 and regenerated catalytic cracking catalyst. The first regenerated flue gas 14 is then separated by the second gas-solid separation unit 11. The gas phase outlet of the separation unit outputs the regenerated catalytic cracking catalyst, which enters the riser reactor through the second connecting pipe 12. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of the catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through the eighth connecting pipe 25 for catalyst regeneration treatment, resulting in a third product including regenerated flue gas and regenerated catalyst. The third product enters the third gas-solid separation unit through the outlet of the second catalyst regeneration unit for third gas-solid separation, resulting in second regenerated flue gas 27 and regenerated methanol-to-olefins catalyst. The second regenerated flue gas 27 is output through the gas phase outlet of the third gas-solid separation unit, and the regenerated methanol-to-olefins catalyst enters the catalyst mixer through the fourth connecting pipe 19.

[0118] The regenerated flue gas from the second and third gas-solid separation units can be output through the gas phase outlet of the settler and enter the subsequent energy recovery system, as shown in Figure 1 as regenerated flue gas 14 and flue gas 27. When the first catalyst regeneration unit 10 and the second catalyst unit 22 are performing catalytic regeneration, they are respectively passed through the first regeneration main air 13 and the second regeneration main air 26.

[0119] In this embodiment, the reaction conditions of the riser reactor are: reaction temperature of 500℃, mass ratio of catalyst to petroleum hydrocarbon feedstock of 7, residence time of 2.0s, and mass ratio of atomized steam to petroleum hydrocarbon feedstock of 0.1; the reaction conditions of the rapid fluidized bed reactor are: reaction temperature of 500℃, mass ratio of stripped catalyst to methanol feedstock of 40, reaction time of 5s, mass ratio of water to methanol in methanol feedstock of 0.2, and ratio of methanol feedstock to diesel fuel of 0.5.

[0120] The mass ratio of the stripping catalyst to be regenerated entering through the first catalyst inlet of the catalyst mixing unit to the regenerated methanol-to-olefins catalyst entering through the second catalyst inlet is 0.5.

[0121] The properties of the diesel feedstock used are shown in Table 1, and the distribution of the obtained products is shown in Table 2.

[0122] Example 2

[0123] The device used is shown in Figure 2.

[0124] Preheated crude oil feedstock 1 is injected into the riser reactor, where it comes into contact with the regenerated catalyst from the second connecting pipeline 12, which has been boosted by pre-lifted gas 2, and undergoes a catalytic cracking reaction to obtain a first product including a first catalyst to be regenerated and a first olefin gas.

[0125] The first product enters the settling tank through the product outlet of the riser reactor for the first gas-solid separation, resulting in the first catalyst to be regenerated and the first olefin gas. The first olefin gas is output through the gas phase outlet of the settling tank (see label 15). The first catalyst to be regenerated enters the stripper and is treated with stripping steam 8 to obtain the stripped catalyst to be regenerated.

[0126] 30% of the stripping catalyst to be regenerated is fed into the catalyst mixer via the third connecting pipe 18, where it is mixed with the regenerated methanol-to-olefins catalyst from the third gas-solid separation unit 23. The mixture then enters the fluidized bed reactor. The remaining 70% of the stripping catalyst to be regenerated is fed into the first catalyst regeneration unit 10 via the sixth connecting pipe 16 for catalyst regeneration treatment.

[0127] After preheating, methanol feedstock 7 is injected from the bottom of the fluidized bed reactor and reacts with the mixed catalyst to produce methanol-to-olefins reaction, resulting in a second catalyst to be regenerated and a second olefin gas. The second olefin gas enters the settler through the fifth connecting pipe 17 and is output from the gas phase outlet of the settler.

[0128] The second catalyst to be regenerated enters the catalyst separation unit 21 through the seventh connecting pipe 24, where it is separated into a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated. The catalytic cracking catalyst to be regenerated enters zone A at the bottom of the catalyst separation unit 21 and enters the first catalyst regeneration unit 10 through the first connecting pipe 9 for catalyst regeneration treatment, resulting in a second product including regenerated flue gas and regenerated catalyst. The regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit 11, and the regenerated catalytic cracking catalyst enters the riser reactor through the second connecting pipe 12. The methanol-to-olefins catalyst to be regenerated enters zone B at the bottom of the catalyst separation unit 21 and enters the second catalyst regeneration unit 22 through the eighth connecting pipe 25 for catalyst regeneration treatment, resulting in a third product including regenerated flue gas and regenerated catalyst. The regenerated flue gas is output through the gas phase outlet of the third gas-solid separation unit 23, and the regenerated methanol-to-olefins catalyst enters the catalyst mixer 20 through the fourth connecting pipe 19.

[0129] The regenerated flue gas from the second and third gas-solid separation units is output through the gas phase outlet of the settler and enters the subsequent energy recovery system, as shown in Figure 2 as regenerated flue gas 14 and flue gas 27.

[0130] In this embodiment, the reaction conditions of the riser reactor are: reaction temperature of 540°C, mass ratio of catalyst to petroleum hydrocarbon feedstock of 9, residence time of 2.0 s, and mass ratio of atomized steam to petroleum hydrocarbon feedstock of 0.25; the reaction conditions of the rapid fluidized bed reactor are: reaction temperature of 510°C, mass ratio of stripped catalyst to methanol feedstock of 50, reaction time of 4 s, mass ratio of water to methanol in methanol feedstock of 0.2, and ratio of methanol feedstock to crude oil of 1.

[0131] The mass ratio of the stripping catalyst to be regenerated entering through the first catalyst inlet of the catalyst mixing unit to the regenerated methanol-to-olefins catalyst entering through the second catalyst inlet is 0.2.

[0132] The properties of the crude oil feedstock used are shown in Table 1, and the distribution of the obtained products is shown in Table 2.

[0133] Comparative Example 1

[0134] The device used is shown in Figure 3.

[0135] Preheated diesel feedstock 1 is injected into the riser reactor, where it comes into contact with the regenerated catalyst from the second connecting pipeline 12, which has been boosted by pre-lifted gas 2, and undergoes a catalytic cracking reaction to obtain a first product including the first catalyst to be regenerated and the first olefin gas.

[0136] The first product enters the settling tank through the product outlet of the riser reactor for the first gas-solid separation, yielding the first catalyst to be regenerated and the first olefin gas. The first olefin gas rises and exits through the gas phase outlet of the settling tank, while the first catalyst to be regenerated descends and enters the stripper for stripping treatment to obtain the stripped catalyst to be regenerated.

[0137] The stripped catalyst to be regenerated enters the catalytic cracking regenerator 10 through an inclined tube for catalyst regeneration treatment, resulting in a second product containing regenerated flue gas and regenerated catalyst.

[0138] The second product is a mixture of gaseous and solid phases containing regenerated flue gas and regenerated catalyst. The second product enters the settling tank through the outlet of the catalytic cracking regenerator for a second gas-solid separation to obtain regenerated flue gas and regenerated catalyst. The regenerated flue gas is output through the gas phase outlet of the settling tank and enters the subsequent energy recovery system, as shown in Figure 3 as regenerated flue gas 14. The regenerated catalyst is input into the riser reactor through the inclined tube through the solid phase outlet of the settling tank, thereby realizing the recycling of the catalyst in the reaction process.

[0139] In this comparative example, the reaction conditions of the riser reactor are as follows: reaction temperature is 500℃, mass ratio of catalyst to petroleum hydrocarbon feedstock is 7, residence time is 2.0s, and mass ratio of atomized steam to petroleum hydrocarbon feedstock is 0.1.

[0140] The properties of the diesel feedstock used are shown in Table 1, and the distribution of the obtained products is shown in Table 2.

[0141] Comparative Example 2

[0142] The device used is shown in Figure 3.

[0143] Preheated crude oil feedstock 1 is injected into the riser reactor, where it comes into contact with the regenerated catalyst from the second connecting pipeline 12, which has been boosted by pre-lifted gas 2, and undergoes a catalytic cracking reaction to obtain a first product including a first catalyst to be regenerated and a first olefin gas.

[0144] The first product enters the settling tank through the product outlet of the riser reactor for the first gas-solid separation, yielding the first catalyst to be regenerated and the first olefin gas. The first olefin gas rises and exits through the gas phase outlet of the settling tank, while the first catalyst to be regenerated descends and enters the stripper for stripping treatment to obtain the stripped catalyst to be regenerated.

[0145] The stripped catalyst to be regenerated enters the catalytic cracking regenerator through a connecting pipeline for catalyst regeneration treatment, resulting in a second product containing regenerated flue gas and regenerated catalyst.

[0146] The second product is a mixture of gaseous and solid phases containing regenerated flue gas and regenerated catalyst. The second product enters the settling tank through the outlet of the catalytic cracking regenerator for a second gas-solid separation to obtain regenerated flue gas and regenerated catalyst. The regenerated flue gas is output through the gas phase outlet of the settling tank and enters the subsequent energy recovery system, as shown in Figure 3 as regenerated flue gas 14. The regenerated catalyst is input into the riser reactor through the solid phase outlet of the settling tank via the second connecting pipe 12, thereby realizing the recycling of the catalyst in the reaction process.

[0147] In this comparative example, the reaction conditions of the riser reactor were: reaction temperature of 540℃, mass ratio of catalyst to petroleum hydrocarbon feedstock of 9, residence time of 2.0s, and mass ratio of atomized steam to petroleum hydrocarbon feedstock of 0.25.

[0148] The properties of the crude oil feedstock used are shown in Table 1, and the distribution of the obtained products is shown in Table 2.

[0149] Table 1. Composition of raw materials used in the examples and comparative examples.

[0150] Name Diesel Feedstock Name Crude Oil Feedstock Molecular Weight, g / mol 221 Residual Carbon, m% 2.02 Density 20℃, kg / m3 86 3.5 C, m% 81.68 Alkanes, v% 36 H, m% 12.33 Monocycloalkanes, v% 14.5 N, m% 0.06 Dicycloalkanes, v% 6 Ca, μg / g 4.44 Tricycloalkanes, v% 2.1 Cu, μg / g 0. 04 Total cycloalkanes, v% 22.6 Pb, μg / g 0.02 Total saturated hydrocarbons, v% 58.6 Ni, μg / g 3.39 Alkylbenzenes, v% 11.5 V, μg / g 3.67 Indene or tetrahydronaphthalene, v% 12.8 Fe, μg / g 2.33 Indene compounds, v% 4.1 Na, % (m / m) 0.0006 Total monocyclic aromatics, v% 28.4 / / Naphthalene, v% 1 / / Naphthalene, v% 3.8 / / Anaphthene, v% 4.1 / / Anaphthene, v% 2.8 / / Total bicyclic aromatics, v% 11.7 / / Tricyclic aromatics, v% 1.3 / / Total aromatics, v% 41.4 / / Atmospheric distillation range, initial boiling point, °C 198.4 / / Atmospheric distillation range, 10 v% recovery temperature, °C 226.9 / / Atmospheric distillation range, 30 v% recovery temperature, °C 253.5 / / Atmospheric distillation range, 5 0% v recovery temperature, 283.2°C / / Atmospheric distillation range 70% v recovery temperature, 314.6°C / / Atmospheric distillation range 80% v recovery temperature, 329.2°C / / Atmospheric distillation range 85% v recovery temperature, 336.6°C / / Atmospheric distillation range 90% v recovery temperature, 345°C / / Atmospheric distillation range 95% v recovery temperature, 358°C / / Atmospheric distillation range final boiling point, 368.1°C / / surface

[0151] Table 2 Composition of the products in the examples and comparative examples

[0152]

[0153] Note: Propylene selectivity refers to the percentage of propylene by mass in liquefied petroleum gas.

[0154] As can be seen from Table 2, the method for preparing olefins in this invention can significantly increase the yields of ethylene, propylene, and butene. The combined feed of petroleum hydrocarbons and methanol can promote the formation of ethylene and propylene, greatly increasing the selectivity of propylene in liquefied petroleum gas, which facilitates subsequent purification, concentration, and separation.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for the combined production of olefins from petroleum hydrocarbon catalytic cracking and methanol-to-olefins, characterized in that, The system includes a petroleum hydrocarbon catalytic cracking unit, a first gas-solid separation unit, a stripping unit, a catalyst mixing unit, a methanol-to-olefins unit, a catalyst separation unit, a first catalyst regeneration unit, a second gas-solid separation unit, a second catalyst regeneration unit, and a third gas-solid separation unit. The product outlet of the petroleum hydrocarbon catalytic cracking unit is connected to the inlet of the first gas-solid separation unit. The solid phase outlet of the first gas-solid separation unit is connected to the stripping material inlet of the stripping unit. The first stripping material outlet of the stripping unit is connected to the first catalyst inlet of the catalyst mixing unit. The catalyst outlet of the catalyst mixing unit is connected to the catalyst inlet of the methanol-to-olefins unit. The gas phase outlet of the catalyst mixing unit is connected to the first gas-solid separation unit. The second inlet of the catalyst is connected to the catalyst outlet of the methanol-to-olefins unit, which is connected to the inlet of the catalyst separation unit. The first outlet of the catalyst separation unit is connected to the first catalyst inlet of the first catalyst regeneration unit. The catalyst outlet of the first catalyst regeneration unit is connected to the catalyst inlet of the second gas-solid separation unit. The catalyst outlet of the second gas-solid separation unit is connected to the catalyst inlet of the petroleum hydrocarbon catalytic cracking unit. The second outlet of the catalyst separation unit is connected to the catalyst inlet of the second catalyst regeneration unit. The catalyst outlet of the second catalyst regeneration unit is connected to the catalyst inlet of the third gas-solid separation unit. The catalyst outlet of the third gas-solid separation unit is connected to the second catalyst inlet of the catalyst mixing unit.

2. The apparatus according to claim 1, characterized in that, The stripping unit further includes a second stripped product outlet, which is connected to the second catalyst inlet of the first catalyst regeneration unit.

3. The apparatus according to claim 1 or 2, characterized in that, The petroleum hydrocarbon catalytic cracking unit is a riser reactor, the first gas-solid separation unit, the second gas-solid separation unit, and the third gas-solid separation unit are settling tanks, the stripping unit is a stripper, the methanol-to-olefins unit is a fluidized bed reactor, the first catalyst regeneration unit and the second catalyst regeneration unit are catalytic cracking regenerators, the catalyst mixing unit is a catalyst mixer, and the catalyst separation unit is a solid catalyst separator.

4. The apparatus according to claim 3, characterized in that, The fluidized bed reactor is one of the following: fast fluidized bed, turbulent fluidized bed, dispersed fluidized bed, and dense phase fluidized bed; the catalyst separation unit is one or a combination of several of the following: cyclone separation, centrifugal separation, sieving separation, filtration separation, gravity separation, and magnetic separation.

5. A method for preparing olefins by combining petroleum hydrocarbon catalytic cracking and methanol-to-olefins, characterized in that, The device described in any one of claims 1 to 4 is used to perform the following steps: feeding a feedstock comprising petroleum hydrocarbons and a catalytic cracking catalyst into the petroleum hydrocarbon catalytic cracking unit via the feedstock inlet to conduct a first reaction, yielding a first product comprising a first catalyst to be regenerated and a first olefin gas; separating the first product into a first gas-solid separation unit via the product outlet of the petroleum hydrocarbon catalytic cracking unit to obtain the first catalyst to be regenerated and the first olefin gas, wherein the first olefin gas is output via the gas phase outlet of the first gas-solid separation unit, and the first catalyst to be regenerated is stripped into a stripping unit to obtain a stripped catalyst to be regenerated. The stripping catalyst to be regenerated enters the catalyst mixing unit through the first catalyst inlet of the catalyst mixing unit, and mixes with the regenerated methanol-to-olefins catalyst that is fed into the second catalyst inlet of the catalyst mixing unit through the catalyst outlet of the third gas-solid separation unit. This mixture then enters the methanol-to-olefins unit, where it undergoes a second reaction with the methanol to obtain a second catalyst to be regenerated and a second olefin gas. The second olefin gas enters the first gas-solid separation unit through the outlet of the catalyst mixing unit and exits from the gas phase outlet of the first gas-solid separation unit. The second catalyst to be regenerated enters the catalyst separation unit through the catalyst outlet of the methanol-to-olefins unit, where it undergoes a second reaction with the methanol to obtain a second catalyst to be regenerated and a second olefin gas. After separation in the catalyst separation unit, a catalytic cracking catalyst to be regenerated and a methanol-to-olefins catalyst to be regenerated are obtained. The catalytic cracking catalyst to be regenerated is transported from the first catalyst outlet of the catalyst separation unit to the first catalyst inlet of the first catalyst regeneration unit for catalyst regeneration treatment, resulting in a second product including regenerated flue gas and regenerated catalyst. The second product enters the second gas-solid separation unit through the outlet of the first catalyst regeneration unit for second gas-solid separation, resulting in first regenerated flue gas and regenerated catalytic cracking catalyst. The first regenerated flue gas is output through the gas phase outlet of the second gas-solid separation unit, and the regenerated catalytic cracking catalyst is further processed by the second gas-solid separation unit. The catalyst outlet is fed into the petroleum hydrocarbon catalytic cracking unit; the methanol-to-olefins catalyst to be regenerated is transported through the second catalyst outlet of the catalyst separation unit to the catalyst inlet of the second catalyst regeneration unit for catalyst regeneration treatment, resulting in a third product including regenerated flue gas and regenerated methanol-to-olefins catalyst; the third product is fed through the outlet of the second catalyst regeneration unit into the third gas-solid separation unit for third gas-solid separation, resulting in second regenerated flue gas and regenerated methanol-to-olefins catalyst; the second regenerated flue gas is output through the gas phase outlet of the third gas-solid separation unit, and the regenerated methanol-to-olefins catalyst is fed into the catalyst mixing unit through the catalyst outlet of the third gas-solid separation unit.

6. The method according to claim 5, characterized in that, In the stripping unit, a portion of the stripped catalyst to be regenerated enters the first catalyst regeneration unit through the second stripped product outlet of the stripping unit, and the remaining portion of the stripped catalyst to be regenerated enters the catalyst mixing unit through the first stripped product outlet of the stripping unit.

7. The method according to claim 5, characterized in that, The mass ratio of methanol feedstock entering the methanol-to-olefins unit to petroleum hydrocarbon feedstock entering the petroleum hydrocarbon catalytic cracking unit is 0.01 to 5.

8. The method according to any one of claims 5 to 7, characterized in that, The reaction conditions for the first reaction are: a reaction temperature of 480–600℃, a mass ratio of catalyst to petroleum hydrocarbon feedstock of 4–20, a reaction time of 0.5–8 s, and a mass ratio of atomized steam to petroleum hydrocarbon feedstock of 0.02–0.

2. The reaction conditions for the second reaction are: a reaction temperature of 420–560℃, a mass ratio of stripping catalyst to methanol feedstock of 5–100, a reaction time of 0.5–20 s, and a mass ratio of water to methanol in the methanol feedstock of 0–1.

9. The method according to claim 8, characterized in that, The mass ratio of the stripping catalyst to be regenerated entering from the catalyst mixing unit to the regenerated methanol-to-olefins catalyst entering from the catalyst mixing unit is 0.01 to 50.

10. The method according to claim 5, characterized in that, The mass ratio of the stripped catalyst to be regenerated entering the catalyst mixing unit from the stripping unit to the stripped catalytic cracking catalyst to be regenerated entering the first catalyst regeneration unit from the stripping unit is 0.01 to 20.

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