RU2810794C1 - Fluidized bed reactor, device and their application - Google Patents

Abstract

FIELD: coking.

SUBSTANCE: invention is related to a fluidized bed reactor including a main shell and a coke control zone shell; the main shell includes an upper shell and a lower shell; the upper shell encloses the gas-solid separation zone, and the lower shell encloses the reaction zone; the reaction zone is in axial communication with the gas-solid separation zone; the shell of the coke content control zone is located along the circumference on the outer wall of the main shell; the shell of the coke content control zone and the main shell cover the annular cavity, and the annular cavity represents the coke content control zone; n partitions are installed radially in the coke control zone, and these n partitions divide the coke control zone into n subzones of the coke control zone, where n is an integer, n has a range of values: 2≤n≤10; subzones of the coke content control zone are provided with an input for raw material for coke content control; and a catalyst circulation hole is formed in each of the n-1 partitions, so that the catalyst entering the coke content control zone flows in an annular direction. The invention is also related to a device and method for producing low-carbon olefins.

EFFECT: ability to control the coke content, the distribution of coke content and coke particles in the catalyst used in the processing of dimethyl ether/methanol into olefins.

10 cl, 4 ex, 2 dwg

Description

TECHNICAL FIELD

The present application relates to a fluidized bed reactor, a device for producing low carbon olefins from an oxygen-containing compound and their use, and also relates to the field of chemical equipment engineering.

BACKGROUND OF THE ART

Methanol-to-olefin technology (MTO) mainly includes the DMTO (methanol-to-olefin) technology of the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences and the MTO technology of UOP from the United States. In 2010, the construction and commissioning of the Shenhua Baotou methanol to olefin processing plant using DMTO technology was completed. This is the world's first industrial application of MTO technology. As of the end of 2019, 14 commercial DMTO plants were operational with a total production capacity of approximately 8 million tons of low-carbon olefins per year.

In recent years, DMTO technology has been further developed and new generation DMTO catalysts with better performance have gradually been introduced into industry, bringing greater benefits to DMTO plants. New generation DMTO catalyst provides higher methanol throughput and low carbon olefin selectivity. It is difficult for existing industrial DMTO devices to take full advantage of the new generation DMTO catalyst. Therefore, there is a need to develop a DMTO production apparatus and method that can efficiently utilize a new generation DMTO catalyst with high methanol processing capacity and high selectivity for low carbon olefins.

DISCLOSURE OF THE INVENTION

According to a first aspect of the present application, there is provided a fluidized bed reactor configured to control coke content, coke content distribution, and coke particles in a dimethyl ether/methanol to olefins (DMTO) catalyst and thereby control control the performance of the DMTO catalyst and improve selectivity for low carbon olefins.

Low carbon olefins mentioned in this application refer to ethylene and propylene.

The fluidized bed reactor includes a main shell and a coke control zone shell; the main shell includes an upper shell and a lower shell; the upper shell encloses the gas-solid separation zone, and the lower shell encloses the reaction zone; the reaction zone is in axial communication with the gas-solid separation zone; the shell of the coke content control zone is located circumferentially on the outer wall of the main shell; the shell of the coke content control zone and the main shell cover the annular cavity, and the annular cavity represents the coke content control zone; n partitions are installed radially in the coke content control zone, and these n partitions divide the coke content control zone into n subzones of the coke content control zone, where n is an integer; subzones of the coke content control zone are provided with an input for raw material for coke content control; and in each of the n-1 partitions, a catalyst circulation hole is formed so that the catalyst entering the coke content control zone flows in an annular direction.

If there is only one zone in the coke control zone, the residence time distribution of the catalyst entering the coke control zone is similar to that of fully mixed tank reactors, and under such conditions the resulting coke controlled catalyst pellets have low content uniformity coke (i.e., some catalyst beads have low coke content and some catalyst beads have high coke content), resulting in low average activity and low average selectivity of the catalyst. In the present application, a coke content control zone is used, and partitions are arranged in a radial direction in the coke content control zone to divide the coke content control zone into a plurality of sub-zones of the coke content control zone, so that the residence time distribution of the catalyst entering the coke content control zone can be controlled such such that the coke controlled catalyst has a narrow coke content distribution, high average activity and high average selectivity. In addition, zone control is also advantageous for controlling coke particles and coke content in a coke-controlled catalyst.

In the present application, the catalyst entering the coke control zone may be fresh catalyst or regenerated catalyst. Preferably, the catalyst may be a regenerated catalyst so that both regeneration and coke control can be achieved on-line.

If necessary, n partitions in the coke content control zone may include the ^1st partition and from the ^2nd partition to the ^nth partition;

in the ^1st partition there may be no hole for catalyst circulation; in each partition from ^{the 2nd} partition to the ^nth partition a hole can be formed for circulation of the catalyst;

in the ^1st subzone of the coke content control zone formed by dividing by the ^1st partition and the ^2nd partition, an inlet for the coke content control zone catalyst can be formed;

in the ^nth subzone of the coke control zone formed by separation by the ^1st partition and the ^nth partition, a pipe for supplying a coke-controlled catalyst can be located, and in the reaction zone an outlet of a pipe for supplying a coke-controlled catalyst can be formed ;

The coke content control raw material inlet may be formed in the lower parts of the subzones of the coke content control zone, and the coke content control raw material inlet may be a coke content control zone distributor; And

a coke control zone gas supply pipe may be provided in the upper portions of the coke control zone subzones, and a coke control zone gas supply pipe outlet may be formed in the gas-solid separation zone.

In particular, one or more openings for catalyst circulation may be formed in each of the partitions, which is not strictly limited in the present application. When a plurality of catalyst circulation holes are formed, their relative positions are not strictly limited in the present application. For example, a plurality of catalyst circulation holes may be arranged in parallel or may be arranged randomly.

In the present application, the shape of the coke controlled catalyst supply pipe is not strictly limited as long as the coke controlled catalyst supply pipe is configured to supply the coke controlled catalyst to the reaction zone. For example, the coke controlled catalyst supply pipe may be an L-shaped pipe, or may have other suitable shapes.

Preferably, the coke controlled catalyst supply pipe may be an L-shaped pipe, so that the outlet of the coke controlled catalyst supply pipe is at a lower position in the reaction zone, and the coke controlled catalyst can effectively interact and react with the raw material , including an oxygen-containing compound supplied from a reaction zone distributor to prevent the controlled coke content catalyst from entering the first stripper or stripper.

A coke control zone distributor may be installed in the lower portions of the coke control zone subzones.

Preferably, the coke control zone distributor may be located at the bottom of each of the subzones of the coke control zone. In this way, all the raw material for coke content control can be supplied to the coke content control zone evenly, which avoids the phenomenon of uneven distribution of the raw material for coke content control between sub-zones, and also properly controls the coke content and the distribution of coke content in the catalyst.

The gas supply pipe may be located in the upper portions of the subzones of the coke control zone.

Preferably, the gas supply pipe may be located at the top of each of the subzones of the coke control zone. In this way, proper control of the distribution of coke content in the catalyst can be ensured.

If necessary, n can have the following range of values: 2 ≤ n ≤ 10.

If necessary, a reaction zone distributor may also be located at the bottom of the reaction zone; And

wherein the reaction zone distributor may be configured to supply raw material for the reaction.

Particularly, in the present application, the raw material for the reaction may be an oxygen-containing compound raw material.

If necessary, the reaction zone may be provided with a fluidized bed reactor cooler, and the lower part of the reaction zone may be provided with a first stripping column; the inlet of the first stripping column may be formed inside the lower shell; the outlet of the first stripping column may be formed outside the lower shell; An open inlet end of the first stripping column may be located above the outlet end of the controlled coke catalyst supply pipe; and the outlet end of the pipe for supplying catalyst with a controlled coke content can be located above the distributor of the reaction zone.

In particular, the open end of the inlet pipe of the first stripping column may be located above the outlet end of the coke-controlled catalyst supply pipe to prevent the coke-controlled catalyst from flowing from the coke-controlled catalyst supply pipe into the inlet pipe of the first stripping column.

The outlet end of the coke-controlled catalyst supply pipe may be located above the reaction zone distributor so that the coke-controlled catalyst can directly and effectively react with the reaction feed material exiting the reaction zone distributor.

If necessary, the gas-solid separation zone may be provided with a first gas-solid separation unit and a second gas-solid separation unit; The catalyst outlet pipe of the first gas-solid separation unit may pass through the upper part of the gas-solid separation zone, and may be inserted into the ^1st subzone of the coke content control zone (i.e., the catalyst outlet pipe of the first gas separation unit and solid matter can be inserted into the ^1st subzone of the coke control zone through the catalyst inlet of the coke control zone); a gas outlet from the first gas-solid separation unit may be formed in a gas-solid separation zone; an inlet of the second gas-solid separation unit may be formed in the gas-solid separation zone; and a catalyst outlet from the second gas/solid separation unit may be located in the reaction zone.

Preferably, the gas supply pipe of the coke control zone may be located above the outlet end of the catalyst of the second gas-solid separation unit.

If necessary, the first gas collection chamber can also be located at the top of the gas-solid separation zone;

a gas outlet from the second gas-solid separation unit may also be in communication with the first gas collection chamber; And

wherein the first gas collection chamber is also configured to communicate with a pipe for supplying a gaseous product.

According to a second aspect of the present application, there is also provided an apparatus for producing low carbon olefins from an oxygen-containing compound, including a fluidized bed regenerator and a fluidized bed reactor as described above.

In particular, the apparatus for producing low-carbon olefins from an oxygen-containing compound proposed in the present application is equipped with a fluidized bed regenerator; wherein a fluidized bed regenerator is used to regenerate the spent catalyst; and the regenerated catalyst is supplied to the coke content control zone to effect coke content control, and then introduced into the reaction zone to participate in the catalytic reaction. According to the present application, the catalyst can be subjected to on-line regeneration and on-line coke control, thereby improving production efficiency.

Optionally, the fluidized bed regenerator may include a regenerator shell; the regenerator shell may include an upper regenerator shell and a lower regenerator shell; the upper shell of the regenerator may enclose the gas-solid separation zone, and the lower shell of the regenerator may enclose the regeneration zone; an inlet for the spent catalyst can be formed in the regenerator shell; and the spent catalyst inlet is configured to communicate with an outlet pipe of the first stripping column through a spent catalyst supply pipe.

If necessary, a regeneration zone distributor can also be located in the lower part of the regeneration zone; And

in this case, the distributor of the regeneration zone can be configured to supply regeneration gas.

If necessary, a second stripping column can be located at the bottom of the regeneration zone; the inlet of the second stripping column may be formed inside the shell of the regenerator; the outlet of the second stripping column may be formed outside the regenerator shell; the second stripping column is configured to communicate with the first gas-solid separation unit via a regenerated catalyst supply pipe; and the open end of the inlet of the second stripping column may be located above the regeneration zone distributor.

If necessary, a third gas-solid separation unit and a second gas collection chamber may also be located in the regenerator shell; a second gas collection chamber may be located in the inner upper part of the regenerator shell; a gas outlet from the third unit may be in communication with the second gas collection chamber for separating the gas and the solid; the second gas collection chamber is configured to communicate with the flue gas supply pipe; and the outlet end of the catalyst from the third gas-solid separation unit may be located above the open end of the inlet pipe of the second stripping column.

According to a third aspect of the present application, there is also provided a method for producing low carbon olefins from an oxygen-containing compound, comprising on-line modification of a DMTO catalyst by performing a coke control reaction using a fluidized bed reactor as described above,

including the following stage:

supplying catalyst and coke control feedstock to a coke control zone, wherein the catalyst reacts with the coke control feedstock while flowing in an annular direction along subzones of the coke control zone to form a product including the grade control catalyst coke, wherein the coke controlled catalyst is a modified DMTO catalyst.

If necessary, the catalyst can flow in an annular direction along the catalyst circulation opening in the baffles; and the coke control raw material may be supplied to the subzones of the coke control zone from the coke control zone distributor to react with the catalyst.

Specifically, when the catalyst flows in an annular direction along the catalyst circulation hole in the baffles, the coke control raw material is supplied to the sub-zones of the coke control zone from the coke control zone distributor located below to come into contact with the catalyst and control the coke content in the catalyst, and the resulting gas phase (including unreacted coke control raw material) is supplied to the gas-solid separation zone through a gas supply pipe above the coke control zone.

Optionally, the resulting coke-controlled catalyst may be introduced into the reaction zone through a coke-controlled catalyst supply pipe, and then contact and react with a feedstock including an oxygen-containing compound supplied through a reaction zone distributor to form stream A with low carbon olefins and spent catalyst; And

the product may further include a gaseous coke control product, and the gaseous coke control product may be supplied to the gas-solid separation zone through a gas supply pipe of the coke control zone.

If necessary, Stream A may be mixed with product gas to control the coke content entering the gas-solid separation zone to produce Stream B;

stream B may be supplied to a second gas-solid separation unit to perform gas-solid separation to obtain a gas-phase stream C and a solid-phase stream D;

gas phase stream C may be a gaseous product containing a low carbon olefin; A

solid phase stream D may include spent catalyst.

If necessary, the gas-phase stream C may enter the first gas collection chamber and then enter the downstream operating section through a product gas supply pipe;

the solid phase stream D may be returned to the reaction zone of the fluidized bed reactor; And

the catalyst located in the reaction zone may enter the first stripper through the open end of the inlet pipe of the first stripper to perform stripping, and then enter the downstream zone.

In particular, the downstream zone may be a regenerator.

If necessary, the raw material for controlling the coke content may include C ₁ -C ₆ hydrocarbon compounds; And

preferably the hydrocarbon compounds may be at least one selected from the group consisting of C ₁ -C ₆ alkanes and C ₁ -C ₆ olefins.

If necessary, the raw material for controlling the coke content may further include at least one selected from the group consisting of hydrogen, an alcohol compound and water; And

the proportion of the total weight of the alcohol compound and water in the weight of the raw material for controlling the coke content may be greater than or equal to 10% by weight. and less than or equal to 50% wt.

If desired, the alcohol compound may be at least one selected from the group consisting of methanol and ethanol.

If necessary, the raw material for controlling the coke content may include hydrogen in an amount of from 0 wt%. up to 20% wt., methane in an amount from 0% wt. up to 50% wt., ethane in amounts from 0% wt. up to 50% wt., ethylene in an amount from 0% wt. up to 20% wt., propane in amounts from 0% wt. up to 50% wt., propylene in amounts from 0% wt. up to 20% wt., butane in amounts from 0% wt. up to 90% wt., butene in an amount from 0% wt. up to 90% wt., pentane in an amount from 0% wt. up to 90% wt., pentene in an amount from 0% wt. up to 90% wt., hexane in an amount from 0% wt. up to 90% wt., hexene in an amount from 0% wt. up to 90% wt., methanol in an amount from 0% wt. up to 50% wt., ethanol in an amount from 0% wt. up to 50% wt. and water in an amount of 0% wt. up to 50% wt.; and the total amount of hydrocarbon compounds may exceed 0%.

If desired, the catalyst may include a SAPO molecular sieve;

the coke content of the catalyst may be less than or equal to 3% by weight;

The coke content in the catalyst with controlled coke content can range from 4 wt%. up to 9% wt.; And

the quartile deviation of the distribution of coke content in a catalyst with controlled coke content can be less than 1% wt.

Specifically, in the present application, the coke content of the coke-controlled catalyst is controlled in the range of 4 wt.%. up to 9% wt. by applying a coke control zone and selecting a coke control process. Since the catalyst is a powder, the coke content of the catalyst refers to the average coke content of the catalyst granules, but the actual coke content of different catalyst granules may vary. In the present application, the quartile deviation of the coke content distribution of the coke controlled catalyst pellets can be controlled to be less than 1 wt.% to narrow the overall coke content distribution of the catalyst, thereby increasing catalyst activity and selectivity for low carbon olefins.

If desired, the coke particles in the controlled coke catalyst may include polymethylbenzene and polymethylnaphthalene;

the total mass of polymethylbenzene and polymethylnaphthalene can be more than 70% by weight. from the total mass of coke or may be equal to the specified amount;

the mass of coke particles with a molecular weight of more than 184 may be less than 25% by weight. from the total mass of coke or may be equal to the specified amount; A

total coke mass may refer to the total mass of coke particles.

In the present application, the types and contents of coke particles are also very important, and are also one of the control objectives in the present application. In the present application, the total weight of polymethylbenzene and polymethylnaphthalene is controlled to be greater than or equal to 70% by weight. of the total coke mass, using a coke control mechanism and selection of coke control process parameters to increase catalyst activity and improve selectivity for low carbon olefins.

If necessary, the coke content in the spent catalyst can be from 9% wt. up to 13% wt.

Optionally, the oxygen-containing compound may be at least one selected from the group consisting of methanol and dimethyl ether (DME).

If necessary, the operating conditions for the process in the coke content control zone can be as follows: apparent linear gas velocity: from 0.1 m/s to 0.5 m/s; reaction temperature: from 300°C to 700°C; reaction pressure: from 100 kPa to 500 kPa; and layer density: from 400 kg/ ^m3 to 800 kg/ ^m3 .

If necessary, the operating conditions for the process in the reaction zone can be as follows: apparent linear gas velocity: from 0.5 m/s to 2.0 m/s; reaction temperature: from 350°C to 550°C; reaction pressure: from 100 kPa to 500 kPa; and layer density: from 150 kg/m ³ to 500 kg/m ³ .

According to a fourth aspect of the present application, there is also provided a method for producing low carbon olefins, comprising producing low carbon olefins using the apparatus described above;

the method for producing low carbon olefins includes the method described above;

The method for producing low-carbon olefins also includes the following steps:

allowing the spent catalyst located in the reaction zone to enter the fluidized bed regenerator and perform processing - regeneration to form a regenerated catalyst, as well as allowing the regenerated catalyst to enter the coke control zone of the fluidized bed reactor, as well as come into contact and enter react with the raw material to control the coke content.

Optionally, the method may include: allowing the spent catalyst present in the reaction zone to enter the fluidized bed regenerator through the first stripper column and through the spent catalyst supply pipe and to contact and react with the regeneration gas to produce a stream E with flue gas and regenerated catalyst; allowing stream E to enter a third gas-solid separation unit to perform separation of the flue gas and the regenerated catalyst; And

allowing the separated regenerated catalyst to enter the coke content control zone of the fluidized bed reactor through the second stripper column, the regenerated catalyst supply pipe, and the first gas-solid separation unit and come into contact and react with the grade control feedstock coke

If necessary, the coke content in the regenerated catalyst can be less than or equal to 3 wt%.

If desired, the regeneration gas may be at least one selected from the group consisting of oxygen, nitrogen, water vapor and air.

If necessary, the regeneration gas may include from 0% wt. up to 100% wt. air, from 0% wt. up to 50% wt. oxygen, from 0% wt. up to 50% wt. nitrogen and from 0% wt. up to 50% wt. water vapor; and the values of air, oxygen, nitrogen and water vapor content cannot be equal to zero at the same time.

If necessary, the operating conditions in the regeneration zone can be as follows: apparent linear gas velocity: from 0.5 m/s to 2.0 m/s; regeneration temperature: from 600°C to 750°C; regeneration pressure: from 100 kPa to 500 kPa; and layer density: from 150 kg/ ^m3 to 700 kg/ ^m3 .

Possible beneficial effects of this application:

(1) The main characteristic of the dimethyl ether/methanol to olefins (DMTO) catalyst is that the selectivity of the low carbon olefin in the methanol conversion process increases with the coke content of the catalyst. Low carbon olefins mentioned in this application refer to ethylene and propylene. Applicants have discovered through research that the main factors affecting DMTO catalyst activity and selectivity for low carbon olefins are coke content, coke content distribution, and coke particles in the catalyst. Given the same average coke content in the catalysts, the narrower the distribution of coke content, the higher the selectivity and activity of low-carbon olefins. The coke particles in the catalyst may include polymethylaromatic hydrocarbons, polymethylcycloalkanes, and the like, and polymethylbenzene and polymethylnaphthalene may contribute to the formation of ethylene. Thus, controlling the coke content, coke content distribution, and coke particles in the catalyst is key to controlling the activity of the DMTO catalyst and improving low carbon olefin selectivity.

The fluidized bed reactor described in the present application is provided with a coke control zone, and the coke control zone is divided into a plurality of subzones by partitions located in the coke control zone, so that the catalyst flows sequentially through these subzones. The residence time distribution of the catalyst through the subzones is controlled to narrow it, thereby controlling the distribution of coke content in the catalyst and causing the distribution of coke content to be narrowed. In addition, coke content and coke particles are also controlled. This increases the activity of the DMTO catalyst and the selectivity for low carbon olefins.

(2) In the method of the present application, the catalyst can only flow from the upstream subzone to the downstream subzone through catalyst circulation holes in the baffles in the coke control zone, so that the average residence time of the catalyst in the coke control zone can be controlled to control the coke content in the catalyst; and a structure of n subzones of the first coke content control zone is used to control the residence time distribution of the catalyst (residence time distribution is similar to the use of n series tank tank reactors with full mixing) and a catalyst with a narrow coke content distribution is obtained.

(3) According to the present application, it is possible to control the conversion and formation of coke particles in the catalyst. On the one hand, the inactive large molecular coke particles remaining in the regenerated catalyst are converted into low molecular weight coke particles; and on the other hand, the coke content control raw material can also enter the catalyst to form high-activity low molecular weight coke particles, and the low molecular weight coke particles are mainly polymethylbenzene and polymethylnaphthalene, which can improve the selectivity for ethylene.

(4) By using the on-line modification method of DMTO catalyst by carrying out the coke control reaction described in this application, a coke-controlled catalyst with a high coke content, a narrow coke content distribution, and polymethylbenzene and polymethylnaphthalene as the main components can be obtained coke, i.e. the regenerated catalyst with low low carbon olefin selectivity is converted to a controlled coke catalyst with high low carbon olefin selectivity.

(5) The regenerated catalyst described herein can be directly used in a process for producing low carbon olefins from an oxygenate compound without treatment to control the coke content, in which case the selectivity for low carbon olefins in the resulting product gas is between 80 wt%. up to 83% wt. When the regenerated catalyst described herein is subjected to coke control treatment and then used in a process for producing low carbon olefins from an oxygenate compound, the selectivity for low carbon olefins in the resulting product gas is 93 wt%. up to 96% wt.

(6) In the method of the present application, the high-temperature regenerated catalyst from the regenerator is first cooled in the coke control zone and then supplied to the reaction zone, i.e. a local high-temperature zone does not appear in the reaction zone; and thus the raw material with the oxygen-containing compound has a low coking coefficient.

(7) The reaction zone of the fluidized bed reactor according to the present application includes a fluidized bed reactor cooler configured to accurately control the temperature in the reaction zone.

BRIEF DESCRIPTION OF THE DRAWINGS

In fig. 1 is a schematic diagram of a DMTO apparatus for producing low carbon olefins from an oxygen-containing compound according to an embodiment of the present application; And

In fig. 2 is a schematic cross-sectional view of a coke control zone of a fluidized bed reactor according to an embodiment of the present application.

List of item numbers:

1 is a fluidized bed reactor; 1-1 represents the main shell; 1-2 is a reaction zone distributor;

1-3 is a fluidized bed reactor cooler; 1-4 is a coke control zone distributor;

1-5 represents the septum; 1-6 represents a first gas-solid separation unit;

1-7 represents a pipe for supplying a catalyst with a controlled coke content; 1-8 represents a gas supply pipe of a coke content control zone;

1-9 represents a second gas-solid separation unit; 1-10 represents the first gas collection chamber;

1-11 represents a pipe for supplying a gaseous product; 1-12 represents the first stripping column;

1-13 is a sliding valve for spent catalyst; 1-14 is a spent catalyst supply pipe;

2 is a fluidized bed regenerator; 2-1 represents the regenerator shell; 2-2 is a regenerator distributor;

2-3 represents a third gas-solid separation unit; 2-4 represents a second gas collection chamber;

2-5 represents a flue gas supply pipe; 2-6 represents a second stripping column; 2-7 represents a regenerator cooler;

2-8 represents a sliding valve for regenerated catalyst; and 2-9 is a regenerated catalyst supply pipe.

IMPLEMENTATION OF THE INVENTION

The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

Possible embodiments of the present invention are described below.

To improve the performance of a DMTO catalyst, the present application proposes a method for on-line modification of a DMTO catalyst by performing a coke control reaction, comprising the following steps:

a) the regenerated catalyst is supplied to the coke control zone;

b) coke control raw material including hydrogen, methane, ethane, ethylene, propane, propylene, butane, butene, pentane, pentene, hexane, hexene, methanol, ethanol and water are supplied to the coke control reactor;

c) the coke control raw material contacts and reacts with the regenerated catalyst in the coke control reactor such that the coke control raw material cokes the regenerated catalyst, wherein the coked catalyst is called a coke control catalyst; The coke content in the catalyst with controlled coke content is from 4% wt. up to 9% weight; coke particles include polymethylbenzene and polymethylnaphthalene, and the total mass of polymethylbenzene and polymethylnaphthalene is more than 70% by weight. from the total mass of coke or equal to the specified amount; and the mass of coke particles with a molecular weight of more than 184 is less than 25% by weight. from the total mass of coke or equal to the specified amount; And

d) catalyst with controlled coke content is fed to the methanol conversion reactor.

The regenerated catalyst may be a DMTO catalyst with a coke content of less than or equal to 3 wt.%, and the active component of the DMTO catalyst may be a SAPO molecular sieve.

The raw material for controlling coke content may consist of hydrogen in amounts ranging from 0 wt%. up to 20% wt., methane in amounts from 0% wt. up to 50% wt., ethane in amounts from 0% wt. up to 50% wt., ethylene in an amount from 0% wt. up to 20% wt., propane in amounts from 0% wt. up to 50% wt., propylene in an amount from 0% wt. up to 20% wt., butane in amounts from 0% wt. up to 90% wt., butene in an amount from 0% wt. up to 90% wt., pentane in an amount from 0% wt. up to 90% wt., pentene in an amount from 0% wt. up to 90% wt., hexane in an amount of 0% wt. up to 90% wt., hexene in an amount from 0% wt. up to 90% wt., methanol in an amount from 0% wt. up to 50% wt., ethanol in an amount from 0% wt. up to 50% wt. and water in an amount of 0% wt. up to 50 wt.%, and the total content of methanol, ethanol and water may exceed or be equal to 10 wt.%.

The coke control reaction temperature can range from 300°C to 700°C.

The present application also provides a method for producing low carbon olefins from an oxygen-containing compound, which includes a method for on-line modification of a DMTO catalyst by carrying out the coke control reaction described above, and an apparatus used therefor. This device includes a fluidized bed reactor 1 and a fluidized bed regenerator 2.

The fluidized bed reactor 1 is divided into a reaction zone, a coke content control zone, and a gas-solid separation zone from bottom to top; The fluidized bed reactor 1 includes a fluidized bed reactor main shell 1-1, a reaction zone distributor 1-2, a fluidized bed reactor cooler 1-3, a coke control zone distributor 1-4, a baffle 1-5, a first unit 1-6 for separating gas and solids, pipe 1-7 for supplying catalyst with controlled coke content, pipe 1-8 for supplying gas of the coke control zone, second block 1-9 for separating gas and solids, first chamber 1- 10 for collecting gas, a pipe 1-11 for supplying a gaseous product, a first stripping column 1-12, a sliding valve 1-13 for spent catalyst, and a pipe 1-14 for supplying spent catalyst; and the spent catalyst sliding valve 1-13 is configured to control the circulation volume of the spent catalyst.

The reaction zone distributor 1-2 is located at the bottom of the reaction zone of the fluidized bed reactor 1, and the fluidized bed reactor cooler 1-3 is located in the reaction zone.

The coke content control zone is located in the annular zone above the reaction zone, n partitions 1-5 are installed in the coke content control zone, and partitions 1-5 divide the coke content control zone into n subzones of the coke content control zone, where n is an integer and 2 ≤ n ≤ 10; the lower part of each of the subzones of the coke content control zone is independently equipped with a distributor 1-4 of the coke content control zone; the cross-section of the coke content control zone is annular, and the cross-section of each of the subzones of the coke content control zone is sector-ring; from the ^1st to the ^nth subzones of the coke content control zone are located sequentially and concentrically; and in partitions 1-5 a hole for catalyst circulation is formed, but in the partition, which is common to the ^1st subzone of the coke content control zone and the ^nth subzone of the coke content control zone, no hole for catalyst circulation is formed.

The first gas-solid separation unit 1-6 is located in the gas-solid separation zone of the fluidized bed reactor 1; the inlet of the first gas-solid separation unit 1-6 is connected to the outlet of the regenerated catalyst supply pipe 2-9, the gas outlet of the first gas-solid separation unit 1-6 is formed in the gas-solid separation zone, and the outlet for the catalyst from the first block 1-6 for separating gas and solids is formed in the ^1st subzone of the coke content control zone; and the inlet of the coke controlled catalyst supply pipe 1-7 is connected to the ^nth subzone of the coke content control zone, and the outlet of the coke controlled catalyst supply pipe 1-7 is formed in the reaction zone.

The upper part of each of the subzones of the coke content control zone is independently provided with a gas supply pipe 1-8 of the coke content control zone, and the outlet of the gas supply pipe 1-8 of the coke content control zone is formed in the gas-solid separation zone; the second gas-solid separation unit 1-9 and the first gas collection chamber 1-10 are located in the gas-solid separation zone of the fluidized bed reactor 1; the inlet of the second gas-solid separation unit 1-9 is formed in the gas-solid separation zone of the fluidized bed reactor 1, the gas outlet from the second gas-solid separation unit 1-9 is connected to the first gas collection chamber 1-10, and a catalyst outlet from the second gas-solid separation unit 1-9 is formed in the reaction zone; a product gas supply pipe 1-11 is connected to an upper part of the first gas collection chamber 1-10; the first stripping column 1-12 is located below the fluidized bed reactor 1, the inlet pipe of the first stripping column 1-12 passes through the lower shell of the fluidized bed reactor through the lower part of the fluidized bed reactor 1 and is open above the reaction zone distributor 1-2; and the inlet of the spent catalyst sliding valve 1-13 is connected to the outlet pipe at the bottom of the first stripping column 1-12, the outlet of the spent catalyst sliding valve 1-13 is connected by pipeline to the inlet of the spent catalyst supply pipe 1-14, and the outlet of the pipe 1 -14 is connected to the middle part of the fluidized bed regenerator 2 to supply spent catalyst.

In a preferred embodiment, the first gas-solid separation unit 1-6 may be a cyclone gas-solid separator.

In a preferred embodiment, the first gas-solid separation unit 1-6 may be a fast gas-solid separator.

In a preferred embodiment, the second gas-solid separation unit 1-9 may have one or more sets of gas-solid separation cyclone separators, and each set of gas-solid separation cyclone separators may include a gas-solid separation cyclone separator and solids of the first stage and a cyclone separator for separating gas and solids of the second stage.

A device is proposed for producing low-carbon olefins from an oxygen-containing compound, which includes a fluidized bed regenerator 2 for catalyst regeneration; wherein the fluidized bed regenerator 2 includes a regenerator shell 2-1, a regenerator distributor 2-2, a third gas-solid separation unit 2-3, a second gas collection chamber 2-4, a flue gas supply pipe 2-5 , a second stripping column 2-6, a regenerator cooler 2-7, a sliding valve 2-8 for the regenerated catalyst, and a pipe 2-9 for supplying the regenerated catalyst;

a regenerator distributor 2-2 is located at the bottom of the fluidized bed regenerator 2, and a third gas-solid separation unit 2-3 is located at the top of the fluidized bed regenerator 2; the inlet of the third gas-solid separation unit 2-3 is formed at the top of the fluidized bed regenerator 2, the gas outlet from the third gas-solid separation unit 2-3 is connected to the second gas collection chamber 2-4, and the outlet for the catalyst from the third gas-solid separation unit 2-3 is formed at the bottom of the fluidized bed regenerator 2; the second gas collection chamber 2-4 is located at the top of the fluidized bed regenerator 2, and the flue gas supply pipe 2-5 is connected to the top of the second gas collection chamber 2-4;

the second stripper column 2-6 is located outside the regenerator shell 2-1, and the inlet pipe of the second stripper column 2-6 passes through the regenerator shell 2-1 and is open above the regenerator distributor 2-2; the regenerator cooler 2-7 is located in the second stripping column 2-6; and the inlet of the regenerated catalyst sliding valve 2-8 is connected by pipeline to the bottom of the regenerator stripping column 2-6, the outlet of the regenerated catalyst sliding valve 2-8 is connected by pipeline to the inlet of the regenerated catalyst supply pipe 2-9, and the outlet of the pipe 2-9 for supplying regenerated catalyst is connected to the inlet of the first block 1-6 for separating gas and solid matter. The sliding valve 2-8 for the regenerated catalyst is configured to control the circulation volume of the regenerated catalyst.

In a preferred embodiment, the third gas-solid separation unit 2-3 may have one or more sets of gas-solid separation cyclone separators, and each set of gas-solid separation cyclone separators may include a gas-solid separation cyclone separator and solids of the first stage and a cyclone separator for separating gas and solids of the second stage.

According to yet another aspect of the present application, there is also provided a method of converting methanol to olefin (Methanol-to-olefin technology, MTO), including a method of modifying a DMTO catalyst on-line by carrying out a coke control reaction, comprising the following steps:

the coke content control raw material is supplied to the coke content control zone of the fluidized bed reactor 1 from the coke content control zone distributor 1-4; the regenerated catalyst is supplied to the first gas-solid separation unit 1-6 from the regenerated catalyst supply pipe 2-9 to perform gas-solid separation, the resulting gas is discharged to the gas-solid separation zone of the fluidized bed reactor 1 through the outlet for gas from the first gas-solid separation unit 1-6, and the resulting regenerated catalyst is discharged to the coke content control zone of the fluidized bed reactor 1 through the catalyst outlet from the first gas-solid separation unit 1-6; the coke control raw material contacts and reacts chemically with the regenerated catalyst in the coke control zone to form a coke control catalyst and a coke control product gas; the catalyst with controlled coke content sequentially passes through subzones from the ^1st to the ^nth zones of the coke content control zone through the holes for catalyst circulation in partitions 1-5, and then enters the reaction zone of the fluidized bed reactor 1 through pipe 1-7 for supplying catalyst with controlled coke content; the gaseous coke control product is supplied to the gas-solid separation zone of the fluidized bed reactor 1 through the coke control zone gas supply pipe 1-8; the raw material with the oxygen-containing compound is supplied to the reaction zone of the fluidized bed reactor 1 from the reaction zone distributor 1-2 to come into contact with the catalyst with a controlled coke content to form a stream A with low carbon olefins and spent catalyst; stream A and the gaseous coke control product are mixed in a gas-solid separation zone to produce stream B, and stream B enters a second gas-solid separation unit 1-9 to perform gas-solid separation to produce gas-phase stream C and a solid phase stream D, wherein the gas phase stream C represents a gaseous product containing a low carbon olefin and the solid phase stream D represents a spent catalyst; the gas-phase stream C enters the first gas collection chamber 1-10 and then enters the downstream working section through the gaseous product supply pipe 1-11, and the solid-phase stream D is returned to the reaction zone of the fluidized bed reactor 1; the spent catalyst in the reaction zone enters the stripper column 1-12 of the fluidized bed reactor through the inlet pipe of the first stripper column 1-12 to perform stripping, and then enters the middle part of the fluidized bed regenerator 2 through the sliding valve 1-13 to spent catalyst and through pipe 1-14 for supplying spent catalyst;

The regeneration gas is supplied from the regenerator distributor 2-2 to the bottom of the fluidized bed regenerator 2, and in the fluidized bed regenerator 2, the regeneration gas comes into contact and chemically reacts with the spent catalyst so that part of the coke in the spent catalyst is burned and removed from forming stream E with flue gas and regenerated catalyst; stream E enters the third gas-solid separation unit 2-3 to perform gas-solid separation to obtain flue gas and regenerated catalyst; the flue gas enters the second gas collection chamber 2-4, and then enters the downstream flue gas treatment system through the flue gas supply pipe 2-5; the regenerated catalyst is returned to the lower part of the fluidized bed regenerator 2; and the regenerated catalyst located in the fluidized bed regenerator 2 enters the second stripper 2-6 for stripping and cooling, and then enters the first gas-solid separation unit 1-6 through the regenerated catalyst sliding valve 2-8 and through pipe 2-9 to supply regenerated catalyst.

In a preferred embodiment, the raw material for controlling coke content according to the present application may consist of hydrogen in an amount of from 0% by weight. up to 20% wt., methane in amounts from 0% wt. up to 50% wt., ethane in amounts from 0% wt. up to 50% wt., ethylene in an amount from 0% wt. up to 20% wt., propane in amounts from 0% wt. up to 50% wt., propylene in an amount from 0% wt. up to 20% wt., butane in amounts from 0% wt. up to 90% wt., butene in an amount from 0% wt. up to 90% wt., pentane in an amount from 0% wt. up to 90% wt., pentene in an amount from 0% wt. up to 90% wt., hexane in an amount of 0% wt. up to 90% wt., hexene in an amount from 0% wt. up to 90% wt., methanol in an amount from 0% wt. up to 50% wt., ethanol in an amount from 0% wt. up to 50% wt. and water in an amount of 0% wt. up to 50 wt.%, and the total content of methanol, ethanol and water may exceed or be equal to 10 wt.%.

In a preferred embodiment, the oxygen-containing compound in the method according to the present application may be one of the group consisting of methanol, dimethyl ether, and mixtures of methanol and dimethyl ether.

In a preferred embodiment, the regeneration gas in the method according to the present application may contain from 0% wt. up to 100% wt. air, from 0% wt. up to 50% wt. oxygen, from 0% wt. up to 50% wt. nitrogen and from 0% wt. up to 50% wt. water vapor.

In a preferred embodiment, the active catalyst component may be a SAPO molecular sieve.

In a preferred embodiment, the coke content of the regenerated catalyst may be less than or equal to 3 wt%.

In a preferred embodiment, the coke content of the controlled coke content catalyst can range from 4 wt.%. up to 9 wt.%, and the quartile deviation of the distribution of coke content in the catalyst with a controlled coke content can be less than 1 wt.%. the coke particles may include polymethylbenzene and polymethylnaphthalene, and the total mass of polymethylbenzene and polymethylnaphthalene may be more than 70% by weight. from the total mass of coke or may be equal to the specified amount; and the mass of coke particles with a molecular weight greater than 184 may be less than 25% by weight. of the total mass of coke or may be equal to the specified amount.

In a preferred embodiment, the coke content of the spent catalyst can range from 9% wt. up to 13% wt. and more preferably, the coke content of the spent catalyst may range from 10 wt%. up to 12% wt..

In a preferred embodiment, the process operating conditions in the coke content control zone of the fluidized bed reactor 1 may be as follows: apparent linear gas velocity: 0.1 m/s to 0.5 m/s; reaction temperature: from 300°C to 700°C; reaction pressure: from 100 kPa to 500 kPa; and layer density: from 400 kg/ ^m3 to 800 kg/ ^m3 .

In a preferred embodiment, the process operating conditions in the reaction zone of the fluidized bed reactor 1 may be as follows: apparent linear gas velocity: 0.5 m/s to 2.0 m/s; reaction temperature: from 350°C to 550°C; reaction pressure: from 100 kPa to 500 kPa; and layer density: from 150 kg/m ³ to 500 kg/m ³ .

In a preferred embodiment, the operating conditions for the process in the fluidized bed regenerator 2 may be as follows: apparent linear gas velocity: 0.5 m/s to 2.0 m/s; regeneration temperature: from 600°C to 750°C; regeneration pressure: from 100 kPa to 500 kPa; and layer density: from 150 kg/ ^m3 to 700 kg/ ^m3 .

According to the method described in this application, the gaseous product may consist of ethylene in an amount of 38 wt%. up to 57% wt., propylene in an amount from 37% wt. up to 55% wt., hydrocarbon compounds C ₄ -C ₆ in an amount of 5% wt. or less and other components in an amount of 3% wt. or less; in this case, other components can be methane, ethane, propane, hydrogen, CO, CO ₂ , etc., and the overall selectivity of ethylene and propylene in the gaseous product can be from 93% wt. up to 96% wt.

In this application, when expressing the unit flow rate, the mass of dimethyl ether in the oxygen-containing compound is equivalently converted to the mass of methanol per mass of element C, and the unit flow rate is ton of methanol per ton of low carbon olefins.

In the method according to this application, the specific production consumption can be from 2.50 to 2.58 tons of methanol per ton of low-carbon olefins.

Example 1

In this example, the device shown in FIG. 1 and fig. 2, in which 2 partitions are installed in the coke control zone of the fluidized bed reactor, i.e. n = 2; the coke content control zone includes 2 subzones of the coke content control zone; and the first gas-solid separating unit is a cyclone gas-solid separator.

In particular, as shown in FIG. 1, the diameter of the connection between the lower shell and the upper shell gradually increases from bottom to top, so that the diameter of the gas-solid separation zone is larger than the diameter of the reaction zone. The coke control zone is located at the junction of the lower shell and the upper shell. The longitudinal section of each of the partitions is a parallelogram.

In this example, the raw material for coke control is a mixture of 6% wt. butane, 81% wt. butene, 2% wt. methanol and 11% wt. water; the oxygen-containing compound is methanol; the regeneration gas is air; the active component of the catalyst is a SAPO-34 molecular sieve; the coke content of the regenerated catalyst is approximately 1% by weight; The coke content of the coke controlled catalyst is approximately 4 wt.%, with the total weight of polymethylbenzene and polymethylnaphthalene being approximately 85 wt.%. of the total mass of coke, the mass of coke particles with a molecular weight of more than 184 is approximately 6% wt. of the total mass of coke, and the quartile deviation of the distribution of coke content in the catalyst with controlled coke content is approximately 0.9% by weight; and the coke content of the spent catalyst is approximately 9% by weight.

The process operating conditions in the coke control zone of the fluidized bed reactor are as follows: apparent linear gas velocity: approximately 0.3 m/s, reaction temperature: approximately 500°C, reaction pressure: approximately 100 kPa, and bed density: approximately 600 kg /m ³ .

The process operating conditions in the reaction zone of a fluidized bed reactor are as follows: apparent linear gas velocity: approximately 2.0 m/s, reaction temperature: approximately 550°C, reaction pressure: approximately 100 kPa, and bed density: approximately 150 kg/m ³ .

The operating conditions for the fluidized bed regenerator process are: apparent linear gas velocity: approximately 0.5 m/s, reaction temperature: approximately 700° C., reaction pressure: approximately 100 kPa and bed density: approximately 700 kg/m ³ .

In this example, the gaseous product consists of ethylene in an amount of 57% by weight, propylene in an amount of 37% by weight, C ₄ -C ₆ hydrocarbon compounds in an amount of 3% by weight. and other components in an amount of 3% by weight, wherein other components include methane, ethane, propane, hydrogen, CO, CO ₂ and the like; and the specific product consumption is 2.55 tons of methanol per ton of low-carbon olefins.

Example 2

In this example, the device shown in FIG. 1 and fig. 2, in which 10 baffles are installed in the coke control zone of the fluidized bed reactor, i.e. n = 10; the coke content control zone includes 10 subzones of the coke content control zone; and the first gas-solid separating unit is a cyclone gas-solid separator.

In this example, the raw material for coke control is a mixture of 22% wt. methane, 24% wt. ethane, 3% wt. ethylene, 28% wt. propane, 4% wt. propylene, 7% wt. hydrogen and 12% wt. water; the oxygen-containing compound is a mixture of 82% wt. methanol and 18% wt. dimethyl ether; The regeneration gas is a mixture of 50% wt. air and 50% wt. water vapor; the active component of the catalyst is a SAPO-34 molecular sieve; the coke content of the regenerated catalyst is approximately 3% by weight; The coke content of the coke controlled catalyst is approximately 9 wt.%, with the total weight of polymethylbenzene and polymethylnaphthalene being approximately 78 wt.%. of the total mass of coke, the mass of coke particles with a molecular weight of more than 184 is approximately 13% wt. of the total mass of coke, and the quartile deviation of the distribution of coke content in the catalyst with controlled coke content is approximately 0.2% by weight; and the coke content of the spent catalyst is approximately 13% by weight.

The process operating conditions in the coke control zone of the fluidized bed reactor are as follows: apparent linear gas velocity: approximately 0.1 m/s, reaction temperature: approximately 300°C, reaction pressure: approximately 500 kPa, and bed density: approximately 800 kg /m ³ .

The process operating conditions in the reaction zone of a fluidized bed reactor are as follows: apparent linear gas velocity: approximately 0.5 m/s, reaction temperature: approximately 350°C, reaction pressure: approximately 500 kPa and bed density: approximately 500 kg/m ³ .

The operating conditions for the fluidized bed regenerator process are as follows: apparent linear gas velocity: approximately 2.0 m/s, reaction temperature: approximately 600° C., reaction pressure: approximately 500 kPa and bed density: approximately 150 kg/m ³ .

In this example, the gaseous product consists of ethylene in an amount of 38% by weight, propylene in an amount of 55% by weight, C ₄ -C ₆ hydrocarbon compounds in an amount of 5% by weight. and other components in an amount of 2% by weight, wherein other components include methane, ethane, propane, hydrogen, CO, CO ₂ and the like; and the specific product consumption is 2.58 tons of methanol per ton of low-carbon olefins.

Example 3

In this example, the device shown in FIG. 1 and fig. 2, in which 4 partitions are installed in the coke control zone of the fluidized bed reactor, i.e. n = 4; the coke content control zone includes 4 subzones of the coke content control zone; and the first gas-solid separating unit is a fast gas-solid separator.

In this example, the raw material for coke control is a mixture of 1 wt.%. propane, 1% wt. propylene, 3% wt. butane, 51% wt. butene, 3% wt. pentane, 22% wt. pentene, 1% wt. hexane, 7% wt. hexene, 2% wt. methanol and 9% wt. water; the oxygen-containing compound is dimethyl ether; The regeneration gas is a mixture of 50% wt. air and 50% wt. oxygen; the active component in the catalyst is a SAPO-34 molecular sieve; the coke content of the regenerated catalyst is approximately 2% by weight; The coke content of the coke controlled catalyst is approximately 6 wt.%, with the total weight of polymethylbenzene and polymethylnaphthalene being approximately 81 wt.%. of the total mass of coke, the mass of coke particles with a molecular weight of more than 184 is approximately 15% wt. of the total mass of coke, and the quartile deviation of the distribution of coke content in the catalyst with controlled coke content is approximately 0.6% by weight; and the coke content of the spent catalyst is approximately 11 wt%.

The process operating conditions in the coke control zone of the fluidized bed reactor are as follows: apparent linear gas velocity: approximately 0.4 m/s, reaction temperature: approximately 700°C, reaction pressure: approximately 300 kPa, and bed density: approximately 500 kg /m ³ .

The process operating conditions in the reaction zone of a fluidized bed reactor are as follows: apparent linear gas velocity: approximately 1.0 m/s, reaction temperature: approximately 450°C, reaction pressure: approximately 300 kPa, and bed density: approximately 300 kg/m ³ .

The operating conditions for the fluidized bed regenerator process are as follows: apparent linear gas velocity: approximately 1.0 m/s, reaction temperature: approximately 750° C., reaction pressure: approximately 300 kPa and bed density: approximately 360 kg/m ³ .

In this example, the gaseous product consists of ethylene in an amount of 48 wt.%, propylene in an amount of 47 wt.%, C ₄ -C ₆ hydrocarbon compounds in an amount of 3 wt.%. and other components in an amount of 2% by weight, wherein other components include methane, ethane, propane, hydrogen, CO, CO ₂ and the like; and the specific product consumption is 2.53 tons of methanol per ton of low-carbon olefins.

Example 4

In this example, the device shown in FIG. 1 and fig. 2, in which 6 partitions are installed in the coke control zone of the fluidized bed reactor, i.e. n = 6; the coke content control zone includes 6 subzones of the coke content control zone; and the first gas-solid separating unit is a fast gas-solid separator.

In this example, the raw material for coke control is a mixture of 5% wt. butane, 72% wt. butene, 8% wt. methanol and 15% wt. water; the oxygen-containing compound is methanol; The regeneration gas is a mixture of 50% wt. air and 50% wt. nitrogen; the active component of the catalyst is a SAPO-34 molecular sieve; the coke content of the regenerated catalyst is approximately 2% by weight; The coke content of the coke controlled catalyst is approximately 6 wt.%, with the total weight of polymethylbenzene and polymethylnaphthalene being approximately 70 wt.%. of the total mass of coke, the mass of coke particles with a molecular weight of more than 184 is approximately 24% wt. of the total mass of coke, and the quartile deviation of the distribution of coke content in the catalyst with controlled coke content is approximately 0.3% by weight; and the coke content of the spent catalyst is approximately 12% by weight.

The process operating conditions in the coke control zone of the fluidized bed reactor are as follows: apparent linear gas velocity: approximately 0.5 m/s, reaction temperature: approximately 600°C, reaction pressure: approximately 200 kPa, and bed density: approximately 400 kg /m ³ .

The process operating conditions in the reaction zone of a fluidized bed reactor are as follows: apparent linear gas velocity: approximately 1.5 m/s, reaction temperature: approximately 500°C, reaction pressure: approximately 200 kPa and bed density: approximately 200 kg/m ³ .

The operating conditions for the fluidized bed regenerator process are: apparent linear gas velocity: approximately 1.5 m/s, reaction temperature: approximately 680° C., reaction pressure: approximately 200 kPa and bed density: approximately 280 kg/m ³ .

In this example, the gaseous product consists of ethylene in an amount of 53 wt.%, propylene in an amount of 43 wt.%, C ₄ -C ₆ hydrocarbon compounds in an amount of 3 wt.%. and other components in an amount of 1% by weight, wherein other components include methane, ethane, propane, hydrogen, CO, CO ₂ and the like; and the specific product consumption is 2.50 tons of methanol per ton of low-carbon olefins.

Comparative example

This comparative example differs from example 4 in that the coke control reaction is not used to modify the DMTO catalyst on-line; and the raw material supplied to the coke control zone is nitrogen, which is an inert gas and does not change the properties of the regenerated catalyst in the coke control zone, i.e. the catalyst entering the reaction zone is regenerated catalyst.

In this example, the gaseous product consists of 43 wt% ethylene, 39 wt% propylene, 12 wt% C ₄ -C ₆ hydrocarbon compounds. and other components in an amount of 6% by weight, wherein other components include methane, ethane, propane, hydrogen, CO, CO ₂ and the like; and the specific product consumption is 2.91 tons of methanol per ton of low-carbon olefins.

This comparative example shows that on-line modification of a DMTO catalyst through a coke control reaction can significantly improve catalyst performance and reduce specific product consumption.

The above examples are just a few examples of the present application and are not intended to limit it in any way. Although the present application has been described above with preferred examples, the present application is not limited to them. Certain changes or modifications that may be suggested by those skilled in the art using the technical content disclosed above without departing from the scope of the technical solutions of this application are equivalent to equivalent embodiments and are included in the specified scope of technical solutions.

Claims (67)

1. A fluidized bed reactor (1) for producing low-carbon olefins from an oxygen-containing compound, comprising a main shell (1-1) and a coke control zone shell; and the main shell contains an upper shell and a lower shell; the upper shell encloses the gas-solid separation zone, and the lower shell encloses the reaction zone; the reaction zone is in axial communication with the gas-solid separation zone; the shell of the coke content control zone is located circumferentially on the outer wall of the main shell; the shell of the coke content control zone and the main shell form an annular cavity, and the annular cavity represents a coke content control zone; n partitions (1-5) are radially located in the coke content control zone and n partitions divide the coke content control zone into n subzones of the coke content control zone, where n is an integer and has a range of values: 2 ≤ n ≤ 10; subzones of the coke content control zone are provided with an input for raw material for coke content control; And In each of the n-1 partitions, a catalyst circulation hole is formed so that the catalyst and coke control raw material supplied to the coke control zone flow in an annular direction. 2. The fluidized bed reactor according to claim 1, wherein in the coke content control zone, the n partitions comprise a 1st partition and from the 2nd partition to an nth partition; there is no hole for catalyst circulation in the 1st partition; a hole for catalyst circulation is formed in each partition from the 2nd partition to the nth partition; in the 1st subzone of the coke content control zone formed by dividing by the 1st partition and the 2nd partition, an inlet for the coke content control zone catalyst is formed; in the n-th subzone of the coke content control zone, formed by separation using the 1st partition and the n-th partition, there is a pipe (1-7) for supplying a catalyst with a controlled coke content, and in the reaction zone a pipe outlet for supplying the catalyst is formed with controlled coke content; an input for raw material for coke content control is formed in the lower parts of subzones of the coke content control zone; and the raw material input for coke content control is a coke content control zone distributor (1-4); And in the upper parts of the subzones of the coke content control zone, a pipe (1-8) is located for supplying gas to the coke content control zone, and in the gas and solid separation zone, a pipe outlet is formed for supplying gas to the coke content control zone; the gas-solid separation zone is provided with a first unit (1-6) for separating gas and solid matter and a second unit (1-9) for separating gas and solid matter; The catalyst outlet pipe of the first gas-solid separation unit passes through the top of the coke control zone and is inserted into the 1st subzone coke control zones; in the gas-solid separation zone, a gas outlet from the first gas-solid separation unit is formed; in the gas-solid separation zone, an inlet of a second gas-solid separation unit is formed; and in the reaction zone, an outlet for catalyst from the second gas-solid separation unit is located; And the first gas collection chamber (1-10) is also located in the upper part of the gas-solid separation zone; a gas outlet from the second gas-solid separation unit communicates with the first gas collection chamber; and the first gas collection chamber is also in communication with the product gas supply pipe (1-11). 3. The fluidized bed reactor according to claim 1, in which a reaction zone distributor (1-2) is also located in the lower part of the reaction zone; And wherein the reaction zone distributor is configured to supply raw material for the reaction; And the reaction zone is provided with a fluidized bed reactor cooler (1-3), and the lower part of the reaction zone is provided with a first stripping column (1-12); the inlet of the first stripping column is formed inside the lower shell; the outlet of the first stripping column is formed outside the lower shell; above the outlet end of the pipe for supplying the catalyst with a controlled coke content is the open end of the inlet of the first stripping column; And the outlet end of the pipe for supplying catalyst with a controlled coke content is located above the reaction zone distributor. 4. A device for producing low-carbon olefins from an oxygen-containing compound, comprising a fluidized bed regenerator (2) and a fluidized bed reactor according to claim 1. 5. The device according to claim 4, in which the fluidized bed regenerator comprises a regenerator shell (2-1); the regenerator shell contains an upper regenerator shell and a lower regenerator shell; the upper shell of the regenerator covers the gas-solid separation zone, and the lower shell of the regenerator covers the regeneration zone; an inlet for the spent catalyst is formed in the regenerator shell; the spent catalyst inlet communicates with the outlet pipe of the first stripping column through a spent catalyst supply pipe (1-14); And the regenerator shell also contains a third block (2-3) for separating gas and solid matter and a second chamber (2-4) for collecting gas; a second gas collection chamber is located in the inner upper part of the regenerator shell; a gas outlet from the third unit communicates with the second gas collection chamber for separating gas and solids; a second gas collection chamber communicates with a pipe (2-5) for supplying flue gas; and above the open end of the second inlet pipe of the stripping column is an outlet end for the catalyst of the third gas-solid separation unit. 6. The device according to claim 4, in which a distributor (2-2) of the regeneration zone is also located in the lower part of the regeneration zone; wherein the regeneration zone distributor is configured to supply regeneration gas; And in the lower part of the regeneration zone there is a second stripping column (2-6); the inlet of the second stripping column is formed inside the regenerator shell; the outlet of the second stripping column is formed outside the regenerator shell; the second stripping column communicates with the first gas-solid separation unit through a pipe (2-9) for supplying the regenerated catalyst; And Above the regeneration zone distributor is the open end of the inlet of the second stripping column. 7. A method for producing low-carbon olefins, comprising producing low-carbon olefins using the device according to claim 4; producing low carbon olefins from an oxygen-containing compound, wherein on-line modification of the dimethyl ether/methanol to olefins (DMTO) catalyst is accomplished by controlling the coke content using a fluidized bed reactor; this method includes the following step: supplying catalyst and coke control feedstock to a coke control zone, wherein the catalyst reacts with the coke control feedstock while flowing in an annular direction along subzones of the coke control zone to form a product comprising the grade-controlled catalyst coke, wherein the coke controlled catalyst is a DMTO catalyst; and additionally including the following steps: allowing the spent catalyst located in the reaction zone of the fluidized bed reactor to enter the fluidized bed regenerator and perform processing - regeneration with the formation of a regenerated catalyst, as well as allowing the regenerated catalyst to enter the coke control zone of the fluidized bed reactor, as well as entering contact and react with the raw material to control the coke content. 8. The method according to claim 7, according to which the catalyst flows in an annular direction along the catalyst circulation opening in the partitions; and the coke control raw material is supplied to the subzones of the coke control zone from the coke control zone distributor to react with the catalyst; the resulting coke-controlled catalyst enters the reaction zone through the coke-controlled catalyst supply pipe and then contacts and reacts with the oxygenate-containing feedstock supplied through the reaction zone distributor to form a low-carbon olefin stream A and spent catalyst; and the product also contains a gaseous product for controlling coke content; and the gaseous coke content control product is supplied to the gas-solid separation zone through a gas supply pipe of the coke content control zone; Stream A is mixed with a gaseous product to control the coke content entering the gas-solid separation zone to produce Stream B; stream B enters a second gas-solid separation unit to perform gas-solid separation to obtain a gas-phase stream C and a solid-phase stream D; gas phase stream C is a gaseous product containing a low carbon olefin; and solid phase stream D contains spent catalyst; and the gas-phase stream C enters the first gas collection chamber and then enters the downstream operating section through a product gas supply pipe; solid phase stream D is returned to the reaction zone of the fluidized bed reactor; and the catalyst in the reaction zone enters the first stripper through the open end of the inlet pipe of the first stripper to perform stripping, and then enters the downstream zone. 9. The method according to claim 7, wherein the raw material for controlling the coke content contains hydrocarbon compounds C ₁ -C ₆ ; the hydrocarbon compounds are at least one selected from the group consisting of C ₁ -C ₆ alkanes and C ₁ -C ₆ olefins; the coke control raw material also contains at least one selected from the group consisting of hydrogen, an alcohol compound and water; and the proportion of the total mass of the alcohol compound and water in the mass of the raw material for controlling the coke content is greater than or equal to 10 wt.% and less than or equal to 50 wt.%; the alcohol compound is at least one selected from the group consisting of methanol and ethanol; the coke content control raw material contains hydrogen in an amount from 0 to 20 wt.%, methane in an amount from 0 to 50 wt.%, ethane in an amount from 0 to 50 wt.%, ethylene in an amount from 0 to 20 wt.% , propane in an amount from 0 to 50 wt.%, propylene in an amount from 0 to 20 wt.%, butane in an amount from 0 to 90 wt.%, butene in an amount from 0 to 90 wt.%, pentane in an amount from 0 up to 90 wt.%, pentene in an amount from 0 to 90 wt.%, hexane in an amount from 0 to 90 wt.%, hexene in an amount from 0 to 90 wt.%, methanol in an amount from 0 to 50 wt.%, ethanol in an amount from 0 to 50 wt.% and water in an amount from 0 to 50 wt.%; and the total amount of hydrocarbon compounds exceeds 0%; the catalyst contains a SAPO molecular sieve; the coke content in the catalyst is less than or equal to 3 wt.%; the coke content of the coke-controlled catalyst is from 4 to 9 wt.%; the quartile deviation of the distribution of coke content in the catalyst with a controlled coke content is less than 1 wt.%; the coke particles in the coke-controlled catalyst contain polymethylbenzene and polymethylnaphthalene; the total mass of polymethylbenzene and polymethylnaphthalene is more than 70 wt.% of the total mass of coke or may be equal to the specified amount; and the total mass of coke refers to the total mass of coke particles; the operating conditions for the process in the coke content control zone are as follows: apparent linear gas velocity from 0.1 to 0.5 m/s; reaction temperature from 300 to 700°C; reaction pressure from 100 to 500 kPa; and layer density from 400 to 800 kg/m ³ ; the method includes allowing the spent catalyst present in the reaction zone to enter the fluidized bed regenerator through the first stripper column and through the spent catalyst supply pipe and to contact and react with the regeneration gas to produce a flue gas stream E and regenerated catalyst; allowing stream E to enter a third gas-solid separation unit to perform separation of the flue gas and the regenerated catalyst; and allowing the separated regenerated catalyst to enter the coke control zone of the fluidized bed reactor through the second stripping column, the regenerated catalyst supply pipe and the first gas-solid separation unit, and come into contact and react with the control raw material coke content; the coke content in the regenerated catalyst is less than or equal to 3 wt.%; the regeneration gas is at least one selected from the group consisting of oxygen, nitrogen, water vapor and air; the regeneration gas contains from 0 to 100 wt.% air, from 0 to 50 wt.% oxygen, from 0 to 50 wt.% nitrogen and from 0 to 50 wt.% water vapor; and the values of the content of air, oxygen, nitrogen and water vapor are not equal to zero at the same time; And operating conditions in the regeneration zone are as follows: apparent linear gas velocity from 0.5 to 2.0 m/s; regeneration temperature from 600 to 750°C; regeneration pressure from 100 to 500 kPa; and layer density from 150 to 700 kg/ ^m3 . 10. The method according to claim 8, according to which the coke content in the spent catalyst is from 9 to 13 wt.%; the oxygen-containing compound is at least one selected from the group consisting of methanol and dimethyl ether (DME); And the operating conditions for the process in the reaction zone are as follows: apparent linear gas velocity from 0.5 to 2.0 m/s; reaction temperature from 350 to 550°C; reaction pressure from 100 to 500 kPa; and layer density: from 150 to 500 kg/ ^m3 .