CN111574369A - Method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol and multi-stage reaction system - Google Patents
Method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol and multi-stage reaction system Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 95
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 238000003541 multi-stage reaction Methods 0.000 title claims abstract description 25
- HSJKGGMUJITCBW-UHFFFAOYSA-N 3-hydroxybutanal Chemical compound CC(O)CC=O HSJKGGMUJITCBW-UHFFFAOYSA-N 0.000 title claims abstract description 24
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 title claims abstract description 24
- 229940017219 methyl propionate Drugs 0.000 title claims abstract description 24
- 238000005575 aldol reaction Methods 0.000 title description 2
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- 238000011069 regeneration method Methods 0.000 claims abstract description 100
- 238000006555 catalytic reaction Methods 0.000 claims abstract description 76
- 239000003054 catalyst Substances 0.000 claims abstract description 72
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 65
- 238000006243 chemical reaction Methods 0.000 claims abstract description 64
- 238000011065 in-situ storage Methods 0.000 claims abstract description 45
- 230000000694 effects Effects 0.000 claims abstract description 36
- 239000002994 raw material Substances 0.000 claims abstract description 27
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- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 33
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 22
- 239000003546 flue gas Substances 0.000 claims description 22
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 11
- 239000000945 filler Substances 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- 238000005882 aldol condensation reaction Methods 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 4
- BGJSXRVXTHVRSN-UHFFFAOYSA-N 1,3,5-trioxane Chemical group C1OCOCO1 BGJSXRVXTHVRSN-UHFFFAOYSA-N 0.000 claims description 3
- 229930040373 Paraformaldehyde Natural products 0.000 claims description 3
- 238000005520 cutting process Methods 0.000 claims description 3
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 claims description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 3
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- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
- C07C67/333—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton
- C07C67/343—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
- B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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Abstract
The invention provides a method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol and a multi-stage reaction system, wherein the multi-stage reaction system at least comprises a three-stage reactor; the raw material gas can enter each stage of reactor respectively and react under the action of a catalyst to generate methyl methacrylate. In the production process, at least two sections of reactors in the multi-section reactors are used for catalytic reaction, and the generated products can respectively enter a reaction product header pipe at the same time; at least one section of the reactor is in situ regeneration; when the activity of the catalyst in the reactor drops to a preset percentage, the reactor is regenerated in situ. The mole fraction of methyl methacrylate after the product generated by the multi-stage reactor enters a total pipeline of reaction products and is mixed is 5.0 percent to 7.5 percent. The method and the system can effectively reduce the variation amplitude of the composition of the reaction product in the initial stage and the final stage of the reaction, ensure the stability of the product quality and reduce the operation load of the subsequent separation process.
Description
Technical Field
The invention belongs to the technical field of methyl methacrylate synthesis, and particularly relates to a method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol and a multi-section reaction system for the method.
Background
Methyl Methacrylate (MMA) is an important organic chemical raw material and is mainly applied to a plurality of production fields of organic glass (PMMA), resin, coating, adhesive and the like. The acetone cyanohydrin process (ACH process) which is the most important MMA production technology at present has a tendency of being gradually eliminated due to the fact that the process is laggard, and the generated waste liquid has serious pollution to the environment. The newly developed MMA preparation technology comprises an isobutylene oxidation method of Mitsubishi, an ethylene method of Basff, an alpha method of cellulous color and the like, and the common characteristics of the technologies are that the process flow is relatively simple, safe and environment-friendly. Wherein, the alpha method synthetic route of the cellulosate is divided into two steps: firstly, the carbonylation of ethylene, carbon monoxide and methanol is carried out to synthesize methyl propionate, and secondly, the condensation of methyl propionate and formaldehyde is carried out to prepare MMA. The raw materials of the alpha method are easy to obtain and cheap, the process flow is greatly shortened by two-step synthesis, the production process is green and environment-friendly, and the development potential is huge. However, at present, the technology is monopolized abroad, the synthesis process is rarely known from the outside, the domestic research is less, and the technology is mainly focused on the research and development aspects of aldol catalysts, such as CN102962062A, CN102350336B, CN109999922A and the like.
The synthesis of MMA from methyl propionate and formaldehyde is carried out at high temperature under the action of a base catalyst, the conversion rate of raw materials in the reaction process is low, the catalyst is easy to form carbon and inactivate, and the service life of the catalyst is short. For this reason, the catalyst must be regenerated by burning carbon to restore the activity. Aiming at the reaction characteristics of preparing MMA by an aldol method, a common strategy is to switch a reaction regeneration mode of a plurality of fixed beds or a reaction regeneration mode of a circulating fluidized bed. The circulating fluidized bed is adopted, the pulverization and the running loss of the catalyst are serious, the annual consumption of the catalyst is huge, the characteristics of low reaction conversion rate and easy coking of the catalyst are combined, the production and operation cost is high, and in addition, the circulating fluidized bed has a complex structure and high equipment cost, so that the circulating fluidized bed is not suitable for preparing MMA by an aldol method in an economic view. The fixed bed switching reaction regeneration mode has larger changes of reaction product compositions in the initial stage and the final stage along with the aggravation of the inactivation degree of the catalyst, brings certain challenges to subsequent separation operation, and is also unfavorable for long-period stable operation of the device.
Disclosure of Invention
In view of the above problems in the prior art, embodiments of the present invention provide a method for preparing methyl methacrylate by aldol condensation of methyl propionate and formaldehyde, which can reduce the variation range of the composition of the reaction product in the initial and final stages and reduce the operation load of the subsequent separation process.
In order to solve the above problems, the embodiment of the present invention provides the following technical solutions:
a method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol utilizes a multi-stage reaction system, and the multi-stage reaction system at least comprises three parallel reactors;
the mixture of raw material gas methyl propionate and a formaldehyde source can respectively enter each section of reactor, and generates aldol condensation reaction to generate methyl methacrylate under the action of a catalyst, and products generated by the reaction in each section of reactor can respectively enter a reaction product header pipe; the regenerated gas can enter each section of reactor respectively to carry out in-situ regeneration on the catalyst in the reactor;
in the production process, at least two sections of the reactors in the plurality of sections of reactors are used for catalytic reaction, and at least one section of the reactor is used for in-situ regeneration; and when the activity of the catalyst in the reactor in the catalytic reaction is reduced to a preset percentage, cutting off the catalytic reaction, and carrying out in-situ regeneration so that the mole fraction of the methyl methacrylate in the product after the product generated by the reaction of the multiple sections of reactors participating in the catalytic reaction enters the reaction product main pipeline and is mixed is 5.0-7.5%.
In some embodiments, the preset percentage is 10% -50%.
In some embodiments, the reactor comprises n segments, wherein n is equal to or greater than 3 and equal to or less than 10, and n is a positive integer, and the n segments are the first segment reactor, the second segment reactor, the third segment reactor …, the n-1 segment reactor, the nth segment reactor, respectively; the method comprises the steps of firstly starting the first-stage reactor to perform catalytic reaction, starting the second-stage reactor to perform catalytic reaction when the activity of the catalyst of the first-stage reactor is reduced to 1/(n-1), starting the third-stage reactor to perform catalytic reaction … when the activity of the catalyst of the second-stage reactor is reduced to 1/(n-1), and so on, and starting the nth-stage reactor to perform catalytic reaction, wherein at least the first-stage reactor is in an in-situ regeneration process.
In some embodiments, the reactor comprises n segments, wherein n is equal to or greater than 3 and equal to or less than 10, and n is a positive integer, and the n segments are the first segment reactor, the second segment reactor, the third segment reactor …, the n-1 segment reactor, the nth segment reactor, respectively;
when n is more than or equal to 3 and less than or equal to 5, firstly starting the first-stage reactor to perform catalytic reaction, when the activity of the catalyst of the first-stage reactor is reduced to 1/2, starting the second-stage reactor to perform catalytic reaction, when the activity of the catalyst of the second-stage reactor is reduced to 1/2, starting the third-stage reactor to perform catalytic reaction, when the third-stage reactor is started to perform catalytic reaction, the first-stage reactor is in an in-situ regeneration process, and the steps are circulated;
when n is more than or equal to 6 and less than or equal to 10, the first-stage reactor and the second-stage reactor are started to perform catalytic reaction, when the activity of the catalyst of the first-stage reactor and the second-stage reactor is reduced to 1/2, the third-stage reactor and the fourth-stage reactor are started to perform catalytic reaction, when the activity of the catalyst of the third-stage reactor and the fourth-stage reactor is reduced to 1/2, the fifth-stage reactor and the sixth-stage reactor are started to perform catalytic reaction, at least the first-stage reactor and the second-stage reactor are in an in-situ regeneration process when the fifth-stage reactor and the sixth-stage reactor are started to perform catalytic reaction, and the steps are repeated.
In some embodiments, the process conditions for the catalytic reaction in each stage of the reactor are as follows: the reaction temperature is 300-380 ℃, the reaction pressure is 50-600 KPa, and the weight hourly space velocity is 0.5-10/h.
In some embodiments, the regeneration gas for in situ regeneration of each section of the reactor is nitrogen and air; the process conditions are as follows: the regeneration temperature is 340-450 ℃, the regeneration pressure is 100-800 KPa, and the volume space velocity is 300-3000/h.
In some embodiments, the formaldehyde source is one or more of trioxymethylene, paraformaldehyde, methylal, formaldehyde;
the feed gas further comprises methanol as a solvent; the molar ratio of the methyl propionate to the formaldehyde source is 1: 5-10: 1, and the molar ratio of the formaldehyde source to the methanol is 1: 10-2: 1.
The embodiment of the invention also provides a multi-stage reaction system which comprises at least three parallel stages of reactors, wherein the upper part of each stage of reactor is provided with an inlet, the inlet is connected with a raw material pipeline and a regeneration gas pipeline so as to be used for inputting reaction raw materials into the reactor when the reactor is in a catalytic reaction process, and after the activity of a catalyst in the reactor is reduced to 10-50% and is switched to a regeneration process, the regeneration gas is input into the reactor so as to carry out in-situ regeneration; in the production process, at least two sections of the reactors are in the catalytic reaction process, and at least one section of the reactors is in the in-situ regeneration process;
the lower part of each section of the reactor is provided with an outlet, the outlet is connected with a reaction product pipeline and a flue gas pipeline, the reaction product pipeline of each section of the reactor is connected to a reaction product main pipeline so as to converge all the reaction products of the reactor in the catalytic reaction process to the reaction product main pipeline through the reaction product pipeline, the mole fraction of the methyl methacrylate after the reaction products generated by the plurality of sections of the reactors enter the reaction product main pipeline for mixing is 5.0-7.5%, and the flue gas generated by the reactor in the in-situ regeneration process enters the flue gas pipeline.
In some embodiments, each reactor section has the same structure and is an adiabatic fixed bed reactor with a vertical cylindrical structure; a support grid is arranged in the reactor, and a first inert filler layer, a catalyst bed layer and a second inert filler layer are sequentially loaded on the support grid from top to bottom; and a feeding distributor is arranged above the first inert filler layer.
In some embodiments, the raw material pipeline and the regeneration gas pipeline of each section of the reactor are respectively provided with an inlet valve, and the reaction product pipeline and the flue gas pipeline of each section of the reactor are respectively provided with an outlet valve, so as to control the reactor to switch between the catalytic reaction process and the in-situ regeneration process.
Compared with the prior art, the embodiment of the invention has the beneficial effects that: the method and the multi-stage reaction system of the embodiment of the invention can effectively reduce the variation amplitude of the composition of the reaction product in the initial stage and the final stage of the reaction, ensure the stability of the product quality and reduce the operation load of the subsequent separation process.
Drawings
FIG. 1 is a schematic structural diagram of a multi-stage reaction system according to an embodiment of the present invention.
Description of reference numerals:
1-a first stage reactor; 2-a second stage reactor; 3-a third stage reactor; 4-an inlet; 5-raw material pipeline; 6-a regeneration gas pipeline; 7-an outlet; 9-flue gas pipeline; 10-reaction product main line; 11-a first inlet valve; 12-a second inlet valve; 13-a first outlet valve; 14-second outlet valve.
Detailed Description
In order to make the technical solutions of the embodiments of the present invention better understood, the present invention will be described in detail with reference to the accompanying drawings and the detailed description.
The embodiment of the invention provides a method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol, which uses methyl propionate, a formaldehyde source and methanol (methanol is used as a solvent and does not participate in reaction) as reaction raw materials, and adopts a multi-stage reaction system shown in figure 1, wherein the multi-stage reaction system at least comprises three parallel reactors; the reaction raw materials can respectively enter each section of reactor at the same time, and Methyl methacrylate (MMA for short) is generated by the aldol condensation reaction between Methyl propionate and formaldehyde in the reactor under the action of the catalyst; reaction products generated by the reaction in each section of the reactor can respectively enter a reaction product main pipeline 10; the regeneration gas can enter each section of reactor respectively to carry out in-situ regeneration on the catalyst in the reactor.
In the production process, at least two sections of the reactors in the plurality of sections of reactors are used for catalytic reaction, and at least one section of the reactor is used for in-situ regeneration; and when the activity of the catalyst in the reactor for catalytic reaction is reduced to a preset percentage, cutting off the catalytic reaction, carrying out in-situ regeneration, and continuously using the regenerated reactor for catalytic reaction, and circulating the steps so that the mole fraction of the methyl methacrylate in the reaction product generated by the reaction of the multiple sections of reactors participating in the catalytic reaction is 5.0-7.5% after the reaction product enters the reaction product main pipeline 10 and is mixed.
According to the method provided by the embodiment of the invention, during the reaction (in the reaction process), carbon formation is formed on the surface of the catalyst, so that the performance of the catalyst is reduced, when the activity of the catalyst in a certain section of the reactor is reduced to a preset percentage, the section of the reactor needs to be cut out of the reaction system for in-situ regeneration instead of regeneration when the catalyst is completely deactivated, during the production process, one section of the reactor is always in the in-situ regeneration process in the whole multi-section reaction system, so that the composition of a reaction product is relatively stable in the initial stage and the final stage of the reaction, and particularly, the molar fraction of MMA can be controlled within the range of 5.0-7.5%, thereby being beneficial to reducing the operation load of a subsequent separation process.
It should be noted that, when just starting production, each reactor section is started step by step, and one reactor section may be started first, or multiple reactor sections may be started simultaneously; similarly, each reactor is gradually stopped when production is finished; therefore, the production process refers to the stage when the multi-stage reaction system is operated to form the circular production, one section of the reactor is always in the in-situ regeneration process in the whole multi-stage reaction system, and at least two sections of the reactors are in the catalytic reaction process and are not suitable for starting the production and ending the production.
In some embodiments, to prevent frequent reactor changes from increasing operating costs and to maximize catalyst utilization, the in situ regeneration process is switched on when the catalyst activity is reduced to 10% -50%, which both ensures that the MMA mole fraction in the reaction product mixture of the multistage reactor is controlled within the range of 5.0% to 7.5% and reduces production costs.
The total number of the reactor sections in the multi-section reaction system is preferably 3-10, namely the reactor comprises n sections, wherein n is more than or equal to 3 and less than or equal to 10, n is a positive integer, and the n sections of the reactor are respectively a first section reactor 1, a second section reactor 2, a third section reactor 3 …, a nth-1 section reactor and an nth section reactor; the method comprises the steps of firstly starting the first-stage reactor 1 to perform catalytic reaction, starting the second-stage reactor 2 to perform catalytic reaction when the activity of the catalyst in the first-stage reactor 1 is reduced to 1/(n-1), starting the third-stage reactor 3 to perform catalytic reaction … when the activity of the catalyst in the second-stage reactor 2 is reduced to 1/(n-1), and the like, wherein at least the first-stage reactor 1 is in an in-situ regeneration process when the nth-stage reactor is started to perform catalytic reaction. The method of this example utilizes a multistage reaction system in which at least two reactors are in catalytic reaction and at least one reactor is in regeneration when entering the production process, and the activity of the catalyst in the reactor in catalytic reaction is not less than 10%, so that the variation of the composition of the reaction product at the initial and final stages of the reaction is not large, that is, the molar fraction of MMA after the reaction product of each reactor enters the reaction product main line 10 and is mixed is controlled to be 5.0% to 7.5% during the entire reaction including the initial and final stages of the reaction. The product quality is stable, and the operation load of the subsequent separation process is reduced.
During the production operation, the reaction switching operation of each reactor can be carried out at certain time intervals, and is preferably carried out alternately. For example, the first stage reactor 1 is first opened to perform the reaction, when the catalyst activity is reduced to, for example, 50%, the second stage reactor 2 is opened, the first stage reactor 1 continues to operate, when the catalyst activity of the first stage reactor 1 is reduced to any value within the range of 10% to 50%, the third stage reactor 3 is opened to perform the reaction, and the first stage reactor 1 is cut off to perform the catalytic reaction to perform the in-situ regeneration. When the activity of the catalyst of the second-stage reactor 2 is reduced to any value within 10% -50%, the regenerated first-stage reactor 1 is started to perform reaction, and meanwhile, the second-stage reactor 2 is cut off for catalytic reaction to perform in-situ regeneration of the catalyst.
Thus, the operation steps are circulated according to the reaction time interval of each reactor, the continuous and stable operation of n reactors can be realized, the variation amplitude of the composition of the reaction product is effectively reduced, and the fluctuation amplitude of the composition of the reaction product is smaller when the number of the adopted stages is more.
For example, when the multi-stage reaction system has a small total number of reactors, such as 3 to 5 stages, only one stage of the reactor may be in situ regeneration and at least two stages of the reactor may be in catalytic reaction. Specifically, when n is more than or equal to 3 and less than or equal to 5, the first-stage reactor 1 is started to perform catalytic reaction, when the activity of the catalyst in the first-stage reactor 1 is reduced to 1/2, the second-stage reactor 2 is started to perform catalytic reaction, when the activity of the catalyst in the second-stage reactor 2 is reduced to 1/2, the third-stage reactor 3 is started to perform catalytic reaction, when the third-stage reactor 3 is started to perform catalytic reaction, the first-stage reactor 1 is in an in-situ regeneration process, and the steps are repeated.
For example, when the total number of reactors in the multi-stage reaction system is large, for example, 6 to 10 stages, two stages of reactors may be in situ regeneration process, and at least two stages of reactors may be in catalytic reaction process. Specifically, when n is more than or equal to 6 and less than or equal to 10, the first-stage reactor 1 and the second-stage reactor 2 are started to perform catalytic reaction, when the activity of the catalyst in the first-stage reactor 1 and the second-stage reactor 2 is reduced to 1/2, the third-stage reactor 3 and the fourth-stage reactor are started to perform catalytic reaction, when the activity of the catalyst in the third-stage reactor 3 and the fourth-stage reactor is reduced to 1/2, the fifth-stage reactor and the sixth-stage reactor are started to perform catalytic reaction, at least the first-stage reactor 1 and the second-stage reactor 2 are in an in-situ regeneration process, and the steps are repeated.
It should be noted that the start-up sequence and the number of simultaneous start-up of each reactor section in the process of the present invention are not limited, as long as at least two reactor sections are ensured to be in the catalytic reaction process and at least one reactor section is in the regeneration process during the production operation, and the catalytic reaction must be cut off and the regeneration process is carried out when the activity of the catalyst in the reactor is reduced to 10% -50%, and the molar fraction of Methyl Methacrylate (MMA) in the reaction product mixture produced by the reactor sections is 5.0% to 7.5%.
In order to ensure that the catalytic reaction is smoothly and stably carried out and the production process is continuously operated, the process conditions of the catalytic reaction of each section of the reactor can be as follows: the reaction temperature is 300-380 ℃, the reaction pressure is 50-600 KPa, and the weight hourly space velocity is 0.5-10/h; more preferably, the reaction temperature is 320-350 ℃, more preferably, the reaction pressure is 100-350 KPa, and more preferably, the weight hourly space velocity is 2-5/h.
The catalyst deactivation is mainly characterized in that coke is attached to the surface of the catalyst in the reaction process, the coke on the surface of the catalyst is combusted, namely, is burnt to be regenerated and reactivated, and the gas for combustion, namely the regeneration gas is the mixed gas of nitrogen and oxygen. The regeneration process is started, firstly nitrogen is introduced, then air is introduced gradually, the introduction amount of the air is increased gradually, and the introduction amount of the nitrogen is reduced until the introduction of the nitrogen is stopped, namely the oxygen concentration is increased gradually from 0 to 21 percent (only air is introduced) along with the gradual increase of the oxygen concentration in the regeneration process, namely the coke burning regeneration process is a process for dynamically increasing the oxygen concentration gradually. When the temperature of the inlet 4 of the reactor is the same as the temperature of the catalyst bed layer of the reactor (which indicates that coke is completely combusted and cannot generate heat any more, and the temperature of the catalyst bed layer is unchanged) and the oxygen concentration of the flue gas is 21% (because the coke is completely combusted, the introduced air does not participate in combustion any more and is directly discharged as the flue gas), the in-situ regeneration is completed.
In some embodiments, the regeneration gas for in-situ regeneration of each section of the reactor is nitrogen and air, and the regeneration is started by firstly introducing; the in-situ regeneration process conditions are as follows: the regeneration temperature is 340-450 ℃, the regeneration pressure is 100-800 KPa, and the volume space velocity is 300-3000/h. The more preferable regeneration temperature is 350-380 ℃, the more preferable regeneration pressure is 100 KPa-350 KPa, and the more preferable volume space velocity is 400-550/h.
The formaldehyde source for aldol condensation with methyl propionate may be one or more of trioxymethylene, paraformaldehyde, methylal, and formaldehyde. In addition, the raw material gas also comprises methanol as a solvent; the molar ratio of the methyl propionate to the formaldehyde source is 1: 5-10: 1, and the molar ratio of the formaldehyde source to the methanol is 1: 10-2: 1.
The embodiment of the invention also provides a multi-stage reaction system, as shown in fig. 1, the multi-stage reaction system comprises at least three parallel stages of reactors, the upper part of each stage of the reactor is provided with an inlet 4, the inlet 4 is connected with a raw material pipeline 5 and a regeneration gas pipeline 6 so as to input reaction raw materials into the reactor when the reactor is in a catalytic reaction process, and after the activity of a catalyst in the reactor is reduced to 10% -50% and is switched to a regeneration process, the regeneration gas is input into the reactor so as to carry out in-situ regeneration; the lower part of each section of reactor is provided with an outlet 7, the outlet 7 is connected with a reaction product pipeline and a flue gas pipeline 9, and the reaction product pipeline of each section of reactor is connected with a reaction product main pipeline 10 so as to converge the reaction products of all the reactors in the catalytic reaction process to the reaction product main pipeline 10 through the reaction product pipeline.
With continuing reference to FIG. 1, each reactor section has the same structure and is a vertical cylindrical adiabatic fixed bed reactor; the reactor is provided with a support grid (not shown), which may be a metal mesh. The support grid is sequentially loaded with a first inert filler layer, a catalyst bed layer and a second inert filler layer from top to bottom. The feeding distributor is arranged above the first inert packing layer, so that the effect of uniform gas distribution can be achieved after the feed gas or the regenerated gas passes through the gas distributor and the first inert packing layer.
Specifically, as shown in fig. 1, an inlet 4 is disposed at the top of the reactor, and a raw material pipeline 5 and a regeneration gas pipeline 6 are connected and then connected to the inlet 4 through a common section, so that both raw material gas and regeneration gas can enter the reactor through the inlet 4. That is, the inlet 4 is common to the feed gas and the regeneration gas. The outlet 7 is arranged at the bottom of the reactor, and the reaction product pipeline and the flue gas pipeline 9 are connected and then connected into the outlet 7 through a common section, so that the reaction product and the flue gas during regeneration can respectively enter the reaction product pipeline and the flue gas pipeline 9 through the outlet 7. The reaction product pipelines of the multi-stage reactor are converged and communicated to the reaction product main pipeline 10, so that the mole fraction of the methyl methacrylate is 5.0-7.5% after the reaction products generated by the multi-stage reactor enter the reaction product main pipeline 10 to be mixed, and the flue gas generated by the reactor in the in-situ regeneration process enters the flue gas pipeline 9.
In some embodiments, the raw material pipeline 5 and the regeneration gas pipeline 6 of each reactor section are respectively provided with an inlet valve, and the reaction product pipeline and the flue gas pipeline 9 of each reactor section are respectively provided with an outlet valve, so as to control the reactors to switch between the catalytic reaction process and the in-situ regeneration process.
Specifically, as shown in fig. 1, the multi-stage reaction system includes three reactors, which are a first stage reactor 1, a second stage reactor 2 and a third stage reactor 3. The inlets 4 at the top of the three-stage reactor are respectively communicated with a raw material pipeline 5 and a regeneration gas pipeline 6. The raw material pipeline 5 is respectively provided with a first inlet valve 11, and the regeneration gas pipeline 6 is provided with a second inlet valve 12; outlets 7 at the bottoms of the three reactors are respectively communicated with a reaction product pipeline and a flue gas pipeline 9. A first outlet valve 13 is arranged on the reaction product pipeline; a second outlet valve 13 is arranged on the flue gas pipeline 9. When the reactor is in the catalytic reaction process, closing the second inlet valve 12, and opening the first inlet valve 11 to introduce reaction raw materials into the reactor, and blocking the regenerated gas from entering the reactor, so that the catalytic reaction is performed in the reactor; the second outlet valve 13 is closed and the first outlet valve 13 is opened to allow the reaction product produced in the reactor to flow through the reaction product line into the reaction product main line 10. When the activity of the catalyst in the reactor is reduced to 10-50%, closing the first inlet valve 11, opening the second inlet valve 12 to introduce the regeneration gas into the reactor, and blocking the reaction raw material from entering the reactor to regenerate the catalyst in the reactor; and closing the first outlet valve 13, and opening the second outlet valve 13 to enable the flue gas generated by regeneration in the reactor to enter the flue gas pipeline 9.
In the production process of the multi-stage reaction system provided by the embodiment of the invention, the multi-stage reactors are connected in parallel, reaction raw materials can respectively enter each stage of reactor at the same time, methyl propionate and formaldehyde are subjected to aldol condensation reaction under the action of a catalyst to generate MMA, and outlet products generated by each stage of reactor can respectively enter the reaction product main pipeline 10 through respective reaction product pipelines. In the production process, at least two sections of reactors in the whole multi-section reaction system are used for catalytic reaction, and one section of reactor is always used for regeneration. During the production process, the catalyst surface in the reactor forms carbon formation, which results in the performance reduction of the catalyst, when the catalyst activity of a certain section of the reactor is reduced to 10-50%, the section of the reactor is cut out from a multi-section reaction system for in-situ regeneration, so that the relative stability of the reaction product composition in the early and late stages of the reaction can be ensured, and particularly, the MMA mole fraction can be controlled within the range of 5.0-7.5%. The product quality is stable, and the operation difficulty of the subsequent process is reduced.
Example 1
The multistage reactor process for preparing methyl methacrylate by condensing methyl propionate and formaldehyde by an aldol process as shown in fig. 1 comprises a first stage reactor 1, a second stage reactor 2 and a third stage reactor 3, wherein two stages are used for reaction, and one stage is used for catalyst regeneration. The reaction process conditions are as follows: the weight hourly space velocity is 3/h, the reaction pressure is normal pressure, the reaction temperature is 330 ℃, the molar ratio of the raw material methyl propionate to the formaldehyde is 2:1, and the molar ratio of the formaldehyde to the methanol is 1: 4; the regeneration process conditions are as follows: the volume space velocity is 600/h, the regeneration temperature is 400 ℃, and the regeneration pressure is normal pressure. The service life of the catalyst is 336h, namely the regeneration is needed after 336h of reaction, each reactor is switched with 168 h of reaction interval, and the composition of the initial stage and the final stage of the reaction according to the process conditions is shown in Table 1.
Example 2
A multi-stage reactor for preparing methyl methacrylate by condensing methyl propionate and formaldehyde by an aldol process comprises a first stage reactor, a second stage reactor, a third stage reactor and a fourth stage reactor, wherein the three stages of reactors are used for reaction, and one stage of reactor is used for regeneration of a catalyst. The reaction process conditions are as follows: the weight hourly space velocity is 3/h, the reaction pressure is normal pressure, the reaction temperature is 330 ℃, the molar ratio of the raw material methyl propionate to the formaldehyde is 2:1, and the molar ratio of the formaldehyde to the methanol is 1: 4; the regeneration process conditions are as follows: the volume space velocity is 600/h, the regeneration temperature is 400 ℃, and the regeneration pressure is normal pressure. The service life of the catalyst is 336h, namely the regeneration is needed after 336h of reaction, each reactor is switched by 112 h, and the composition of the initial stage and the final stage of the reaction according to the process conditions is shown in Table 1.
Comparative examples 1 to 2
For comparison with examples 1 and 2, the reaction was carried out using a single reactor, the process conditions and the catalyst used were the same as in examples 1 and 2, and the initial and final reaction compositions are shown in Table 1.
Table 1 reaction product composition:
the above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.
Claims (10)
1. A method for preparing methyl methacrylate by condensing methyl propionate and formaldehyde aldol is characterized in that a multi-stage reaction system is utilized, and the multi-stage reaction system at least comprises three parallel reactors;
the mixture of raw material gas methyl propionate and a formaldehyde source can respectively enter each section of reactor, and generates aldol condensation reaction to generate methyl methacrylate under the action of a catalyst, and products generated by the reaction in each section of reactor can respectively enter a reaction product header pipe; the regenerated gas can enter each section of reactor respectively to carry out in-situ regeneration on the catalyst in the reactor;
in the production process, at least two sections of the reactors in the plurality of sections of reactors are used for catalytic reaction, and at least one section of the reactor is used for in-situ regeneration; and when the activity of the catalyst in the reactor in the catalytic reaction is reduced to a preset percentage, cutting off the catalytic reaction, and carrying out in-situ regeneration so that the mole fraction of the methyl methacrylate in the product after the product generated by the reaction of the multiple sections of reactors participating in the catalytic reaction enters the reaction product main pipeline and is mixed is 5.0-7.5%.
2. The method according to claim 1, wherein the preset percentage is 10% -50%.
3. The method of claim 1, wherein the reactor comprises n sections, wherein n is equal to or greater than 3 and equal to or less than 10, and n is a positive integer, and the n sections of the reactor are respectively a first section reactor, a second section reactor, a third section reactor …, a n-1 section reactor and an nth section reactor; the method comprises the steps of firstly starting the first-stage reactor to perform catalytic reaction, starting the second-stage reactor to perform catalytic reaction when the activity of the catalyst of the first-stage reactor is reduced to 1/(n-1), starting the third-stage reactor to perform catalytic reaction … when the activity of the catalyst of the second-stage reactor is reduced to 1/(n-1), and so on, and starting the nth-stage reactor to perform catalytic reaction, wherein at least the first-stage reactor is in an in-situ regeneration process.
4. The method of claim 1, wherein the reactor comprises n sections, wherein n is equal to or greater than 3 and equal to or less than 10, and n is a positive integer, and the n sections of the reactor are respectively a first section reactor, a second section reactor, a third section reactor …, a n-1 section reactor and an nth section reactor;
when n is more than or equal to 3 and less than or equal to 5, firstly starting the first-stage reactor to perform catalytic reaction, when the activity of the catalyst of the first-stage reactor is reduced to 1/2, starting the second-stage reactor to perform catalytic reaction, when the activity of the catalyst of the second-stage reactor is reduced to 1/2, starting the third-stage reactor to perform catalytic reaction, when the third-stage reactor is started to perform catalytic reaction, the first-stage reactor is in an in-situ regeneration process, and the steps are circulated;
when n is more than or equal to 6 and less than or equal to 10, the first-stage reactor and the second-stage reactor are started to perform catalytic reaction, when the activity of the catalyst of the first-stage reactor and the second-stage reactor is reduced to 1/2, the third-stage reactor and the fourth-stage reactor are started to perform catalytic reaction, when the activity of the catalyst of the third-stage reactor and the fourth-stage reactor is reduced to 1/2, the fifth-stage reactor and the sixth-stage reactor are started to perform catalytic reaction, at least the first-stage reactor and the second-stage reactor are in an in-situ regeneration process when the fifth-stage reactor and the sixth-stage reactor are started to perform catalytic reaction, and the steps are repeated.
5. The method of claim 1, wherein the catalytic reaction in each stage of the reactor is carried out under the following process conditions: the reaction temperature is 300-380 ℃, the reaction pressure is 50-600 KPa, and the weight hourly space velocity is 0.5-10/h.
6. The method of claim 1, wherein the regeneration gas for in-situ regeneration of each section of the reactor is nitrogen and air; the process conditions are as follows: the regeneration temperature is 340-450 ℃, the regeneration pressure is 100-800 KPa, and the volume space velocity is 300-3000/h.
7. The method according to claim 1, wherein the formaldehyde source is one or more of trioxymethylene, paraformaldehyde, methylal, and formaldehyde;
the feed gas further comprises methanol as a solvent; the molar ratio of the methyl propionate to the formaldehyde source is 1: 5-10: 1, and the molar ratio of the formaldehyde source to the methanol is 1: 10-2: 1.
8. A multi-stage reaction system is characterized by comprising at least three parallel stages of reactors, wherein the upper part of each stage of reactor is provided with an inlet, the inlet is connected with a raw material pipeline and a regeneration gas pipeline so as to be used for inputting reaction raw materials into the reactor when the reactor is in a catalytic reaction process, and after the activity of a catalyst in the reactor is reduced to 10% -50% and is switched to a regeneration process, the regeneration gas is input into the reactor so as to carry out in-situ regeneration; in the production process, at least two sections of the reactors are in the catalytic reaction process, and at least one section of the reactors is in the in-situ regeneration process;
the lower part of each section of the reactor is provided with an outlet, the outlet is connected with a reaction product pipeline and a flue gas pipeline, the reaction product pipeline of each section of the reactor is connected to a reaction product main pipeline so as to converge all the reaction products of the reactor in the catalytic reaction process to the reaction product main pipeline through the reaction product pipeline, the mole fraction of the methyl methacrylate after the reaction products generated by the plurality of sections of the reactors enter the reaction product main pipeline for mixing is 5.0-7.5%, and the flue gas generated by the reactor in the in-situ regeneration process enters the flue gas pipeline.
9. The multi-stage reaction system according to claim 8, wherein each stage of the reactor has the same structure and is an adiabatic fixed bed reactor having a vertical cylindrical structure; a support grid is arranged in the reactor, and a first inert filler layer, a catalyst bed layer and a second inert filler layer are sequentially loaded on the support grid from top to bottom; and a feeding distributor is arranged above the first inert filler layer.
10. The multi-stage reaction system according to claim 8, wherein the raw material pipeline and the regeneration gas pipeline of each stage of the reactor are respectively provided with an inlet valve, and the reaction product pipeline and the flue gas pipeline of each stage of the reactor are respectively provided with an outlet valve, so as to control the reactor to switch between the catalytic reaction process and the in-situ regeneration process.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115414871A (en) * | 2022-08-30 | 2022-12-02 | 中国科学院过程工程研究所 | Method and device for synthesizing methyl (meth) acrylate |
| WO2023071490A1 (en) * | 2021-10-31 | 2023-05-04 | 浙江新和成股份有限公司 | Preparation method and apparatus for methyl methacrylate |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA439330A (en) * | 1947-01-21 | Van Horn Lee | Apparatus for the catalytic conversion of hydrocarbons | |
| GB777459A (en) * | 1953-04-09 | 1957-06-26 | Standard Oil Co | Improvements in or relating to hydrocarbon reforming with platinum catalyst and regeneration system therefor |
| CN1040516A (en) * | 1989-03-15 | 1990-03-21 | 中国石油化工总公司 | Variable bed total height catalytic reaction method and device thereof |
| JPH06279324A (en) * | 1993-03-30 | 1994-10-04 | Cosmo Sogo Kenkyusho:Kk | Production of durene |
| CN1281839A (en) * | 1999-07-22 | 2001-01-31 | 中国石油化工集团公司 | Isoalkane and alkylation method of olefine |
| KR20070113640A (en) * | 2006-05-25 | 2007-11-29 | 에스케이에너지 주식회사 | Continuous regeneration process for bifunctional catalysts |
| US20080022851A1 (en) * | 2006-07-20 | 2008-01-31 | Sang Kook Lee | Pressure swing adsorption method and system with multiple-vessel beds |
| CN105319295A (en) * | 2015-02-17 | 2016-02-10 | 浙江大学 | Method for judging reaction inactivation of methanol-to-propylene catalyst |
| CN106674010A (en) * | 2015-11-10 | 2017-05-17 | 上海浦景化工技术股份有限公司 | Process for preparing methyl methacrylate according to aldol condensation method |
| EP3299440A1 (en) * | 2016-09-23 | 2018-03-28 | Evonik Degussa GmbH | Method for controlling the product spectrum in the catalytic cracking of oxygenates at the catalytic converter with high long-term stability |
| US20190024000A1 (en) * | 2015-12-22 | 2019-01-24 | Sabic Global Technologies B.V. | Process for converting mixed hydrocarbon streams to lpg and btx |
| CN109293511A (en) * | 2018-11-12 | 2019-02-01 | 西南化工研究设计院有限公司 | A kind of method of methyl propionate and formaldehyde aldol condensation methyl methacrylate |
-
2020
- 2020-06-08 CN CN202010512287.1A patent/CN111574369B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA439330A (en) * | 1947-01-21 | Van Horn Lee | Apparatus for the catalytic conversion of hydrocarbons | |
| GB777459A (en) * | 1953-04-09 | 1957-06-26 | Standard Oil Co | Improvements in or relating to hydrocarbon reforming with platinum catalyst and regeneration system therefor |
| CN1040516A (en) * | 1989-03-15 | 1990-03-21 | 中国石油化工总公司 | Variable bed total height catalytic reaction method and device thereof |
| JPH06279324A (en) * | 1993-03-30 | 1994-10-04 | Cosmo Sogo Kenkyusho:Kk | Production of durene |
| CN1281839A (en) * | 1999-07-22 | 2001-01-31 | 中国石油化工集团公司 | Isoalkane and alkylation method of olefine |
| KR20070113640A (en) * | 2006-05-25 | 2007-11-29 | 에스케이에너지 주식회사 | Continuous regeneration process for bifunctional catalysts |
| US20080022851A1 (en) * | 2006-07-20 | 2008-01-31 | Sang Kook Lee | Pressure swing adsorption method and system with multiple-vessel beds |
| CN105319295A (en) * | 2015-02-17 | 2016-02-10 | 浙江大学 | Method for judging reaction inactivation of methanol-to-propylene catalyst |
| CN106674010A (en) * | 2015-11-10 | 2017-05-17 | 上海浦景化工技术股份有限公司 | Process for preparing methyl methacrylate according to aldol condensation method |
| US20190024000A1 (en) * | 2015-12-22 | 2019-01-24 | Sabic Global Technologies B.V. | Process for converting mixed hydrocarbon streams to lpg and btx |
| EP3299440A1 (en) * | 2016-09-23 | 2018-03-28 | Evonik Degussa GmbH | Method for controlling the product spectrum in the catalytic cracking of oxygenates at the catalytic converter with high long-term stability |
| CN109293511A (en) * | 2018-11-12 | 2019-02-01 | 西南化工研究设计院有限公司 | A kind of method of methyl propionate and formaldehyde aldol condensation methyl methacrylate |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023071490A1 (en) * | 2021-10-31 | 2023-05-04 | 浙江新和成股份有限公司 | Preparation method and apparatus for methyl methacrylate |
| CN115414871A (en) * | 2022-08-30 | 2022-12-02 | 中国科学院过程工程研究所 | Method and device for synthesizing methyl (meth) acrylate |
| CN115414871B (en) * | 2022-08-30 | 2024-05-31 | 中国科学院过程工程研究所 | Method and device for synthesizing methyl methacrylate |
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