Multi-section reactor for methanol-to-olefin fixed fluidized bed micro-reaction device
By designing a multi-stage reactor, the gradually connected pipeline structure slows down the catalyst outflow rate, solving the problems of catalyst outflow and pneumatic valve blockage, and improving the test accuracy and instrument life.
Patent Information
- Application Number
- CN202421146021.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-05-24
AI Technical Summary
In the fixed fluidized bed micro-reverse device of methanol to olefins, the catalyst is prone to flow out and causes the filter to be blocked, and the pneumatic valve of the gas chromatograph is also prone to be blocked, affecting the test accuracy and instrument life.
A multi-stage reactor is designed, and its reaction section is gradually connected from bottom to top by multiple pipes of different sizes, which changes the interaction between nitrogen and vaporized methanol and the catalyst, slows down the effluent of the catalyst, thereby avoiding catalyst outflow and pneumatic valve blockage.
It effectively reduces the risk of catalyst efflux and pneumatic valve blockage, improves the accuracy of catalyst performance evaluation, and extends the service life of the gas chromatograph.
Smart Images
Figure CN222753230U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of a methanol to olefin fixed fluidized bed micro-reactor, and in particular relates to a multi-stage reactor for a methanol to olefin fixed fluidized bed micro-reactor, which can effectively prevent the outflow of a catalyst and the blockage of a pneumatic valve of a gas chromatograph. Background Art
[0002] The methanol to olefins reaction is generally carried out in a fixed fluidized bed microreactor. The reactor used in the device is generally divided into two parts: a support section and a reaction section (such as Figure 2 a). Before the test, the molecular sieve catalyst is poured into the reactor from the upper end of the reaction section to ensure that the catalyst is located on the support gasket, and then nitrogen is introduced from the lower end of the reactor to activate the catalyst in a fluidized state. After activation, the nitrogen is turned off, and the raw methanol is vaporized by a high-temperature vaporizer, and then enters from the lower end of the reactor to contact and react with the catalyst. The generated gaseous products and unreacted methanol flow out from the upper end of the reactor and then enter the gas chromatograph for analysis. The process flow is as follows: Figure 1 As shown. The catalyst used in this reaction is usually a molecular sieve catalyst, and its particle size is generally between 30 and 120 μm. Since the nitrogen that activates the catalyst and the vaporized methanol have certain thermal power, during the reaction process, the catalyst particles will be worn and their particle size will be reduced. On the other hand, some small particles of catalyst will gradually flow out from the upper part of the reactor. Some of the small particles of catalyst that flow out will block the filter at the outlet, thereby causing the pressure in the reactor to change. Over time, it will cause a certain deviation in the catalyst performance evaluation data. At the same time, a small number of small particles of catalyst will slowly pass through the filter and enter the pneumatic valve of the gas chromatograph. Over time, the blocking of the pneumatic valve will reduce the test accuracy of the instrument and shorten the service life of the instrument. In addition, since the products generated by methanol to olefins contain high-boiling-point organic substances such as carbon four and carbon five, in order to prevent these organic substances from condensing and blocking the pipeline, the pipeline between the reactor outlet and the chromatograph needs to be protected at a high temperature of about 170°C, but long-term heating will cause damage to the filter (the filter is usually not resistant to high temperatures), so the filter needs to be replaced regularly.
[0003] In view of the above technical background, the utility model proposes a multi-stage reactor for preventing catalyst outflow and chromatograph pneumatic valve blockage in a methanol to olefin fixed fluidized bed microreactor. Utility Model Content
[0004] The utility model proposes a multi-stage reactor for a methanol to olefin fixed fluidized bed micro-reactor, which has the following advantages: first, a conventional methanol to olefin reactor (such as Figure 2 a) The outlet needs to be connected to a filter, and the filter needs to be replaced regularly, and the multi-stage reactor described in the utility model (such as Figure 2b) The outlet does not need to be connected to a filter, reducing the cost of regular filter replacement; secondly, the multi-stage reactor described in the utility model can significantly inhibit the catalyst from flowing out with the gas product during the reaction and clogging the filter and the pneumatic valve of the gas chromatograph, thereby improving the accuracy of catalyst performance evaluation and extending the service life of the gas chromatograph.
[0005] The utility model discloses a multi-stage reactor for a methanol to olefin fixed fluidized bed microreactor, such as Figure 2 As shown in b;
[0006] Furthermore, the total height of the multi-stage reactor described in the utility model and the traditional reactor are both 500mm, and both include a support section (diameter 26mm, height 80mm) and a reaction section. The difference lies in the reaction section; the reaction section of the traditional reactor is a cylindrical pipe with a diameter of 20mm and a height of 420mm, and the reaction section of the multi-stage reactor described in the utility model is composed of multiple sections (3 to 6 sections) of pipes of different sizes connected gradually from bottom to top; further, the reaction section is composed of 4 sections of cylindrical pipes of different sizes connected gradually from bottom to top, and the diameters of the cylindrical pipes are 20mm, 27-29mm, 33-35mm and 20mm, respectively, and the corresponding heights of the cylindrical pipes are 60mm, 100-120mm, 150-170mm and 60mm, respectively, the gradient parts are all truncated cone-shaped pipes with a height of 10mm, and the total height is 420mm; further, the reactor is made of stainless steel with a wall thickness of 2mm.
[0007] The utility model discloses a multi-stage reactor for a fixed fluidized bed micro-reactor for methanol to olefins. In the activation and reaction stages, nitrogen and vaporized methanol enter from the lower end of the multi-stage reactor successively, driving the granular catalyst to flow upward. Due to the changes in the diameter and height of the reaction tubes of the second stage (diameter 27-29 mm, height 100-120 mm) and the third stage (diameter 33-35 mm, height 150-170 mm), the interaction between nitrogen and vaporized methanol and the catalyst changes, which in turn causes the flow rate of the catalyst in the reactor to slowly decrease, so that the catalyst does not flow out from the outlet at the upper end of the reactor, thereby no longer blocking the pneumatic valve (such as the valve of the gas chromatograph) of the gas chromatograph. Figure 2 b).
[0008] The beneficial effects of the multi-stage reactor involved in the utility model include: first, the use of filters in the device is reduced, and the manufacturing is simple, which reduces the use cost of the device; second, it can inhibit the catalyst from flowing out of the reactor with the airflow without affecting the catalyst evaluation effect, and at the same time reduces the risk of gas chromatograph pipeline blockage, improves the test accuracy of the gas chromatograph and extends its service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In order to more clearly illustrate the utility model patent, the traditional reactor and the utility model patent are introduced in detail through comparative examples and embodiments. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, it is difficult to obtain the process parameters of the reactor in the drawings without creative work.
[0010] Figure 1 This is the evaluation flow chart of the methanol to olefins microreactor;
[0011] Figure 2 (a) is a schematic diagram of a conventional reactor structure of a methanol to olefins microreactor with a filter added to the outlet;
[0012] Figure 2 (b) is a schematic diagram of the multi-stage reactor structure of the methanol to olefins micro-reactor described in the present invention. DETAILED DESCRIPTION
[0013] Comparative Example 1
[0014] This comparative example uses a traditional reactor with an outlet filter ( Figure 2 a) The catalyst is tested for performance, wherein the reactor consists of a support section and a reaction section. The support section is a cylindrical stainless steel pipe with a diameter of 26 mm and a height of 80 mm, which is filled with quartz sand and catalyst support gaskets; the reaction section is a cylindrical stainless steel pipe with a diameter of 20 mm and a height of 420 mm, and a wall thickness of 2 mm. The catalyst testing process is as follows Figure 1 As shown (corresponding to the case with a filter), the details are as follows:
[0015] 6 g of fresh SAPO-34 catalyst (with a particle size of 30 to 120 μm) was poured into the reactor from the upper end to ensure that the catalyst was on the catalyst support gasket in the reactor. The reactor was then placed in a reactor heating jacket. The upper and lower ports of the heating jacket were filled and insulated with quartz wool. The reactor was then fixed vertically with an iron stand. The reactor was slowly heated by a fixed fluidized bed control system. At the same time, nitrogen (flow rate 30 mL / min) was introduced from the feed port at the lower end of the reactor. When the reactor was heated to 480° C. and stabilized for 1 hour, the introduction of nitrogen was then stopped. The plunger pump was turned on to allow the liquid methanol raw material to enter the methanol vaporization furnace for vaporization. The vaporized methanol entered from the feed port at the lower end of the reactor to fully contact and react with the catalyst. The product flowed out from the discharge port at the upper end of the reactor and passed through the filter of the insulation section into a gas chromatograph for analysis to obtain the activity data of the catalyst.
[0016] After the reaction, the pneumatic valve between the reactor and the gas chromatograph was checked and purged, and a small amount of catalyst powder was found in the filter and the pneumatic valve of the gas chromatograph. Subsequently, the performance test of the same batch of catalysts was repeated twice. The highest ethylene selectivity in the three tests was 59.4%, 58.2% and 60.3% respectively. The average data was 59.3 and the standard deviation was 0.8.
[0017] Example 1
[0018] This embodiment adopts a new multi-stage reactor ( Figure 2 b) The performance of the catalyst is tested, wherein the reactor consists of a support section and a reaction section, the support section is a cylindrical stainless steel pipe with a diameter of 26 mm and a height of 80 mm, filled with quartz sand and a catalyst support gasket; the cylindrical pipe of the reaction section is gradually connected (the gradually changing pipe is a truncated cone with a height of 10 mm), the diameters of the cylindrical pipe from bottom to top are 20 mm, 28 mm, 34 mm, and 20 mm, respectively, the corresponding heights are 60 mm, 110 mm, 160 mm, and 60 mm, respectively, and the wall thickness is 2 mm; the catalyst testing process is as follows:
[0019] like Figure 1 As shown (corresponding to the case without filter), the specific process is as follows:
[0020] 6 g of fresh SAPO-34 catalyst (with a particle size of 30 to 120 μm) was poured into the reactor from the upper end to ensure that the catalyst was on the catalyst support pad in the reactor. The reactor was then placed in a reactor heating jacket. The upper and lower ports of the heating jacket were filled and insulated with quartz wool. The reactor was then fixed vertically with an iron stand. The reactor was slowly heated by a fixed fluidized bed control system. At the same time, nitrogen (flow rate 30 mL / min) was introduced from the feed port at the lower end of the reactor. When the reactor was heated to 480° C. and stabilized for 1 hour, the introduction of nitrogen was then stopped. The plunger pump was turned on to allow the liquid methanol raw material to enter the vaporizer for vaporization. The vaporized methanol entered from the feed port at the lower end of the reactor to fully contact and react with the catalyst. The product flowed out from the discharge port at the upper end of the reactor and entered the gas chromatograph through the insulation section for analysis to obtain the activity data of the catalyst.
[0021] After the reaction, the reactor outlet pipeline and the pneumatic valve of the gas chromatograph were checked and purged, and no small particles of catalyst were found. Subsequently, the same batch of catalysts were subjected to two repeated performance tests. The highest ethylene selectivities in the three tests were 59.2%, 58.9%, and 59.6%, respectively. The average data was 59.2, and the standard deviation was 0.3.
[0022] Compared with the test experiment of traditional reactors, no catalyst outflow was found in the reaction tube after testing with a multi-stage reactor. At the same time, the standard deviation of the data obtained was lower and the data was more stable, indicating that the multi-stage reactor has innovative and practical performance compared with traditional reactors.
[0023] Anything not described in detail in this utility model is a conventional technical means known to those skilled in the art. The above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this utility model shall be included in the protection scope of this utility model.
Claims
1. A multi-stage reactor for a methanol to olefin fixed fluidized bed microreactor, comprising a support section and a reaction section, characterized in that: The reaction section is composed of 4 sections of cylindrical pipes of different sizes connected gradually from bottom to top; the diameter of the support section is 26mm and the height is 80mm; the diameters of the cylindrical pipes in the reaction section from bottom to top are 20mm, 27~29mm, 33~35mm and 20mm, respectively, and the corresponding heights of the cylindrical pipes are 60mm, 100~120mm, 150~170mm and 60mm, respectively. The gradient parts are all truncated cone-shaped pipes with a height of 10mm; the total height of the reaction section is 420mm; the reactor is made of stainless steel with a wall thickness of 2mm.