CN110882673A - A chemical reaction method and device based on impingement flow - Google Patents

Abstract

The invention discloses a chemical reaction method and device based on impingement flow. The chemical reaction method is to make high-speed moving raw materials collide with each other at high speed in an impinging flow reactor to produce a chemical reaction. The invention creatively makes the high-speed moving raw materials collide with each other at high speed in the impinging flow reactor, so that the chemical reaction can be instantaneously completed by utilizing the kinetic energy of the raw materials, thereby significantly improving the chemical reaction rate, which is not only easy to realize, simple to operate, and does not require high temperature , high concentration can achieve a significant increase in the reaction rate, save energy, and do not affect the selectivity of the reaction.

Description

A chemical reaction method and device based on impingement flow

technical field

The invention relates to a chemical reaction method and device, in particular to a chemical reaction method and device based on impingement flow, and belongs to the technical field of chemical reaction.

Background technique

Chemical reaction refers to the process in which molecules are broken into atoms, and atoms are rearranged and combined to form new substances. Various products (such as chemicals, fuels, drugs, polymers, etc.) can be produced through chemical reactions. Chemical reactions are almost ubiquitous. For example, chemical, chemical, energy, medicine, environmental protection, metallurgy and other industries are full of various chemical reactions.

For most chemical reactions, we generally want to have high selectivity to improve the utilization of raw materials, but also have a fast reaction rate. At present, the improvement of the reaction rate is mainly achieved by increasing the concentration of reactants, increasing the reaction temperature and using catalysts.

The method of increasing the concentration of reactants is a more common method to increase the reaction rate. Increasing the concentration of reactants can increase the collision frequency between reactant molecules. According to the collision theory of chemical reactions, the collision and contact of reactant molecules is the prerequisite for the occurrence of chemical reactions. For chemical reactions to occur, contact and collision between reactant molecules must occur. Therefore, increasing the concentration of reactants is conducive to increasing the reaction rate. However, for chemical reactions, the concentration of chemical reactions is usually maintained within a certain range. It has good selectivity. If the concentration of reactants is too high, it will inevitably cause adverse effects on the selectivity of chemical reactions.

因此提高反应温度能显著提高反应物分子热运动速率，从而提高其具有的能量，进而促进反应速率的提高。但是，反应温度的提高也必然带来一些不利的结果，如能耗过高，可能会影响平衡转化率和选择性，可能会导致副反应(如原料的分解)等，对原料的热稳定性要求较高。The method of increasing the reaction temperature is the most direct method to increase the reaction rate at present. According to the collision theory of chemical reaction, the collision contact of reactant molecules is a prerequisite for a chemical reaction, but not every collision can lead to a reaction, and an effective collision must occur. Two conditions are met: (1) the energy factor, that is, the energy of the reactant molecules must reach a certain critical value; (2) the space factor, the activated molecules must collide with each other in a certain direction to react; and the energy of the reactant molecules , from a macroscopic point of view, it refers to its temperature. The higher the temperature, the higher the energy it has. And from the perspective of molecular thermal motion, the formula for calculating the average rate of molecular thermal motion is as follows:

Therefore, increasing the reaction temperature can significantly increase the thermal motion rate of the reactant molecules, thereby increasing the energy it has, thereby promoting the increase of the reaction rate. However, the increase of the reaction temperature will inevitably bring some unfavorable results, such as excessive energy consumption, which may affect the equilibrium conversion rate and selectivity, and may lead to side reactions (such as the decomposition of raw materials), etc., which will affect the thermal stability of the raw materials. Higher requirements.

The catalyst method refers to adding an appropriate amount of catalyst during the chemical reaction to promote the chemical reaction. A catalyst is a substance that changes the reaction rate by changing the activation energy, and the catalyst will not be destroyed or changed during the reaction and can be repeated. Activation energy refers to the minimum energy required for the initiation or natural occurrence of a reaction. The higher the activation energy, the more difficult it is to initiate the reaction and the slower the reaction rate. The use of catalysts can reduce the activation energy of the reaction, thus increasing the reaction rate. . However, the catalysts used in many chemical reactions are not easy to obtain and are expensive, which makes the production cost relatively high, and there are thousands of types of catalysts, and it takes a lot of work to select a suitable catalyst itself.

To sum up, there are unavoidable defects in increasing the concentration of reactants, increasing the reaction temperature and using catalysts to increase the reaction rate. Therefore, it is necessary to develop a new method to increase the chemical reaction rate.

Impingement flow is a special flow pattern first proposed by Elperin. Its concept is that two or more fluids (gas-solid, liquid-liquid or gas-liquid) flow toward each other along the same axis after sufficient acceleration. When the impact occurs, a highly turbulent impact area is formed, which can effectively reduce the external resistance during the transfer process, strengthen heat and mass transfer, and promote mixing. At present, impinging flow technology and impinging flow equipment based on impinging flow principle (eg, impinging flow reactor) have been widely used in chemical processes such as absorption, mixing, heat transfer, extraction, and drying. However, the current impingement flow technology is mainly to achieve rapid mixing of raw materials, and the promotion of the reaction is mainly to improve mass transfer. The velocity of the feedstock flow is low (usually less than 20 m/s), which has a low kinetic energy, which is not sufficient to directly affect the rate and selectivity of the chemical reaction, but can only be indirectly changed through the effect on mass/heat transfer Reaction rate and selectivity.

SUMMARY OF THE INVENTION

In view of the above problems existing in the prior art, the purpose of the present invention is to provide a chemical reaction method and device based on impingement flow.

For realizing the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is as follows:

A chemical reaction method based on impingement flow is to make high-speed moving raw materials collide with each other at high speed in an impinging flow reactor to produce a chemical reaction.

The feedstock includes a catalyst.

The feedstock is impinged in a continuous or intermittent manner.

The high-speed impact means that the impact speed is higher than 100 m/s, further, close to or higher than the speed of sound.

As a preferred solution, the kinetic energy of the high-speed moving raw material exceeds the activation energy of the chemical reaction, thereby promoting the occurrence of the reaction. The high-speed motion refers to a speed higher than 50 m/s (further, higher than 100 m/s; further, close to or higher than the speed of sound), under this high-speed motion, the kinetic energy of the fluid exceeds the reaction activation energy, This can promote the occurrence of chemical reactions.

The raw material is gas phase or liquid phase.

As a preferred solution, the high speed of the raw material is obtained by first pressurizing and then depressurizing.

As a further preferred solution, when the raw material is a gas phase, the gas phase raw material is first pressurized into a high-pressure gas-phase raw material, and then the high-pressure gas-phase raw material pressurizing unit is decompressed to obtain a high speed; when the raw material is a liquid phase, the liquid-phase raw material is first pressurized to High-pressure liquid-phase raw materials, and then decompress the high-pressure liquid-phase raw materials to obtain high speed, or directly decompress the high-pressure gas to push the liquid-phase raw materials to obtain high speed.

A chemical reaction device based on impinging flow, comprising an impinging flow reactor, at least a pair of nozzles are arranged in the impinging flow reactor, each pair of nozzles is relatively arranged on the inner side wall of the impinging flow reactor, and also includes a plurality of high-pressure raw materials A supply unit, the high-pressure raw material supply unit includes a raw material storage container and a pressurizing unit, and the pressurizing unit is connected with the outlet of the raw material storage container and the inlet of the nozzle through a pipeline.

As a preferred solution, the pressurizing unit is a pressurizing device or a high-pressure gas injection device.

As a further preferred solution, the pressurizing device includes, but is not limited to, a pressurizing pump and a pressure multiplier.

As a preferred solution, the high-pressure raw material supply unit includes an energy storage device and a temperature control device, the energy storage device is connected to the outlet of the pressurizing unit and the inlet of the nozzle through a pipeline, and the temperature control device is provided in the energy storage device on or at the inlet end of the energy storage device.

As a further preferred solution, the temperature control device includes a heat exchanger.

As a preferred solution, a collection unit is included, and the collection unit is connected to the outlet of the impinging flow reactor.

As a preferred solution, a quick-opening valve is included, and the quick-opening valve is provided on the pipeline between the outlet end of the high-pressure raw material supply unit and the inlet end of the nozzle.

As a preferred solution, the distance and angle between each pair of nozzles can be adjusted.

Based on the above-mentioned chemical reaction principle of the present invention, it can be used in various chemical reactions to synthesize various chemical substances, such as: can be used for the preparation of NaA molecular sieves, as follows:

A kind of preparation method of NaA molecular sieve based on impingement flow, comprises the steps:

a) Dissolve sodium hydroxide and sodium metaaluminate in water, add silica sol, stir and mix evenly to obtain a molar ratio of (2.5～3.5)Na ₂ O:1Al ₂ O ₃ :(1.5～2.5)SiO ₂ :( 120～130) raw material liquid of H ₂ O, standby;

b) Preheating the raw material liquid to 95-100 °C, pushing the raw material liquid with high pressure gas, the raw material liquid enters the impinging flow reactor rapidly through the nozzle in the impinging flow reactor and collides with each other at a high speed to crystallize the raw material;

c) collecting the crystallized product to obtain the NaA molecular sieve.

Compared with the prior art, the present invention has the following significant beneficial effects:

The invention creatively makes the high-speed moving raw materials collide with each other at high speed in the impingement flow reactor, and the chemical reaction can be instantaneously completed by utilizing the kinetic energy of the raw materials, thereby significantly improving the chemical reaction rate. A high concentration can achieve a significant increase in the reaction rate, save energy, and do not affect the selectivity of the reaction; in addition, the device of the present invention is simple in structure, convenient in operation, low in cost, widely used, and strong in practicability, compared to the prior art. Has significant progress and outstanding beneficial effects.

Description of drawings

1 is a schematic structural diagram of a chemical reaction device based on impingement flow provided by an embodiment of the present invention;

2 is a schematic structural diagram of a chemical reaction device based on impingement flow provided with an energy storage device and a temperature control device according to an embodiment of the present invention;

3 is a schematic structural diagram of an impinging flow-based chemical reaction device with an energy storage device and a temperature control device provided in an embodiment of the present invention;

Fig. 4 is the installation schematic diagram of the nozzle in the embodiment of the present invention;

5 is the XRD pattern of the product after heating at 98° C. for 25 to 40 minutes before the impact of the raw material liquid in step b) of the application example of the present invention;

6 is a SEM photo of the product after heating at 98° C. for 25 to 40 minutes before the impact of the raw material liquid in step b) of the application example of the present invention;

Fig. 7 is the XRD pattern of the product after the raw material liquid is heated at 98 DEG C for 30 minutes in step b) in the application example of the present invention, and then the product after the opposite impact occurs under the impelling of different pressure gases;

Fig. 8 is the SEM photograph of the product after the opposite impact occurs under the impelling of 50bar pressure gas after the raw material liquid is heated at 98 DEG C for 30 minutes in step b) in the application example of the present invention;

The symbols in the figure are as follows: 1-impinging flow reactor; 2-nozzle; 3-high pressure raw material supply unit; 31-raw material storage container; 32-pressurizing unit; 33-energy storage device; 34-temperature control device; 4- Collection unit; 5-Quick-open valve.

Detailed ways

The technical solutions of the present invention will be further described in detail below with reference to the embodiments, drawings and application examples.

Example

The invention provides a chemical reaction method based on impingement flow, which is to make high-speed moving raw materials collide with each other at high speed in an impinging flow reactor to produce a chemical reaction. Wherein, the kinetic energy of the high-speed moving raw material exceeds the activation energy of the chemical reaction, thereby promoting the occurrence of the reaction.

The raw material is gas phase or liquid phase. The high speed is obtained by first pressurizing and then decompressing the raw material. Specifically, when the raw material is a gas phase, the gas phase raw material is first pressurized by a pressurizing device, and then the high speed is obtained by decompressing the nozzle; when the raw material is a liquid phase, the high speed is obtained. The liquid-phase raw material is first pressurized by a pressurizing device, and then decompressed by a nozzle to obtain high speed, or directly inject high-pressure gas into the liquid-phase raw material to pressurize the raw material, and then use the high-pressure gas to decompress the liquid-phase raw material to obtain high-speed. .

In order to realize the above chemical reaction method, as shown in FIGS. 1 to 4 : the present invention also provides a chemical reaction device based on impingement flow, including an impingement flow reactor 1, and the impingement flow reactor 1 is provided with a For the nozzles 2, each pair of nozzles 2 are relatively arranged on the inner side wall of the impinging flow reactor 1, and also include a plurality of high-pressure raw material supply units 3, and the high-pressure raw material supply units 3 include a raw material storage container 31 and a pressurizing unit 32, so The pressurizing unit 32 is connected to the outlet of the raw material storage container 31 and the inlet of the nozzle 2 through pipelines.

When using this device for chemical reaction, the raw material flows out from the raw material storage container 31 and is pressurized by the pressurizing unit 32, and the pressurized raw material is decompressed and accelerated by the nozzle 2 (the pressure in the nozzle 2 is much lower than that of the pressurized raw material) The pressure of the pressurized material passing through the nozzle 2 is actually equivalent to a throttling expansion process), so that the material passing through the nozzle 2 obtains a very high velocity (above 50 m/s; further, higher than 100 m/s Second; further, close to or higher than the speed of sound) and kinetic energy, the high-speed moving raw material is ejected from the nozzle 2 and enters the impinging flow reactor 1 for high-speed impact (the impact speed is related to the moving speed of the raw material, usually higher than 100 m/s; further, close to or higher than the speed of sound), so that the kinetic energy of the raw material can be used to promote the rapid chemical reaction between the raw material components to obtain the desired target product;

In this process, in order to ensure that the kinetic energy of the raw material is sufficient to promote the rapid chemical reaction between the raw material components, the raw material should have a high flow rate, so that the kinetic energy of the raw material exceeds the activation energy of the chemical reaction.

In the above reaction process, the raw materials sprayed from each nozzle 2 can be the same or different, that is, the same raw materials can be sprayed from different nozzles 2 at the same time, so that each component in the raw materials chemically reacts, or After several raw materials for the desired chemical reaction are sprayed from different nozzles 2, chemical reactions occur between the raw materials.

The core point of the present invention is to make the raw material have extremely high speed and kinetic energy, and then use the high-speed impact of the raw material with high kinetic energy to promote the rapid chemical reaction between the raw material components, the raw material can be gas phase or liquid phase, (the raw material is In the gas phase, the raw material itself can be a gas; when the raw material is a liquid phase, the raw material itself can be a liquid or a solid; when it is a liquid, it can be the raw material itself, or a solution prepared by dissolving it with a suitable solvent; when it is a solid, it can be used A suitable solvent is dissolved and prepared into a solution so that the raw materials enter the impinging flow reactor for impact; the raw materials can include the reactants themselves, and can also include necessary catalysts), and this reaction method can effectively reduce the reaction rate compared to the traditional reaction method. temperature, saving energy consumption, avoiding the occurrence of side reactions, and making the raw materials not limited to thermally stable raw materials.

As a preferred option:

The pressurizing unit 32 is a pressurizing device or a high-pressure gas injection device, and the pressurizing device can be a pressurizing device commonly used in the market, including but not limited to a pressurizing pump and a pressure multiplier; the pressurizing unit 32 is a pressurizing device When the raw material is in liquid phase or gas phase, the raw material is directly pressurized by the pressurizing unit 32 to be a high-pressure raw material, and then decompressed through the nozzle 2, so that the raw material can be obtained at a high speed, and the raw material here can be a liquid phase or a gas phase. When the pressurizing unit 32 is a high-pressure gas injection device, the raw material is a liquid-phase raw material, and the high-pressure gas is directly injected into the liquid-phase raw material through the high-pressure gas injection device to pressurize the raw material, and then the raw material is sprayed from the nozzle 2 under the push of the high-pressure gas. out and depressurized to obtain high velocity for the starting material.

As shown in FIGS. 2 and 3 , the high-pressure raw material supply unit 3 includes an energy storage device 33 and a temperature control device 34 , and the energy storage device 33 is connected to the outlet of the pressurizing unit 32 and the inlet of the nozzle 2 through pipelines After the raw material is released from the raw material storage container 31, it passes through the pressurizing unit 32, and the obtained high-pressure raw material enters the energy storage device 33, and then enters the nozzle 2 through the pipeline. The temperature control device 34 is provided on the energy storage device 33 (as shown in the figure 2) or at the inlet end of the energy storage device 33 (as shown in Figure 3), when it is installed on the energy storage device 33, the pressurized high-pressure raw material enters the energy storage device 33 and is regulated by the temperature control device 34 to a suitable temperature, and then the high-pressure raw material with suitable temperature enters the nozzle 2 from the energy storage device 33; when it is set at the inlet end of the energy storage device 33, the pressurized high-pressure raw material is adjusted to a suitable temperature by the temperature control device 34 and then stores the energy. In the device 33 , the high-pressure feedstock with suitable temperature then enters the nozzle 2 from the energy storage device 33 .

The temperature control device 34 includes a heat exchanger, through which the raw material has a suitable temperature. The temperature control device 34 may also include a temperature sensor and a temperature controller (not shown in the figure), the temperature sensor is electrically connected to the temperature controller, so as to implement intelligent monitoring of the temperature of the raw material, and the temperature sensor can be installed on the energy storage device 33 .

The chemical reaction device includes a collection unit 4 connected to the outlet of the impinging flow reactor 1 to collect the products after the chemical reaction is completed.

The chemical reaction device includes a quick-opening valve 5, and the quick-opening valve 5 is arranged on the pipeline between the outlet end of the high-pressure raw material supply unit 3 and the inlet end of the nozzle 2. Specifically, it is arranged between the pressurizing unit 32 and the inlet end of the nozzle 2. on the pipe between nozzles 2 to quickly release high-pressure raw materials into nozzles 2. When the high-pressure raw material supply unit 3 includes the energy storage device 33 , the quick-opening valve 35 is provided on the pipeline between the energy storage device 33 and the nozzle 2 to rapidly release the high-pressure raw material. The quick-opening valves 5 can be connected in parallel, so as to control the raw materials in different high-pressure raw material supply units 3 to enter into different nozzles 2 at the same time.

The number of the high-pressure raw material supply units 3 is at least two.

The distance and angle between each pair of nozzles 2 can be adjusted. Specifically, as shown in FIG. 4 , the distance D between each pair of nozzles 2 and the angle θ between each pair of nozzles 2 can be freely adjusted according to actual needs.

At the same time, both the raw material storage container 31 and the energy storage device 33 of the present invention may be provided with a flow meter or a flow regulating valve (not shown) to facilitate operation and regulation of the flow.

The core point of the present invention is to make the raw materials have extremely high speed and kinetic energy, and then use the high-speed impact of the raw materials with high kinetic energy to promote the rapid chemical reaction between the raw material components, as long as the raw materials can have extremely high speed and kinetic energy. That is, as shown in the embodiment of the present invention, the raw material can be provided with extremely high speed and kinetic energy by the change of pressure, and other means or methods can also be used.

Application example

a) dissolving sodium hydroxide and sodium metaaluminate in water, adding silica sol, stirring and mixing uniformly to obtain a raw material solution with a molar ratio of 3.165Na ₂ O:1Al ₂ O ₃ :1.926SiO ₂ :128H ₂ O, for subsequent use;

b) The raw material liquid is heated to 98°C and kept for 25 to 40 minutes, and then the heated raw material liquid is input into the nozzle 2 (nozzle 2) installed in the impinging flow reactor 1 through the pipeline with high pressure gas (pressure is 5 to 70 bar). The relative distance between them is 15mm), since the nozzle 2 is directly vented to the atmosphere, the pressure in the nozzle 2 is normal pressure, so that the gas pressure difference that pushes the raw material liquid can be controlled at 5-70 bar, and the raw material liquid is in the pressure difference. Under the action, extremely high speed (at 50bar, the speed is about 100 m/s) and kinetic energy, the high-speed moving raw material liquid is sprayed from the nozzle 2 into the impinging flow reactor 1 and collides with each other at a high speed (the impact speed is the liquid outlet. Twice the speed, about 200 m/s at 50 bar) to crystallize the raw material;

c) Collect the crystallized product to obtain NaA molecular sieve.

In this application example, the whole process from heating to impact to crystallization and synthesizing NaA molecular sieve does not exceed 45 minutes, while the traditional NaA molecular sieve is synthesized by hydrothermal method, and the molecular sieve mother liquor is usually prepared and placed in a crystallization kettle The reaction can be completed in 4 hours at 100 DEG C. It can be seen that the present invention significantly improves the synthesis rate of NaA molecular sieve.

Fig. 5 is the XRD pattern of the product after the raw material liquid is heated at 98° C. for 25 to 40 minutes before the impact in step b) in this application example; it can be seen from Fig. 5 that the raw material liquid is heated at 98° C. for 25 to 30 minutes before the impact. During the crystallization reaction, the product was in an amorphous state. After heating for 30 and 40 minutes, although the characteristic peak of the A-type molecular sieve appeared, the crystallinity was not high, indicating that the crystallization reaction of the molecular sieve was not complete.

Fig. 6 is the SEM photograph of the product after heating at 98°C for 25 to 40 minutes before the impact of the raw material liquid in step b) in this application example; wherein, a and b are the SEM photographs of the product after being heated at 98°C for 30 minutes, c, d is the SEM photo of the product after heating at 98 °C for 35 minutes; e and f are the SEM photos of the product after heating at 98 °C for 40 minutes; it can be seen from Figure 6 that the raw material solution was heated at 98 °C for 30 minutes before the impact, and basically no crystallization After the reaction, the product was in an amorphous state, and no molecular sieve crystals with regular morphology were observed; after heating for 35 and 40 minutes, square molecular sieve crystals appeared in the SEM pictures, with a diameter of about 1 micron, which was typical of type A molecular sieves. However, the proportion of molecular sieve crystals is small, indicating that the degree of crystallization reaction of molecular sieve is small.

Fig. 7 is the XRD pattern of the product after the raw material liquid is heated at 98°C for 30 minutes in step b) in this application example, and then collided with different pressure gases; the contrast in the figure refers to heating at 98°C for 30 minutes, The XRD pattern of the unimpacted XRD pattern can be seen from Figure 7. Under the premise that the heating time is fixed at 30 minutes, with the increase of the pushing gas pressure, the velocity obtained by the liquid at the nozzle outlet is also higher. The corresponding XRD pattern of the product The peak height increases, and the crystallinity of the A-type molecular sieve also increases, indicating that with the increase of the impact speed of the raw material liquid, that is, the increase of the kinetic energy of the raw material, the promotion of the crystallization of the molecular sieve is more significant.

Fig. 8 is the SEM photograph of the product after the raw material liquid is heated at 98°C for 30 minutes in step b) in this application example, and then collided with each other under the pressure of 50 bar gas; it can be seen from Fig. 8 that a large number of cubes appear in the SEM photograph. The crystals are consistent with the typical morphology of A-type molecular sieves, indicating that the high-speed impact of the raw material liquid significantly promotes the crystallization reaction.

Finally, it should be pointed out here that the above are only some preferred embodiments of the present invention, and should not be construed as limiting the protection scope of the present invention, and some non-essential improvements and adjustments made by those skilled in the art according to the above-mentioned content of the present invention All belong to the protection scope of the present invention.

Claims (8)

1. a chemical reaction method based on impingement flow, it is characterized in that: make high-speed moving raw material in impingement flow reactor high-speed opposite impact and produce chemical reaction. 2. The chemical reaction method according to claim 1, wherein the raw material is a gas phase or a liquid phase. 3 . The chemical reaction method according to claim 1 , wherein the raw materials are impinged in the mode of continuous feeding or intermittent feeding. 4 . 4 . The chemical reaction method according to claim 1 , wherein the kinetic energy of the high-speed moving raw material exceeds the activation energy of the chemical reaction. 5 . 5. A chemical reaction device based on impinging flow, comprising an impinging flow reactor, at least a pair of nozzles are provided in the impinging flow reactor, and each pair of nozzles is relatively arranged on the inner sidewall of the impinging flow reactor, characterized in that : It also includes several high-pressure raw material supply units, the high-pressure raw material supply units include a raw material storage container and a pressurizing unit, and the pressurizing unit is connected with the outlet of the raw material storage container and the inlet of the nozzle through a pipeline. 6 . The chemical reaction device according to claim 5 , wherein the high-pressure raw material supply unit comprises an energy storage device and a temperature control device, and the energy storage device passes through a pipeline, an outlet of the pressurizing unit and an inlet of a nozzle. 7 . connected, the temperature control device is arranged on the energy storage device or at the inlet end of the energy storage device. 7. The chemical reaction device according to claim 5, characterized in that it comprises a collection unit, and the collection unit is connected with the outlet of the impinging flow reactor. 8 . The chemical reaction device according to claim 5 , characterized in that it comprises a quick-opening valve, and the quick-opening valve is arranged on the pipeline between the outlet end of the high-pressure raw material supply unit and the inlet end of the nozzle. 9 .

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