Closed semi-continuous gas-liquid reaction system and method
Technical Field
The invention relates to a closed semi-continuous gas-liquid reaction system and a method.
Background
In the chemical field, some liquid materials, such as molten salt, liquid active metal and the like, can adopt a gas-liquid two-phase contact mode to achieve the purpose of purification. The purification process comprises a plurality of process stages, each process stage having a different temperature gradient. This type of material is characterized by the fact that it cannot come into contact with air.
In the prior art, a single-stage bubble reactor is generally used for purification treatment, so that the production efficiency is low.
Disclosure of Invention
The invention provides a closed semi-continuous gas-liquid reaction system and a closed semi-continuous gas-liquid reaction method, aiming at the requirements of liquid materials such as fluoride fused salt, liquid active metal and the like in the chemical field on tightness and reaction conditions, and the defects of low production efficiency, poor expandability and frequent repeated temperature rise and fall and easy aging of a reactor due to process requirements in the prior art.
The invention solves the technical problems through the following technical scheme:
the invention provides a closed semi-continuous gas-liquid reaction system, which comprises: a feeding-preprocessor, at least 2 bubbling reactors connected in series, a gas preprocessor, a temporary storage-shunt tank and a storage tank;
the outlet of the feeding-pretreating device is connected with the liquid inlet of the first bubble reactor through a first liquid pipeline, and pipe orifices at two ends of the first liquid pipeline respectively extend into the bottom of the feeding-pretreating device and the upper part of the first bubble reactor;
the bubbling reactors are connected through a second liquid pipeline, and pipe orifices at two ends of the second liquid pipeline respectively extend into the bottom of a higher-level bubbling reactor and the upper part of a lower-level bubbling reactor;
the liquid outlet of the last bubbling reactor is connected with the temporary storage-diversion tank through a third liquid pipeline; pipe orifices at two ends of the third liquid pipeline respectively extend into the bottom of the last bubbling reactor and the upper part of the temporary storage-diversion tank;
the outlet of the gas preprocessor is connected with the last bubbling reactor through a reaction gas pipeline;
the outlet of the temporary storage and diversion tank is connected with the feeding and pre-treating device on the one hand and the storage tank on the other hand.
In the invention, the gas preprocessor is used for preprocessing reaction gas and simultaneously used as a buffer area to prevent molten salt from suck back and freezing and blocking pipelines. Preferably, the gas pre-processor is provided with a heating system, the heating system is used for heating the reaction gas on one hand, and on the other hand, when the molten salt is sucked back, the heating system can heat the gas pre-processor to enable the sucked molten salt to be restored to a molten state and return to the bubbling reactor.
Preferably, the feed-preconditioner is provided with a feed opening through which the material to be treated enters the feed-preconditioner.
Preferably, the number of the bubble reactors is 2 to 10, and more preferably, the number of the bubble reactors is 2 to 4 (e.g., 3).
Preferably, a first non-return cut-off device is further arranged between the feed-preprocessor and the first bubble reactor.
Preferably, a second non-return cut-off device is further arranged between the last bubbling reactor and the temporary storage-diversion tank.
Preferably, a fourth check stopping device is further arranged between the temporary storage-distribution tank and the storage tank.
Preferably, a third non-return cut-off device is further arranged between the temporary storage-distribution tank and the feeding-pretreatment device.
The first non-return cut-off device to the fourth non-return cut-off device are used for controlling the on-off of the flowing of the liquid material and limiting the unidirectional flowing of the liquid material.
Preferably, a temporary storage tank is further arranged between the temporary storage-diversion tank and the feeding-pre-processor, and the temporary storage tank is used for temporarily storing liquid materials.
Preferably, a third non-return cut-off device is arranged between the temporary storage tank and the feeding-pre-processor.
The invention also provides a closed semi-continuous gas-liquid reaction method which is carried out by adopting the closed semi-continuous gas-liquid reaction system and comprises the following steps:
(1) adding a material to be processed into a feeding-pre-processor for pre-processing to obtain a liquid material;
(2) sequentially charging the liquid feed from the feed-preconditioner into at least one bubble reactor; if at least one bubble reactor is not filled with the liquid material, the following steps S1-S4 are carried out:
s1, repeating the step (1), and preprocessing the material to be processed to obtain a liquid material;
meanwhile, adding reaction gas into a gas preprocessor for preprocessing, introducing the preprocessed reaction gas into the last bubble reactor, passing through each bubble reactor in the reverse order, and carrying out gas-liquid two-phase contact reaction with the liquid material in the bubble reactor; stopping introducing the reaction gas after the material pretreatment in the feeding-pretreatment device is finished;
s2, enabling the liquid material subjected to gas-liquid two-phase contact reaction to enter a lower-stage bubbling reactor, and enabling the liquid material in the feeding-pretreating device to enter the bubbling reactor;
s3, repeating the steps (S1) to (S2) until all the bubbling reactors are filled with liquid materials;
s4, adding reaction gas into a gas preprocessor for preprocessing, introducing the preprocessed reaction gas into the last bubble reactor, leading the preprocessed reaction gas to pass through each bubble reactor in the reverse order, and carrying out gas-liquid two-phase contact reaction on the preprocessed reaction gas and the liquid material in each bubble reactor;
the materials which finish the gas-liquid two-phase contact reaction in each bubbling reactor enter a temporary storage-shunt tank;
when the materials in the temporary storage-shunt tank do not need to be repeatedly treated, the reaction materials flow into the storage tank;
when the materials in the temporary storage-shunt tank need to be repeatedly treated, returning the reaction materials to the feeding-pretreatment device;
repeating the step (1) during the gas-liquid two-phase contact reaction, and pretreating the material to be treated to obtain a liquid material;
if the liquid material is filled in each bubbling reactor, directly performing the step S4;
(3) and (3) repeating the step (2), so that the liquid material pretreated by the feeding-pretreatment device enters each bubble reactor in a semi-continuous mode, flows into a storage tank after gas-liquid two-phase contact reaction, or returns to the feeding-pretreatment device.
In the closed semi-continuous gas-liquid reaction method, while the liquid material and gas are in gas-liquid two-phase contact reaction in the bubbling reactors, the next batch of material to be processed is added into the feeding-pretreating device for pretreatment, after the gas-liquid two-phase contact reaction is finished, the material in the bubbling reactors, which is finished with the gas-liquid two-phase contact reaction, sequentially enters the temporary storage-shunting tank in a pressure difference driving mode, and the liquid material in the feeding-pretreating device is sequentially filled into each bubbling reactor, so that semi-continuous production is realized.
In the present invention, the liquid material may be flowed by means of a technique conventional in the art, for example, by means of a pressure difference drive. Preferably, a gas is injected into the space above the liquid material in the feed-preconditioner, and the liquid material in the feed-preconditioner is sequentially charged into at least one bubble reactor by the pressure of the gas. And injecting gas into the space above the liquid material in the bubbling reactor, and enabling the liquid material in the bubbling reactor to flow into a next-stage bubbling reactor or the temporary storage-diversion tank through the pressure of the gas. More preferably, the gas is used for generating gas pressure to drive the liquid material to flow, and the gas can be inert gas, hydrogen gas or hydrogen-hydrogen fluoride mixed gas; to ensure the reliability of the apparatus, the gas is preferably an inert gas (e.g., argon). The inert gas may be an inert gas conventional in the art, such as argon, helium, or nitrogen.
Preferably, the pipe orifices at both ends of the first liquid pipeline respectively extend into the liquid level below the liquid level of the feeding-preprocessor and the liquid level above the liquid level of the first bubble reactor.
Preferably, the pipe orifices at two ends of the second liquid pipeline respectively extend into the liquid level of the upper stage bubbling reactor and the liquid level of the lower stage bubbling reactor. Before the reaction starts and after the reaction finishes, the second liquid pipeline is used as a transmission pipeline of the liquid material, so that the liquid material flows from the upper stage bubble reactor to the lower stage bubble reactor in sequence; during the reaction process, the second liquid pipeline is used as a transmission pipeline of the reaction gas, so that the reaction gas flows from the lower-stage bubble reactor to the upper-stage bubble reactor in a reverse order.
Preferably, the pipe orifices at both ends of the third liquid pipeline respectively extend below the liquid level of the last bubbling reactor and above the liquid level of the temporary storage-diversion tank.
Preferably, the reaction gas line extends below the liquid level in the last of the bubble reactors.
In the invention, the material to be treated can be selected according to the requirement, such as molten salt (such as ternary mixed molten salt of LiF, NaF and KF) or liquid active metal.
In the feed-preconditioner, the pretreatment may be a pretreatment method conventional in the art for such materials, preferably by one or more of heat baking, agitation, aeration, decantation and standing. Further, the pretreatment is heating baking, so that the solid material is melted into liquid material, the heating temperature is preferably 10-300 ℃ higher than the melting point of the material to be treated, and the heating time is preferably 1-72h (for example 12 h).
The reaction gas may be selected according to the nature of the material to be treated and the desired reaction, such as argon, hydrogen or a mixture of hydrogen and hydrogen fluoride. Preferably, the reaction gas is a hydrogen-hydrogen fluoride mixed gas, wherein the volume flow ratio of the hydrogen to the hydrogen fluoride is (4-20): 1, preferably (5-10): 1 (e.g., 5:1, 10:1), more preferably 10: 1.
In the gas pre-treater, the pre-treatment may be a pre-treatment method conventional in the art for such gases, preferably one or more of heating, purification, pressure regulation, flow regulation and buffer setting.
When the gas-liquid two-phase contact reaction is performed, the temperature of each bubble reactor can be set conventionally, and preferably, the temperature of each bubble reactor is 100 to 850 ℃, and more preferably 500 to 650 ℃. Preferably, when the number of the bubble reactors is 3, the temperature of the first and second bubble reactors is 600 ℃ and the temperature of the last bubble reactor is 650 ℃.
In the present invention, the time of the gas-liquid two-phase contact reaction may be a reaction time that is conventional in such reactions in the field, and preferably, the time of the gas-liquid two-phase contact reaction of the liquid material is 0.5 to 120 hours in total, preferably 0.5 to 72 hours, for example, 36 hours. The time of the gas-liquid two-phase contact reaction here means the sum of the times of the gas-liquid two-phase contact reaction with the reaction gas in the bubble reactor for the same batch of liquid materials fed at the same time.
In the present invention, "order" means the order from the first bubble reactor to the last bubble reactor. The "reverse order" refers to the order from the last bubble reactor to the first bubble reactor.
In the present invention, the upstream bubble reactor is an upper-stage bubble reactor, and the downstream bubble reactor is a lower-stage bubble reactor, in the direction of flow of the liquid material.
The positive progress effects of the invention are as follows:
the closed semi-continuous gas-liquid reaction system has a simple structure, adopts a full-static sealing mode, avoids a dynamic sealing mode, and improves the reliability of equipment while ensuring the sealing property; the dead volume is small, and the product yield is improved; the plurality of bubble reactors are connected in series, so that the reaction can be carried out simultaneously, the contact time of gas and liquid is prolonged, and the potential expandability of increasing series stages is provided; compared with a single-tank reactor, the semi-continuous production mode improves the production efficiency; during semi-continuous production, the temperature of each bubbling reactor is independently controllable, so that the time spent on the temperature rise and fall of the reactors is saved, the problems of fatigue and aging of equipment due to frequent temperature change are avoided, and the service life is prolonged; the liquid material is conveyed in an air pressure mode, and the operation is simple.
Drawings
FIG. 1 is a schematic view of a closed semi-continuous gas-liquid reaction system in example 1 of the present invention.
Feed-preconditioner 10
Charging opening 101
Bubbling reactors 111-113
Gas pre-processor 12
Temporary storage-diversion tank 13
Storage tank 14
First non-return stopper 151
Second non-return stop 152
Third check stop 153
Fourth check stop 154
Temporary storage tank 16
First liquid line 201
Second liquid line 202
Third liquid line 203
Reaction gas line 30
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
Example 1
The present embodiment provides a closed semi-continuous gas-liquid reaction system, which includes: a feeding-preprocessor 10, 3 bubbling reactors 111-113 connected in series, a gas preprocessor 12, a temporary storage-diversion tank 13 and a storage tank 14;
the feeding-pretreating device 10 is used for feeding and pretreating materials, and an outlet of the feeding-pretreating device 10 is connected with a liquid inlet of the first bubbling reactor 111 through a first liquid pipeline 201;
the pipe orifices at the two ends of the first liquid pipeline 201 respectively extend into the liquid level of the feeding-pretreating device 10 and the liquid level of the first bubbling reactor 111;
the bubbling reactors 111-113 are connected through a second liquid pipeline 202, and pipe orifices at two ends of the second liquid pipeline 202 respectively extend into the positions below the liquid level of the upper bubbling reactor and the positions above the liquid level of the lower bubbling reactor;
the bubbling reactors 111-113 are used for enabling the materials to be in gas-liquid two-phase contact, and a liquid outlet of the last bubbling reactor 113 is connected with the temporary storage-diversion tank 13 through a third liquid pipeline 203;
the pipe orifices at the two ends of the third liquid pipeline 203 respectively extend into the liquid level of the last bubbling reactor 113 and the liquid level of the temporary storage-diversion tank 13;
the gas preprocessor 12 is used for preprocessing reaction gas and simultaneously used as a buffer area to prevent molten salt from being sucked backwards and freezing and blocking pipelines; the outlet of the gas pre-processor 12 is connected with the last bubble reactor 113 through a reaction gas pipeline 30;
the temporary storage-diversion tank 13 is used for temporary storage and diversion of reaction materials, and the outlet of the temporary storage-diversion tank 13 is connected with the feeding-preprocessor 10 on one hand and the storage tank 14 on the other hand;
the storage tank 14 is used for storing the materials after the reaction.
The feed-preconditioner 10 is provided with a feed inlet 101 through which material enters the feed-preconditioner 10.
The gas pre-processor 12 is provided with a heating system for heating the reaction gas on the one hand and, on the other hand, in case of back-suction of the molten salt, the heating system may heat the gas pre-processor 12 to return the back-sucked molten salt to the molten state to the last bubble reactor 113.
Before the reaction starts and after the reaction finishes, the second liquid pipeline 202 is used as a conveying pipeline of the liquid material, so that the liquid material flows from the upper stage bubble reactor to the lower stage bubble reactor in sequence; during the reaction, the second liquid line 202 serves as a transfer line for the reaction gas, which flows in reverse order from the lower bubble reactor to the upper bubble reactor.
A first non-return stop 151 is also provided between the feed-preconditioner 10 and the first bubble reactor 111.
A second non-return cut-off device 152 is also arranged between the last bubbling reactor 113 and the temporary storage-diversion tank 13.
A fourth non-return stop 154 is also provided between the buffer-dividing tank 13 and the storage tank 14.
A temporary storage tank 16 is also arranged between the temporary storage-diversion tank 13 and the feeding-preprocessor 10, and the temporary storage tank 16 is used for temporarily storing liquid materials.
A third non-return stop 153 is also provided between the buffer tank 16 and the feed preconditioner 10.
The non-return cut-off device is used for controlling the on-off of the flowing of the liquid material and limiting the unidirectional flowing of the liquid material.
Example 2
The embodiment provides a closed semi-continuous gas-liquid reaction method which is carried out by using the closed semi-continuous gas-liquid reaction system of the embodiment 1, and the method specifically comprises the following steps:
before starting, the working states of the first to fourth check stoppers 151 to 154 are confirmed to be 'off';
(1) powdery 35.1kg of lithium fluoride (LiF), 14.0kg of sodium fluoride (NaF) and 70.9kg of potassium fluoride (KF) were injected from a feed port 101 into a feed-preconditioner 10, the temperature of the feed-preconditioner 10 was set to 600 ℃, and the solid material was melted into a liquid material, i.e., FLiNaK molten salt (ternary mixed salt of LiF, NaF and KF), by treatment at 600 ℃ for 12 hours under the protection of argon atmosphere.
(2) Opening the first non-return cut-off device 151, injecting argon gas into the space above the liquid material in the feeding-pretreating device 10 at a rate of 10L/min, and making the liquid material flow into the first bubble reactor 111 through the first non-return cut-off device 151 and the first liquid pipe 201 by using the pressure of the gas; closing the first non-return stopper 151;
(3) repeating the step (1), feeding the feeding-preprocessor 10 again, and treating for 12 hours at 600 ℃ under the protection of argon atmosphere to melt the solid material into liquid material;
meanwhile, after the reaction gas is heated to 100 ℃ by the gas preprocessor 12, the reaction gas (hydrogen-hydrogen fluoride mixed gas with a volume flow ratio of 10:1) is introduced into the last bubble reactor 113 at a rate of 10L/min, the reaction gas enters the first bubble reactor 111 to contact and react with the liquid material after passing through the last bubble reactor 113 and the second bubble reactor 112 in sequence, and the residual reaction gas flows out from a gas outlet of the first bubble reactor 111;
after the solid material in the feeding-preprocessor 10 is melted into a liquid material, stopping introducing the reaction gas, opening the first non-return cut-off device 151, injecting argon gas into the space above the liquid material in the first bubble reactor 111, and making the liquid material flow into the second bubble reactor 112 through the second liquid pipeline 202 by using the gas pressure; injecting argon gas into the space above the liquid material in the feeding-pretreating device 10, making the liquid material flow into the first bubble reactor 111 through the first non-return stopper 151 and the first liquid line 201 by using the pressure of the gas, and closing the first non-return stopper 151;
(4) repeating the step (1), feeding the feeding-preprocessor 10 again, and treating for 12 hours at 600 ℃ under the protection of argon atmosphere to melt the solid material into liquid material;
meanwhile, after the reaction gas is heated to 100 ℃ by the gas preprocessor 12, the reaction gas (hydrogen-hydrogen fluoride mixed gas with a volume flow ratio of 10:1) is introduced into the last bubble reactor 113 at a rate of 10L/min, the reaction gas enters the second bubble reactor 112 and the first bubble reactor 111 to contact and react with the liquid material after passing through the last bubble reactor 113 in sequence, and the residual reaction gas flows out from the gas outlet of the first bubble reactor 111;
after the solid material in the feeding-pretreating device 10 is melted into a liquid material, stopping introducing the reaction gas, opening the first non-return cut-off device 151, making the liquid material in the second bubble reactor 112 flow into the last bubble reactor 113 by adopting the same pressure difference driving mode as the step (3), making the liquid material in the first bubble reactor 111 flow into the second bubble reactor 112, making the liquid material in the feeding-pretreating device 10 flow into the first bubble reactor 111, and closing the first non-return cut-off device 151; so far, liquid materials are filled into the bubbling reactors 111-113;
(5) repeating the step (1), feeding the feeding-preprocessor 10 again, and treating for 12 hours at 600 ℃ under the protection of argon atmosphere to melt the solid material into liquid material;
meanwhile, after the reaction gas is heated to 100 ℃ by the gas preprocessor 12, the reaction gas (hydrogen-hydrogen fluoride mixed gas with a volume flow ratio of 10:1) is introduced into the last bubble reactor 113 at a rate of 10L/min, the reaction gas sequentially enters the last bubble reactor 113, the second bubble reactor 112 and the first bubble reactor 111 to contact and react with the liquid material, and the residual reaction gas flows out from a gas outlet of the first bubble reactor 111;
after the solid material in the feeding-preprocessor 10 is melted into a liquid material, stopping introducing the reaction gas, opening the second non-return cut-off device 152, making the liquid material of the last bubble reactor 113 flow into the temporary storage-diversion tank 13 through the second non-return cut-off device 152 and the third liquid pipeline 203 by adopting the same pressure difference driving mode as the step (3), and closing the second non-return cut-off device 152; wherein, when the reaction material in the temporary storage-diversion tank 13 does not need to be repeatedly processed, the fourth check stop valve 154 is opened to allow the liquid material to flow into the storage tank 14, and the fourth check stop valve 154 is closed; when the reaction materials in the temporary storage-diversion tank 13 need to be repeatedly processed, the third check valve 153 is opened to allow the reaction materials to flow into the feeding-preprocessor 10;
opening the first non-return cut-off device 151, making the liquid material of the second bubble reactor 112 flow into the last bubble reactor 113, making the liquid material of the first bubble reactor 111 flow into the second bubble reactor 112, making the liquid material of the feed-preconditioner 10 flow into the first bubble reactor 111, and closing the first non-return cut-off device 151 in the same pressure difference driving mode as the step (3);
(6) and (5) repeating the step to enable the liquid material to be added from the feeding port 101 in a semi-continuous mode, and finally flowing into the storage tank 14 after being processed.
In the above steps, when the reaction gas and the liquid material are subjected to contact reaction, the temperature of the first bubble reactor 111 is set to 600 ℃, the temperature of the second bubble reactor 112 is set to 600 ℃, and the temperature of the last bubble reactor 113 is set to 650 ℃.
The product in the tank 14 was analyzed using a force available (LECO) elemental analyzer, inductively coupled plasma atomic emission spectrometry (ICP-AES), chemical titration, and the results are shown in table 1.
TABLE 1
Example 3
This example provides a closed semi-continuous gas-liquid reaction process, which differs from example 2 only in that:
the temperature of the feed-preconditioner 10 was set at 550 ℃;
when the reaction gas and the liquid material are in contact reaction, the temperature of the bubbling reactor 111-113 is set to 550 ℃.
The product in tank 14 was analyzed as in example 2 and the results are shown in table 2.
TABLE 2
Example 4
This example provides a closed semi-continuous gas-liquid reaction process, which differs from example 2 only in that: the treatment time for the feed-preconditioner 10 was 8 hours. The treatment time of the bubble reactor was 8 hours.
The product in tank 14 was analyzed as in example 2 and the results are shown in Table 3.
TABLE 3
Example 5
This example provides a closed semi-continuous gas-liquid reaction process, which differs from example 2 only in that: in the case of contact reaction, the reaction gas ratios are different, H2The feed-preconditioner 10 and bubble reactor were set up as in example 2 and the treatment time was the same as in example 2, 3: 1/HF.
The product in tank 14 was analyzed as in example 2 and the results are shown in table 4.
TABLE 4
Comparative example 1
This comparative example provides a closed semi-continuous gas-liquid reaction process, which differs from example 2 only in that:
in the case of using a closed semi-continuous gas-liquid reaction system having only 1 bubble reactor, the temperature of the bubble reactor was set to 600 ℃ when the contact reaction was carried out in the step (5). The rest of the conditions refer to example 2.
The product in tank 14 was analyzed as in example 2 and the results are shown in table 5.
TABLE 5
While specific embodiments of the invention have been described, it will be understood by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.