Multi-station continuous reaction device for preparing formic acid through carbon dioxide hydrogenation

Abstract

The utility model discloses a multi-station continuous reaction device for preparing formic acid by hydrogenating carbon dioxide, which belongs to the technical field of formic acid preparation and comprises at least two reaction mechanisms, a gas transmission mechanism connected with the input end of each reaction mechanism and a detection mechanism connected with the output end of each reaction mechanism. In the use process, a plurality of reaction mechanisms are arranged, each reaction mechanism can independently control the air pressure and the temperature, and a plurality of groups of formic acid preparation processes with the same or different conditions can be simultaneously carried out according to requirements; in addition, the gas output by each reaction mechanism is independently detected by the same detection mechanism, so that the utilization rate of rear-end detection equipment is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of formic acid preparation, in particular to a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid. Background Technique

[0002] Formic acid (HCOOH) is a carboxylic acid with the least carbon number content and is the most basic organic chemical raw material, which is widely used in fields such as medicine and chemical industry. There are many synthesis methods of formic acid. At present, more research is focused on the carbon dioxide method, that is, directly hydrogenating carbon dioxide to form acid. According to the thermodynamic data of the reaction of hydrogenating carbon dioxide to formic acid, the reaction of gaseous carbon dioxide hydrogenating to formic acid cannot proceed in the forward direction and requires high temperature and high pressure conditions.

[0003] Chinese Patent "Application No.: 202311098283.3" discloses "a continuous reaction device for hydrogenating carbon dioxide to formic acid". In the solution provided by this patent, a carbon dioxide gas path, a hydrogen gas path and a nitrogen gas path are provided at the input end of the high-pressure reaction kettle. After adding a reaction solvent and filling a catalyst in the high-pressure reaction kettle, after opening the nitrogen gas path to purge the pipeline to remove gas, the carbon dioxide gas path is opened to pressurize to 1-3 MPa and then the carbon dioxide gas path is closed. The hydrogen gas path is opened until the pressure in the high-pressure reaction kettle reaches 2-4 MPa, and after closing the hydrogen gas path, the reaction is carried out at 80°C.

[0004] However, during the process of the inventor's conception and implementation of the above application, it was found that: the solution provided by this patent only sets one reaction kettle. Each time an experiment is carried out, it is necessary to reconfigure the reactants and the environmental conditions required for the reaction. The gas chromatograph of the backend detection equipment is mainly used to analyze the components of the reactants and products in the high-pressure reaction kettle. However, the detection process of the gas chromatograph is relatively short and does not require multiple detections, resulting in too much idle time for the backend detection equipment. Therefore, a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid is needed, which can simultaneously carry out multiple formic acid production processes with the same or different conditions and improve the utilization rate of the backend detection equipment. Summary of the Utility Model

[0005] The main purpose of the utility model is to provide a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid, aiming to solve the technical problems of simultaneously carrying out multiple formic acid production processes with the same or different conditions and improving the utilization rate of the backend detection equipment.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] A multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid, comprising:

[0008] At least two reaction mechanisms, each of which is provided with a reaction kettle, and the reaction kettles are respectively connected to the output end of an intake pipe, the input end of an outlet pipe, and a temperature control component; the intake pipe is provided with a first valve, the outlet pipe is provided with a second valve, the middle part of the outlet pipe is connected to the input end of a branch pipe, the branch pipe is provided with a third valve, the outlet pipe is provided with a pressure gauge, and the pressure gauge is located on the side of the branch pipe adjacent to the reaction kettle;

[0009] An air delivery mechanism, the input end of each intake pipe is connected to the output end of the air delivery mechanism, and the air delivery mechanism is used for delivering gas to each reaction kettle;

[0010] A detection mechanism, the output end of each branch pipe is connected to the input end of the detection mechanism, and the detection mechanism is used for detecting and quantitatively analyzing the gas output by each reaction mechanism.

[0011] As a further improvement of the present utility model, the temperature control component is provided with a circulation pump and a heat exchanger, the wall of the reaction kettle is provided with a hollow interlayer, the interlayer is respectively connected to the circulation pump and the heat exchanger through a conduit, the circulation pump is connected to the heat exchanger through a conduit, and a heat exchange medium is provided in the interlayer.

[0012] As a further improvement of the present utility model, the reaction mechanism is further provided with a heating tape, and the outer walls of the outlet pipe and the branch pipe are both provided with heating tapes.

[0013] As a further improvement of the present utility model, the reaction mechanism is further provided with a first temperature sensor and a second temperature sensor, the first temperature sensor is arranged inside the reaction kettle, and the second temperature sensor is arranged on the branch pipe.

[0014] As a further improvement of the present utility model, the air delivery mechanism is provided with a buffer tank whose output end is connected to the input end of each intake pipe, the input end of the buffer tank is respectively connected to the output ends of a carbon dioxide generator, a hydrogen generator and a nitrogen generator through pipelines, the pipeline connected to the output end of the carbon dioxide generator is provided with a first mass flow controller, and the pipeline connected to the output end of the hydrogen generator is provided with a second mass flow controller.

[0015] As a further improvement of the present utility model, the detection mechanism is provided with a sampler connected to the output end of each branch pipe, and the output end of the sampler is connected to the input end of a gas chromatograph through a pipeline.

[0016] The technical solution provided by the present utility model may include the following beneficial effects:

[0017] During the use of the present utility model, two or more reaction mechanisms can be selected according to requirements. Each reaction mechanism is connected to the same gas transmission mechanism and detection mechanism. Each reaction mechanism is provided with a first valve and a second valve. When the second valve is closed, by controlling the closing timing of the first valve, the air pressure in each reaction kettle can be made different; each reaction mechanism is provided with a temperature control component, so that the temperature inside each reaction kettle can be made different, and multiple groups of formic acid production processes with the same or different conditions can be carried out simultaneously according to requirements; in addition, each reaction mechanism is provided with a third valve. By changing the opening and closing timing of the third valve, the same detection mechanism can independently detect the gases output by each reaction mechanism, improving the utilization rate of the backend detection equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By describing the exemplary embodiments of the present utility model in more detail in conjunction with the drawings, the above and other objects, features and advantages of the present utility model will become more obvious. Among them, in the exemplary embodiments of the present utility model, the same reference numerals generally represent the same components.

[0019] Figure 1 is a schematic diagram of the frame structure of a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid Figure 1 ;

[0020] Figure 2 is Figure 1 the schematic diagram of the structure of the reaction mechanism in

[0021] Figure 3 is a schematic diagram of the frame structure of a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid Figure 2 ;

[0022] REFERENCE SIGNS:

[0023] 200, reaction mechanism; 100, gas transmission mechanism; 300, detection mechanism;

[0024] 1, reaction kettle; 101, interlayer; 2, inlet pipe; 3, outlet pipe; 4, branch pipe; 5, first valve; 6, second valve; 7, third valve; 8, pressure gauge; 9, temperature control component; 901, circulation pump; 902, heat exchanger; 10, heating tape; 11, first temperature sensor; 12, second temperature sensor; 13, carbon dioxide generator; 14, hydrogen generator; 15, nitrogen generator; 16, buffer tank; 17, first mass flow controller; 18, second mass flow controller; 19, injector; 20, gas chromatograph. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Without conflict, the embodiments and the features in the embodiments of the present utility model can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative work belong to the scope of protection of the present utility model.

[0026] Figure 1 Fig. shows an embodiment of a multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid of the present utility model. Refer to Figure 1 , in this embodiment, the multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid includes: at least two reaction mechanisms 200, and a gas transmission mechanism 100 and a detection mechanism 300 respectively connected to each reaction mechanism 200.

[0027] Among them, refer to Figure 2 , the reaction mechanism 200 is provided with a reaction kettle 1, the reaction kettle 1 is respectively connected to the output end of an inlet pipe 2 and the input end of an outlet pipe 3, and the middle part of the outlet pipe 3 is connected to the input end of a branch pipe 4; the input end of each inlet pipe 2 is connected to the output end of the gas transmission mechanism 100, and the output end of each branch pipe 4 is connected to the input end of the detection mechanism 300. The process of carbon dioxide to formic acid is affected by various factors, and it is necessary to explore the optimal process conditions or screen out the best catalyst by changing one or more conditions such as temperature, pressure or catalyst type. By setting multiple reaction mechanisms 200, and setting the same or different conditions for each reaction mechanism 200, the best formic acid preparation process can be quickly and effectively found, or the best catalyst can be screened out, improving the experimental efficiency and shortening the experimental or production time cycle; at the same time, the subsequent detection mechanism 300 analyzes the reactants and products of each group of reaction mechanisms 200 respectively, which can improve the utilization rate of the subsequent detection equipment.

[0028] Furthermore, refer to Figure 2 , the reaction mechanism 200 further includes a first valve 5 provided on the inlet pipe 2, a second valve 6 provided on the outlet pipe 3, and a third valve 7 provided on the branch pipe 4. The first valve 5 is used to control the on-off of the reaction inlet pipe 2, the second valve 6 is used to control the on-off of the outlet pipe 3, and the third valve 7 is used to control the on-off of the branch pipe 4.

[0029] Furthermore, refer to Figure 2 , the reaction mechanism 200 further includes a pressure gauge 8 provided on the outlet pipe 3. The pressure gauge 8 is located on the side of the branch pipe 4 adjacent to the reaction kettle 1 and is used to detect the internal air pressure of the reaction kettle 1 in real time so as to adjust the environmental air pressure required for carbon dioxide to formic acid.

[0030] Further, referring to Figure 2 , the reaction mechanism 200 further includes a temperature control component 9. The temperature control component 9 is provided with a circulation pump 901 and a heat exchanger 902 disposed outside the reaction kettle 1. The wall of the reaction kettle 1 is provided with a hollow interlayer 101. The output end of the heat exchanger 902 and the input end of the circulation pump 901 are both connected to the interlayer 101 through pipelines. The input end of the heat exchanger 902 is connected to the output end of the circulation pump 901 through a pipeline. A liquid or gaseous heat exchange medium is filled in the loop formed by connecting the interlayer 101, the heat exchanger 902, and the circulation pump 901. The circulation pump 901 does work to make the heat exchange medium in the loop circulate, and the heat exchanger 902 does work to increase or decrease the temperature of the flowing heat exchange medium, and transfers heat to the inside of the reaction kettle 1 through the flowing heat exchange medium, or dissipates the heat inside the reaction kettle 1, so as to change the temperature inside the reaction kettle 1.

[0031] Further, referring to Figure 2 , the reaction mechanism 200 further includes a heating tape 10. The heating tape 10 is provided outside both the gas outlet pipe 3 and the branch pipe 4. The heating tape 10 can heat the outer walls of the gas outlet pipe 3 and the branch pipe 4 to prevent the temperature of the gas in the gas outlet pipe 3 and the branch pipe 4 from decreasing, thereby ensuring the accuracy of the data output by the detection mechanism 300.

[0032] Further, referring to Figure 2 , the reaction mechanism 200 further includes a first temperature sensor 11 disposed inside the reaction kettle 1 and a second temperature sensor 12 disposed on the branch pipe 4. The first temperature sensor 11 is used to detect the temperature inside the reaction kettle 1, and the second temperature sensor 12 is used to detect the temperature inside the branch pipe 4.

[0033] Among them, referring to Figure 3 , the gas transmission mechanism 100 includes a carbon dioxide generator 13, a hydrogen generator 14, a nitrogen generator 15, and a buffer tank 16. The output ends of the carbon dioxide generator 13, the hydrogen generator 14, and the nitrogen generator 15 are all connected to the input end of the buffer tank 16 through pipelines. The output end of the buffer tank 16 is connected to the input end of each intake pipe 2 through a pipeline. The carbon dioxide generator 13, the hydrogen generator 14, and the nitrogen generator 15 are respectively used to generate carbon dioxide gas, hydrogen, and nitrogen and transport them to the buffer tank 16. The buffer tank 16 is used to buffer the gas pressure fluctuation to achieve good dispersion and full mixing between different fluids.

[0034] Further, referring to Figure 3 , the pipelines connecting the output ends of the carbon dioxide generator 13 and the hydrogen generator 14 to the buffer tank 16 are respectively provided with a first mass flow controller 17 and a second mass flow controller 18. The first mass flow controller 17 and the second mass flow controller 18 are respectively used to control the gas amounts transported by the carbon dioxide generator 13 and the hydrogen generator 14 to the buffer tank 16.

[0035] Optionally, the carbon dioxide generator 13 is a cylinder containing liquid carbon dioxide, the hydrogen generator 14 is a cylinder containing liquid hydrogen, and the nitrogen generator 15 is a cylinder containing liquid nitrogen. A valve is provided at the output port of each cylinder. By controlling the opening or closing of the valves at the output ports of each cylinder, the timing of delivering carbon dioxide gas, hydrogen, or nitrogen to the buffer tank 16 can be controlled.

[0036] Among them, referring to Figure 3 , the detection mechanism 300 includes an injector 19 and a gas chromatograph 20. The output end of each branch pipe 4 is connected to the input end of the injector 19, and the output end of the injector 19 is connected to the input end of the gas chromatograph 20 through a pipeline. The injector 19 is used to quantitatively collect the gas output from each branch pipe 4 and transport it to the gas chromatograph 20. The gas chromatograph 20 uses chromatographic separation technology and detection technology to qualitatively and quantitatively analyze the gas output from each branch pipe 4, and finally calculates the formic acid concentration.

[0037] Optionally, the injector 19 is a six-way valve injector, which can most effectively collect the gas output from each branch pipe 4.

[0038] Optionally, in this embodiment, setting four reaction mechanisms 200 is the best embodiment. The detection limit of each gas chromatograph 20 is four reaction mechanisms 200. When the number of reaction mechanisms 200 exceeds four, an additional gas chromatograph 20 is added, and all gas chromatographs 20 are connected in parallel.

[0039] For example, the usage method of the multi-station continuous reaction device for hydrogenating carbon dioxide to formic acid:

[0040] S1. Select the reaction mechanism 200 according to the requirements. Each reaction mechanism 200 corresponds to a set of setting schemes, and a certain amount of catalyst and reaction solvent required are loaded into the corresponding reaction kettle 1 according to each scheme.

[0041] S2. Control to open the nitrogen generator 15, each first valve 5, each second valve 6, and each third valve 7, and purge the original gas in each intake pipe 2, each reaction kettle 1, each outlet pipe 3, and each branch pipe 4 with nitrogen.

[0042] S3. Open the hydrogen generator 14 and input hydrogen into each reaction kettle 1. When the air pressure in each reaction kettle 1 reaches the first preset air pressure set by the corresponding scheme, control to close the first valve 5 of the corresponding reaction mechanism 200. When each first valve 5 is closed, control to close the hydrogen generator 14.

[0043] S4. Open the carbon dioxide generator 13 and each first control valve, and input carbon dioxide gas into each reaction kettle 1. When the air pressure in each reaction kettle 1 reaches the second preset air pressure set in the corresponding scheme, control to close the first valve 5 of the corresponding reaction mechanism 200. When all the first valves 5 are closed, control to turn off the carbon dioxide generator 13;

[0044] S5. While performing step S4, control each circulation pump 901 and heat exchanger 902 to do work. When the temperature in each reaction kettle 1 reaches the preset temperature of the corresponding scheme, control to close the circulation pump 901 and heat exchanger 902 of the corresponding reaction mechanism 200;

[0045] S6. The materials in each reaction kettle 1 undergo a chemical reaction to produce formic acid. When the materials in each reaction kettle 1 undergo a chemical reaction to produce formic acid, the air pressure in the reaction kettle 1 decreases. Open each second valve 6, and the gas in each reaction kettle 1 will be transported to the external collection vessel and branch pipe 4 through the air outlet pipe 3;

[0046] S7. While performing step S6, control each heating tape 10 to do work to keep the temperature in the corresponding air outlet pipe 3 and branch pipe 4 at the preset temperature.

[0047] S8. According to the sequence of each set scheme, successively open the third valve 7 of the corresponding reaction mechanism 200. The sampler 19 collects samples and transmits them to the gas chromatograph analyzer. The gas chromatograph analyzer performs qualitative and quantitative analysis on the samples, and finally calculates the formic acid concentration of the corresponding scheme through calculation.

[0048] It should be noted that the hydrogenation of carbon dioxide to formic acid is affected by various factors. It is necessary to explore the optimal process conditions or screen out the best catalyst by changing conditions such as temperature, pressure, or the type of catalyst, so that the catalysts, the first preset air pressure, the second preset air pressure, and the preset temperature of each scheme are all different.

[0049] In this embodiment, there are two or more reaction mechanisms 200. Each reaction mechanism 200 is connected to the same gas transmission mechanism 100 and detection mechanism 300. Each reaction mechanism 200 is provided with a first valve 5 and a second valve 6. The second valve 6 is closed. By controlling the closing timing of the first valve 5, the air pressure in each reaction kettle 1 can be made different; each reaction mechanism 200 is provided with a temperature regulating component 9, which can make the temperature inside each reaction kettle 1 different, and multiple formic acid production processes with the same or different conditions can be carried out simultaneously according to requirements; in addition, each reaction mechanism 200 is provided with a third valve 7. By changing the opening and closing timing of the third valve 7, the same detection mechanism 300 can independently detect the gases output by each reaction mechanism 200, improving the utilization rate of the backend detection equipment.

[0050] It should be noted that the structures and / or methods not described in detail in this application are known to those skilled in the art in combination with common general knowledge and / or the prior art, and are not the key points of disclosure in this application.

[0051] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A multi-station carbon dioxide hydrogenation formic acid continuous reaction device, characterized in that: include: At least two reaction mechanisms, each of which is provided with a reaction kettle, each of which is respectively connected to an output end of an inlet pipe, an input end of an outlet pipe and a temperature control component; the inlet pipe is provided with a first valve, the outlet pipe is provided with a second valve, the middle of the outlet pipe is connected to the input end of a branch pipe, the branch pipe is provided with a third valve, the outlet pipe is provided with a pressure gauge, and the pressure gauge is located on a side of the branch pipe adjacent to the reaction kettle; A gas delivery mechanism, wherein the input end of each gas inlet pipe is connected to the output end of the gas delivery mechanism, and the gas delivery mechanism is used to deliver gas to each reactor; The detection mechanism, the output end of each branch pipe is connected to the input end of the detection mechanism, and the detection mechanism is used to detect and quantitatively analyze the gas output by each reaction mechanism.

2. The multi-station carbon dioxide hydrogenation to formic acid continuous reaction device according to claim 1, characterized in that: The temperature control component is provided with a circulation pump and a heat exchanger, the wall of the reactor is provided with a hollow interlayer, the interlayer is connected to the circulation pump and the heat exchanger respectively through a conduit, the circulation pump is connected to the heat exchanger through a conduit, and a heat exchange medium is provided in the interlayer.

3. The multi-station carbon dioxide hydrogenation to formic acid continuous reaction device according to claim 1, characterized in that: The reaction mechanism is also provided with a heating belt, and the outer walls of the outlet pipe and the branch pipe are both provided with a heating belt.

4. The multi-station carbon dioxide hydrogenation to formic acid continuous reaction device according to claim 1, characterized in that: The reaction mechanism is further provided with a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is arranged inside the reaction kettle, and the second temperature sensor is arranged on the branch pipe.

5. The multi-station carbon dioxide hydrogenation to formic acid continuous reaction device according to claim 1, characterized in that: The gas transmission mechanism is provided with a buffer tank whose output end is respectively connected to the input end of each intake pipe, and the input end of the buffer tank is respectively connected to the output ends of the carbon dioxide generator, the hydrogen generator and the nitrogen generator through pipelines, the pipeline connected to the output end of the carbon dioxide generator is provided with a first mass flow controller, and the pipeline connected to the output end of the hydrogen generator is provided with a second mass flow controller.

6. The multi-station carbon dioxide hydrogenation to formic acid continuous reaction device according to claim 1, characterized in that: The detection mechanism is provided with a sample injector connected to the output end of each branch pipe, and the output end of the sample injector is connected to the input end of a gas chromatograph through a pipeline.

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