Preparation method and device of carbonyl iron

Abstract

The invention belongs to the technical field of preparation of metal organic compounds, and particularly relates to a preparation method and device of carbonyl iron. The preparation method comprises the following steps: S1, introducing iron powder and carbon monoxide into a reaction device, and carrying out catalytic reaction under the action of a catalyst to generate crude carbonyl iron; s2, cooling the crude carbonyl iron to obtain liquid carbonyl iron; s3, carrying out reduced pressure distillation on the cooled liquid carbonyl iron; and S4, purifying the liquid carbonyl iron after reduced pressure distillation to obtain the final product carbonyl iron. The preparation device comprises a storage tank, a purifier, a reaction kettle, a condenser, a reduced pressure distillation tower and a recrystallization device which are sequentially arranged along the material flow direction. The method provided by the invention can obviously improve the reaction rate of carbonyl iron, improve the product purity and reduce the safety risk.

Description

Technical Field

[0001] The present application belongs to the technical field of preparation of metal organic compounds, and specifically relates to a method and device for preparing carbonyl iron. Background Art

[0002] Carbonyl iron is an important organometallic compound whose unique chemical structure and properties give it broad application prospects in many fields. However, traditional methods for preparing carbonyl iron have some limitations, which restrict its large-scale production and application.

[0003] Early carbonyl iron preparation methods were mainly based on high-pressure reaction conditions and needed to be carried out at relatively high pressures and temperatures, which placed extremely high demands on reaction equipment, increasing production costs and safety risks. For example, Chinese patent publication number CN101696038B discloses a method for preparing carbonyl iron powder under high-pressure circulation, wherein an iron raw material and carbon monoxide are used to carry out a synthesis reaction in a synthesis reactor under 11.0-30.0 MPa conditions to generate pentacarbonyl iron and a synthesis residue. Another example is Chinese patent publication number CN105967242B, which discloses a method for preparing nanocarbonyl iron powder, wherein an iron raw material is placed in a high-pressure reactor, CO gas is introduced into the high-pressure reactor, and the reaction pressure is controlled to be 12-18 MPa. Other methods require that iron react with carbon monoxide under pressures of several hundred atmospheres or even higher. This high-pressure environment not only requires the reactor to have extremely high pressure resistance, but also presents a potential explosion hazard during operation.

[0004] With the continuous development of science and technology, higher requirements are being placed on the quality and yield of carbonyl iron. Traditional methods not only have harsh reaction conditions, but also relatively low reaction efficiency and long reaction times, resulting in extended production cycles and production efficiency that cannot meet the growing market demand. At the same time, there are certain difficulties in controlling the purity of the product. Complex separation and purification steps are often required to obtain high-purity carbonyl iron products, which further increases production costs and process complexity. With the continuous development of science and technology, higher requirements are being placed on the quality and yield of carbonyl iron.

[0005] Therefore, it is urgent to develop a preparation method and device that is efficient, safe, low-cost and capable of producing high-purity carbonyl iron to solve the problems existing in the production of high-purity carbonyl iron in the prior art. Summary of the Invention

[0006] In view of the problems of low efficiency and high cost in the preparation of carbonyl iron in the prior art, this application proposes a method and device for preparing carbonyl iron. The solution of this application is as follows:

[0007] In one aspect, the present application provides a method for preparing carbonyl iron, comprising the following steps:

[0008] Step S1. introducing iron powder and carbon monoxide into a reaction device, and catalytically reacting in the presence of a catalyst to produce crude carbonyl iron;

[0009] The reaction formula is: Fe+5CO→Fe(CO)5.

[0010] Step S2. cooling the crude carbonyl iron to obtain liquid carbonyl iron;

[0011] Step S3. distilling the cooled liquid carbonyl iron under reduced pressure;

[0012] Step S4: purifying the liquid carbonyl iron after the reduced pressure distillation to obtain the final product carbonyl iron.

[0013] Preferably, the purity of the iron powder is greater than 99%, and the particle size of the iron powder is 1-100 μm; the purity of the carbon monoxide is ≥99.5%, and the flow rate is 0.3-3 L / min.

[0014] Further preferably, the purity of the iron powder is 99.2% to 99.8%, and the particle size of the iron powder is 20 to 80 μm. Iron powder with moderate particle size has a larger specific surface area, which is conducive to full contact with carbon monoxide gas and increases the reaction rate; the purity of the carbon monoxide is 99.6% to 99.8%.

[0015] Preferably, the temperature of the catalytic reaction is 100-300° C., and the pressure is 1-10 MPa.

[0016] Further preferably, the temperature of the catalytic reaction is 150-250°C. Within this temperature range, the reaction can be guaranteed to have a sufficient rate while avoiding increased side reactions and energy waste caused by excessively high temperatures; the pressure is 3-7 MPa. Within this pressure range, it is beneficial to maintain the concentration of carbon monoxide gas in the reaction system and promote the formation of carbonyl iron.

[0017] Preferably, the catalyst is a metal halide, and the added amount of the catalyst is 0.1% to 5% of the mass of the iron powder.

[0018] More preferably, the added amount of the catalyst is 1% to 3% of the mass of the iron powder.

[0019] Preferably, the metal halide is ferric chloride or ferric bromide, or a mixture of the two.

[0020] Preferably, the cooling temperature is -20 to 20°C.

[0021] More preferably, the cooling temperature is 0-10°C.

[0022] Preferably, the pressure of the reduced pressure distillation is 0.1-1 MPa.

[0023] More preferably, the pressure of the reduced pressure distillation is 0.3-0.7 MPa.

[0024] Preferably, the purification is carried out by recrystallization, and the specific operation is: dissolving the liquid carbonyl iron obtained by vacuum distillation in toluene or benzene, and then cooling to -10°C at a rate of 0.5-1°C / min, so that the carbonyl iron crystals are precipitated.

[0025] On the other hand, the present application proposes a device for preparing carbonyl iron, comprising a storage tank for storing carbon monoxide, a purifier for purifying carbon monoxide, a reactor for catalytic reaction, a condenser for condensing carbonyl iron, a vacuum distillation tower for distilling liquid carbonyl iron, and a recrystallization device for purifying carbonyl iron, which are arranged in sequence along the material flow direction; valves are provided on the pipelines connecting the storage tank, purifier, reactor, condenser, vacuum distillation tower and recrystallization device; a flow meter is provided on the pipeline connecting the storage tank and the purifier, and a pipeline connecting the storage tank and the purifier is located above the vacuum distillation tower.

[0026] Preferably, the reactor is made of stainless steel, and is provided with a magnetic stirring device and a jacketed heating and cooling device inside the reactor; the monoxide tower storage tank is a high-pressure steel cylinder, and the purifier is filled with one or two of activated carbon and molecular sieve adsorbents; the condenser is a shell and tube condensation structure, and the cooling medium is water or liquid nitrogen; the vacuum distillation tower is a packed tower structure, and is filled with stainless steel wire mesh or ceramic Raschig ring filler; the recrystallization device includes a dissolving tank and a crystallizer.

[0027] Further preferably, the adsorbent is a mixture of activated carbon and molecular sieves, the cooling medium of the condenser is water, and the interior of the vacuum distillation tower is filled with stainless steel wire mesh.

[0028] Beneficial effects:

[0029] (1) Improved Reaction Efficiency: By optimizing reaction conditions, including appropriate temperature, pressure, and catalyst, the preparation method of this application can significantly increase the reaction rate of carbonyl iron. Compared with traditional methods, the reaction time can be shortened by 30% to 50%, thereby improving production efficiency and reducing production costs.

[0030] (2) Improving product purity: The product processing process of this application includes multiple steps such as cooling, vacuum distillation, and recrystallization, which can effectively remove impurities in the product and obtain a high-purity carbonyl iron product. The product purity can reach over 99%, meeting the purity requirements of carbonyl iron in high-end application fields;

[0031] (3) Reduced safety risks: Although the reaction of the present application is still carried out under a certain pressure, compared with the traditional high-pressure preparation method, the reaction pressure is controlled between 1 and 10 MPa, which significantly reduces the pressure resistance requirements for the reaction equipment, reduces safety risks, and improves the safety of the production process.

[0032] (4) Resource recycling: During the product processing process, unreacted carbon monoxide gas can be recovered and reused through vacuum distillation, which reduces the consumption of raw materials, improves resource utilization, and further reduces production costs; BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram of the carbonyl iron preparation device of this application.

[0034] Figure numerals: 1. storage tank; 2. flow meter; 3. purifier; 4. reactor; 5. condenser; 6. vacuum distillation tower; 7. recrystallization device. DETAILED DESCRIPTION

[0035] In order to further illustrate the technical means and effects adopted by this application to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of this application are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0036] Device embodiment

[0037] This embodiment provides a device for preparing carbonyl iron, which is as follows:

[0038] It includes a storage tank 1 for storing carbon monoxide, a purifier 3 for purifying carbon monoxide, a reactor 4 for catalytic reaction, a condenser 5 for condensing carbonyl iron, a vacuum distillation tower 6 for distilling liquid carbonyl iron, and a recrystallization device 7 for purifying carbonyl iron, which are arranged in sequence along the material flow direction; valves are provided on the pipelines connecting the storage tank 1, the purifier 3, the reactor 4, the condenser 5, the vacuum distillation tower 6 and the recrystallization device 7, a flow meter 2 is provided on the pipeline connecting the storage tank 1 and the purifier 3, and a pipeline connecting the storage tank 1 and the purifier 3 is located above the vacuum distillation tower 6.

[0039] The reactor 4 is made of stainless steel. A magnetic stirring device and a jacketed heating and cooling device are provided inside the reactor 4. The stirring speed of the magnetic stirring device can be adjusted between 100 and 1000 r / min, preferably between 300 and 800 r / min; the heating power of the heating and cooling device can be adjusted between 1 and 10 kW, and the cooling power can be adjusted between 0.5 and 5 kW, for controlling the temperature in the reactor 4 between 100 and 300°C, preferably between 3 and 8 kW, and between 1 and 4 kW.

[0040] The storage tank 1 is a high-pressure steel cylinder, and the purifier 3 is filled with one or two of activated carbon and molecular sieve adsorbents, preferably a mixture of activated carbon and molecular sieve, for purifying the purity of carbon monoxide to not less than 99.5%;

[0041] The condenser 5 is a shell-and-tube condensation structure. The shell-and-tube structure can improve the condensation efficiency by increasing the heat dissipation area and adjusting the flow rate. The cooling medium is water or liquid nitrogen, preferably water, which can quickly cool the reaction product carbonyl iron to between -20 and 20°C.

[0042] The vacuum distillation tower 6 is a packed tower structure, and is filled with stainless steel wire mesh or ceramic Raschig ring packing. The preferred packing is stainless steel wire mesh, which can separate unreacted carbon monoxide gas from liquid carbonyl iron at a pressure between 0.1 and 1 MPa.

[0043] The recrystallization device 7 includes a dissolving tank and a crystallizer, which is used to dissolve liquid carbonyl iron in a suitable solvent and crystallize the carbonyl iron by slowly cooling or evaporating the solvent.

[0044] The device's operating principle is as follows: Iron powder is placed in a reactor 4. Carbon monoxide is processed and enters the reactor 4 from a storage tank 1 through a flowmeter 2 and a purifier 3. Impurities in the carbon monoxide, such as carbon dioxide and hydrogen, are removed in the purifier 3. These impurities may react with the iron powder and affect the formation and purity of carbonyl iron. A magnetic stirring device and a jacketed heating device are then activated to catalyze the formation of carbonyl iron. The carbonyl iron generated by the reaction enters a condenser 5 for rapid liquefaction. The liquid carbonyl iron enters a vacuum distillation tower 6 for distillation to separate the unreacted CO gas and recycle it. The distilled liquid carbonyl iron is transferred to a dissolution tank and dissolved in benzene or toluene. The solution is then transferred to a crystallizer and slowly cooled to -10°C at a rate of 0.5-1°C / min to obtain Fe(CO)5 crystals.

[0045] Example 1

[0046] This embodiment provides a method for preparing carbonyl iron, based on the device provided in the device embodiment, including the following steps:

[0047] Step S1. Iron powder and carbon monoxide are introduced into a reaction device, and a catalytic reaction is carried out under the action of a catalyst to produce crude carbonyl iron; the purity of the iron powder is 99.5%, and the particle size of the iron powder is 50-80 μm; the purity of the carbon monoxide is 99.7%, and the flow rate is 2.5 L / min; the temperature of the catalytic reaction is 200°C and the pressure is 6 MPa; the catalyst is ferric chloride, and the amount of the catalyst added is 2.5% of the mass of the iron powder.

[0048] Step S2. Cool the crude carbonyl iron to obtain liquid carbonyl iron at a cooling temperature of 5°C.

[0049] Step S3. The cooled liquid carbonyl iron is subjected to vacuum distillation at a pressure of 0.6 MPa;

[0050] Step S4. Purify the liquid carbonyl iron after vacuum distillation to obtain the final product carbonyl iron. The purification is carried out by recrystallization. The specific operation is: dissolve the liquid carbonyl iron after vacuum distillation in toluene or benzene, and then cool it to -10°C at a rate of 0.7°C / min to allow the carbonyl iron to crystallize.

[0051] After testing, the purity of the carbonyl iron product was 99.7%.

[0052] Example 2

[0053] This embodiment provides a method for preparing carbonyl iron, based on the device provided in the device embodiment, including the following steps:

[0054] Step S1. Introduce iron powder and carbon monoxide into a reaction device, and under the action of a catalyst, catalyze a reaction to produce crude carbonyl iron; the purity of the iron powder is 99.8%, and the particle size of the iron powder is 1 to 20 μm; the purity of the carbon monoxide is 99.5%, and the flow rate is 0.3 L / min; the temperature of the catalytic reaction is 300°C and the pressure is 1 MPa; the catalyst is ferric chloride, and the amount of the catalyst added is 0.1% of the mass of the iron powder.

[0055] Step S2. Cool the crude carbonyl iron to obtain liquid carbonyl iron at a cooling temperature of -20°C.

[0056] Step S3. The cooled liquid carbonyl iron is subjected to vacuum distillation at a pressure of 1 MPa;

[0057] Step S4. Purify the liquid carbonyl iron after vacuum distillation to obtain the final product carbonyl iron. The purification is carried out by recrystallization. The specific operation is: dissolve the liquid carbonyl iron after vacuum distillation in toluene or benzene, and then cool it to -10°C at a rate of 1°C / min to allow the carbonyl iron to crystallize.

[0058] After testing, the purity of the carbonyl iron product was 99.0%.

[0059] Example 3

[0060] This embodiment provides a method for preparing carbonyl iron, based on the device provided in the device embodiment, including the following steps:

[0061] Step S1. Iron powder and carbon monoxide are introduced into a reaction device, and a catalytic reaction is carried out under the action of a catalyst to produce crude carbonyl iron; the purity of the iron powder is 99.2%, and the particle size of the iron powder is 80-100 μm; the purity of the carbon monoxide is 99.8%, and the flow rate is 3 L / min; the temperature of the catalytic reaction is 100°C and the pressure is 10 MPa; the catalyst is ferric bromide, and the amount of the catalyst added is 5% of the mass of the iron powder.

[0062] Step S2. The crude carbonyl iron is cooled to obtain liquid carbonyl iron, and the cooling temperature is 20°C

[0063] Step S3. The obtained liquid carbonyl iron is subjected to vacuum distillation, and the pressure of the vacuum distillation is 0.1 MPa.

[0064] Step S4. The liquid carbonyl iron after the vacuum distillation is purified to obtain the final product carbonyl iron, and the purification is performed by recrystallization. Specifically, the liquid carbonyl iron after the vacuum distillation is dissolved in toluene or benzene, and then cooled to -10°C at a rate of 0.5°C / min, and the carbonyl iron is crystallized and precipitated.

[0065] After detection, the purity of the carbonyl iron product is 99.2%.

[0066] Example 4

[0067] The embodiment provides a preparation method of carbonyl iron, and the preparation method comprises the following steps based on the device provided in the device embodiment:

[0068] Step S1. Iron powder and carbon monoxide are introduced into a reaction device, and the iron powder and the carbon monoxide are catalytically reacted to generate crude carbonyl iron under the action of a catalyst. The purity of the iron powder is 99.7%, and the particle size of the iron powder is 1-100 μm. The purity of the carbon monoxide is 99.8%, and the flow rate is 2.5 L / min. The catalytic reaction temperature is 200°C, and the pressure is 4 MPa. The catalyst is a mixture of iron chloride and iron bromide at a mass ratio of 1:2, and the addition amount of the catalyst is 3% of the mass of the iron powder.

[0069] Step S2. The crude carbonyl iron is cooled to obtain liquid carbonyl iron, and the cooling temperature is 15°C

[0070] Step S3. The obtained liquid carbonyl iron is subjected to vacuum distillation, and the pressure of the vacuum distillation is 0.4 MPa.

[0071] Step S4. The liquid carbonyl iron after the vacuum distillation is purified to obtain the final product carbonyl iron, and the purification is performed by recrystallization. Specifically, the liquid carbonyl iron after the vacuum distillation is dissolved in toluene or benzene, and then cooled to -10°C at a rate of 0.8°C / min, and the carbonyl iron is crystallized and precipitated.

[0072] After detection, the purity of the carbonyl iron product is 99.6%.

[0073] Comparative Example 1

[0074] The difference between the comparative example and the example 1 is that the catalytic reaction pressure of the comparative example is 15 MPa, and the purity of the obtained carbonyl iron is 95.7%. Due to the excessively high reaction pressure, the reactants are relatively active, and side reactions occur, so that the impurities in the product increase, and the subsequent rectification process is difficult to remove.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 1 is that the catalytic reaction temperature in this comparative example is 400° C. The purity of the obtained carbonyl iron is 94.9%. Due to the increase in temperature, more side reactions occur.

[0077] The above description is merely a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for preparing carbonyl iron, characterized in that: The steps include: Step S1. introducing iron powder and carbon monoxide into a reaction device, and catalytically reacting in the presence of a catalyst to produce crude carbonyl iron; Step S2. cooling the crude carbonyl iron to obtain liquid carbonyl iron; Step S3. distilling the cooled liquid carbonyl iron under reduced pressure; Step S4: purifying the liquid carbonyl iron after the reduced pressure distillation to obtain the final product carbonyl iron.

2. The method for preparing carbonyl iron according to claim 1, wherein: The purity of the iron powder is greater than 99%, and the particle size of the iron powder is 1-100 μm; the purity of the carbon monoxide is ≥99.5%, and the flow rate is 0.3-3 L / min.

3. The method for preparing carbonyl iron according to claim 1, wherein: The temperature of the catalytic reaction is 100-300° C., and the pressure is 1-10 MPa.

4. The method for preparing carbonyl iron according to claim 1, wherein: The catalyst is a metal halide, and the added amount of the catalyst is 0.1% to 5% of the mass of the iron powder.

5. The method for preparing carbonyl iron according to claim 4, wherein: The metal halide is ferric chloride or ferric bromide, or a mixture of the two.

6. The method for preparing carbonyl iron according to claim 1, wherein: The cooling temperature is -20 to 20°C.

7. The method for preparing carbonyl iron according to claim 1, wherein: The pressure of the reduced pressure distillation is 0.1-1 MPa.

8. The method for preparing carbonyl iron according to claim 1, wherein: The purification adopts recrystallization, and the specific operation is: dissolving the liquid carbonyl iron obtained by vacuum distillation in toluene or benzene, and then cooling it to -10°C at a rate of 0.5-1°C / min, so that the carbonyl iron crystals are precipitated.

9. The device used in the method for preparing carbonyl iron according to any one of claims 1 to 8, characterized in that: The invention comprises a storage tank (1) for storing carbon monoxide, a purifier (3) for purifying carbon monoxide, a reactor (4) for catalytic reaction, a condenser (5) for condensing carbonyl iron, a vacuum distillation tower (6) for distilling liquid carbonyl iron, and a recrystallization device (7) for purifying carbonyl iron, which are arranged in sequence along the material flow direction; valves are provided on the pipelines connecting the storage tank (1), the purifier (3), the reactor (4), the condenser (5), the vacuum distillation tower (6), and the recrystallization device (7); a flow meter (2) is provided on the pipeline connecting the storage tank (1) and the purifier (3); and a pipeline connecting the storage tank (1) and the purifier (3) is located above the vacuum distillation tower (6).

10. The device used in the method for preparing carbonyl iron according to claim 9, characterized in that: The reactor (4) is made of stainless steel, and is provided with a magnetic stirring device and a jacketed heating and cooling device inside the reactor (4); the storage tank (1) is a high-pressure steel cylinder, and the purifier (3) is filled with one or two of activated carbon and molecular sieve adsorbents; the condenser (5) is a shell-and-tube condensation structure, and the cooling medium is water or liquid nitrogen; the vacuum distillation tower (6) is a packed tower structure, and is filled with stainless steel wire mesh or ceramic Raschig ring packing; the recrystallization device (7) includes a dissolving tank and a crystallizer.

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