CN114853651B - Method for synthesizing liquid sodium N-methyldithiocarbamate by micro-channel reactor - Google Patents
Method for synthesizing liquid sodium N-methyldithiocarbamate by micro-channel reactor Download PDFInfo
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- 239000007788 liquid Substances 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000002194 synthesizing effect Effects 0.000 title claims abstract description 11
- AFCCDDWKHLHPDF-UHFFFAOYSA-M metam-sodium Chemical compound [Na+].CNC([S-])=S AFCCDDWKHLHPDF-UHFFFAOYSA-M 0.000 title claims description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims abstract description 108
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 claims abstract description 72
- 238000006243 chemical reaction Methods 0.000 claims abstract description 61
- QGJOPFRUJISHPQ-NJFSPNSNSA-N carbon disulfide-14c Chemical compound S=[14C]=S QGJOPFRUJISHPQ-NJFSPNSNSA-N 0.000 claims abstract description 15
- 239000002994 raw material Substances 0.000 claims abstract description 11
- QGJOPFRUJISHPQ-UHFFFAOYSA-N Carbon disulfide Chemical compound S=C=S QGJOPFRUJISHPQ-UHFFFAOYSA-N 0.000 claims description 91
- 239000000463 material Substances 0.000 claims description 25
- 238000004519 manufacturing process Methods 0.000 abstract description 13
- 230000035484 reaction time Effects 0.000 abstract description 12
- 238000007086 side reaction Methods 0.000 abstract description 6
- 238000003756 stirring Methods 0.000 abstract description 5
- CJDORTNLPIVZKI-UHFFFAOYSA-N methylcarbamodithioic acid;sodium Chemical compound [Na].CNC(S)=S CJDORTNLPIVZKI-UHFFFAOYSA-N 0.000 abstract description 3
- 239000008346 aqueous phase Substances 0.000 abstract description 2
- 238000005265 energy consumption Methods 0.000 abstract description 2
- 238000005580 one pot reaction Methods 0.000 abstract description 2
- 239000012074 organic phase Substances 0.000 abstract description 2
- 239000012071 phase Substances 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 93
- 239000000243 solution Substances 0.000 description 50
- 230000000052 comparative effect Effects 0.000 description 24
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- 238000004458 analytical method Methods 0.000 description 20
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- 238000003860 storage Methods 0.000 description 14
- 230000015572 biosynthetic process Effects 0.000 description 12
- 238000001035 drying Methods 0.000 description 10
- 239000003513 alkali Substances 0.000 description 7
- 239000002689 soil Substances 0.000 description 7
- DQRQIQZHRCRSDB-UHFFFAOYSA-M potassium;n-methylcarbamodithioate Chemical compound [K+].CNC([S-])=S DQRQIQZHRCRSDB-UHFFFAOYSA-M 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- HYVVJDQGXFXBRZ-UHFFFAOYSA-N metam Chemical compound CNC(S)=S HYVVJDQGXFXBRZ-UHFFFAOYSA-N 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000005086 pumping Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 241000196324 Embryophyta Species 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 4
- 238000003825 pressing Methods 0.000 description 4
- 241000233866 Fungi Species 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
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- 239000006283 soil fumigant Substances 0.000 description 3
- 239000002023 wood Substances 0.000 description 3
- 241000238631 Hexapoda Species 0.000 description 2
- LGDSHSYDSCRFAB-UHFFFAOYSA-N Methyl isothiocyanate Chemical compound CN=C=S LGDSHSYDSCRFAB-UHFFFAOYSA-N 0.000 description 2
- 241000244206 Nematoda Species 0.000 description 2
- 241000779819 Syncarpia glomulifera Species 0.000 description 2
- 241000607479 Yersinia pestis Species 0.000 description 2
- GZUXJHMPEANEGY-UHFFFAOYSA-N bromomethane Chemical compound BrC GZUXJHMPEANEGY-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000003958 fumigation Methods 0.000 description 2
- 239000001739 pinus spp. Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000003784 tall oil Substances 0.000 description 2
- 229940036248 turpentine Drugs 0.000 description 2
- 235000001674 Agaricus brunnescens Nutrition 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 241000218631 Coniferophyta Species 0.000 description 1
- 244000150195 Cyperus longus Species 0.000 description 1
- 235000018109 Cyperus longus Nutrition 0.000 description 1
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- 244000061176 Nicotiana tabacum Species 0.000 description 1
- 235000002637 Nicotiana tabacum Nutrition 0.000 description 1
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- 235000005010 Scirpus paludosus Nutrition 0.000 description 1
- 244000273928 Zingiber officinale Species 0.000 description 1
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- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
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- 230000002401 inhibitory effect Effects 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 229940102396 methyl bromide Drugs 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000009335 monocropping Methods 0.000 description 1
- 239000005645 nematicide Substances 0.000 description 1
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- 108090000623 proteins and genes Proteins 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
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- -1 thiomethyl isothiocyanate Chemical class 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C333/00—Derivatives of thiocarbamic acids, i.e. compounds containing any of the groups, the nitrogen atom not being part of nitro or nitroso groups
- C07C333/14—Dithiocarbamic acids; Derivatives thereof
- C07C333/16—Salts of dithiocarbamic acids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0093—Microreactors, e.g. miniaturised or microfabricated reactors
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The application provides a method for synthesizing liquid N-methyldithiocarbamic acid sodium by a microchannel reactor, which adopts carbon disulfide, monomethylamine and sodium hydroxide as raw materials in a molar ratio of 1: (1.006-1.012): (0.999-1.016). The application uses a pipeline reactor to replace a kettle reactor of the traditional process to produce the Withanmu, and the organic phase (CS) 2 ) The two-phase mass transfer and reaction process of the aqueous phase (monomethylamine solution and sodium hydroxide solution) is completed in a micro-reactor channel, the one-step reaction is directly carried out to synthesize the carb acre, the production process is continuous, and the conventional stirring process is not needed, so that the structure of the reactor is simplified, and the power energy consumption is reduced. The reaction time is shortened from a few hours required by the traditional batch reactor to 20-30s after the micro-channel reactor is adopted, so that the reaction efficiency is improved. The application has less side reaction, and the product purity and yield are higher.
Description
Technical Field
The application relates to a method for synthesizing sodium N-methyldithiocarbamate, in particular to a method for synthesizing liquid sodium N-methyldithiocarbamate by a microchannel reactor, belonging to the field of chemical synthesis.
Background
The N-methyl dithiocarbamic acid sodium is called as 'carb mu' in the fields of pesticides and agriculture, is a low-toxicity, pollution-free and wide-application range thiomethyl isothiocyanate nematicide with sterilization and weeding effects, is applied to soil before crop planting, gradually emits methyl isothiocyanate, has fumigation effect, and can effectively kill nematodes, soil insects, fungi, weed seeds, weeds and other harmful organisms in the soil by inhibiting biological cell division and synthesis of DNA, RNA and protein and blocking biological respiration. The plant-growing agent is suitable for fumigation of greenhouse, plastic arch shed, flower, tobacco, chinese herbal medicine, seedling bed soil of economic crops such as ginger and Chinese yam, soil for continuous cropping planting, tissue culture seedling culture medium, bonsai soil, edible fungus mushroom bed soil and the like, can prevent various plant diseases and insect pests caused by nematodes, fungi, bacteria, underground pests and the like, and can prevent weeds such as mare pond, myrtle, nutgrass galingale and the like. As a substitute for methyl bromide, a soil fumigant that has been internationally registered for use, wilms will occupy the main market of domestic soil fumigants for a period of time in the future; in addition, the fresh conifer wood is piled and stored, the tall oil and the turpentine are rapidly lost, and after the pine wood chips are treated by using the sodium N-methyldithiocarbamic acid, the wood does not generate heat, and the tall oil and the turpentine are lossless, so that the method has high importance in the industry. Therefore, research to improve yield, reduce cost, and improve purity for special use has become an important issue for research and attention both at home and abroad.
The main research results of the existing carb acre are as follows: the synthesis method of Heyile is introduced in the third edition of Sichuan chemical and corrosion control in 2001 by the publication of efficient soil fumigant Weibaimu, but specific technological parameters, raw material conversion rate, finished product yield and other indexes are not provided; in the synthesis process proposed by Chinese patent publication No. CN102267931A (patent name: wibpa production process), a monomethylamine solution with the concentration of 40% is mixed with carbon disulfide and then reacted at the temperature of 10-30 ℃ for 2-3 hours to obtain N-methyldithiocarbamic acid, then a sodium hydroxide solution with the concentration of 30% is added dropwise for neutralization reaction at the temperature of 35-60 ℃ for 2 hours to obtain the solid content of 97.5% and the yield of 98.6%. Chinese patent publication No. CN111848478A (patent name: one-step method for synthesizing carb acre) proposes a one-step method for synthesizing carb acre, which comprises the steps of stirring and mixing water, monomethylamine aqueous solution and sodium hydroxide aqueous solution, dripping carbon disulfide for 2 hours, and continuing to stir for 0.5 hours after the dripping is finished, so as to obtain a liquid finished product with the content of 36.3%, the yield of 98.0% and the appearance of yellow to reddish brown. The main defect of the patent is as follows: 1. the yield is low (98.0%); 2. poor appearance (yellow to reddish brown liquid), indicating that side reactions occurred during synthesis to produce colored materials; 3. the reaction time was long (2 hours for carbon disulfide was added dropwise, and the reaction was continued for 0.5 hour after completion of stirring).
The synthesis process of the product potassium N-methyldithiocarbamate with the same structure and similar function as the sodium N-methyldithiocarbamate comprises the steps of reacting a monomethylamine solution with carbon disulfide to obtain the N-methyldithiocarbamate, then dropwise adding a potassium hydroxide solution, and finally obtaining an aqueous solution of the potassium N-methyldithiocarbamate in a new process for producing potassium N-methyldithiocarbamate in the publication of 2017 in Shandong chemical industry, yin Yongjun and the like; chinese patent publication No. CN102391165B (patent No. N-methyldithiocarbamic acid potassium salt production process) is characterized in that carbon disulfide and monomethylamine are mixed to react to generate N-methyldithiocarbamic acid, and then the N-methyldithiocarbamic acid potassium salt is reacted with potassium hydroxide to obtain N-methyldithiocarbamic acid potassium salt solution, wherein the mass percentage concentration is 60%, and the yield is 98.9%.
Although the existing technology is mature and has been widely applied to large-scale industrialized production, the following problems still exist: (1) The reactors of the existing patent and the traditional synthesis process are all stirred reaction kettles, intermittent production is mostly adopted, the batch production is carried out under normal pressure or near normal pressure, liquid-liquid heterogeneous mass transfer barriers exist in a reaction system, and the reaction time is long; in the reaction process, the traditional reaction kettle has small heat exchange area, low heat exchange capability, difficult control of temperature, pressure, heat transfer, mass transfer and the like, poor stable temperature control effect and high flying temperature risk, so that the quality stability of different batches of products cannot be ensured, and the quality index difference between different batches is larger; (2) long production time and low production efficiency; (3) the side reaction is more, the purity is low, and the yield is lower than 99%; (4) The appearance and quality of the product are still to be improved; and (5) the quality guarantee period of the product is shorter.
To date, no technological study has been made of the Withanmu synthesis in a microchannel-continuous reaction.
Disclosure of Invention
Aiming at the defects existing in the prior art, the application provides a method for synthesizing liquid sodium N-methyldithiocarbamate by a microchannel reactor, which realizes the following aims:
1. realizing the continuous production of the carb acre;
2. the reaction time is shortened;
3. the occurrence of side reaction is reduced, the purity and yield of the product are improved, and the production cost is reduced;
4. the appearance and the internal quality of the product are improved, and the benefit of the product is improved;
5. the shelf life of the product is prolonged.
In order to solve the technical problems, the application adopts the following technical scheme:
a method for synthesizing liquid sodium N-methyldithiocarbamate by a microchannel reactor adopts carbon disulfide, monomethylamine and sodium hydroxide as raw materials, wherein the molar ratio of the carbon disulfide to the monomethylamine to the sodium hydroxide is 1: (1.006-1.012): (0.999-1.016). The reaction temperature in the micro-channel reactor is controlled to be 75-88 ℃; the residence time is 20-30 seconds, and the reaction pressure is not more than 2.0MPa.
The reaction pressure is 1.8-1.95MPa.
Carbon disulfide, monomethylamine solution and sodium hydroxide solution are simultaneously introduced into the inlet of the microchannel reactor, and the temperature of the materials introduced into the microchannel reactor is room temperature.
Introducing the carbon disulfide into a microchannel reactor at a speed of 40.8-41.2 ml/min; introducing the monomethylamine solution into a microchannel reactor at a speed of 56.5-56.8 ml/min; the sodium hydroxide solution was fed into the microchannel reactor at a rate of 61-61.9 ml/min.
The mass concentration of the monomethylamine solution is 30-40%, and the mass concentration of the sodium hydroxide solution is 30-40%.
The mass concentration of the monomethylamine solution is 38-42%, and the mass concentration of the sodium hydroxide solution is 31-33%.
Compared with the prior art, the application has the following beneficial effects:
1. the application uses a pipeline reactor to replace a kettle reactor of the traditional process to produce the Withanmu, and the organic phase (CS) 2 ) The two-phase mass transfer and reaction process of the aqueous phase (monomethylamine solution and sodium hydroxide solution) is completed in a micro-reactor channel, the one-step reaction is directly carried out to synthesize the carb acre, the production process is continuous, and the conventional stirring process is not needed, so that the structure of the reactor is simplified, and the power energy consumption is reduced.
2. The reaction time is shortened from a few hours required by the traditional batch reactor to 20-30s after the micro-channel reactor is adopted, so that the reaction efficiency is improved.
3. The application has less side reaction, higher product purity and yield, the product purity is 99.11-99.26%, and the product yield is 99.71-99.89%.
4. The preparation method provided by the application has the advantages of simple synthesis process, convenience in operation, mild reaction conditions, easiness in control in the production process, low production cost, no three-waste emission and obvious improvement of the production environment.
5. The product prepared by the preparation method provided by the application is a yellowish transparent liquid with the content of 42.2-42.5%, the density of 1.201-1.211g/ml (20 ℃), the pH value (25 ℃) of 10.5-11.1 and the free alkali (calculated by NaOH) of 0.21-0.25%.
6. The liquid product prepared by the application is analyzed after being stored for one year in a dark and ventilated environment at the temperature of not higher than 25 ℃, the appearance is light yellow transparent liquid, and the content is 42-42.2%.
Detailed Description
In order that the application may be more readily understood, a further description of the process of the application will be provided below in connection with the detailed description. It should not be construed that the scope of the above subject matter of the present application is limited to the following examples. The present application uses a microchannel reactor manufactured by corning corporation.
In the present document, unless otherwise specified, wt% is indicated.
Example 1
1. Preparation of materials
Pressing carbon disulfide from a storage tank into a carbon disulfide metering tank (the height of water used as a liquid seal in the metering tank is not less than 15mm, which is required to be ensured), and setting a low liquid level alarm;
pumping monomethylamine solution with the concentration of 40% into a high-level tank, and setting a low liquid level alarm for the metering tank;
sodium hydroxide solution with the concentration of 32% is pumped into a high-level tank, and the metering tank is provided with a low liquid level alarm.
2. Synthesis
Setting the reaction temperature to be 76 ℃, setting the material to stay in the reaction channel for 30 seconds, setting the reaction pressure to be 1.8MPa, and setting a high-pressure alarm and DCS interlocking control system.
Checking flow data of the arranged carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution from a microcomputer, and secondarily checking and confirming process data such as reaction temperature, reaction pressure and the like;
after checking and confirming that DCS sets the volume flow of the reaction raw materials, carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution are simultaneously pumped into inlets of the microchannel reactor from respective metering tanks according to the flow rates of 41ml/min, 56.5ml/min and 61.5ml/min by using a metering pump, the temperature when the mixture is injected into the microchannel reactor is room temperature, and the synthesis reaction is carried out by accurately controlling the reaction temperature by the DCS. And observing the appearance condition of the generated carb acre, and timely sampling and analyzing the obtained finished product, wherein the analysis result is shown in Table 1.
TABLE 1 results of product analysis
The product yield was calculated to be 99.71% based on carbon disulphide at 2 tons of product obtained by the operation.
Storing the liquid product prepared in the example 1 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 99.26%;
the liquid product prepared in example 1 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had an appearance of pale yellow transparent liquid with a content of 42.1%.
Example 2
1. Preparation of materials
Pressing carbon disulfide from a storage tank into a carbon disulfide metering tank (the height of water used as a liquid seal in the metering tank is not less than 15mm, which is required to be ensured), and setting a low liquid level alarm;
pumping monomethylamine solution with the concentration of 40% into a high-level tank, and setting a low liquid level alarm for the metering tank;
sodium hydroxide solution with the concentration of 32% is pumped into a high-level tank, and the metering tank is provided with a low liquid level alarm.
2. Synthesis
Setting the reaction temperature to 82 ℃, setting the material to stay in the reaction channel for 25 seconds, setting the reaction pressure to 1.8MPa, and setting a high-pressure alarm and DCS interlocking control system.
Checking flow data of the arranged carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution from a microcomputer, and secondarily checking and confirming process data such as reaction temperature, reaction pressure and the like;
after checking and confirming that DCS sets the volume flow of the reaction raw materials, carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution are simultaneously pumped into inlets of the microchannel reactors from respective metering tanks according to the flow rates of 41ml/min, 56.6ml/min and 61ml/min by using a metering pump, the temperature when the mixture is injected into the microchannel reactors is room temperature, and the synthesis reaction is carried out by accurately controlling the reaction temperature by the DCS. And observing the appearance condition of the generated carb acre, and timely sampling and analyzing the obtained finished product, wherein the analysis result is shown in Table 2.
TABLE 2 analysis results of products
The product yield was calculated to be 99.83% based on carbon disulphide at 2 tons of product obtained by operation.
Storing the liquid product prepared in the example 2 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 99.11%;
the liquid product prepared in example 2 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had an appearance of pale yellow transparent liquid with a content of 42.2%.
Example 3
1. Preparation of materials
Pressing carbon disulfide from a storage tank into a carbon disulfide metering tank (the height of water used as a liquid seal in the metering tank is not less than 15mm, which is required to be ensured), and setting a low liquid level alarm;
pumping monomethylamine solution with the concentration of 40% into a high-level tank, and setting a low liquid level alarm for the metering tank;
sodium hydroxide solution with the concentration of 32% is pumped into a high-level tank, and the metering tank is provided with a low liquid level alarm.
2. Synthesis
Setting the reaction temperature to be 85 ℃, setting the material to stay in the reaction channel for 25 seconds, setting the reaction pressure to be 1.95MPa, and setting a high-pressure alarm and DCS interlocking control system.
Checking flow data of the arranged carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution from a microcomputer, and secondarily checking and confirming process data such as reaction temperature, reaction pressure and the like;
after checking and confirming that DCS sets the volume flow of the reaction raw materials, carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution are simultaneously pumped into inlets of the microchannel reactor from respective metering tanks according to the flow rates of 41ml/min, 56.8ml/min and 61.9ml/min by using a metering pump, the temperature when the mixture is injected into the microchannel reactor is room temperature, and the synthesis reaction is carried out by accurately controlling the reaction temperature by the DCS. And observing the appearance condition of the generated carb acre, and timely sampling and analyzing the obtained finished product, wherein the analysis result is shown in Table 3.
TABLE 3 results of product analysis
The product yield was calculated to be 99.86% based on carbon disulfide at 2 tons of product obtained by the operation.
Storing the liquid product prepared in the example 3 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 99.17%;
the liquid product prepared in example 3 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a light yellow transparent liquid appearance with a content of 42.0%.
Example 4
1. Preparation of materials
Pressing carbon disulfide from a storage tank into a carbon disulfide metering tank (the height of water used as a liquid seal in the metering tank is not less than 15mm, which is required to be ensured), and setting a low liquid level alarm;
pumping monomethylamine solution with the concentration of 40% into a high-level tank, and setting a low liquid level alarm for the metering tank;
sodium hydroxide solution with the concentration of 32% is pumped into a high-level tank, and the metering tank is provided with a low liquid level alarm.
2. Synthesis
Setting the reaction temperature to 88 ℃, setting the material to stay for 20 seconds in the reaction channel, setting the reaction pressure to 1.9MPa, and setting a high-pressure alarm and DCS interlocking control system.
Checking flow data of the arranged carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution from a microcomputer, and secondarily checking and confirming process data such as reaction temperature, reaction pressure and the like;
after checking and confirming that DCS sets the volume flow of the reaction raw materials, carbon disulfide, 40% monomethylamine solution and 32% sodium hydroxide solution are simultaneously pumped into inlets of the microchannel reactor from respective metering tanks according to the flow rates of 41ml/min, 56.8ml/min and 61.5ml/min by using a metering pump, the temperature when the mixture is injected into the microchannel reactor is room temperature, and the synthesis reaction is carried out by accurately controlling the reaction temperature by the DCS. The appearance of the produced carb acre is observed, the obtained finished product is sampled and analyzed in time, and the analysis result is shown in Table 4.
TABLE 4 results of product analysis
The product yield was calculated to be 99.89% based on carbon disulfide at 2 tons of product obtained by the operation.
Storing the liquid product prepared in the example 4 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 99.13%;
example 4 the liquid product was analysed after one year of storage at a temperature of not more than 25 ℃ in a light-protected, ventilated environment and had an appearance of a pale yellow transparent liquid with a content of 42.2%.
Comparative example 1
The same procedure and material ratios were used as in example 2, except that the reaction temperatures were different. The reaction temperature of this comparative example was 74 ℃. The quality of the prepared product is shown in Table 5.
TABLE 5 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is 95.36 percent by taking carbon disulfide as a reference.
Storing the liquid product prepared in the comparative example 1 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 97.22%;
the liquid product prepared in comparative example 1 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a pale yellow opaque liquid appearance with a content of 38.2%;
as can be seen from the analysis result of the product, the product is unqualified, and the lower reaction temperature causes the unqualified four indexes of the appearance, density, pH value and free alkali of the product.
Comparative example 2
The same procedure and material ratios were used as in example 2, except that the reaction temperatures were different. The reaction temperature of this comparative example was 90 ℃. The quality of the prepared product is shown in Table 6.
TABLE 6 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is 94.92 percent by taking carbon disulfide as a reference.
Storing the liquid product prepared in comparative example 2 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 96.51%;
the liquid product prepared in comparative example 2 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a pale yellow opaque liquid appearance with a content of 38.2%;
as can be seen from the analysis result of the product, the appearance of the product is a brown yellow liquid instead of a light yellow liquid, which indicates that the reaction temperature is higher, and four indexes of the appearance, the density, the pH value and the free alkali of the product are disqualified.
Comparative example 3
The same procedure and material ratios were used as in example 2, except that the reaction times were different. The reaction time of this comparative example was 18 seconds. The quality of the prepared product is shown in Table 7.
TABLE 7 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is calculated by taking carbon disulfide as a reference to be 96.38 percent.
Storing the liquid product prepared in the comparative example 3 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product 96.91%;
the liquid product prepared in comparative example 3 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a pale yellow opaque liquid appearance, the content of which was 39.1%;
as can be seen from the analysis result of the product, when the reaction time is 18 seconds, four indexes of the appearance, the density, the pH value and the free alkali of the product are unqualified, and the product is an unqualified product.
Comparative example 4
The same procedure and material ratios were used as in example 2, except that the reaction times were different. The reaction time of this comparative example was 35 seconds. The quality of the prepared product is shown in Table 8.
TABLE 8 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is 96.01 percent by taking carbon disulfide as a reference.
Storing the liquid product prepared in comparative example 4 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product to be 95.83%;
the liquid product prepared in comparative example 4 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark, ventilated environment, and had a dark yellow turbid liquid appearance with a content of 40.1%.
As can be seen from the analysis result of the product, the product has poor appearance, and although the content, the pH value and the free alkali are qualified, the product is judged to be unqualified according to the quality standard. The reaction time is 35 seconds, the prepared product content, pH value and free alkali are qualified, but the product appearance is poor, and the product is an unqualified product.
Comparative example 5
The same operation as in example 2 was used, with the same operating parameters, except that the material ratios, i.e., the flow rates of the three materials, were changed. The comparative examples carbon disulfide, 40% monomethylamine solution, 32% sodium hydroxide solution were simultaneously fed from the respective metering tanks into the inlet of the microchannel reactor at a flow rate of 41ml/min, 61.1ml/min, 61 ml/min. The quality of the prepared product is shown in Table 9.
TABLE 9 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is calculated by taking carbon disulfide as a reference to be 96.59 percent.
Storing the liquid product prepared in the comparative example 5 at 5 ℃ for 2 hours to obtain crystals (the surface is provided with attached crystal-shaped materials), drying for 20 minutes under negative pressure (vacuum degree is 0.08 MPa), and detecting the purity of the product to be 96.06%;
the liquid product prepared in comparative example 5 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a dark yellow turbid liquid appearance, and the solution had floating crystal particles with a content of 41.15%;
as can be seen from the analysis result of the product, the product has poor appearance, only has qualified content, and the other indexes such as pH value and free alkali are unqualified to judge that the product is unqualified. The method has the advantages that the content of the product prepared after the flow rate of the monomethylamine solution is increased by 40 percent is qualified, the other indexes are all unqualified, the product yield is low, and the product is an unqualified product.
Comparative example 6
The same operation as in example 2 was used, with the same operating parameters, except that the material ratios, i.e., the flow rates of the three materials, were changed. The comparative examples carbon disulfide, 40% monomethylamine solution, 32% sodium hydroxide solution were simultaneously fed from the respective metering tanks into the inlet of the microchannel reactor at a flow rate of 41ml/min, 56.6ml/min, 64.1 ml/min. The quality of the prepared product is shown in Table 10.
TABLE 10 results of product analysis
When 200Kg of product is obtained by operation, the yield of the product is 98.47 percent by taking carbon disulfide as a reference.
Storing the liquid product prepared in the comparative example 6 at 5 ℃ for 2 hours to obtain crystals, drying the crystals for 20 minutes under negative pressure (vacuum degree 0.08 MPa), and detecting the purity of the product 97.52%;
the liquid product prepared in comparative example 6 was analyzed after one year of storage at a temperature of not higher than 25 ℃ in a dark and ventilated environment, and had a brown transparent liquid appearance with a flaky suspended matter content of 41.2%;
as can be seen from the analysis result of the product, the product has poor appearance, only the content is qualified, and other indexes are unqualified. The product prepared by improving the flow rate of the sodium hydroxide solution by 32 percent is unqualified except the content, and the unqualified product is judged.
Principle of reaction
The total equation of the wilfordii synthesis reaction is:
CH 3 NH + CS 2 + NaOH → CH 3 NCS 2 Na + H 2 O
the detailed reaction process is recognized in the current academia: the reaction is divided into two steps, wherein the first step is that monomethylamine and carbon disulfide firstly generate N-methyldithiocarbamic acid, and the second step is that N-methyldithiocarbamic acid reacts with sodium hydroxide to generate the carb acre.
(II) production operation procedure
And respectively pumping the three raw materials of the monomethylamine solution, the carbon disulfide and the sodium hydroxide solution into the inlet of the microchannel reactor by using a metering pump, controlling the material proportion (flow), the reaction temperature and the reaction pressure, and obtaining the Withanmu product at the outlet.
In the process, the starting control valves of the three raw materials of monomethylamine solution, carbon disulfide and sodium hydroxide solution are connected with a DCS system, and after the starting control valves are started, the flow rates of the three raw materials of monomethylamine solution, carbon disulfide and sodium hydroxide solution, the flow rate of materials, the flow rate of the materials in a channel and the length of the channel are accurately and effectively controlled by a metering pump, so that the materials can be accurately proportioned, the residence time and the reaction time of the materials under the reaction condition can be accurately controlled, the productivity is improved, and the stability of the reaction is ensured; the control points are reasonably arranged in the microchannel reactor, the control instrument is connected with the DCS system to form a linkage loop, the reaction pressure and the reaction temperature can be effectively controlled, the manual control is reduced to realize automatic control, the generation of other side reactions is reduced, the reaction can be stably carried out, the artificial factors and errors are reduced, the formation of explosive mixtures of carbon disulfide and air is avoided, the potential safety hazard is eliminated, and the safety is improved.
Claims (2)
1. A method for synthesizing liquid sodium N-methyldithiocarbamate by a microchannel reactor, which is characterized in that: the adopted raw materials are carbon disulfide, monomethylamine and sodium hydroxide, and the molar ratio of the three is 1: (1.006-1.012): (0.999-1.016); the reaction temperature in the micro-channel reactor is controlled to be 75-88 ℃; the residence time is 20-30 seconds;
the reaction pressure is 1.8-1.95MPa; simultaneously introducing carbon disulfide, monomethylamine solution and sodium hydroxide solution into an inlet of a microchannel reactor;
introducing the carbon disulfide into a microchannel reactor at a speed of 40.8-41.2 ml/min; introducing the monomethylamine solution into a microchannel reactor at a speed of 56.5-56.8 ml/min; the sodium hydroxide solution is introduced into the microchannel reactor at a speed of 61-61.9 ml/min;
the mass concentration of the monomethylamine solution is 38-42%, and the mass concentration of the sodium hydroxide solution is 31-33%.
2. A method for synthesizing liquid sodium N-methyldithiocarbamate by a microchannel reactor as defined in claim 1, wherein: the temperature of the material as it passes into the microchannel reactor was room temperature.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0316787A2 (en) * | 1987-11-19 | 1989-05-24 | BASF Aktiengesellschaft | Process for the preparation of mono- or bis-dithiocarbamic acids and their salts and derivatives |
| CN102267931A (en) * | 2011-07-18 | 2011-12-07 | 利民化工股份有限公司 | Metham production process |
| CN106995396A (en) * | 2017-03-30 | 2017-08-01 | 山东斯递尔化工科技有限公司 | A kind of method that utilization micro-reaction device continuously prepares SDD |
| CN111848478A (en) * | 2020-07-30 | 2020-10-30 | 济南锐铂化工有限公司 | Method for synthesizing metham in one step |
| CN112028803A (en) * | 2020-08-21 | 2020-12-04 | 青岛中科荣达新材料有限公司 | Method for synthesizing liquid sodium dimethyl dithiocarbamate by using microchannel reactor |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0316787A2 (en) * | 1987-11-19 | 1989-05-24 | BASF Aktiengesellschaft | Process for the preparation of mono- or bis-dithiocarbamic acids and their salts and derivatives |
| CN102267931A (en) * | 2011-07-18 | 2011-12-07 | 利民化工股份有限公司 | Metham production process |
| CN106995396A (en) * | 2017-03-30 | 2017-08-01 | 山东斯递尔化工科技有限公司 | A kind of method that utilization micro-reaction device continuously prepares SDD |
| CN111848478A (en) * | 2020-07-30 | 2020-10-30 | 济南锐铂化工有限公司 | Method for synthesizing metham in one step |
| CN112028803A (en) * | 2020-08-21 | 2020-12-04 | 青岛中科荣达新材料有限公司 | Method for synthesizing liquid sodium dimethyl dithiocarbamate by using microchannel reactor |
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