CN112961055A - Continuous preparation method of chloroformate - Google Patents
Continuous preparation method of chloroformate Download PDFInfo
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- CN112961055A CN112961055A CN202110133547.9A CN202110133547A CN112961055A CN 112961055 A CN112961055 A CN 112961055A CN 202110133547 A CN202110133547 A CN 202110133547A CN 112961055 A CN112961055 A CN 112961055A
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- chloroformate
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- FZFAMSAMCHXGEF-UHFFFAOYSA-N chloro formate Chemical compound ClOC=O FZFAMSAMCHXGEF-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 238000002360 preparation method Methods 0.000 title claims abstract description 13
- 238000003786 synthesis reaction Methods 0.000 claims abstract description 70
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 claims abstract description 69
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 68
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 45
- 238000006243 chemical reaction Methods 0.000 claims abstract description 40
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000002994 raw material Substances 0.000 claims abstract description 37
- 238000010521 absorption reaction Methods 0.000 claims abstract description 35
- 239000007789 gas Substances 0.000 claims abstract description 34
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims abstract description 33
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims abstract description 33
- 238000007872 degassing Methods 0.000 claims abstract description 30
- 239000006227 byproduct Substances 0.000 claims abstract description 16
- 239000000047 product Substances 0.000 claims abstract description 11
- 239000012043 crude product Substances 0.000 claims abstract description 7
- 239000000376 reactant Substances 0.000 claims abstract description 6
- 238000005406 washing Methods 0.000 claims abstract description 6
- 238000007670 refining Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 34
- 238000011437 continuous method Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 239000007795 chemical reaction product Substances 0.000 claims description 3
- -1 chloroformate diester Chemical class 0.000 claims description 3
- 150000001491 aromatic compounds Chemical group 0.000 claims description 2
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 claims description 2
- 125000001931 aliphatic group Chemical group 0.000 claims 2
- AOGYCOYQMAVAFD-UHFFFAOYSA-N chlorocarbonic acid Chemical class OC(Cl)=O AOGYCOYQMAVAFD-UHFFFAOYSA-N 0.000 claims 1
- 239000007788 liquid Substances 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 9
- 238000010924 continuous production Methods 0.000 abstract description 3
- 230000036632 reaction speed Effects 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 27
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 description 21
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 19
- 150000002148 esters Chemical class 0.000 description 9
- XMJHPCRAQCTCFT-UHFFFAOYSA-N methyl chloroformate Chemical compound COC(Cl)=O XMJHPCRAQCTCFT-UHFFFAOYSA-N 0.000 description 9
- 229910052757 nitrogen Inorganic materials 0.000 description 9
- 235000019445 benzyl alcohol Nutrition 0.000 description 7
- HSDAJNMJOMSNEV-UHFFFAOYSA-N benzyl chloroformate Chemical compound ClC(=O)OCC1=CC=CC=C1 HSDAJNMJOMSNEV-UHFFFAOYSA-N 0.000 description 7
- RIFGWPKJUGCATF-UHFFFAOYSA-N ethyl chloroformate Chemical compound CCOC(Cl)=O RIFGWPKJUGCATF-UHFFFAOYSA-N 0.000 description 7
- 238000010586 diagram Methods 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000002912 waste gas Substances 0.000 description 3
- SESFRYSPDFLNCH-UHFFFAOYSA-N benzyl benzoate Chemical compound C=1C=CC=CC=1C(=O)OCC1=CC=CC=C1 SESFRYSPDFLNCH-UHFFFAOYSA-N 0.000 description 2
- 238000001944 continuous distillation Methods 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 150000007824 aliphatic compounds Chemical group 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229960002903 benzyl benzoate Drugs 0.000 description 1
- NRDQFWXVTPZZAZ-UHFFFAOYSA-N butyl carbonochloridate Chemical compound CCCCOC(Cl)=O NRDQFWXVTPZZAZ-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
- C07C68/02—Preparation of esters of carbonic or haloformic acids from phosgene or haloformates
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the technical field of chloroformate synthesis, and particularly relates to a continuous chloroformate preparation method, which comprises the following steps: 1) feeding reactant raw material alcohol and phosgene into a synthesis tower together through an absorption tower for reaction to generate a crude product chloroformate and a byproduct hydrogen chloride; 2) sending the crude chloroformate formed in the step 1) into a degassing tower, returning phosgene removed from the degassing tower into a synthesis tower for continuous reaction, and rectifying the chloroformate subjected to phosgene removal in a refining system to obtain a target chloroformate; 3) sending the byproduct hydrogen chloride formed in the step 1) into an absorption tower, washing with raw material alcohol, and then entering a tail gas system. The invention has the beneficial effects that: the continuous production of synthesis and deacidification of chloroformate products is realized, the synthesis reaction speed is improved, and the deacidification time is shortened; meanwhile, the phosgene is recycled, so that the consumption of raw materials is reduced, and clean, intrinsically safe and automatic production is formed.
Description
Technical Field
The invention belongs to the technical field of chloroformate synthesis, and particularly relates to a continuous chloroformate preparation method.
Background
The most widespread chloroformate technology at present comprises: the intermittent method and the semi-continuous method have long synthesis and deacidification time of chloroformate products, do not realize the production of continuous synthesis and continuous deacidification, have low automation degree and high consumption cost of raw materials.
The intermittent method is mainly characterized in that quantitative alcohol and phosgene are added into a synthesis kettle for reaction, and after the reaction is finished, the materials are sent to a deacidification kettle for deacidification by introducing nitrogen until the product reaches the index; the single-kettle reaction time is 24 hours, the deacidification time is about 24 hours, the single-kettle production efficiency is low, and the reaction selectivity is low.
The semi-continuous method is characterized in that phosgene and alcohol are continuously introduced from the bottom of a synthesis tower by utilizing a reaction tower, a semi-finished product is continuously overflowed from the top of the tower, the generated ester enters a deacidification kettle through a pipeline, nitrogen is introduced for deacidification when the ester in each deacidification kettle reaches a certain amount, the single-kettle deacidification time reaches about 24 hours, and the production efficiency is low.
In the existing batch method and semi-continuous method processes, phosgene-containing tail gas generated in the reaction process and tail gas generated in the degassing process directly enter a tail gas treatment system, and catalytic phosgene removal is needed firstly, and then hydrochloric acid absorption and alkali washing are needed. Excessive phosgene in the ingredients exists in tail gas and needs to be removed by adopting a catalytic reaction method, so that the production cost is increased, and the safety risk is high.
The prior chloroformate products are produced by processes including batch and semi-continuous processes, which have disadvantages including:
1. the single kettle reaction time is about 24 hours, the reaction speed is slow, and the reaction selectivity is low.
2. The deacidification time is about 24 hours, and the single kettle production efficiency is low.
3. In order to improve the productivity, a large number of deacidification kettles need to be arranged, and the fixed asset investment is high.
4. And a large amount of nitrogen is needed during deacidification, so that the energy consumption is high, and the waste gas treatment cost is high.
5. Most operations need manual field switching operation, the automation degree is low, the labor intensity is high, and the occupational health is not facilitated.
6. The phosgene raw material needs to be excessive in quantity, the phosgene consumption is high, and the waste gas treatment cost is high.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a continuous preparation method of chloroformate, thereby realizing the synthesis and deacidification continuous production of chloroformate products, improving the synthesis reaction speed and shortening the deacidification time; meanwhile, the consumption of raw materials is reduced by recycling phosgene; the equipment investment is reduced, the automation control level is improved, the labor intensity is reduced, and clean and intrinsically safe automatic production is formed.
In order to achieve the purpose, the invention adopts the technical scheme that:
a continuous preparation method of chloroformate, which comprises the following steps:
1) the method comprises the following steps of (1) enabling reactant raw material alcohol to enter a synthesis tower through an absorption tower, and reacting with phosgene fed into the synthesis tower to generate a crude product chloroformate and a byproduct hydrogen chloride;
2) sending the crude chloroformate formed in the step 1) into a degassing tower, returning phosgene removed from the degassing tower into a synthesis tower for continuous reaction, and rectifying the residual chloroformate and the chloroformate diester after removing the phosgene into a refining system to obtain a target chloroformate;
3) sending the byproduct hydrogen chloride formed in the step 1) into an absorption tower, washing with raw material alcohol, then sending into a tail gas system, and sending alcohol after absorbing phosgene into a synthesis tower for reaction.
In the step 1), the raw material alcohol is preferably fed from the top of the synthesis column, and phosgene is fed from the bottom of the synthesis column, so that the countercurrent contact reaction is performed.
Preferably, in step 2), the chloroformate flows out from the top of the purification system, and the diester chloroformate flows out from the bottom of the purification system.
Preferably, in the step 1), the raw material alcohol firstly absorbs a small amount of phosgene in the reaction tail gas in the absorption tower and then enters the synthesis tower for reaction. The alcohol after absorbing phosgene is ester generated by reaction, and the generated ester and raw material alcohol enter a synthesis tower together.
Preferably, in the step 2), the reaction product from the bottom of the synthesis tower enters a degassing tower, phosgene and hydrogen chloride gas contained in the material are removed by rectification, and the removed gas returns to the synthesis tower to be mixed with the raw material phosgene for reaction.
In the step 3), phosgene carried in the byproduct hydrogen chloride is washed by raw material alcohol in an absorption tower to form alcohol solution of product ester, and the alcohol solution enters a synthesis tower for reaction; the purified hydrogen chloride gas enters a tail gas tower for subsequent preparation of hydrochloric acid.
Preferably, in the step 1), the molar ratio of the raw material alcohol to the phosgene is 1:1 to 1: 1.5.
preferably, in the step 1), the molar ratio of the raw material alcohol to the phosgene is 1:1 to 1: 1.1.
preferably, the structural formula of the raw material alcohol is R-OH, wherein R is an aliphatic compound or an aromatic compound.
Preferably, R in R-OH is one of benzyl or C1-C4 fatty group.
Preferably, the temperature of the rectifying tower is 10-90 ℃, preferably, the tower top temperature is 10-50 ℃/the tower kettle temperature is 50-90 ℃, and the tower top pressure is-0.1 MPa.
Preferably, the temperature of the degassing tower is 10-90 ℃, preferably, the temperature of the top of the tower is 10-40 ℃, the temperature of the bottom of the tower is 50-90 ℃, and the pressure is-0.1 MPa.
Preferably, the temperature of the absorption tower is 0-40 ℃, and the pressure is 0-0.1 MPa.
Preferably, the temperature in the synthesis column is between 5 and 50 ℃, preferably between 10 and 25 ℃.
The synthesis column of the present invention may be selected from a tube bundle type reactor, but is not limited to this structure.
Compared with the prior art, the invention has the beneficial effects that:
1. continuous countercurrent phosgenation synthesis and continuous distillation deacidification refining are adopted, so that the selectivity and the production efficiency of the reaction are improved, the generation rate of chloroformate is over 95 percent, the equipment specification is reduced, and the material holding amount of a reaction system is reduced.
2. The gas from the top of the degassing tower returns to the synthesis tower again to continue to participate in the reaction, thereby reducing the consumption of raw materials.
3. The byproduct hydrogen chloride in the gas phase at the top of the synthesis tower is washed by raw material alcohol and then is subjected to phosgene removal, and the hydrogen chloride directly enters a tail gas tower for treatment; unreacted phosgene in the gas phase is absorbed by raw material alcohol to form alcohol solution containing ester, the phosgene is recycled, the conversion rate of the phosgene can reach 85-95 percent, the utilization rate of the raw material is improved, and the load of waste gas treatment is reduced.
4. Raw material alcohol enters from the top of the synthesis tower, phosgene enters from the bottom of the synthesis tower, and the two phases are in countercurrent and full contact for reaction, so that heat transfer is facilitated, and the reaction selectivity is improved; meanwhile, the conversion rate of the raw material alcohol reaches more than 99 percent, and the reaction is basically complete.
5. The deacidification is carried out by heating and rectifying, thereby realizing continuous distillation deacidification, reducing the auxiliary production time of equipment, improving the utilization rate of the equipment, not adopting nitrogen gas stripping, and having no nitrogen consumption (20 Nm of nitrogen is consumed by using an intermittent method or a semi-continuous method by using alcohol and phosgene with the same molar ratio3Batch, the temperature of hydrogen chloride brought out by nitrogen is 80 ℃, a large amount of heat is consumed, energy waste is caused, and the cost is increased).
6. The method of the invention does not need solvent, reduces the procedures of removing the solvent and recovering the solvent, and has simple operation and low cost.
Drawings
FIG. 1 is a process flow diagram for the preparation of methyl chloroformate in example 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
the process flow diagram for preparing methyl chloroformate according to the present invention is shown in fig. 1, and specifically comprises the following steps:
1) placing reactants methanol and phosgene in a molar ratio of 1:1.1 into a synthesis tower for reaction, wherein the methanol enters from the top of the synthesis tower through an absorption tower, the phosgene enters from the bottom of the synthesis tower at the reaction temperature of 25 ℃, and the methanol and the phosgene form counter flow in the synthesis tower and are in full contact reaction to form a crude product of methyl chloroformate and a byproduct of hydrogen chloride;
2) crude product methyl chloroformate formed in the synthesis tower flows out from the bottom of the tower and enters a degassing tower, the temperature of the top of the degassing tower is 40 ℃/the temperature of a tower kettle is 90 ℃, and the pressure of the top of the degassing tower is 0.1MPa, phosgene is removed from the degassing tower, and the removed phosgene is combined with raw material phosgene by a pipeline and enters the synthesis tower to complete phosgene recovery; a small amount of hydrogen chloride gas in the degassing tower enters a synthesis tower and enters an absorption tower along with newly generated hydrogen chloride gas; meanwhile, after removing gas in the degassing tower, feeding the residual methyl chloroformate into a rectifying tower for refining, wherein the tower top temperature of the rectifying tower is 32 ℃/the tower bottom temperature is 70 ℃, and the tower top pressure is-0.05 MPa, and rectifying to obtain a target product, namely methyl chloroformate; and the byproduct hydrogen chloride, unreacted phosgene and a small amount of ester generated in the synthesis tower flow out from the tower top and enter an absorption tower, and raw material methanol is used for spraying and washing in the absorption tower. Methanol enters an absorption tower at normal pressure, the absorption tower is operated at a micro-negative pressure, the temperature at the top of the tower is 10 ℃, raw material methanol reacts with unreacted phosgene flowing out of the synthesis tower to form a methanol solution containing methyl chloroformate, the methanol solution enters the synthesis tower, and the washed hydrogen chloride enters a tail gas system. The full-flow continuous feeding and discharging are carried out, the purity of the methyl chloroformate is 98.8 percent, the yield is 96 percent, and the phosgene conversion rate is 90.9 percent. The whole process does not use nitrogen, so that the deacidification time is short, and continuous deacidification and continuous preparation of methyl chloroformate are realized.
In the embodiment, methanol is used for washing reaction tail gas in the absorption tower, and unreacted phosgene reaction products are returned to the synthesis tower, so that the phosgene utilization rate and the product yield are improved, meanwhile, hydrogen chloride can be separated out, and the separated hydrogen chloride enters a tail gas system for treatment.
It should be noted that fig. 1 is a schematic diagram for explaining the process flow of the present invention, and is not the only form of the present invention, the present invention is protection for the process flow and method, other structures capable of achieving the corresponding effects of the process of the present invention can also be used in the present invention,
example 2:
the method for preparing ethyl chloroformate specifically comprises the following steps:
1) placing reactants ethanol and phosgene in a molar ratio of 1:1.15 into a synthesis tower for reaction, wherein the ethanol enters from the top of the synthesis tower through an absorption tower, the phosgene enters from the bottom of the synthesis tower, and the reaction temperature is as follows: the two are in countercurrent and fully contacted and reacted in a synthesis tower at the temperature of 20 ℃ to form crude ethyl chloroformate and byproduct hydrogen chloride;
2) crude product ethyl chloroformate formed in the synthesis tower flows out from the bottom of the tower and enters a degassing tower, the temperature of the tower top of the degassing tower is 40 ℃/the temperature of a tower kettle is 60 ℃, and the pressure of the tower top is-0.08 MPa, phosgene is removed in the degassing tower, and the removed phosgene is combined with raw material phosgene by a pipeline and enters the synthesis tower to complete phosgene recovery; a small amount of hydrogen chloride gas in the degassing tower enters a synthesis tower and enters an absorption tower along with newly generated hydrogen chloride gas; simultaneously, the residual ethyl chloroformate after the gas removal in the degassing tower enters a rectifying tower, the tower top temperature of the rectifying tower is 45 ℃/the tower bottom temperature is 70 ℃, the tower top pressure is-0.09 MPa, and the ethyl chloroformate is rectified to obtain a target product; and by-products of hydrogen chloride, unreacted phosgene and a small amount of ester generated in the synthesis tower flow out from the tower top and enter an absorption tower, raw material ethanol is used for absorption in the absorption tower, the ethanol enters the absorption tower at normal temperature, the absorption tower is operated under the micro negative pressure, the temperature at the tower top is 15 ℃, the raw material ethanol reacts with the unreacted phosgene escaped from the synthesis tower to form ethanol solution containing ethyl chloroformate, the ethanol solution enters the synthesis tower, and the washed hydrogen chloride enters a tail gas system. The full-flow continuous feeding and continuous discharging are carried out, the purity of the ethyl chloroformate is 99.1 percent, the yield is 98 percent, and the phosgene conversion rate is 86.9 percent. The whole process does not use nitrogen, so that the deacidification time is short, and continuous deacidification and continuous preparation of butyl chloroformate are realized.
Example 3:
the method for preparing benzyl chloroformate specifically comprises the following steps:
1) placing reactants of benzyl alcohol and phosgene in a molar ratio of 1:1.05 in a synthesis tower for reaction, wherein the benzyl alcohol enters from the top of the synthesis tower through an absorption tower, the phosgene enters from the bottom of the synthesis tower, and the reaction temperature is as follows: the two are in countercurrent and fully contact reaction in a synthetic tower at 15 ℃ to form crude benzyl chloroformate and byproduct hydrogen chloride;
2) crude product benzyl chloroformate formed in the synthesis tower flows out from the bottom of the tower and enters a degassing tower, the temperature of the top of the degassing tower is 12 ℃/the temperature of a tower kettle is 65 ℃, and the pressure of the top of the degassing tower is-0.09 MPa, phosgene is removed from the degassing tower, and the removed phosgene is combined with raw material phosgene by a pipeline and enters the synthesis tower to complete phosgene recovery; a small amount of hydrogen chloride gas in the degassing tower enters a synthesis tower and enters an absorption tower along with newly generated hydrogen chloride gas; meanwhile, the residual benzyl chloroformate after the gas removal in the degassing tower enters a rectifying tower, the tower top temperature of the rectifying tower is 45 ℃/80 ℃ of the tower kettle, and the tower top pressure is-0.095 Mpa, and the target product benzyl chloroformate is obtained by rectification; and by-products of hydrogen chloride, unreacted phosgene and a small amount of ester generated in the synthesis tower escape from the tower top and enter an absorption tower, benzyl alcohol serving as a raw material is used for absorption in the absorption tower, the benzyl alcohol enters the absorption tower at the temperature of 5 ℃, the absorption tower is operated under the micro negative pressure, the temperature of the tower top is 20 ℃, the benzyl alcohol serving as the raw material reacts with the unreacted phosgene escaping from the synthesis tower to form benzyl benzoate-containing benzyl alcohol solution, the benzyl alcohol solution enters the synthesis tower, and the washed hydrogen chloride enters a tail gas system. The full-flow continuous feeding and discharging are carried out, the purity of the benzyl chloroformate is 98.7 percent, the yield is 95.5 percent, and the phosgene conversion rate is 95.2 percent. The whole process does not use nitrogen, so that the deacidification time is short, and continuous deacidification and continuous preparation of benzyl chloroformate are realized.
The present invention has been described in detail with reference to the examples, but the present invention is only preferred examples of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.
Claims (13)
1. A continuous method for the preparation of chloroformates, comprising the steps of:
1) the method comprises the following steps of (1) enabling reactant raw material alcohol to enter a synthesis tower through an absorption tower, and reacting with phosgene fed into the synthesis tower to generate a crude product chloroformate and a byproduct hydrogen chloride;
2) sending the crude chloroformate formed in the step 1) into a degassing tower, returning phosgene removed from the degassing tower into a synthesis tower for continuous reaction, and rectifying the residual chloroformate and the chloroformate diester after removing the phosgene into a refining system to obtain a target chloroformate;
3) sending the byproduct hydrogen chloride formed in the step 1) into an absorption tower, washing the byproduct hydrogen chloride with raw material alcohol, then sending the product into a tail gas system, and sending the absorbed liquid into a synthesis tower for reaction.
2. The method according to claim 1, wherein in the step 1), the raw material alcohol is fed from the top of the synthesis tower through the absorption tower, and phosgene is fed from the bottom of the synthesis tower, and the countercurrent contact reaction is carried out.
3. The method as claimed in claim 1), wherein in the step 1), the raw material alcohol firstly absorbs a small amount of phosgene in the reaction tail gas in the absorption tower and then enters the synthesis tower.
4. The method as claimed in claim 1, wherein in the step 2), the reaction product from the bottom of the synthesis tower enters a degassing tower, and phosgene and hydrogen chloride gas contained in the material are removed in a rectifying manner.
5. The method according to claim 1, characterized in that in the step 3), phosgene entrained in the byproduct hydrogen chloride is washed with raw alcohol in an absorption tower, and purified hydrogen chloride gas enters a tail gas tower for subsequent preparation of hydrochloric acid.
6. The method according to claim 1, wherein in step 1), the molar ratio of the raw material alcohol to the phosgene is 1:1 to 1: 1.5.
7. the method according to claim 6, wherein in the step 1), the molar ratio of the raw material alcohol to the phosgene is 1:1 to 1: 1.1.
8. the method of claim 1, wherein the starting alcohol has the formula R-OH, wherein R is an aliphatic or aromatic compound.
9. The method of claim 8, wherein R in R-OH is one of benzyl or a C1-C4 aliphatic group.
10. The method according to claim 1, wherein the temperature at the top of the degassing tower is 10 to 40 ℃, the temperature at the bottom of the degassing tower is 50 to 90 ℃, and the pressure is-0.1 to 0.1 MPa.
11. The process according to claim 1, wherein the temperature of the absorption column is 0 to 40 ℃ and the pressure is 0 to 0.1 MPa.
12. The process according to claim 1, characterized in that the temperature in the synthesis column is 5-50 ℃.
13. The process according to claim 1, characterized in that the temperature in the synthesis column is 10-25 ℃.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118771985A (en) * | 2024-09-13 | 2024-10-15 | 山东天安化工股份有限公司 | A one-pot method for preparing methyl chloroformate and 2-amino-4,6-dimethoxypyrimidine |
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2021
- 2021-02-01 CN CN202110133547.9A patent/CN112961055A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118771985A (en) * | 2024-09-13 | 2024-10-15 | 山东天安化工股份有限公司 | A one-pot method for preparing methyl chloroformate and 2-amino-4,6-dimethoxypyrimidine |
| CN118771985B (en) * | 2024-09-13 | 2024-12-17 | 山东天安化工股份有限公司 | Synthesis method for preparing methyl chloroformate and 2-amino-4, 6-dimethoxy pyrimidine by one-pot method |
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