CN113943205A - Method for dehydrating and concentrating formaldehyde solution - Google Patents
Method for dehydrating and concentrating formaldehyde solution Download PDFInfo
- Publication number
- CN113943205A CN113943205A CN202111127318.2A CN202111127318A CN113943205A CN 113943205 A CN113943205 A CN 113943205A CN 202111127318 A CN202111127318 A CN 202111127318A CN 113943205 A CN113943205 A CN 113943205A
- Authority
- CN
- China
- Prior art keywords
- formaldehyde
- solution
- carboxylic acid
- water
- concentrating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 title claims abstract description 140
- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000008098 formaldehyde solution Substances 0.000 title claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 38
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims abstract description 21
- 238000005882 aldol condensation reaction Methods 0.000 claims abstract description 12
- 238000006243 chemical reaction Methods 0.000 claims abstract description 9
- 239000002994 raw material Substances 0.000 claims abstract description 9
- 150000002148 esters Chemical class 0.000 claims abstract description 8
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims abstract description 6
- 238000004064 recycling Methods 0.000 claims abstract description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 21
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 claims description 15
- 229940017219 methyl propionate Drugs 0.000 claims description 15
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 claims description 14
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 7
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 claims description 5
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 claims description 5
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 claims description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 4
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 2
- 235000011054 acetic acid Nutrition 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 230000018044 dehydration Effects 0.000 claims description 2
- 238000006297 dehydration reaction Methods 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- 235000019260 propionic acid Nutrition 0.000 claims description 2
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 claims description 2
- 238000000926 separation method Methods 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 238000003786 synthesis reaction Methods 0.000 abstract description 2
- 239000000243 solution Substances 0.000 description 12
- 239000000203 mixture Substances 0.000 description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000007788 liquid Substances 0.000 description 4
- 150000001735 carboxylic acids Chemical class 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 150000001733 carboxylic acid esters Chemical class 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- CKFGINPQOCXMAZ-UHFFFAOYSA-N methanediol Chemical compound OCO CKFGINPQOCXMAZ-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000010533 azeotropic distillation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- MGJURKDLIJVDEO-UHFFFAOYSA-N formaldehyde;hydrate Chemical compound O.O=C MGJURKDLIJVDEO-UHFFFAOYSA-N 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C45/82—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
- C07C45/84—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation by azeotropic distillation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
- C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation
- C07C51/46—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation by azeotropic distillation
Abstract
The invention provides a method for concentrating a formaldehyde solution, and belongs to the technical field of formaldehyde separation. The solution contains formaldehyde, water and carboxylic acid, the formaldehyde solution and the water entrainer are rectified, so that the carboxylic acid in the solution enters the concentrated formaldehyde and returns to be used as a reaction raw material for recycling. The invention provides a method for dehydrating and concentrating formaldehyde solution, which is particularly suitable for treating the unreacted formaldehyde solution in the synthesis process of preparing unsaturated carboxylic acid or ester thereof by an aldol condensation method.
Description
Technical Field
The invention belongs to the technical field of methane recovery, and particularly relates to a method for dehydrating and concentrating a formaldehyde solution.
Background
Formaldehyde is a commodity chemical, and common specifications include 37 wt.% and 55 wt.% aqueous formaldehyde solutions, often with small amounts of methanol. Formaldehyde mainly forms a complex with water or methanol, and exists in the form of formaldehyde hydrate or hemiformal and the like.
In the process of preparing unsaturated carboxylic ester such as methyl acrylate, methyl methacrylate and the like by using formaldehyde in the aldol condensation method, an easily available industrial formaldehyde solution (with the concentration of 37 wt.% and 55 wt.%) is used as a formaldehyde source, water is introduced in the reaction, the catalyst is adversely affected, hydrolysis reaction of ester reactants such as methyl acetate, methyl propionate and the like and ester products such as methyl acrylate, methyl methacrylate and the like can be accelerated, and the water is also a product of the aldol condensation reaction, and the amount of water introduced into the reaction zone along with the feed is preferably minimized so that the water content in the reaction atmosphere is as low as possible.
In addition, raw material formaldehyde in the aldol condensation reaction is generally difficult to be completely converted, and residual formaldehyde and water brought by the raw material, water generated in the reaction or water introduced by other modes form a mixed solution containing formaldehyde with lower concentration, which brings great difficulty to the recycling of the formaldehyde. The aldol condensation reaction product is subjected to various separation processes to separate out most of the organic components therein, and the resulting aqueous formaldehyde solution usually also contains carboxylic acids.
The ideal process for concentration of formaldehyde should avoid the introduction of other compounds in large amounts during the formaldehyde-water separation, especially out of the reaction system, since other compounds need to be removed from the process in a subsequent step. In addition, since carboxylic acid is a raw material for aldol condensation reaction or participates in aldol condensation reaction after esterification, it is not preferable to cause loss of effective components such as carboxylic acid in the aqueous formaldehyde solution.
Disclosure of Invention
The invention aims to provide a more efficient method for dehydrating and concentrating formaldehyde solution, in particular to the unreacted formaldehyde solution in the process of preparing unsaturated carboxylic acid or ester thereof by using an aldol condensation method, wherein the formaldehyde solution usually also contains carboxylic acid, and the concentrated material is recycled as a reaction raw material.
The purpose of the invention is realized by the following technical scheme:
a method for dewatering and concentrating formaldehyde solution comprises the steps of rectifying the formaldehyde solution and a water entrainer to enable carboxylic acid in the solution to enter concentrated formaldehyde and return the carboxylic acid and the concentrated formaldehyde together to be used as reaction raw materials for recycling.
Further, the carboxylic acid is one or more of formic acid, acetic acid, propionic acid, acrylic acid and methacrylic acid.
Further, the total content of carboxylic acids in the solution is higher than 1 wt.%, and more than 95% of carboxylic acids in the solution enter the concentrated formaldehyde.
Further, the water entrainer is one or more of methyl acetate, methyl acrylate, methyl propionate and methyl methacrylate. Methyl acetate, methyl acrylate, methyl propionate or methyl methacrylate can form an azeotrope with lower boiling point with water, and is extracted from the top of the tower in the rectification process. The extracted azeotrope can be returned to the oil phase after phase separation to be continuously used as the entrainer. The use of methyl acetate, methyl acrylate, methyl propionate or methyl methacrylate is also advantageous in that these materials, which are major or minor components of the system for preparing unsaturated carboxylic esters by aldol condensation, do not have a large effect on the catalyst performance, separation process and product quality after being introduced as an entrainer.
Further, the azeotropic agent content in the concentrated formaldehyde is less than 10 wt.%, more preferably less than 1 wt.%.
Further, the solution is a formaldehyde solution which is not reacted in the process of preparing unsaturated carboxylic acid or ester thereof by aldol condensation. Wherein the unsaturated carboxylic acid or its ester comprises unsaturated carboxylic acid, methyl acrylate, methyl methacrylate.
Further, the mass ratio of formaldehyde to water in the solution is greater than 0.8: 1, i.e. a concentration of formaldehyde to water higher than 44 wt.%.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a method for dehydrating and concentrating formaldehyde solution, which is particularly suitable for treating the unreacted formaldehyde solution in the synthesis process of preparing unsaturated carboxylic acid or ester thereof by an aldol condensation method.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
Experimental apparatus: the phi 100 multiplied by 3800mm silver-plated rectifying tower is filled with glass filler, and the composition of the formaldehyde-containing mixture solution is as follows: 39 wt% of formaldehyde, 47 wt% of water, 13 wt% of acetic acid and other components, methyl propionate is used as a water entrainer, and water in the mixture is brought out by utilizing the azeotropy of the methyl propionate and the water, so that the concentration of the formaldehyde is realized. The mass ratio of the feeding amount of the formaldehyde solution to the methyl propionate refluxed at the top of the rectifying tower is 1: 6, the temperature of the top of the tower is 70 ℃, and the temperature of the bottom of the tower is 105 ℃.
A mixture of methyl propionate and water is extracted from the top of the tower, tower bottom liquid contains 63 wt% of formaldehyde, 14 wt% of water, 20 wt% of acetic acid and 1.7 wt% of methyl propionate, and the mass ratio of the formaldehyde to the water in the tower bottom liquid is 4.5: 1, the concentration of formaldehyde relative to water was 81.82 wt%, while the mass ratio of formaldehyde to water in the raw material mixture solution was 0.83:1 and the concentration of formaldehyde relative to water was 45.36 wt%, it was found that the formaldehyde concentration was increased to achieve the (partial) dehydration, and more than 99% of the acetic acid remained in the column bottoms.
Example 2
Experimental apparatus: the method comprises the following steps of filling glass filler in a silver-plated rectifying tower with the diameter of 100 multiplied by 3800mm, wherein a formaldehyde-containing mixture solution comprises 50 wt% of formaldehyde, 43 wt% of water, 6 wt% of acetic acid and other components, taking methyl propionate as a water entrainer, and carrying out azeotropic removal of water in the mixture by utilizing the methyl propionate and the water to realize formaldehyde concentration. The mass ratio of the mixture solution to the refluxing methyl propionate is 1:4, the tower top temperature is 68 ℃, and the tower bottom temperature is 104 ℃.
And (3) collecting a mixture of methyl propionate and water from the tower top, wherein the mass ratio of formaldehyde to water in the tower bottom liquid is 1.70: 1, the concentration of formaldehyde to water is 62.96 wt%, and the mass ratio of formaldehyde to water in the raw material mixture solution is 1.16: 1, the concentration of formaldehyde relative to water was 53.70 wt%, it can be seen that the formaldehyde concentration was increased and acetic acid remained in the column bottoms. In addition, the content of methyl propionate in the tower bottom liquid is only 1.0 wt%, and the subsequent use of the concentrated formaldehyde is not greatly influenced.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (7)
1. A method for dehydrating and concentrating a formaldehyde solution is characterized in that the solution contains formaldehyde, water and carboxylic acid, the formaldehyde solution and a water entrainer are rectified, the carboxylic acid in the solution enters the concentrated formaldehyde, and the carboxylic acid and the concentrated formaldehyde are returned together to be used as reaction raw materials for recycling.
2. The method for dehydrating and concentrating a formaldehyde solution according to claim 1, wherein the carboxylic acid is one or more of formic acid, acetic acid, propionic acid, acrylic acid, and methacrylic acid.
3. The method according to claim 1, wherein the total carboxylic acid content of the solution is higher than 1 wt.%, and more than 95% of the carboxylic acid in the solution is introduced into the concentrated formaldehyde.
4. The method for dehydrating and concentrating a formaldehyde solution according to claim 1, wherein the water entrainer is one or more of methyl acetate, methyl acrylate, methyl propionate and methyl methacrylate.
5. A process for the dehydration concentration of formaldehyde solutions according to claim 1, wherein the azeotropic agent content in the concentrated formaldehyde is less than 10 wt.%, preferably less than 1 wt.%.
6. The method according to claim 1, wherein the formaldehyde solution is unreacted formaldehyde solution in the process of preparing unsaturated carboxylic acid or ester thereof by aldol condensation.
7. The method for dehydrating and concentrating the formaldehyde solution according to claim 1, wherein the mass ratio of the formaldehyde to the water in the solution is more than 0.8: 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111127318.2A CN113943205A (en) | 2021-09-26 | 2021-09-26 | Method for dehydrating and concentrating formaldehyde solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111127318.2A CN113943205A (en) | 2021-09-26 | 2021-09-26 | Method for dehydrating and concentrating formaldehyde solution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113943205A true CN113943205A (en) | 2022-01-18 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111127318.2A Pending CN113943205A (en) | 2021-09-26 | 2021-09-26 | Method for dehydrating and concentrating formaldehyde solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113943205A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH330481A (en) * | 1954-07-09 | 1958-06-15 | Rhone Poulenc Chemicals | Process for separating the components of a mixture containing at least one aliphatic carboxylic acid from water and formaldehyde |
| CN1304396A (en) * | 1998-06-05 | 2001-07-18 | 伊尼奥斯丙烯酸英国有限公司 | Dewatering process |
| CN106831380A (en) * | 2017-01-19 | 2017-06-13 | 中国科学院成都有机化学有限公司 | The method of formalin dehydration concentration |
| CN111718256A (en) * | 2019-03-20 | 2020-09-29 | 中国石油化工股份有限公司 | Acetic acid dehydration method |
| CN112409178A (en) * | 2020-11-25 | 2021-02-26 | 西南化工研究设计院有限公司 | Method for preparing methyl methacrylate by taking methyl acetate as raw material |
-
2021
- 2021-09-26 CN CN202111127318.2A patent/CN113943205A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH330481A (en) * | 1954-07-09 | 1958-06-15 | Rhone Poulenc Chemicals | Process for separating the components of a mixture containing at least one aliphatic carboxylic acid from water and formaldehyde |
| CN1304396A (en) * | 1998-06-05 | 2001-07-18 | 伊尼奥斯丙烯酸英国有限公司 | Dewatering process |
| CN1566057A (en) * | 1998-06-05 | 2005-01-19 | 卢西特国际英国有限公司 | Dewatering process |
| CN106831380A (en) * | 2017-01-19 | 2017-06-13 | 中国科学院成都有机化学有限公司 | The method of formalin dehydration concentration |
| CN111718256A (en) * | 2019-03-20 | 2020-09-29 | 中国石油化工股份有限公司 | Acetic acid dehydration method |
| CN112409178A (en) * | 2020-11-25 | 2021-02-26 | 西南化工研究设计院有限公司 | Method for preparing methyl methacrylate by taking methyl acetate as raw material |
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| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220118 |