CN100406419C - Method for preparing dibasic alcohol - Google Patents
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- CN100406419C CN100406419C CNB2006100269032A CN200610026903A CN100406419C CN 100406419 C CN100406419 C CN 100406419C CN B2006100269032 A CNB2006100269032 A CN B2006100269032A CN 200610026903 A CN200610026903 A CN 200610026903A CN 100406419 C CN100406419 C CN 100406419C
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Abstract
The present invention relates to a method for preparing dibasic alcohol of which the structure is disclosed in the formula (1), which comprises the following main steps: epoxy ethane (epoxy propane) and carbon dioxide are used as raw materials; under the action of catalysts, carbonic acid ethene ester (carbonic acid propylene ester) are prepared by reaction; under the action of pressurization and no catalysts, the carbonic acid ethene ester (carbonic acid propylene ester) reacts with water to generate ethylene glycol (propylene glycol) and carbon dioxide; after being recovered, the carbon dioxide is returned to a carbonic acid ethene ester (carbonic acid propylene ester) synthesizing reactor to be recycled; after hydrolysate products are decompressed and rectified, the ethylene glycol (propylene glycol) of which the purity is more than 99.5% is obtained, and the yield of the ethylene glycol (propylene glycol) reaches more than 95%. (calculated according to epoxy ethane (epoxy propane)). The present invention has the obvious advantage that catalysts are not used in the process of hydrolyzing carbonic acid ethene ester (carbonic acid propylene ester). Thereby, the problems of the recovery and the loss of hydrolyzing catalysts in the prior art are solved, and the cost of preparing the ethylene glycol (propylene glycol) is reduced.
Description
Technical field
The present invention relates to a kind of preparation method of dibasic alcohol, specifically, relate to a kind of C
2～C
3The preparation method of dibasic alcohol.
Background technology
C
2～C
3Dibasic alcohol, its typical case is represented as ethylene glycol and 1, and 2-propylene glycol (hereinafter to be referred as propylene glycol) is an important chemical material.
At present, the large-scale production second in countries in the world (third) glycol all adopts directly the pressurize technology of hydration of epoxy second (third) alkane, and following two kinds of reactions mainly take place this reaction process:
Main reaction: EO (or PO)+H
2O → EG (or PG)
Side reaction: EO (or PO)+EG (or PG) → DEG (or DPG)
EO (or PO)+DEG (or DPG) → TEG (or TPG)
Wherein: EO representative ring oxidative ethane, PO representative ring Ethylene Oxide, EG represent that ethylene glycol, PG represent that propylene glycol, DEG represent that a condensed ethandiol, DPG represent to contract propylene glycol, TEG represent that tirethylene glycol, TPG represent two propylene glycol that contract.
Be that epoxy second (third) alkane hydration reaction is except the main reaction that generates purpose product second (third) glycol, the parallel-series side reaction is also arranged simultaneously, produce by product one second (third) glycol (DEG or DPG) and two second (third) glycol (TEG or TPG) that contracts that contracts, in order to obtain higher second (third) glycol yield, existing preparation second (third) glycol process using increases the feed water ratio, and promptly the mol ratio of water and epoxy second (third) alkane reaches (15～20): 1.If feed water is than being the mol ratio of 20[water and epoxy second (third) alkane 20: 1], the main reaction yield is 88.0%, separation system yield 95.9%, omnidistance product yield 84.4%.Need to consume big energy after the hydration reaction and remove water, a plurality of vaporizers are set in the device, cause the technological process of production long, equipment is many and big, and investment is high, energy consumption is high, is a kind of uneconomic production method.
In order to reduce the unit consumption and the energy consumption of second (third) glycol production process, a lot of scientific workers have carried out unremitting effort, have developed epoxy second (third) alkane catalytic hydration technology.CN1721384 discloses with compound resin and has made catalyzer, and epoxy alkane and water are 60～150 ℃ of temperature of reaction, and reaction pressure is 0.5～2.0 MPa, and water/epoxy alkane mol ratio is 5～15: 1, and the liquid air speed is 3～6 hours
-1React the production dibasic alcohol under the condition; CN1559684 discloses use silica gel skeleton catayst, and oxyethane and water carry out the technology of catalytic hydration, oxyethane transformation efficiency＞99.0%, glycol selectivity＞97.0%.CN107894 is disclosed to be the synthesis technique of catalyzer with sodium formiate or potassium acetate, water than 160 ℃ of 2 (mol ratios), temperature under, the selectivity of propylene glycol has reached more than 90.0%.The clear 62-126145 of day disclosure special permission communique disclosed with carboxylic acid and carboxylate salt as combination catalyst, and in the propylene oxide catalytic hydration technology of carrying out as combination catalyst with carboxylic acid and nitrogenous carboxylate salt, propylene glycol has reaction yield preferably, as at water than 2, the basic metal of catalyzer acetate and acetate or alkaline-earth metal salts contg 2.0%～5.0%, 160 ℃ were reacted 1 hour down, and the reaction yield of propylene glycol can reach 91.0%～93.0%; If make catalyzer with an alkali metal salt or the alkaline earth salt of formic acid and formic acid, content 2.5%～5.2%, 160 ℃ were reacted 1 hour down, and the reaction yield of propylene glycol can reach 93.8%～96.1%.Epoxy second (third) has also been brought problems although alkane catalytic hydration technology can improve the selectivity of propylene glycol, has the shortcoming that catalytic amount is big and be difficult to recycle as the homogeneous catalysis method; The heterogeneous catalysis method exists catalyst life weak point, transformation efficiency selectivity to be difficult to meet the requirements of shortcoming.
Since epoxy second (third) alkane can with carbon dioxide reaction, obtain ethylene (third) the alkene ester of high yield, ethylene (third) alkene ester under proper condition can with water generation hydrolysis reaction, generate second (third) glycol, discharge CO simultaneously
2, epoxy second (third) alkane does not directly contact with second (third) glycol, has reduced side reaction, has improved the selectivity of second (third) glycol.As US.Pat.No.6,187,972 disclose under the halide catalyst effect of basic metal or alkaline-earth metal, preparing ethyl glycol by hydrolysis of ethylene carbonate, the water ratio is 1～5, temperature of reaction is 50～200 ℃, ethylene carbonate ester conversion rate 〉=99.0%, glycol selectivity 〉=97%; US.Pat.No.4,508,927 disclose with organic halogenation quaternary ammonium phosphine and have made catalyzer, and ethylene glycol is produced in the NSC 11801 hydrolysis, and water is than 1～5, ethylene carbonate ester conversion rate 100%, glycol selectivity 〉=99.0%; US.Pat.No.4,283,580 disclose with potassium molybdate or potassium wolframate compounds and have made the technology that ethylene glycol is produced in the hydrolysis of catalyst carbon vinyl acetate, and water is than 3～10, transformation efficiency 〉=99.0%, selectivity 〉=99.0%; US.Pat.No.4,117,250 disclose with salt of wormwood and have made catalyzer, the technology of NSC 11801 hydrolysis preparing ethylene glycol, water is than 1.5～2.5, ethylene carbonate ester conversion rate 99.0%, glycol selectivity 99.0%; JP 82106631 discloses and has used Al
2O
3Make catalyzer, the method for NSC 11801 hydrolysis preparing ethylene glycol, water is than 1.24, ethylene carbonate ester conversion rate 100%, selectivity 99.8%.Because hydrolytic process has all adopted catalyzer in the aforesaid method, therefore can relate to the recovery and the loss problem of catalyzer, thereby cause the production cost of second (third) glycol to increase.
Summary of the invention
The object of the invention is, a kind of C cheaply is provided
2～C
3The preparation method of dibasic alcohol.
The dibasic alcohol that the present invention will prepare, its structure be as the formula (1):
In the formula (1): R is H or CH
3
It is to be starting raw material with compound shown in the formula (2) [be called for short compound (2)], at first, then the direct pressurized hydrolysis (catalyst-free) of compound (3) is made target compound [compound (1)] with compound (2) and compound shown in the gaseous carbon dioxide reaction production (3) [being called for short compound (3)].
The implication of formula (2) and the middle R of formula (3) is with identical described in the formula (1).
Reactional equation is as follows:
The implication of R is described identical with preamble in the reactional equation.
The said preparation method's of the present invention key step is: at first compound (2) and gaseous carbon dioxide are carried out esterification under the catalyzer existence condition and make compound (3), then compound (3) is made target compound [being called for short compound (1)] through hydrolysis reaction under the catalyst-free condition;
Wherein: said catalyzer is: guanidine compound (as Hydrogen bromide guanidine, Guanidinium carbonate or Guanidinium hydrochloride etc.), ureas halogen compound (as bromine hydracid urea or urea hydrochloride etc.), hydrazine or hydrazine dibrominated hydrogen compounds, heterocyclic amine compound (as pyridine, acridine or quinoline etc.), quaternary ammonium compound (as tetraethyl-ammonium bromide etc.), the mixture (KI/PEG) of metal bromide (as lithiumbromide etc.) or potassiumiodide and polyoxyethylene glycol; Compound (3) is 1 with the mol ratio of water: (1～10), hydrolysising reacting temperature are 60～260 ℃, the pressure 0.01～10.0MPa of hydrolysis reaction, hydrolysis time 10min～300min.
Among the present invention, compound (3) hydrolysis gained carbonic acid gas can be used as the raw material of compound (2) esterification through recovery, recycles; Preferred catalyzer is the mixture of tetraethyl-ammonium bromide or potassiumiodide and polyoxyethylene glycol; Compound (3) is preferably 1 with the mol ratio of water: (1～5); Preferred 80～240 ℃ of said hydrolysising reacting temperature; Preferred 0.3～the 7.0Mpa of said hydrolysis reaction pressure; Preferred 30～240 minutes of said hydrolysis time.
In the method for preparing second (third) glycol [compound (1)] provided by the invention, the hydrolysis of ethylene (third) alkene ester [compound (3)] need not catalyzer, the hydrolyst of having avoided can't avoiding in the prior art reclaims and the loss problem, has reduced second (third) glycol preparation cost.
Description of drawings
Fig. 1 is the said preparation method's of the present invention schematic flow sheet
Wherein the part icon is described as follows:
The 4-synthesis reactor, 8-recirculation cooler, 12-adiabatic reactor, 16-compressor, 17-flash tank, 21-vaporizer, 23-condenser, 26-pump, 27-hydrolysis reactor, 30-rectifying tower, 32-condenser.
Concrete real-time mode
The present invention is further elaborated below in conjunction with accompanying drawing:
By accompanying drawing 1 as seen, the said preparation method of the present invention comprises three technological processs such as refining of the hydrolysis of synthesis and purification, compound (3) of ethylene (third) alkene ester [compound (3)] and second (third) glycol [compound (1)].
Epoxy second (third) alkane [compound (2)] enters the top of synthesis reactor 4, additional CO from managing 1
2From the CO that manages 2, reclaims
2Enter the bottom of synthesis reactor 4 after mixing from managing 3.Part reactant is from managing 5, enters recirculation cooler 8 coolings after manage 9 with after recycling catalyst in the pipe 14 mixes through pump 7, mixes with the compound (2) of managing in 1 through managing 11, enters synthesis reactor 4 from managing 10;
Another part reactant enters another adiabatic reactor 12, unreacted compound (2) and CO from managing 6 in the synthesis reactor 4
2Further after the reaction, enter flash tank 17, excessive CO from the pipe 13 on top
2Go out from managing 18; Liquid in the flash tank 17 enters the vaporizer 21 from managing 19, and catalyzer separates with compound (3), and catalyzer returns synthesis reactor 4 from managing 20 through pump 15; Compound (3) steam comes out from managing 22, after condenser 23 condensations, enters hydrolysis reactor 27, the CO that hydrolysis reactor 27 comes out from managing 24 through pump 26
2The CO of gas and pipe 18
2After the mixing, after compressed machine 16 compressions, return synthesis reactor 4 by pipe 3;
The water that replenishes enters hydrolysis reactor 27 from managing 25 recirculated waters with pipe 34 from the bottom, guarantee that the compound (3) and the mol ratio of water are 1: (1～5), in hydrolysis reactor 27, hydrolysis temperature is 80～240 ℃, hydrolysis reaction pressure is 0.3～7.0Mpa, hydrolysis time 30～240 minutes, hydrolysis reaction generates second (third) glycol [compound (1)] and CO
2, CO
2Through managing 28 recycling uses.Compound (1) and excessive water enter rectifying tower 30 from managing 29;
The steam of rectifying tower 30 cats head is after condenser 32 condensations, a part is returned rectifying tower 30 as backflow, another part turns back to hydrolysis reactor 27, qualified compound (1) is drawn [can obtain purity after the rectifying be more than 99.5% compound (1)] from the side line 33 of rectifying tower 30, and heavy component is emitted from the tower bottom tube line 31 of rectifying tower;
Wherein: said synthesis reactor 4 and adiabatic reactor 12 add the void tower (in add plate washer to reduce back-mixing) of plate washer in being; Said catalyzer is the mixture (KI/PEG) of tetraethyl-ammonium bromide or potassiumiodide and polyoxyethylene glycol; Said hydrolysis reactor 27 is an aspect ratio greater than 5 tubular reactor or tower reactor; Said rectifying tower is conventional packing tower or tray column.
The invention will be further described below by embodiment, and its purpose only is better to understand content of the present invention and unrestricted protection scope of the present invention:
Control CO
2The molar ratio of/propylene oxide is 1.1, enters synthesis reactor, and the amount of catalyzer Tetraethylammonium bromide is 1.0% of a propylene oxide weight, 180 ℃ of temperature of reaction, 1 hour reaction times, the purity 99.5% of propylene carbonate, yield 99.5% (in propylene oxide)
The molar ratio of regulating water/propylene carbonate is 2, enters hydrolysis reactor, pressure 0.3MPa, and temperature of reaction remains on 80 ℃, reacts propylene carbonate ester conversion rate 99.5%, the selectivity 100% of propylene glycol 0.5 hour.
Rectifying tower is a packing tower, 20 of theoretical plate numbers, and reflux ratio 3.0, tower internal pressure 0.018Mpa, 160 ℃ of tower still temperature, propylene glycol purity be more than 99.5%, rectifying yield 97%.Propylene glycol total recovery 96.0% (in propylene oxide).
Control CO
2The molar ratio of/oxyethane is 1.05, enters synthesis reactor, and the amount of catalyzer KI/PEG is 1.0% of a propylene oxide weight, 150 ℃ of temperature of reaction, 1 hour reaction times, the purity 99.5% of NSC 11801, yield 99.5% (in propylene oxide)
The molar ratio of regulating water/NSC 11801 is 1.5, enters hydrolysis reactor, pressure 7.0MPa, and temperature of reaction remains on 240 ℃, reacts 4.0 hours, and NSC 11801 obtains transformation efficiency 100%, the selectivity 100% of ethylene glycol.
Rectifying tower is a tray column, 30 of theoretical plate numbers, and reflux ratio 2.5, tower internal pressure 0.018Mpa, 165 ℃ of tower still temperature, ethylene glycol purity be more than 99.5%, rectifying yield 98%.Ethylene glycol total recovery 97.5% (in oxyethane).
Claims (9)
1. method for preparing structure dibasic alcohol as the formula (1), it is characterized in that, said preparation method's key step is: at first compound (2) and gaseous carbon dioxide are carried out esterification under the catalyzer existence condition and make compound (3), then compound (3) is made target compound through hydrolysis reaction under the catalyst-free condition;
Wherein: said catalyzer is a guanidine compound, ureas halogen compound, hydrazine or hydrazine dibrominated hydrogen compounds, heterocyclic amine compound, quaternary ammonium compound, the mixture of metal bromide or potassiumiodide and polyoxyethylene glycol; Compound (3) is 1 with the mol ratio of water: (1～10); Hydrolysising reacting temperature is 60～260 ℃; Pressure 0.01～the 10.0MPa of hydrolysis reaction; Hydrolysis time 10 minutes～300 minutes;
R is H or CH in the formula (1), formula (2) and formula (3)
3
2. preparation method as claimed in claim 1 is characterized in that, wherein said catalyzer is the mixture of tetraethyl-ammonium bromide or potassiumiodide and polyoxyethylene glycol.
3. preparation method as claimed in claim 1 is characterized in that, wherein compound (3) is 1 with the mol ratio of water: (1～5).
4. preparation method as claimed in claim 1 is characterized in that, wherein said hydrolysising reacting temperature is 80～240 ℃; Said hydrolysis reaction pressure is 0.3～7.0Mpa; Said hydrolysis time is 30～240 minutes.
5. preparation method as claimed in claim 1 is characterized in that, wherein compound (3) hydrolysis gained carbonic acid gas can be used as the raw material of compound (2) esterification through recovery, recycles.
6. as any described preparation method in the claim 1～6, it is characterized in that said preparation method comprises the steps:
Compound (2) enters the top of synthesis reactor (4), additional CO from pipe (1)
2CO from pipe (2), recovery
2From managing the bottom that enters synthesis reactor (4) after mix (3), part reactant is from pipe (5), through pump (7) enter recirculation cooler (8) cooling after pipe (9) with after recycling catalyst in managing (14) mixes, compound (2) in managing (11) and managing (1) mixes, and enters synthesis reactor (4) from pipe (10);
Another part reactant enters another adiabatic reactor (12), unreacted compound (2) and CO from pipe (6) in the synthesis reactor (4)
2Further after the reaction, enter flash tank (17), excessive CO from the pipe (13) on top
2Go out from pipe (18); Liquid in the flash tank (17) enters the vaporizer (21) from pipe (19), and catalyzer separates with compound (3), and catalyzer returns synthesis reactor (4) from pipe (20) through pump (15); Compound (3) steam comes out from pipe (22), after condenser (23) condensation, enters hydrolysis reactor (27) through pump (26), the CO that hydrolysis reactor (27) comes out from pipe (24)
2The CO that gas and pipe (18) come
2After the mixing, after compressed machine (16) compression, return synthesis reactor (4) by pipe (3);
The water that replenishes enters hydrolysis reactor (27) from the recirculated water of pipe (25) with pipe (34) from the bottom, guarantee that the compound (3) and the mol ratio of water are 1: (1～5), in hydrolysis reactor (27), hydrolysis temperature is 80～240 ℃, hydrolysis reaction pressure is 0.3～7.0Mpa, hydrolysis time 30～240 minutes, hydrolysis reaction generates compound (1) and CO
2, CO
2Through pipe (28) recycling use, compound (1) and excessive water enter rectifying tower (30) from pipe (29);
The steam of rectifying tower (30) cat head is after condenser (32) condensation, a part is returned rectifying tower (30) as backflow, another part turns back to hydrolysis reactor (27), qualified compound (1) is drawn from the side line (33) of rectifying tower (30), and heavy component is emitted from the tower bottom tube line (31) of rectifying tower;
Wherein: said catalyzer is the mixture of tetraethyl-ammonium bromide or potassiumiodide and polyoxyethylene glycol.
7. preparation method as claimed in claim 6 is characterized in that, wherein said synthesis reactor (4) and adiabatic reactor (12) add the void tower of plate washer in being.
8. preparation method as claimed in claim 6 is characterized in that, wherein said hydrolysis reactor (27) is an aspect ratio greater than 5 tubular reactor or tower reactor.
9. preparation method as claimed in claim 6 is characterized in that, wherein said rectifying tower (30) is filler or plate distillation column.
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103012063B (en) * | 2011-09-28 | 2014-12-03 | 中国石油化工股份有限公司 | Preparation method of propylene glycol |
| CN103100422B (en) * | 2013-01-08 | 2014-07-23 | 大连理工大学 | High-activity catalysis system for synthesizing dihydric alcohol |
| CN105367387A (en) * | 2015-11-26 | 2016-03-02 | 上海交通大学 | Method for preparing ethylene glycol by using ethylene carbonate |
| CN107915577B (en) * | 2016-10-08 | 2020-12-29 | 中国石油化工股份有限公司 | Method for synthesizing ethylene glycol by hydrolyzing ethylene carbonate |
| CN110437200B (en) * | 2019-07-09 | 2021-04-02 | 惠州凯美特气体有限公司 | Preparation method of propylene carbonate based on carbon dioxide raw material |
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