CN102442905A - Method for preparing dimethyl adipate by continuous esterification - Google Patents
Method for preparing dimethyl adipate by continuous esterification Download PDFInfo
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- CN102442905A CN102442905A CN2010105114068A CN201010511406A CN102442905A CN 102442905 A CN102442905 A CN 102442905A CN 2010105114068 A CN2010105114068 A CN 2010105114068A CN 201010511406 A CN201010511406 A CN 201010511406A CN 102442905 A CN102442905 A CN 102442905A
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Abstract
The invention discloses a method for preparing dimethyl adipate by continuous esterification, comprising the steps of (1) pre-esterifying mixture of adipic acid and methanol in a tubular reactor with an inner component on the catalyst-free condition, wherein the temperature is 90-180 degrees centigrade and the pressure is 0.05-3 MPa; (2), sending the pre-esterified product to upper part of a continuous catalytic rectifying tower; enabling the dried methanol to enter the lower part of the catalytic rectifying tower after being vaporized; enabling the pre-esterified material to contact the methanol steam in the catalytic rectifying tower in a counter-current manner; and further performing esterifying. The method overcomes the problems that the traditional process has device corrosion and pollution problem caused by the sulphuric acid catalyst, and has no continuous pre-esterification and large catalyst consumption.
Description
Technical field
The present invention relates to a kind ofly 1, the working method of 6-dimethyl adipate particularly uses solid acid to do the dimethyl adipate working method of catalyzer.
Background technology
1, the 6-dimethyl adipate is good cold resistant plasticizer, can give the good low-temperature pliability of goods can, and have must photo and thermal stability and water tolerance.1, the 6-dimethyl adipate still is important organic synthesis raw material, and chemical intermediate can produce 1 through hydrogenation, the 6-pinakon.
At present, about 1, the report of 6-dimethyl adipate working method has: GB143069 discloses a kind of comparatively primary process method, uses the vitriol oil as catalyzer, adopts the method for tank reactor reaction distillation to dewater.Adopting inorganic liquid acid is catalyzer, has the problem of environmental pollutions such as three wastes processing of inorganic liquid acid to corrosion on Equipment and reaction product.DE19610564 discloses a kind of a plurality of tank reactor series connection, is reflected at and carries out periodical operation under the agitation condition, and adopt rhythmic reaction to be unfavorable for the continuous industry production of mass-producing.WO99/62852 discloses a kind of cyclohexane oxidation by product hexanodioic acid and methanol esterification method, uses sulfuric acid to be catalyzer, tubular reactor, and distillation dewaters, and obtains dimethyl adipate.CN 200610112688.8 is disclosed to be to adopt fixed bed; With hexanodioic acid and methyl alcohol is raw material; Solid acid catalyst, the fixed bed continuous esterification production of adipic acid dimethyl ester, raw material gets into flow reactor after need passing through preparatory esterification treatment; Pre-esterification reactor need add catalyzer, has increased production cost.
Of above-mentioned prior art; Hexanodioic acid esterification reaction needed catalyzer exist and suitable condition under carry out; Esterifying catalyst is generally an acidic catalyst; Like sulfuric acid, sodium pyrosulfate, molecular sieve, heteropolyacid, acidic resins etc., hexanodioic acid can be dissolved in ethanol, methyl alcohol equal solvent under usual conditions, but esterification does not take place.
Summary of the invention
The object of the present invention is to provide a kind of method of hexanodioic acid continuous esterification, overcome existing hexanodioic acid esterification and produce in the dimethyl adipate process, esterification can not the successive problem in advance.
The method that continuous esterification of the present invention prepares dimethyl adipate may further comprise the steps:
(1) hexanodioic acid and methyl alcohol are added in the raw materials mix jar, head tank is the non-pressure vessel that has stirring, and hexanodioic acid and methyl alcohol are through after mixing; Do not use catalyzer; Squeeze in the tubular reactor that has inner member 90-180 ℃ of tubular reactor temperature of reaction, preferred 110-150 ℃ by pump; Pressure 0.05-3MPa, preferred 0.5-1MPa, material is 0.2-6h in the inner reaction tube residence time, preferred 2-4h.
(2) cold material heat exchange in tubular reactor outlet logistics and the raw materials mix jar, after the heat exchange in the head tank mixing raw material temperature be not higher than 70 ℃, be generally 40～70 ℃, the preparatory esterification material after heat exchange is lowered the temperature gets into follow-up catalytic rectifying tower.
(3) the preparatory esterification material after the heat exchange cooling is delivered to catalytic rectifying tower top, and exsiccant methyl alcohol gets into the catalytic rectifying tower bottom after vaporizing, and material behind the pre-esterification reactor and methanol steam counter current contact in esterification column is further carried out esterification.Temperature of reaction in the catalytic rectifying tower is 70-150 ℃; Material air speed behind the pre-esterification reactor is that 0.1～2.0kg/kgh (per hour gets into the ratio of the weight of catalytic rectifying tower reaction mass to catalyst weight; As follows), the methyl alcohol air speed is 0.1～10.0kg/kgh.The dimethyl adipate that the catalytic distillation reaction obtains is discharged at the bottom of tower, and the water vapor that excessive methyl alcohol and stripping go out is discharged from cat head.
In the inventive method, used pre-esterification reactor device is the tubular reactor that has inner member, and inner member is generally baffle, twisted blade.Tubular reactor can be single, also can be many polyphones, also can be many and connects.The selected twisted blade angle of tubular reactor inner member is the 0-180 degree, and the ratio range of individual blade and diameter (tubular reactor internal diameter) is L/D=0.5-2, and unit number is 1-100.In the practice, can use the static mixer of any structure.
In the inventive method, the dimethyl adipate of discharging at the bottom of the catalytic rectifying tower can adopt the method for rectifying further to purify, and the moisture vapor methyl alcohol that the catalytic distillation cat head is discharged further recycles behind the rectifying and dewatering.Aforesaid method can adopt the conventional method in this area.
The hexanodioic acid solid is by spiral fresh feed pump charging feed mixing tank, and methyl alcohol is by methanol pump charging feed jar, and the raw materials mix jar is the container of normal pressure band stirring; In coil heat exchanger is arranged, mixed serum is carried out preliminary preheating, raw materials mix jar outlet is connected with fresh feed pump; The fresh feed pump discharge port is connected with tubular reactor; Tubular reactor can be single or a plurality of polyphones or parallel connection, and the tubular reactor outlet is connected with reducing valve, and reducing valve goes out to connect snakelike heat exchange tube; Incoming stock mixing tank and wherein material heat exchange link to each other with catalytic rectifying tower top opening for feed through the esterification feed pump then.
In the inventive method, can use the highly acidic resin catalyzer in the catalytic rectifying tower, specifically can select the conventional commercially available highly acidic resin catalyst prod in this area for use.
Because adopt above technical scheme, the inventive method has following technique effect:
(1) the pre-esterification reactor process combines with the catalytic distillation esterification reaction process; Because esterification process has carried out the esterification of certain transformation efficiency in advance; Therefore when improving the hexanodioic acid transformation efficiency; Reduce the reaction load of catalytic distillation esterification, reduced the highly acidic resin catalyst consumption, reduced process cost.
(2) adopt have inner member tubular reactor as the pre-esterification reactor device, having solved preparatory esterification can't the successive problem.Hexanodioic acid is slightly soluble in methyl alcohol, and the pasty mixture of hexanodioic acid and methyl alcohol can not must carry out preparatory esterification directly as the catalytic distillation charging; And the tubular reactor that has inner member is equivalent to the withstand voltage still with stirring; Be superior to withstand voltage still again, withstand voltage still can not be realized operate continuously, and tubular reactor can be continuous; Can control level of response better through the length of adjustable pipe and the residence time of material.
(3) in advance after the esterification temperature of charge more than 100 ℃; It is temperature required to be higher than the catalytic rectifying tower inlet, so utilize this strand material and raw material heat exchange, the esterification temperature of charge can reach catalytic rectifying tower charging requirement in advance; Improved preparatory esterification feed temperature simultaneously; Save the raw material preheating process furnace, practiced thrift the energy, improved plant factor.
(4) the inventive method is compared with CN00610112688.8, has simplified the pre-esterifying process step, because catalyzer is not used in esterification in advance, has practiced thrift production cost, has saved catalyst filtration step, has practiced thrift process cost.Show through research; Hexanodioic acid and methyl alcohol are difficult for taking place esterification under usual conditions; Even the less demanding preliminary pre-esterification reactor of transformation efficiency also need carry out under catalyzer and the condition that suits, therefore, those of ordinary skills can not expect not using the preparatory esterification process of catalyzer.The present invention is through discover in a large number, under given conditions, and as under suitable reaction pressure and temperature of reaction; Can excite the catalytic performance of hexanodioic acid self, realize certain esterification transformation efficiency, though along with the carrying out that reacts; Hexanodioic acid content reduces, and makes the self-catalysis of pre-esterification reactor system reduce, but has reached the requirement of pre-esterification reactor; Therefore, can realize not using the pre-esterification reactor process of catalyzer fully.
Description of drawings
Fig. 1 is an adipic acid ester metallization processes experiment flow synoptic diagram of the present invention.
Wherein: 1-raw materials mix jar, 2-fresh feed pump, 3-tubular reactor, 4-methanol tank, 5-reducing valve, 6-catalytic rectifying tower, 7-esterification feed pump, 8-methyl alcohol vaporizer, 9-coil heat exchanger, 10-methyl alcohol tundish, 11-condensing surface, 12-methanol feeding pump.
Embodiment
Further specify scheme of the present invention and effect below in conjunction with accompanying drawing.
Shown in Fig. 1 experimental technique flow process of the present invention, the equipment of use comprises raw materials mix jar 1, fresh feed pump 2, tubular reactor 3; Methanol tank 4, pressurizing valve 5, catalytic rectifying tower 6 esterification feed pumps 7, methyl alcohol vaporizer 8; Coil heat exchanger 9, methyl alcohol tundish 10, condensing surface 11, methyl alcohol tundish 10.
Hexanodioic acid and methyl alcohol carry out pre-esterification reactor under catalyst-free existence and appropriate processing condition in the pre-esterification reactor device; The pre-esterification reactor product gets into the catalytic rectifying tower top after reducing pressure; Carry out further esterification with the methanol steam that gets into from catalytic distillation reaction tower bottom; The reaction product dimethyl adipate is discharged entering ester rectifying and purifying system at the bottom of catalytic rectifying tower, the water that excessive methanol that the catalytic distillation cat head is discharged and stripping go out gets into the methanol purification recovery system.
Further specify the present invention program and effect through embodiment below.
Embodiment 1
The pre-esterification reactor experiment
Mix methyl alcohol and hexanodioic acid by alcohol/sour mol ratio 3～5; Through tubular reactor, pipe range 5m, internal diameter 1cm; 180 ° of twisted blades this tower ladder gram mixing tank of 90 ° of arrangements that staggers; Under the catalyst-free condition, hexanodioic acid and methyl alcohol generation pre-esterification reactor, experimental result is seen table 1 (the hexanodioic acid transformation efficiency is pressed the liquid-phase chromatographic analysis result and calculated).
Table 1 embodiment 1 pre-esterification reactor result
The test of embodiment 2 pre-esterification reactors
Mix methyl alcohol and hexanodioic acid by alcohol/sour mol ratio 3～5, through tubular reactor, pipe range 1m; Internal diameter 1cm; 180 ° of twisted blades this tower ladder gram mixing tank of 90 ° of arrangements that staggers, the reaction times is 2h, under the catalyst-free condition; Hexanodioic acid and methyl alcohol generation pre-esterification reactor, experimental result are seen table 2 (the hexanodioic acid transformation efficiency is pressed the liquid-phase chromatographic analysis result and calculated).
Table 2 embodiment 2 pre-esterification reactor results
| The experiment sequence number | Molar ratio of alcohol to acid | Temperature of reaction, ℃ | The hexanodioic acid transformation efficiency, % |
| 1 | 3 | 120 | 84.2％ |
| 2 | 3 | 130 | 91.4％ |
| 3 | 3 | 140 | 95.6％ |
Comparative example 1
Test the material proportion of sequence number 1 by embodiment, under 80 ℃ of conditions of normal pressure, mixed 2 hours, tangible esterification does not take place.Add the resin catalyst of hexanodioic acid weight 5%, stirring and refluxing was mixed 2 hours under 80 ℃ of condition of normal pressure, and the hexanodioic acid transformation efficiency is 70.1%.
Esterification experimental result under the embodiment 3 different air speeds
Utilize the mixture behind embodiment 1 pre-esterification reactor to carry out the continuous esterification experiment; The DNW-type that uses Dandong Mingzhu Special Type Resin Co., Ltd. to produce is catalyzer; The reaction of employing catalytic distillation is provided with 10 blocks of column plates, uniform distribution resin catalyst on every block of column plate in catalytic rectifying tower.Operation is pressed and is normal pressure, and column bottom temperature is 120 ℃, and tower top temperature is 95 ℃, and the reaction result under different condition is seen table 3.
Table 3 catalytic distillation esterification condition and result
Claims (10)
1. a continuous esterification prepares the method for dimethyl adipate, it is characterized in that may further comprise the steps:
(1) hexanodioic acid and methyl alcohol are added in the raw materials mix jar; Head tank is the non-pressure vessel that has stirring, and hexanodioic acid and methyl alcohol do not use catalyzer through after mixing; Squeeze in the tubular reactor that has inner member by pump; The tubular reactor temperature of reaction is 90-180 ℃, and pressure is 0.05-3MPa, and material is 0.2-6h in the inner reaction tube residence time;
(2) cold material heat exchange in tubular reactor outlet logistics and the raw materials mix jar, after the heat exchange in the head tank mixing raw material temperature be not higher than 70 ℃, the preparatory esterification material after heat exchange is lowered the temperature gets into follow-up catalytic rectifying tower;
(3) the preparatory esterification material after the heat exchange cooling is delivered to catalytic rectifying tower top; Exsiccant methyl alcohol gets into the catalytic rectifying tower bottom after vaporizing; Material behind the pre-esterification reactor and methanol steam counter current contact in esterification column; Further carry out esterification, the dimethyl adipate that the catalytic distillation reaction obtains is discharged at the bottom of tower, and the water vapor that excessive methyl alcohol and stripping go out is discharged from cat head.
2. according to the described method of claim 1, it is characterized in that: the tubular reactor temperature of reaction is 110-150 ℃, and pressure is 0.5-1MPa, and material is 2-4h in the inner reaction tube residence time.
3. according to the described method of claim 1, it is characterized in that: after the heat exchange in the head tank mixing raw material temperature be 40～70 ℃.
4. according to the described method of claim 1, it is characterized in that: the temperature of reaction in the catalytic rectifying tower is 70-150 ℃, and the material air speed behind the pre-esterification reactor is 0.1～2.0kg/kgh, and the methyl alcohol air speed is 0.1～10.0kg/kgh.
5. according to the described method of claim 1, it is characterized in that: the pre-esterification reactor device is the tubular reactor that has inner member, and inner member is baffle or twisted blade.
6. according to claim 1 or 5 described methods, it is characterized in that: tubular reactor is single, or many polyphones, or many and connect.
7. according to the described method of claim 5, it is characterized in that: the selected twisted blade angle of tubular reactor inner member is the 0-180 degree, and the ratio range of individual blade and diameter is L/D=0.5-2, and unit number is 1-100.
8. according to the described method of claim 1, it is characterized in that: tubular reactor is a static mixer.
9. according to the described method of claim 1, it is characterized in that: the dimethyl adipate of discharging at the bottom of the catalytic rectifying tower adopts the method for rectifying further to purify, and recycles behind the further rectifying and dewatering of moisture vapor methyl alcohol that the catalytic distillation cat head is discharged.
10. according to the described method of claim 1, it is characterized in that: use the highly acidic resin catalyzer in the catalytic rectifying tower.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103342638A (en) * | 2013-07-31 | 2013-10-09 | 山东兰典生物科技股份有限公司 | Preparation method of dibutyl succinate |
| CN104557536A (en) * | 2013-10-24 | 2015-04-29 | 中国石油化工股份有限公司 | Method for preparing mono-methyl succinate |
| CN105435726A (en) * | 2015-12-09 | 2016-03-30 | 安徽华业香料股份有限公司 | Continuous reaction device special for synthesizing gamma-lactone |
| CN103694215B (en) * | 2013-12-10 | 2016-05-11 | 安徽丰原发酵技术工程研究有限公司 | A kind of continuity is prepared method and the device of DXPE |
| CN106220499A (en) * | 2016-08-03 | 2016-12-14 | 中国石油大学(华东) | A kind of Apparatus and method for producing dimethyl adipate |
| CN106242970A (en) * | 2016-08-03 | 2016-12-21 | 中国石油大学(华东) | A kind of Apparatus and method for producing dimethyl adipate |
| CN109748791A (en) * | 2017-11-01 | 2019-05-14 | 中国石油化工股份有限公司 | Produce the power-economizing method of dimethyl adipate |
| CN109748790A (en) * | 2017-11-01 | 2019-05-14 | 中国石油化工股份有限公司 | The method for producing dimethyl adipate |
| CN111320543A (en) * | 2018-12-13 | 2020-06-23 | 中国石油化工股份有限公司 | Method for producing dimethyl adipate from adipic acid |
| CN113443983A (en) * | 2021-07-30 | 2021-09-28 | 浙江工业大学 | Production method of dimethyl sebacate |
| CN114829332A (en) * | 2020-11-17 | 2022-07-29 | 株式会社Lg化学 | Process for preparing diester materials |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101134725A (en) * | 2006-08-30 | 2008-03-05 | 中国石油天然气股份有限公司 | Method and equipment for continuous esterification production of adipic acid dimethyl ester |
-
2010
- 2010-10-12 CN CN201010511406.8A patent/CN102442905B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101134725A (en) * | 2006-08-30 | 2008-03-05 | 中国石油天然气股份有限公司 | Method and equipment for continuous esterification production of adipic acid dimethyl ester |
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| CN103342638A (en) * | 2013-07-31 | 2013-10-09 | 山东兰典生物科技股份有限公司 | Preparation method of dibutyl succinate |
| CN103342638B (en) * | 2013-07-31 | 2015-01-14 | 山东兰典生物科技股份有限公司 | Preparation method of dibutyl succinate |
| CN104557536A (en) * | 2013-10-24 | 2015-04-29 | 中国石油化工股份有限公司 | Method for preparing mono-methyl succinate |
| CN104557536B (en) * | 2013-10-24 | 2016-03-30 | 中国石油化工股份有限公司 | A kind of preparation method of monomethyl succinate |
| CN103694215B (en) * | 2013-12-10 | 2016-05-11 | 安徽丰原发酵技术工程研究有限公司 | A kind of continuity is prepared method and the device of DXPE |
| CN105435726A (en) * | 2015-12-09 | 2016-03-30 | 安徽华业香料股份有限公司 | Continuous reaction device special for synthesizing gamma-lactone |
| CN106220499B (en) * | 2016-08-03 | 2018-05-04 | 中国石油大学(华东) | A kind of device and method for producing dimethyl adipate |
| CN106242970A (en) * | 2016-08-03 | 2016-12-21 | 中国石油大学(华东) | A kind of Apparatus and method for producing dimethyl adipate |
| CN106220499A (en) * | 2016-08-03 | 2016-12-14 | 中国石油大学(华东) | A kind of Apparatus and method for producing dimethyl adipate |
| CN106242970B (en) * | 2016-08-03 | 2018-09-21 | 中国石油大学(华东) | A kind of device and method producing dimethyl adipate |
| CN109748791A (en) * | 2017-11-01 | 2019-05-14 | 中国石油化工股份有限公司 | Produce the power-economizing method of dimethyl adipate |
| CN109748790A (en) * | 2017-11-01 | 2019-05-14 | 中国石油化工股份有限公司 | The method for producing dimethyl adipate |
| CN109748790B (en) * | 2017-11-01 | 2021-08-03 | 中国石油化工股份有限公司 | Method for producing dimethyl adipate |
| CN111320543A (en) * | 2018-12-13 | 2020-06-23 | 中国石油化工股份有限公司 | Method for producing dimethyl adipate from adipic acid |
| CN114829332A (en) * | 2020-11-17 | 2022-07-29 | 株式会社Lg化学 | Process for preparing diester materials |
| CN113443983A (en) * | 2021-07-30 | 2021-09-28 | 浙江工业大学 | Production method of dimethyl sebacate |
| CN113443983B (en) * | 2021-07-30 | 2022-02-22 | 浙江工业大学 | Production method of dimethyl sebacate |
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