CN1480443A - Prepn. process for fined acroleic acid - Google Patents
Prepn. process for fined acroleic acid Download PDFInfo
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- CN1480443A CN1480443A CNA031526888A CN03152688A CN1480443A CN 1480443 A CN1480443 A CN 1480443A CN A031526888 A CNA031526888 A CN A031526888A CN 03152688 A CN03152688 A CN 03152688A CN 1480443 A CN1480443 A CN 1480443A
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Abstract
The method for producing the refined acrylic acid comprises adding a hydrazine compound to acrylic acid obtained by gas phase catalytic oxidation process followed by distilling the acrylic acid at <=100[deg.]C in the presence of copper dithiocarbamate, wherein the distillation is carried out as follows: a demister with the upper part consisting of a packing bed packed with a packing material and the lower part consisting of a sieve tray is installed in a distillation column and the demister is fed with part of the refined acrylic acid distilled out of the distillation column as washing liquid.
Description
Technical field that the present invention belongs to
The present invention relates to refining method for producing acrylic acid, in further detail, relate in the presence of hydrazine compound and dithiocarbamic acid copper, will be by the refining method for producing acrylic acid of the vinylformic acid distillatory that the gas phase contact oxidation method obtains.
Background of invention
Preparing acrylic acid by the gas phase contact oxidation method is known as acrylic acid industrial making method, but ketone such as aldehydes such as this preparation method's by-product furfural, phenyl aldehyde and acetone etc.
Usually, acrylic acid refining undertaken by distillation, but there are the problem of removing difficulty by the distillating method of routine in such impurity, particularly furfural in the vinylformic acid that obtains by the gas phase contact oxidation method.
In recent years, vinylformic acid is as its increases in demand such as raw material of absorbent resin, in such purposes, and special requirement high purity and non-staining.But, if the refining vinylformic acid that routine distillation is obtained uses as the raw material of absorbent resin, then when polyreaction, problem such as delays that react, polymerization degree decline, polymkeric substance are painted, as one of them reason, the above-mentioned impurity of by-product in the time of can enumerating vinylformic acid and prepare.
For solve since such impurity due to problem, proposed when vinylformic acid distills, add hydrazine, make reactions such as itself and furfural, distill acrylic acid (Japanese Patent disclose clear 49-30312, Japanese Patent disclose clear 63-14752, Japanese Patent discloses clear 61-218556) simultaneously.Though this method is removed effectively about above-mentioned impurity, this other problems of a large amount of polymerizations of vinylformic acid when distilling when producing distillation.Because the polymerizing acrylic acid thing is attached to the reboiler heat-transfer surface of distillation tower, not only cause the decline of heat transfer property, and cause the reduction of distillation tower usefulness and the obstruction of distillation tower inside, adopt under the situation of this distillating method, in order to clean distillation tower inside, must stop once acrylic acid preparation, long-time continuously its preparation of continuation becomes difficult.
The inventor has developed in the presence of hydrazine and dithiocarbamic acid copper in order to address these problems, distillation acrylic acid (Japanese Patent discloses flat 7-228548).
Summary of the invention
The objective of the invention is to, a kind of refining method for producing acrylic acid more excellent than this method is provided.
The inventor, for furtheing investigate by the refining acrylic acid of vinylformic acid preparation that obtains by the gas phase contact oxidation method, found that: adopt following method, the fog of fully removing in the distillation tower promptly is set, and polymkeric substance is difficult to the mist eliminator of adherent structure and distills acrylic acid, specifically, for example, use is arranged on top and has the packing layer of having filled weighting material in distillation tower, the distillation tower that has the mist eliminator of sieve tray in the bottom, to supply with this mist eliminator as washings from the refining acrylic acid part of distillation tower distilled, and distillatory method, can prepare the refining vinylformic acid of painted reduction continuously for a long time, thereby finish the present invention by the vinylformic acid that obtains by the gas phase contact oxidation method.
That is to say, the invention provides refining method for producing acrylic acid, it is characterized in that, in the presence of hydrazine and dithiocarbamic acid copper, prepare in the refining acrylic acid at the vinylformic acid that distillation below 100 ℃ obtains by the gas phase contact oxidation method, use is arranged on top and has the packing layer of having filled weighting material in distillation tower, have the distillation tower of the mist eliminator of sieve tray in the bottom, will supply with mist eliminator and distillation from the refining acrylic acid part of distillation tower distilled.
The simple declaration of accompanying drawing
Fig. 1 is the figure of an example that expression can be implemented the water distilling apparatus of the inventive method.Nomenclature
1. distillation tower
2. mist eliminator
3. constitute the packing layer on mist eliminator top
4. constitute the sieve tray of mist eliminator bottom
5. condenser
6. reboiler
7. crude acrylic acid (supply liquid)
8. refining vinylformic acid (distillate)
9. the washings of mist eliminator
10. liquid at the bottom of the tower
The working of an invention mode
Fig. 1 represents an example of the water distilling apparatus of the inventive method that can implement, with Fig. 1 an embodiment of the invention are described below, but method of the present invention is not limited to this mode.
In the inside of distillation tower 1, be arranged on top and have the packing layer 3 of having filled weighting material, have the mist eliminator 2 of sieve tray 4 in the bottom.By the crude acrylic acid 7 (supply liquid) that the gas phase contact oxidation method obtains, supply with the distillation tower bottom with hydrazine compound and dithiocarbamic acid copper.The vinylformic acid steam of heating and gasifying is by mist eliminator 2 in reboiler 6, condensation in condenser 5, its result obtains refining vinylformic acid 8 (distillate), should make with extra care an acrylic acid part as washings 9, supply between the filling bed and sieve tray of mist eliminator.Coloring components, the polymerization composition that is captured by sieve tray 4 removed in washing thus, can think and suppress resulting refining acrylic acid painted and because obstruction of the distillation tower inside that polymkeric substance causes.Extract liquid 10 at the bottom of the tower that contains high boiling material, polymkeric substance etc. out from the tower bottom of distillation tower.
The vinylformic acid that obtains by the gas phase contact oxidation method obtains by gas phase catalytic oxidation propylene and/or propenal, usually contains the ketone of the aldehydes of furfural, phenyl aldehyde etc. of by-product and acetone etc. as impurity.
As the hydrazine compound that uses among the present invention, for example, can enumerate hydrazine hydrate, phenyl hydrazine, hydrazonium sulfate, hydrazine hydrochloride etc.Hydrazine compound optimum amount in vinylformic acid becomes according to the content of impurity etc., with respect to the crude acrylic acid of supplying with distillation tower, can for about 50ppm to about 5000ppm, be preferably about 200ppm and arrive about 3000ppm.By there being hydrazine compound, the above-mentioned impurity that contains in can fractionation by distillation vinylformic acid, when particularly distilling easily and the furfural that accompanies of vinylformic acid.
As the dithiocarbamic acid copper that uses among the present invention, can enumerate, cupric dimethyldithiocarbamate, copper diethyl dithiocarbamate, dipropyl dithiocarbamic acid copper, copper dialkyldithiocarbamates such as copper dibutyldithiocarbamate, ethylene thiocarbamate copper, tetramethylene dithiocarbamic acid copper, pentamethylene dithiocarbamic acid copper, the cyclic alkylidene dithiocarbamic acid copper of hexa-methylene dithiocarbamic acid copper, ring-type oxygen such as oxygen diethylidene dithiocarbamic acid copper two alkylidene group dithiocarbamic acid copper etc.The preferred copper dialkyldithiocarbamate that uses.
The best amount of dithiocarbamic acid copper in vinylformic acid, in vinylformic acid as the washings of mist eliminator, can for about 1ppm to about 1000ppm, be preferably about 10ppm and arrive about 500ppm.In as the vinylformic acid that distills liquid at the bottom of the Tata, can arrive about 3000ppm for about 100ppm.When the addition of dithiocarbamic acid copper is too much, prevent aspect the polymerization effect no problem especially, but when distilling at the bottom of the tower dithiocarbamic acid copper concentration in the liquid become too high, the anxiety of the corrosion of equipment of causing is arranged.
Among the present invention, preferably will supply with the liquid crude acrylic acid and supply at the bottom of the distillation Tata.Dithiocarbamic acid copper concentration is the highest in the distillation tower, at the bottom of mist eliminator ground squarer far away, supplies with crude acrylic acid, can prevent polymerization, and bring into play the function of mist eliminator efficiently.
Be provided with in the inside of distillation tower and have packing layer of having filled weighting material and the mist eliminator that has sieve tray in the bottom on top.
As weighting material, can use Pall ring, Raschig ring, the small-sized ring of stepwise etc., its size can be about 1-2 inch.
The height of packing layer can be the about 500mm of about 100mm-.
As sieve tray, can use aperture opening ratio to be about 10～about 40%.About 25mm can be arrived for about 12mm in its aperture.
The exponent number of sieve tray can be about 5 rank of about 1-, is preferably about 2 to about 4 rank.
In addition, these weighting materials or sieve tray, unnecessary have a separation performance essential in the general distillation.As mist eliminator (fog separator), can be to collide fog that accompanies with gas and the function that captures fog.
Among the present invention, can use the scarce round mist eliminator sieve tray of part with whole about 20%～about 30% area of shortcoming.Lacking rotary strainer plate tower tray can use separately, and preferable case is scarce rotary strainer plate tower tray further to be set below above-mentioned sieve tray to use.Lack rotary strainer plate tower tray, though since polymkeric substance adhere to and make hole plug owing to have scarce circular portion, can wholely not stop up yet, be configured to further be provided with below above-mentioned sieve tray under the situation that lacks rotary strainer plate tower tray, comprise above-mentioned sieve tray, exponent number amounts to and can reach about 10 rank.Preferably, use about 2～about 4 rank exponent number above-mentioned sieve tray or add the scarce rotary strainer plate tower tray of the left and right sides, 2 rank exponent number thereon.
According to the fog situation occurred in the distillation Tata, the adhesion situation of polymkeric substance, below the sieve tray of the exponent number on about 2～about 4 rank, replace above-mentioned scarce rotary strainer plate tower tray, the packing layer of highly about 100mm～about 500mm also can further be set, but this structure, the obstruction that also easy sometimes generation causes because of polymkeric substance according to the distillation condition difference.
Among the present invention, will offer mist eliminator as washings, preferably supply between the packing layer and sieve tray of mist eliminator from the refining acrylic acid part of distillation tower distilled.By this operation, particularly the fog washing that is captured by sieve tray can be removed the feed rate of this washings, every 1m
2Comprise the tray surfaces long-pending (being the surface-area that comprises peristome of sieve tray internal surface) of peristome, the washings feed rate is about 0.2 to about 5m
3/ h is preferably about 0.3 to about 3m
3/ h, washings can be supplied with continuously, also can supply with off and on, but from the viewpoint of continuous operation, supply with continuously usually.
By the above-mentioned mist eliminator that in distillation tower, is provided with, the fog of following steam to steam in the time of can removing distillation efficiently.Particularly, the fog of following steam to steam is captured by the sieve tray that constitutes the mist eliminator bottom, and its fog that is captured is removed by the washings washing.Simultaneously, the packing layer that constitutes mist eliminator top is removed the fog that is not captured by the sieve tray of bottom.Thus, can fully remove the fog that in distillation tower, produces, can prevent as distillate obtain refining acrylic acid painted, this mist eliminator in the application of the invention, adhering to of polymkeric substance tails off, be difficult to take place the obstruction of distillation tower, the continuous operation of the distillation tower of longer time becomes possibility.
Among the present invention, the distillation of crude acrylic acid can be carried out simple distillation.
The reaction product of hydrazine compound and aldehydes and acrylic acid fractionation by distillation are not the precise distillation that need use the packed tower or the sieve tray of multistage especially.Carry out under the situation of precise distillation, since many at inside stuffing etc., so take place sometimes because the obstruction that polymkeric substance causes.
Among the present invention, preferred distillation is under reduced pressure carried out, and distillation temperature can be preferably below 80 ℃ for below 100 ℃, more preferably below 70 ℃.In order to suppress acroleic acid polymerization, preferably under lower temperature, make acrylic acid residence time reduce ground, carrying out isolating velocity ranges such as impurity, heat up in a steamer vinylformic acid rapidly.Preferred liquid at the bottom of the tower that will extract out from distillation tower distills under the lower decompression in than its distillation tower, and its distillate is recovered in the distillation tower.
Among the present invention, forbid agent as polymerization, except that dithiocarbamic acid copper, can add quinhydrones or metoquinone phenol such as (メ ト キ ノ Application), amines such as thiodiphenylamine are preferably united and are used these polymerizations to forbid agent.
The invention effect
The method according to this invention by the vinylformic acid that obtains by the gas phase contact oxidation method, can the preparation of long-time continuous ground fully be removed impurity and the painted few refining vinylformic acid that becomes the composition of coloration reason.The refining vinylformic acid of gained effectively utilizes its advantage, and preferably the raw material as absorbent resin uses.
Embodiment
Embodiment 1
Use inner distillation tower (tower diameter: Φ 1000mm, material: SUS304), make with extra care acrylic acid preparation by simple distillation with mist eliminator.Mist eliminator has been filled by top that the packing layer of floor height 400mm Pall ring (size: 1.5 inches), 2 sections aperture opening ratios in the bottom are 28% sieve tray, in its lower section 2 sections aperture opening ratios 21.5%, 25% sieve tray of lacking circle constitutes again, washings is supplied with the sieve tray of bottom.
Contain as polymerization forbid the 200ppm thiodiphenylamine, 30ppm copper dibutyldithiocarbamate of inhibitor, as the 50ppm furfural of impurity, in the crude acrylic acid that gas phase contact oxidation method by propylene obtains, after adding the hydrazine of 500ppm, supplying with to the tower bottom of distillation tower with 2.5t/h, is that 30torr, column bottom temperature are to implement distillation under 63 ℃ the condition at tower top pressure.The condensation overhead vapours obtains refining vinylformic acid as goods, on the other hand, as washings, supplies with 0.6t/h to mist eliminator, adds copper dibutyldithiocarbamate so that its concentration is 100ppm in this washings.Extract liquid at the bottom of the tower out with 0.5t/h at the bottom of the tower.Liquid distills under 20torr at the bottom of the tower of extracting out, and its distillate is recovered in the above-mentioned distillation tower.
Its result, distillation tower can runs steadily three months, and in addition, the furfural concentration in the refining vinylformic acid that obtains is less than 1ppm.For the degree that the spittle of determining in the refining vinylformic acid is followed, measured the concentration of the thiodiphenylamine in the refining vinylformic acid that obtains, the result is less than 0.1ppm.The refining vinylformic acid sample that obtains is deposited a week, be still water white state.
Embodiment 2
Lack rotary strainer plate tower tray except not being provided with, the bottom of mist eliminator only is that 2 rank aperture opening ratios are outside 28% the sieve tray, implement distillation similarly to Example 1, distillation tower can steady running three months as a result, at this moment, furfural concentration is less than 1ppm in the refining vinylformic acid that obtains, and the concentration of thiodiphenylamine is less than 0.1ppm.The refining vinylformic acid sample that obtains is deposited a week, be still water white state.
Embodiment 3
Except the sieve tray that lacks circle is not set, the bottom of mist eliminator is provided with the sieve tray of 2 rank aperture opening ratios 28%, with size is arranged in its underpart is outside 2 inches the stepwise small, annular packing layer (floor height 500mm), implement distillation similarly to Example 1, distillation tower can continuous operation three months as a result, at this moment, furfural concentration is less than 1ppm in the refining vinylformic acid that obtains, and the concentration of thiodiphenylamine is less than 0.1ppm.The refining vinylformic acid sample that obtains is deposited a week, be still water white state.Comparative example 1
Replace the sieve tray of 2 rank aperture opening ratios 28% and the sieve tray that 2 rank aperture opening ratios 21.5%, 25% lack circle, make the stepwise small, annular packing layer (floor height 500mm) of the bottom of mist eliminator for 2 inches of sizes, do not supply with washings, with crude acrylic acid be not supply with tower at the bottom of, but supply with outside the supply unit of washings, implement distillation similarly to Example 1.Copper dibutyldithiocarbamate added in crude acrylic acid and was 50ppm this moment, it is running of distillation tower effluxion after month as a result, tower bottom pressure rises, must shut down, open the result of inspection, adhering to fusible polymkeric substance and obstruction on the packing layer of mist eliminator bottom firmly, the packing layer on mist eliminator top is by the xanchromatic polymer plugging in addition.Comparative example 2
Except the packing layer that the mist eliminator bottom is not set, similarly implement distillation with comparing embodiment 1, its result, at this moment, the concentration of thiodiphenylamine is 0.3ppm in the vinylformic acid that obtains, and shuts down.When the refining vinylformic acid sample retention that will obtain,, be colored as pink along with effluxion.Comparative example 3
Remove the sieve tray and the 2 rank aperture opening ratios 21.5%, 25% that replace 2 rank aperture opening ratios 28% and lack round sieve tray, make outside the stepwise small, annular packing layer (floor height 500mm) of bottom for 2 inches of sizes of mist eliminator, implement distillation similarly to Example 1.As a result, the concentration of thiodiphenylamine is 0.2ppm in the vinylformic acid that obtain this moment, shuts down.When refining vinylformic acid that preservation obtains, the process along with the time is colored as pink.Comparative example 4
Except the size that mist eliminator top is not set is 1.5 inches Pall ring packing layer, implement distillation similarly to Example 3, the result, the concentration of thiodiphenylamine has surpassed 1ppm in the refining vinylformic acid that obtain this moment, and running stops.
Claims (13)
1, a kind of refining method for producing acrylic acid, it is characterized in that, in the presence of hydrazine compound and dithiocarbamic acid copper, below 100 ℃, the vinylformic acid that distillation is obtained by the gas phase contact oxidation method prepares in the refining acrylic acid, use is provided with the distillation tower that has the packing layer of having filled weighting material on top, has the mist eliminator of sieve tray in the bottom in distillation tower, will supply with mist eliminator and distillation from the refining acrylic acid part of distillation tower distilled.
2, the refining method for producing acrylic acid of claim 1 record wherein, will be supplied with the tower bottom that distillatory vinylformic acid supplies to distillation tower.
3, the refining method for producing acrylic acid of claim 1 record, wherein, weighting material is Pall ring, Raschig ring, the small-sized ring of stepwise, its size is the 1-2 inch.
4, the preparation method of claim 1 record, wherein the height of packing layer is 100mm～500mm.
5, the preparation method of claim 1 record, wherein the aperture opening ratio of sieve tray is 10-40%.
6, the preparation method of claim 1 record, wherein the exponent number of sieve tray is the 1-5 rank.
7, the preparation method of claim 1 record, wherein the feed rate of washings is every 1m
2The area (be sieve tray internal surface comprise peristome at interior surface-area) that comprises the sieve tray peristome is 0.2～5m
3/ h.
8, the preparation method of claim 1 record, wherein, the concentration of dithiocarbamic acid copper is 1ppm～1000ppm in washings, is 100ppm～3000ppm in liquid at the bottom of the tower of distillation tower.
9, the preparation method of claim 1 record wherein, supplies with washings between mist eliminator packing layer and sieve tray.
10, the preparation method of claim 1 record wherein, distills and is simple distillation.
11, the preparation method of claim 1 record, wherein, liquid distills under the lower decompression than this distillation tower at the bottom of the tower that distillation tower is extracted out, and its distillate is recovered in this distillation tower.
12, the preparation method of claim 1 record wherein, as sieve tray, is the sieve tray (lacking rotary strainer plate tower tray) with area shortcoming part.
13, the preparation method of claim 1 record, wherein, as sieve tray, configuration does not have the sieve tray of area shortcoming part and scarce rotary strainer plate tower tray and uses.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002219299A JP3841031B2 (en) | 2002-07-29 | 2002-07-29 | Method for producing purified acrylic acid |
| JP219299/2002 | 2002-07-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1480443A true CN1480443A (en) | 2004-03-10 |
Family
ID=31940239
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA031526888A Pending CN1480443A (en) | 2002-07-29 | 2003-07-26 | Prepn. process for fined acroleic acid |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP3841031B2 (en) |
| CN (1) | CN1480443A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103894204A (en) * | 2012-12-27 | 2014-07-02 | 中国石油化工股份有限公司 | Catalyst for catalyzing acrolein oxidation reaction to prepare acrylic acid, and preparation method thereof |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5247997B2 (en) * | 2005-08-19 | 2013-07-24 | 東レ・ダウコーニング株式会社 | Method for producing methacryloxy group- or acryloxy group-containing organosilicon compound |
| EP2135656A1 (en) * | 2008-05-30 | 2009-12-23 | Rohm and Haas Company | Method for production of purified (Meth)acrylic acid |
| JP6047880B2 (en) * | 2011-12-28 | 2016-12-21 | 東ソー株式会社 | Ion exchange membrane filling method |
| CN104667555B (en) * | 2015-02-13 | 2016-08-24 | 侯翔宇 | A kind of multi-functional foam removal rectifying column |
-
2002
- 2002-07-29 JP JP2002219299A patent/JP3841031B2/en not_active Expired - Fee Related
-
2003
- 2003-07-26 CN CNA031526888A patent/CN1480443A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103894204A (en) * | 2012-12-27 | 2014-07-02 | 中国石油化工股份有限公司 | Catalyst for catalyzing acrolein oxidation reaction to prepare acrylic acid, and preparation method thereof |
| CN103894204B (en) * | 2012-12-27 | 2016-09-07 | 中国石油化工股份有限公司 | Catalyst by acrolein oxidation acrylic acid synthesizing and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004059494A (en) | 2004-02-26 |
| JP3841031B2 (en) | 2006-11-01 |
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