CA2017580A1 - Process for the preparation of storage-stable levulinic acid - Google Patents
Process for the preparation of storage-stable levulinic acidInfo
- Publication number
- CA2017580A1 CA2017580A1 CA002017580A CA2017580A CA2017580A1 CA 2017580 A1 CA2017580 A1 CA 2017580A1 CA 002017580 A CA002017580 A CA 002017580A CA 2017580 A CA2017580 A CA 2017580A CA 2017580 A1 CA2017580 A1 CA 2017580A1
- Authority
- CA
- Canada
- Prior art keywords
- acid
- acetylsuccinate
- levulinic acid
- process according
- boiling point
- 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.)
- Abandoned
Links
- JOOXCMJARBKPKM-UHFFFAOYSA-N 4-oxopentanoic acid Chemical compound CC(=O)CCC(O)=O JOOXCMJARBKPKM-UHFFFAOYSA-N 0.000 title claims abstract description 88
- 229940040102 levulinic acid Drugs 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 239000002253 acid Substances 0.000 claims abstract description 19
- YIXSKDRXJTZCHT-UHFFFAOYSA-N 2-acetylbutanedioic acid Chemical class CC(=O)C(C(O)=O)CC(O)=O YIXSKDRXJTZCHT-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000009835 boiling Methods 0.000 claims abstract description 12
- 229910052500 inorganic mineral Inorganic materials 0.000 claims abstract description 12
- 239000011707 mineral Substances 0.000 claims abstract description 12
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000006243 chemical reaction Methods 0.000 claims abstract description 9
- 238000007127 saponification reaction Methods 0.000 claims abstract description 7
- 150000007513 acids Chemical class 0.000 claims abstract description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- -1 acetylsuccinate acetylsuccinate Chemical compound 0.000 claims description 4
- 150000001298 alcohols Chemical class 0.000 claims description 3
- WSUKOTLKORRMSH-UHFFFAOYSA-N 2-acetylbutanedioic acid;dimethyl 2-acetylbutanedioate Chemical compound CC(=O)C(C(O)=O)CC(O)=O.COC(=O)CC(C(C)=O)C(=O)OC WSUKOTLKORRMSH-UHFFFAOYSA-N 0.000 claims 1
- 150000005690 diesters Chemical class 0.000 claims 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 12
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical compound OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 description 12
- 229960000443 hydrochloric acid Drugs 0.000 description 8
- 235000011167 hydrochloric acid Nutrition 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 239000006227 byproduct Substances 0.000 description 7
- XREKLQOUFWBSFH-UHFFFAOYSA-N dimethyl 2-acetylbutanedioate Chemical compound COC(=O)CC(C(C)=O)C(=O)OC XREKLQOUFWBSFH-UHFFFAOYSA-N 0.000 description 6
- 239000000126 substance Substances 0.000 description 5
- PVNIIMVLHYAWGP-UHFFFAOYSA-N Niacin Chemical compound OC(=O)C1=CC=CN=C1 PVNIIMVLHYAWGP-UHFFFAOYSA-N 0.000 description 4
- 239000011541 reaction mixture Substances 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- 230000008646 thermal stress Effects 0.000 description 4
- UAGJVSRUFNSIHR-UHFFFAOYSA-N Methyl levulinate Chemical compound COC(=O)CCC(C)=O UAGJVSRUFNSIHR-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- 125000002777 acetyl group Chemical group [H]C([H])([H])C(*)=O 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- DVSDDICSXBCMQJ-UHFFFAOYSA-N diethyl 2-acetylbutanedioate Chemical compound CCOC(=O)CC(C(C)=O)C(=O)OCC DVSDDICSXBCMQJ-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 230000035882 stress Effects 0.000 description 2
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 2
- 238000005292 vacuum distillation Methods 0.000 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 description 1
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 1
- 239000003377 acid catalyst Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229940077731 carbohydrate nutrients Drugs 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 235000014633 carbohydrates Nutrition 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 238000006114 decarboxylation reaction Methods 0.000 description 1
- 125000004177 diethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 239000000727 fraction Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000003385 ring cleavage reaction Methods 0.000 description 1
- 239000001384 succinic acid Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
Abstract
Abstract A process for the preparation of colour-stable levulinic acid by saponification of acetylsuccinates with aqueous mineral acids, by continuously treating the starting products with steam in counter-current in a reactor cascade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of the aqueous azeotrope being formed.
Description
2 ~'7~
Process for the preparation of storaae-stable levulinic _cid The invention relates to a proce~s for the preparation of storage-stable levulinic acid by saponif-ication of acetylsuccinates.
Levulinic acid is a startin~ product for the preparation of organic chemicals, dyestuffs, polymers, pharmaceutically active compounds and f~avour substances.
Particularly in the use of levulinic acid for the prepar-ation of polymers, pharmaceutically active compounds and flavour substances, stringent requirements regarding purity, colour and stability of the levulinic acid are laid down.
Several processeq for the preparation of levu-linic acid, on the basis of different starting compounds, are already known.
The preparation of levulinic acid from carbo-hydrates by the action of mineral acids is known from G.J. Mulder, J.prakt.Chem. 21, 219 ~1840~, cited in ~.F. Wiggins, Research 3, (1950), 140. In addition to formic acid, further by-products, of which some are insoluble and som0 are deeply coloured and which cannot be co~pletely separated off, are formed in yields of 40-60%. Levulinic acid prepared in thi~ way already show~
a marked brown to reddish-tinged coloration and rapidly darkens further on storage, that is to say it is not colour-stable.
DE-A 2,112,726 has disclosed the preparation of levulinic acid starting from furfuryl alcohol by ring cleavage with hydrochloric acid or oxalic acid. To ~mprove the yield, thi~ process i8 carried out in a very dilute solution, which entails a high energy consumption in ~eparating off the solvent. Levulinic acid prepared in this way, however, shows very rapid dark discoloration eve~ under a brief thermal stress, that i8 to say it has a low colour stability.
EP-A 0,028,234 ha~ disclosed a proces~ for the preparation of levulinic acid, wherein furfuryl alcohol is firqt e~terified in the presence of an acid catalyst . ~ -- . . : ~ , , ,.: - .
- , ,:
ZC~
to give a levulinic acid ester, this e~ter i8 purified by distillation in the presence of a high-boiling solvent and then hydrolysed in the presence of water and a strong lacid, an aqueou~ levulinic acid ~olution being formed.
This levulinic acid ~olution show~ a slight coloration, ]but the le w linic acid likewise darkens rapidly under a brief thermal stress.
In spite of its disadvantages, the preparation of levulinic acid from urfuryl alcohol i~ the only proces~
which has so far been carried out industrially.
In M. Conrad, Ber.Dt.Chem.Ges. 11, 211 (1878) and M. Conrad, Ann. 188, 1216 (1877), the saponification of diethyl ace~ylsuccinate with concentrated hydrochloric acid or with Ba~OH)2 or KOH to give levulinic acid i8 described. In the acidic saponification, ethyl levu~
linate i8 formed as a by-product. In the alkaline saponi-fication, elimination of the acetyl group takes place, 80 that succinic acid is formed as a by-product. Levulinic acid prepared in this way by ~aponification of diethyl acetylsuccinate show~ a dark coloration even after isolation by distlllation under the slightest possible temperature stress, and this rapidly deteriorates on storage.
Surprisingly, a process for the preparation of levulinic acid, ~tarting from acstyl~uccinates, has now been found, wherein colour-stable lew linic acid i8 obtained in high purity with a good yield.
The invention therefore relate~ to a process for the preparAtion of colour-stable levulinic acid by saponification of acetylsuccinate~ with aqueQus mineral acid~, which i8 characterized in that the starting products are continuously trested with ~team in counter-current in a reactor ca~cade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of th~ aqueous azeotrope being formed.
The starting compounds used are acetylsuccinates whiCh are dQrivsd from alcohols whose boiling point or who~o boiling point in the azeotrope with water i8 below ' : .. ' ':` ~ ,, ::
-_ 3 _ 2~17~
100C. Examples of ~uch alcohols are methanol, ethanol,propanol, i-propanol, n-butanol and t-butanol. Prefer-ably, dimethyl acetylsuccinate or diethyl acetylsuccinate and, particularly preferably, dLmethyl acetylsuccinate i~
used. Hydrochloric acid or ~ulphuric acid can be u~ed as 1;he mineral acids, and preferably aqueous hydrochloric clCid i8 used.
For carrying out the process, the star~ing compound~ are mixed, the acetylsuccinate : miner2i acid molar ratio being 1 : 1 to 7 : 1, preferably 3 : 1.
The starting compounds are fed to the upper part of the reactor cascade, which is preferably constructed as a tray column, and treated with steam in counter-current, at least 0.85 kg of steam being fed per kg of acetylsuccinate.
The residence time in the reactor cascade ~hould allow as quantitative as possible a decarbo~ylation of the acetylsuccinate and hydroly~is of the resulting levulinic acid esters to give levulinic acid. The re3i-dence time required for this purpo~e depends on the liquid level on the trays and on the number of trays.
Preferably, a tray column with a defined liquid level on the tray~ (hold-up) i8 used, it being intended that the trays do not run empty. A~ a rule, re~idence times of 30-60 minute~ ~re sufficient.
~he top and bottom temperatures of the reactor cascade are controlled in such a way that the alcohol formed in the reaction is stripped out of the column together with water and CO2, but the mineral acid remains in the column, a temperature difference of at lea~t lO-C
between the top and bottom temperatures being preferably maintained. When hydrochloric acid is used as the mineral a¢id, a top temperature o~ 90-lOO-C and a bottom temper-ature of 110-140C are preferably maintained.
Due to the continuou~ removal of the alcohol being formed in the hydrolysis of the levulinic acid ester resul~ing after the decarboxylation, the levulinic acid ester content in the end product is minimized.
At the bottom of the column, crude lew linic acid . :.. , .. . ~ .
' . ' ~
:
~ ~ 7~
is taken off and then purified by distillation under the ~lightest posQible tempsrature stre~. The hydrochloric acid thus separated off can be fed ba~k to the column if de~ired.
SPigure 1 show~ a preferred embodiment of the proces~ according to the invention~ In Figure 1, 1 is the re~lctor cascade, for example a bubble-cap tray column, 2 is the heat exchanger, 3 i~ a dephlegma~or, 4 i~ the acetylsucci~ate feed line, 5 is the mineral acid feed 10line, 6 is the feed line for the mixed starting com-pounds, 7 i-~ the vapour line, 8 i8 the steam feed and 9 is the take-off line for crude levulinic acid.
Acetyl~uccinate from line 4 is mixed with mineral acid from line 5 and the mixture is fed via line 6 to the 15upper part of the colu~n at a temperature of about 100.
Superheated steam i~ blown in via line 8 and p~ssed upwards through the column.
}n the bottom of the column, the reaction mixture running off from the lowest tray of the column is con-20centrstsd via heat exchanger 2 by evaporation of water.
The crude levulinic acid formed is discharged via line 9 and purified in a down~tream vacuum di~tillation at the ~lightest pos~ible temperature stress. At the top of the column, the t~mperature iB controlled by the dephleg-25mator 3 in such a way that the mineral acid i8 not discharged via the vapour line 7 together with the alcohol, water and CO2, but predominantly remain~ in tha crude levulinic acid. Depending on the bottom tempera-tur~, the crude levulinic acid taken off via line 9 30contains differing guantitie~ of mineral acid, which can be separated off in the vacuum distillation and fed back to the column via line 5.
By the proce~s according to the invention, levulinic acid i~ obtainad at short re~idence times in 35high yield and ex~ellen~ colour stability. A~ a rule, yields of 85-95% of theory, relative to acetylsuccinate, are achieved. ?he re~idence time i8 in general only between 30 and 60 mi~utes, wheroby the formation of by-products, which are in~oluble or cannot be separated off 5 ~7~
and which impair the purity, colour and colour ~tability, i~ avoided. The total reaction time i~ about 1-2 hour~.
After purification by di~tillation, the levulinic acLd prepared according to the invention shows a Gardener coLour number of about 2 according to ASTM D1544-8, which, even under strong thermal stress, deteriorates only 810wly and to a far smaller extent as compared with levulinic acid prepared by known proce~ses.
ExamPle 1:
In a reactor cascade, shown in Figure 1, with 28 bubble-capped trays and a diameter of 300 mm, 87.5 kg of reaction mixture were fed per hour to tray 23. The mixture consisted of 57.5 kg of dimethyl acetylsuccinate and 30 kg of a 12~ hydrochloric acid. 50 kg of steam per hour were blown into the column below the bottom tray.
The bottom temperature was maintained at 115C. 84.3 kg per hour of a vapour mixture consisting of methanol, water, CO2 and a little hydrochloric acid escaped over the top. The temperature of this mixture escaping through line 5 wa~ maintained at 99 100C by mean~ of the dephlegmator 3.
53.2 kg per hour of crude levulinlc acid of the following chemical composition:
65.8% of levulinic acid 1.2~ of methyl levulinate 0.2% of dimethyl acatyl~uccinate O.5% of unknown by-product~ (which were introduced with the technical dim~thyl acetylsucci-nate employed) 28.0% of water 4.3% of HCl left the bottom of the column via line 9.
The crude levulinic acid was purified by frac-tional vacuu~ di~tillation, 33.8 kg of pure levulinic acld being obtained per hour, corresponding to a ~ield of 95.2%. The levulinic acid purified in thi~ way had a ~ardener colour number of 1-2 and showed no colo~r deterioration on storag~.
. . ,. . ~ .
:`
Example 2:
In the apparatus described in Example 1 and ~igure 1, 87.5 kg/hour of reaction mixture were f~d to tray 23. The mixture con~isted of 57.5 kg of dimethyl acetylsuccinate and 30 kg of the first distillate frac-tion from the pure levulinic acid distillation, and this wa~ made up with 36~ HCl, so that the HCl concentration was about 11-12~.
The~e 30 kg were compo3ed of 57.7% of water 23.0% of levulinic acid 12.0% of HCl 6.7~ of methyl levulinate O.6~ of methanol and unknown by-product~. _ 50 kg per hour of steam were blown into the column below the bottom tray. The bottom temperature was maintained at 115C. 71.5 kg~hour of vapour mixture con~isting of methanol, water, C02 and a little hydro-chloric acid escapad over the top. The temperature o~
this e~caping mixture i~ maintained at lOO-C by means of the dephlegmator.
66 kg per hour of crude levulinic acid of the following chemical compo~itions 64.2% of levulinic acid 3.0% of methyl levulinate 0.2% of dimethyl acetylsuccinate 0.4% of unknown by-products twhich are introduced with the technical dimethyl acetyl-succinate used) 28.0~ of water 4.2% of HCl left the bottom of the column.
This crude levulinic acid was purified by frac-tional vacuum distillation, 33.5 kg per hour of pure levulinic acid being ubtained, corresponding to a yield of 94.6%. The~lew linic acid purified in this way had a Gardener colour number of 1-2 and -showed no colour deterioration on storage.
Comparison Exampl~
244.6 g of dimethyl acetylsuccinate and 520 ml of HCl (17~) were heated under reflux until the end of the reaction had been reached at the end of CO2 evolution.
The reaction tLme was 5 hours. The reaction mixture was concentrated and the residue was then distilled at O.013 bar. 86 g (57~ of theory) of levulinic acid were obtained.
Boiling point 138-140C at 0.013 bar.
The levulinic acid thus obtained showed a Gardener colour number of 2, which deteriorated to a Gardener colour number of 6 after ~torage for one month at room temperature.
To investigate the colour stability, levulinic lS acid prepared according to Example 1 was sub~ected to different thermal stresses and compared with a levulinic acid prepared (by Otsuka) from furfuryl alcohol according to DE-A 2,112,726. The results are shown in Table 1:
a levulinic acid prepared according to Example 1 b levulinic acid prepared (by Otsuka) from furfuryl alcohol c levulinic acid prepared according to the comparison example ~able 1 Gardener colour number under different thermal ~treYses T(DC) 35 100 150 h a b c a b c a b c 1 2 1 3 3 l 3 5 13 10 2 1 3 4 3 4 8 17 }6 , . . . , ~
, .
- ., . :
. . - :.. .... .
. , ~ " ..
:` ~
-
Process for the preparation of storaae-stable levulinic _cid The invention relates to a proce~s for the preparation of storage-stable levulinic acid by saponif-ication of acetylsuccinates.
Levulinic acid is a startin~ product for the preparation of organic chemicals, dyestuffs, polymers, pharmaceutically active compounds and f~avour substances.
Particularly in the use of levulinic acid for the prepar-ation of polymers, pharmaceutically active compounds and flavour substances, stringent requirements regarding purity, colour and stability of the levulinic acid are laid down.
Several processeq for the preparation of levu-linic acid, on the basis of different starting compounds, are already known.
The preparation of levulinic acid from carbo-hydrates by the action of mineral acids is known from G.J. Mulder, J.prakt.Chem. 21, 219 ~1840~, cited in ~.F. Wiggins, Research 3, (1950), 140. In addition to formic acid, further by-products, of which some are insoluble and som0 are deeply coloured and which cannot be co~pletely separated off, are formed in yields of 40-60%. Levulinic acid prepared in thi~ way already show~
a marked brown to reddish-tinged coloration and rapidly darkens further on storage, that is to say it is not colour-stable.
DE-A 2,112,726 has disclosed the preparation of levulinic acid starting from furfuryl alcohol by ring cleavage with hydrochloric acid or oxalic acid. To ~mprove the yield, thi~ process i8 carried out in a very dilute solution, which entails a high energy consumption in ~eparating off the solvent. Levulinic acid prepared in this way, however, shows very rapid dark discoloration eve~ under a brief thermal stress, that i8 to say it has a low colour stability.
EP-A 0,028,234 ha~ disclosed a proces~ for the preparation of levulinic acid, wherein furfuryl alcohol is firqt e~terified in the presence of an acid catalyst . ~ -- . . : ~ , , ,.: - .
- , ,:
ZC~
to give a levulinic acid ester, this e~ter i8 purified by distillation in the presence of a high-boiling solvent and then hydrolysed in the presence of water and a strong lacid, an aqueou~ levulinic acid ~olution being formed.
This levulinic acid ~olution show~ a slight coloration, ]but the le w linic acid likewise darkens rapidly under a brief thermal stress.
In spite of its disadvantages, the preparation of levulinic acid from urfuryl alcohol i~ the only proces~
which has so far been carried out industrially.
In M. Conrad, Ber.Dt.Chem.Ges. 11, 211 (1878) and M. Conrad, Ann. 188, 1216 (1877), the saponification of diethyl ace~ylsuccinate with concentrated hydrochloric acid or with Ba~OH)2 or KOH to give levulinic acid i8 described. In the acidic saponification, ethyl levu~
linate i8 formed as a by-product. In the alkaline saponi-fication, elimination of the acetyl group takes place, 80 that succinic acid is formed as a by-product. Levulinic acid prepared in this way by ~aponification of diethyl acetylsuccinate show~ a dark coloration even after isolation by distlllation under the slightest possible temperature stress, and this rapidly deteriorates on storage.
Surprisingly, a process for the preparation of levulinic acid, ~tarting from acstyl~uccinates, has now been found, wherein colour-stable lew linic acid i8 obtained in high purity with a good yield.
The invention therefore relate~ to a process for the preparAtion of colour-stable levulinic acid by saponification of acetylsuccinate~ with aqueQus mineral acid~, which i8 characterized in that the starting products are continuously trested with ~team in counter-current in a reactor ca~cade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of th~ aqueous azeotrope being formed.
The starting compounds used are acetylsuccinates whiCh are dQrivsd from alcohols whose boiling point or who~o boiling point in the azeotrope with water i8 below ' : .. ' ':` ~ ,, ::
-_ 3 _ 2~17~
100C. Examples of ~uch alcohols are methanol, ethanol,propanol, i-propanol, n-butanol and t-butanol. Prefer-ably, dimethyl acetylsuccinate or diethyl acetylsuccinate and, particularly preferably, dLmethyl acetylsuccinate i~
used. Hydrochloric acid or ~ulphuric acid can be u~ed as 1;he mineral acids, and preferably aqueous hydrochloric clCid i8 used.
For carrying out the process, the star~ing compound~ are mixed, the acetylsuccinate : miner2i acid molar ratio being 1 : 1 to 7 : 1, preferably 3 : 1.
The starting compounds are fed to the upper part of the reactor cascade, which is preferably constructed as a tray column, and treated with steam in counter-current, at least 0.85 kg of steam being fed per kg of acetylsuccinate.
The residence time in the reactor cascade ~hould allow as quantitative as possible a decarbo~ylation of the acetylsuccinate and hydroly~is of the resulting levulinic acid esters to give levulinic acid. The re3i-dence time required for this purpo~e depends on the liquid level on the trays and on the number of trays.
Preferably, a tray column with a defined liquid level on the tray~ (hold-up) i8 used, it being intended that the trays do not run empty. A~ a rule, re~idence times of 30-60 minute~ ~re sufficient.
~he top and bottom temperatures of the reactor cascade are controlled in such a way that the alcohol formed in the reaction is stripped out of the column together with water and CO2, but the mineral acid remains in the column, a temperature difference of at lea~t lO-C
between the top and bottom temperatures being preferably maintained. When hydrochloric acid is used as the mineral a¢id, a top temperature o~ 90-lOO-C and a bottom temper-ature of 110-140C are preferably maintained.
Due to the continuou~ removal of the alcohol being formed in the hydrolysis of the levulinic acid ester resul~ing after the decarboxylation, the levulinic acid ester content in the end product is minimized.
At the bottom of the column, crude lew linic acid . :.. , .. . ~ .
' . ' ~
:
~ ~ 7~
is taken off and then purified by distillation under the ~lightest posQible tempsrature stre~. The hydrochloric acid thus separated off can be fed ba~k to the column if de~ired.
SPigure 1 show~ a preferred embodiment of the proces~ according to the invention~ In Figure 1, 1 is the re~lctor cascade, for example a bubble-cap tray column, 2 is the heat exchanger, 3 i~ a dephlegma~or, 4 i~ the acetylsucci~ate feed line, 5 is the mineral acid feed 10line, 6 is the feed line for the mixed starting com-pounds, 7 i-~ the vapour line, 8 i8 the steam feed and 9 is the take-off line for crude levulinic acid.
Acetyl~uccinate from line 4 is mixed with mineral acid from line 5 and the mixture is fed via line 6 to the 15upper part of the colu~n at a temperature of about 100.
Superheated steam i~ blown in via line 8 and p~ssed upwards through the column.
}n the bottom of the column, the reaction mixture running off from the lowest tray of the column is con-20centrstsd via heat exchanger 2 by evaporation of water.
The crude levulinic acid formed is discharged via line 9 and purified in a down~tream vacuum di~tillation at the ~lightest pos~ible temperature stress. At the top of the column, the t~mperature iB controlled by the dephleg-25mator 3 in such a way that the mineral acid i8 not discharged via the vapour line 7 together with the alcohol, water and CO2, but predominantly remain~ in tha crude levulinic acid. Depending on the bottom tempera-tur~, the crude levulinic acid taken off via line 9 30contains differing guantitie~ of mineral acid, which can be separated off in the vacuum distillation and fed back to the column via line 5.
By the proce~s according to the invention, levulinic acid i~ obtainad at short re~idence times in 35high yield and ex~ellen~ colour stability. A~ a rule, yields of 85-95% of theory, relative to acetylsuccinate, are achieved. ?he re~idence time i8 in general only between 30 and 60 mi~utes, wheroby the formation of by-products, which are in~oluble or cannot be separated off 5 ~7~
and which impair the purity, colour and colour ~tability, i~ avoided. The total reaction time i~ about 1-2 hour~.
After purification by di~tillation, the levulinic acLd prepared according to the invention shows a Gardener coLour number of about 2 according to ASTM D1544-8, which, even under strong thermal stress, deteriorates only 810wly and to a far smaller extent as compared with levulinic acid prepared by known proce~ses.
ExamPle 1:
In a reactor cascade, shown in Figure 1, with 28 bubble-capped trays and a diameter of 300 mm, 87.5 kg of reaction mixture were fed per hour to tray 23. The mixture consisted of 57.5 kg of dimethyl acetylsuccinate and 30 kg of a 12~ hydrochloric acid. 50 kg of steam per hour were blown into the column below the bottom tray.
The bottom temperature was maintained at 115C. 84.3 kg per hour of a vapour mixture consisting of methanol, water, CO2 and a little hydrochloric acid escaped over the top. The temperature of this mixture escaping through line 5 wa~ maintained at 99 100C by mean~ of the dephlegmator 3.
53.2 kg per hour of crude levulinlc acid of the following chemical composition:
65.8% of levulinic acid 1.2~ of methyl levulinate 0.2% of dimethyl acatyl~uccinate O.5% of unknown by-product~ (which were introduced with the technical dim~thyl acetylsucci-nate employed) 28.0% of water 4.3% of HCl left the bottom of the column via line 9.
The crude levulinic acid was purified by frac-tional vacuu~ di~tillation, 33.8 kg of pure levulinic acld being obtained per hour, corresponding to a ~ield of 95.2%. The levulinic acid purified in thi~ way had a ~ardener colour number of 1-2 and showed no colo~r deterioration on storag~.
. . ,. . ~ .
:`
Example 2:
In the apparatus described in Example 1 and ~igure 1, 87.5 kg/hour of reaction mixture were f~d to tray 23. The mixture con~isted of 57.5 kg of dimethyl acetylsuccinate and 30 kg of the first distillate frac-tion from the pure levulinic acid distillation, and this wa~ made up with 36~ HCl, so that the HCl concentration was about 11-12~.
The~e 30 kg were compo3ed of 57.7% of water 23.0% of levulinic acid 12.0% of HCl 6.7~ of methyl levulinate O.6~ of methanol and unknown by-product~. _ 50 kg per hour of steam were blown into the column below the bottom tray. The bottom temperature was maintained at 115C. 71.5 kg~hour of vapour mixture con~isting of methanol, water, C02 and a little hydro-chloric acid escapad over the top. The temperature o~
this e~caping mixture i~ maintained at lOO-C by means of the dephlegmator.
66 kg per hour of crude levulinic acid of the following chemical compo~itions 64.2% of levulinic acid 3.0% of methyl levulinate 0.2% of dimethyl acetylsuccinate 0.4% of unknown by-products twhich are introduced with the technical dimethyl acetyl-succinate used) 28.0~ of water 4.2% of HCl left the bottom of the column.
This crude levulinic acid was purified by frac-tional vacuum distillation, 33.5 kg per hour of pure levulinic acid being ubtained, corresponding to a yield of 94.6%. The~lew linic acid purified in this way had a Gardener colour number of 1-2 and -showed no colour deterioration on storage.
Comparison Exampl~
244.6 g of dimethyl acetylsuccinate and 520 ml of HCl (17~) were heated under reflux until the end of the reaction had been reached at the end of CO2 evolution.
The reaction tLme was 5 hours. The reaction mixture was concentrated and the residue was then distilled at O.013 bar. 86 g (57~ of theory) of levulinic acid were obtained.
Boiling point 138-140C at 0.013 bar.
The levulinic acid thus obtained showed a Gardener colour number of 2, which deteriorated to a Gardener colour number of 6 after ~torage for one month at room temperature.
To investigate the colour stability, levulinic lS acid prepared according to Example 1 was sub~ected to different thermal stresses and compared with a levulinic acid prepared (by Otsuka) from furfuryl alcohol according to DE-A 2,112,726. The results are shown in Table 1:
a levulinic acid prepared according to Example 1 b levulinic acid prepared (by Otsuka) from furfuryl alcohol c levulinic acid prepared according to the comparison example ~able 1 Gardener colour number under different thermal ~treYses T(DC) 35 100 150 h a b c a b c a b c 1 2 1 3 3 l 3 5 13 10 2 1 3 4 3 4 8 17 }6 , . . . , ~
, .
- ., . :
. . - :.. .... .
. , ~ " ..
:` ~
-
Claims (9)
1. Process for the preparation of colour-stable levulinic acid by saponification of acetylsuccinates with aqueous mineral acids, comprising treating the starting products continuously with steam in counter-current in a reactor cascade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of the aqueous azeotrope being formed.
2. Process according to Claim 1, comprising using acetylsuccinates which are those diesters of acetylsuccinic acid which are derived from alcohols whose boiling point or whose boiling point in the azeotrope with water is below 100°C.
3. Process according to Claim 2, comprising using the acetylsuccinate dimethyl acetylsuccinate.
4. Process according to Claim 1, comprising using aqueous hydrochloric acid as the aqueous mineral acid.
5. Process according to Claim 1, comprising the acetylsuccinate acetylsuccinate : HC1 molar ratio being 1 : 1 to 7 : 1.
6. Process according to Claim 5, comprising the acetylsuccinate : HC1 molar ratio being 3 : 1.
7. Process according to Claim 1, comprising using at least 0,85 kg of steam per kg of acetylsuccinate.
8. Process according to Claim 1, comprising the residence time in the reactor cascade being 30 - 60 minutes.
9. Process according to Claim 1 comprising maintaining a temperature between 110 and 140°C
in the bottom of the reactor cascade and a temperature between 90 and 100°C at the top of the reactor cascade, a temperature difference of at least 10°C being maintained between the top and bottom.
in the bottom of the reactor cascade and a temperature between 90 and 100°C at the top of the reactor cascade, a temperature difference of at least 10°C being maintained between the top and bottom.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ATA1356/89 | 1989-06-05 | ||
| AT1356/89A AT392468B (en) | 1989-06-05 | 1989-06-05 | METHOD FOR PRODUCING STORAGE-STABLE LAEVULINIC ACIDS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2017580A1 true CA2017580A1 (en) | 1990-12-05 |
Family
ID=3512120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002017580A Abandoned CA2017580A1 (en) | 1989-06-05 | 1990-05-25 | Process for the preparation of storage-stable levulinic acid |
Country Status (13)
| Country | Link |
|---|---|
| EP (1) | EP0401532B1 (en) |
| JP (1) | JP2844382B2 (en) |
| AT (2) | AT392468B (en) |
| CA (1) | CA2017580A1 (en) |
| DD (1) | DD294934A5 (en) |
| DE (2) | DE3920340A1 (en) |
| DK (1) | DK0401532T3 (en) |
| ES (1) | ES2039988T3 (en) |
| GR (1) | GR3007472T3 (en) |
| HR (1) | HRP940818A2 (en) |
| HU (1) | HU206664B (en) |
| PL (1) | PL162981B1 (en) |
| YU (1) | YU108590A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2176998C2 (en) * | 1998-04-22 | 2001-12-20 | Иркутский государственный университет | Method of preparing levulinic acid |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3752849A (en) * | 1970-03-18 | 1973-08-14 | Otsuka Kagaku Yakuhin | Manufacture of levulinic acid |
| US4236021A (en) * | 1979-05-07 | 1980-11-25 | The B. F. Goodrich Company | Process for the manufacture of levulinic acid and esters |
-
1989
- 1989-06-05 AT AT1356/89A patent/AT392468B/en not_active IP Right Cessation
- 1989-06-21 DE DE3920340A patent/DE3920340A1/en not_active Withdrawn
-
1990
- 1990-05-10 DE DE9090108761T patent/DE59001067D1/en not_active Expired - Fee Related
- 1990-05-10 ES ES199090108761T patent/ES2039988T3/en not_active Expired - Lifetime
- 1990-05-10 EP EP90108761A patent/EP0401532B1/en not_active Expired - Lifetime
- 1990-05-10 AT AT90108761T patent/ATE87294T1/en not_active IP Right Cessation
- 1990-05-10 DK DK90108761.9T patent/DK0401532T3/en not_active Application Discontinuation
- 1990-05-25 CA CA002017580A patent/CA2017580A1/en not_active Abandoned
- 1990-06-01 HU HU903300A patent/HU206664B/en not_active IP Right Cessation
- 1990-06-01 DD DD90341258A patent/DD294934A5/en not_active IP Right Cessation
- 1990-06-04 YU YU108590A patent/YU108590A/en unknown
- 1990-06-04 JP JP2144594A patent/JP2844382B2/en not_active Expired - Fee Related
- 1990-06-04 PL PL28547790A patent/PL162981B1/en unknown
-
1993
- 1993-03-26 GR GR920402304T patent/GR3007472T3/el unknown
-
1994
- 1994-10-26 HR HR940818A patent/HRP940818A2/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| HU206664B (en) | 1992-12-28 |
| AT392468B (en) | 1991-04-10 |
| HRP940818A2 (en) | 1996-06-30 |
| JP2844382B2 (en) | 1999-01-06 |
| EP0401532A1 (en) | 1990-12-12 |
| ES2039988T3 (en) | 1993-10-01 |
| GR3007472T3 (en) | 1993-07-30 |
| PL285477A1 (en) | 1991-01-28 |
| DD294934A5 (en) | 1991-10-17 |
| DE59001067D1 (en) | 1993-04-29 |
| PL162981B1 (en) | 1994-01-31 |
| DK0401532T3 (en) | 1993-04-19 |
| HU903300D0 (en) | 1990-10-28 |
| JPH03101636A (en) | 1991-04-26 |
| DE3920340A1 (en) | 1991-01-10 |
| YU108590A (en) | 1992-09-07 |
| EP0401532B1 (en) | 1993-03-24 |
| HUT54967A (en) | 1991-04-29 |
| ATE87294T1 (en) | 1993-04-15 |
| ATA135689A (en) | 1990-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR940007525B1 (en) | Process for the preparation of cyclopropylamine | |
| KR101210196B1 (en) | Method for the production of formic acid | |
| US10087162B2 (en) | Preparation of dialkyl esters of 2,5-furandicarboxylic acid | |
| CA2692578A1 (en) | Method for producing ethylene glycol dimethacrylate | |
| US5189215A (en) | Process for the preparation of storage-stable levulinic acid | |
| KR101522743B1 (en) | Method for producing butanediol dimethacrylates | |
| US4730082A (en) | Process for the preparation of methyltrifluoroacetate | |
| US4983761A (en) | Process for the preparation of high-boiling acrylates and methacrylates | |
| US3993651A (en) | Triethylenediamine recovery | |
| US4520209A (en) | Process for cyclizing upsilon-chlorocarboxylic acids | |
| US6235924B1 (en) | Continuous process for preparing benzoic acid esters | |
| JPS6023345A (en) | Manufacture of glyoxylic acid ester | |
| US5068417A (en) | Process for the continuous preparation of glyoxylic acid | |
| US4765869A (en) | Process for the production of a dialkyl maleate | |
| IL29862A (en) | A process for producing ethyleneketal of gamma-ketocarboxylic acid esters | |
| EP0010455B1 (en) | Cracking process for preparing styrene | |
| JPH03101636A (en) | Preparation of levulinic acid stable in storage | |
| US6657075B2 (en) | Continuous process for tertiary butyl esters | |
| US6486358B1 (en) | Process for the purification and formulation of o-phthalaldehyde | |
| JPS62286945A (en) | Manufacture of chloro- or bromoacetaldehyde dialkylacetal | |
| JP2756373B2 (en) | Method for producing 1,1,1-trifluoro-3-nitro-2-propene | |
| US7629490B2 (en) | Process for hydrolysing cyclopropanecarboxylic esters to the free acid | |
| US4921977A (en) | Obtaining maleic anhydride not prone to discolor | |
| US3957730A (en) | Recovery of pure 2-methyl-2-hydroxy-heptanone-6 | |
| SU1735266A1 (en) | Method for producing chloral |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |