U.S. patent application number 14/619525 was filed with the patent office on 2015-08-13 for process for the electrochemical production of 2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid.
This patent application is currently assigned to EVONIK INDUSTRIES AG. The applicant listed for this patent is EVONIK INDUSTRIES AG. Invention is credited to Carl-Friedrich HOPPE, Stephan KOHLSTRUK, Manfred KRECZINSKI, Matthias MENDORF, Holger WIEDERHOLD.
Application Number | 20150225861 14/619525 |
Document ID | / |
Family ID | 52449956 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150225861 |
Kind Code |
A1 |
HOPPE; Carl-Friedrich ; et
al. |
August 13, 2015 |
PROCESS FOR THE ELECTROCHEMICAL PRODUCTION OF 2,2,4-TRIMETHYLADIPIC
ACID AND 2,4,4-TRIMETHYLADIPIC ACID
Abstract
A process for the electrochemical production of
2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid by
electrochemical oxidative ring cleavage of a mixture of cis- and
trans-3,3,5-trimethylcyclohexanol.
Inventors: |
HOPPE; Carl-Friedrich;
(Gruendau, DE) ; KOHLSTRUK; Stephan; (Gladbeck,
DE) ; KRECZINSKI; Manfred; (Herne, DE) ;
MENDORF; Matthias; (Dortmund, DE) ; WIEDERHOLD;
Holger; (Darmstadt, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EVONIK INDUSTRIES AG |
Essen |
|
DE |
|
|
Assignee: |
EVONIK INDUSTRIES AG
Essen
DE
|
Family ID: |
52449956 |
Appl. No.: |
14/619525 |
Filed: |
February 11, 2015 |
Current U.S.
Class: |
205/412 ;
205/440 |
Current CPC
Class: |
C25B 15/02 20130101;
C25B 11/03 20130101; C25B 11/04 20130101; C25B 3/02 20130101; C25B
11/0452 20130101 |
International
Class: |
C25B 3/02 20060101
C25B003/02; C25B 11/03 20060101 C25B011/03; C25B 15/02 20060101
C25B015/02; C25B 11/04 20060101 C25B011/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2014 |
DE |
102014202502.8 |
Claims
1. A process, comprising: electrochemically producing
2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid by
electrochemical oxidative ring cleavage of a mixture comprising
cis- and trans-3,3,5-trimethylcyclohexanol in an aqueous alkaline
solution.
2. The process of claim 1, wherein the aqueous alkaline solution is
an aqueous sodium hydroxide solution or an aqueous potassium
hydroxide solution.
3. The process of claim 1, wherein the electrochemical oxidative
ring cleavage is performed by electrolysis in an electrolytic cell
comprising a cathode and an anode, wherein the electrolytic cell is
a batch electrolytic cell or a continuous flow electrolytic
cell.
4. The process of claim 3, wherein the electrolysis is carried out
in a continuous flow electrolytic cell.
5. The process of claim 3, wherein the anode is a nickel anode.
6. The process of claim 3, wherein the cathode is a stainless steel
anode.
7. The process of claim 3, wherein the anode is in the form of a
gauze, a pellet bed, or a foam.
8. The process of claim 3, wherein anode is a nickel gauze, a
nickel pellet bed, or a nickel foam.
9. The process of claim 5, further comprising: electrochemically
depositing a thin multilayered nickel oxide hydroxide top layer
onto a surface of the nickel anode.
10. The process of claim 3, wherein the electrolysis is run at
elevated temperature.
11. The process of claim 3, wherein the electrolysis is carried out
at temperature from 60.degree. C. to 100.degree. C.
12. The process of claim 3, wherein the electrolysis is carried out
at temperature from 70.degree. C. to 90.degree. C.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a utility application based on,
and claiming benefit to, German Application No. 102014202502.8,
filed on Feb. 12, 2014.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable.
INCORPORATION-BY-REFERENCE OF THE MATERIAL ON THE COMPACT DISC
[0004] Not Applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The invention relates the electrochemical production of
2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid by
electrochemical oxidative ring cleavage of a mixture of cis- and
trans-3,3,5-trimethylcyclohexanol.
[0007] 2. Description of the Related Art Including Information
Disclosed Under 37 CFR 1.97 and 1.98
[0008] According to the current state of the art, the production of
2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid (TMAS)
from a mixture of cis- and trans-3,3,5-trimethylcyclohexanol
(TMCol) is effected by oxidative ring cleavage using nitric
acid.
[0009] Disadvantages of this process due to the use of nitric acid
are, inter alia, corrosion, safety issues, and the formation of
nitrous components.
[0010] It is mentioned in Hans-Jurgen Schafer, Oxidation of organic
compounds at the nickel hydroxide electrode, Topics in Current
Chemistry, Vol. 142, pp. 101-129, 1987, Johannes Kaulen,
Hans-Jurgen Schafer, Oxidation of alcohols by electrochemically
regenerated nickel oxide hydroxide. Selective oxidation of
hydroxysteroids, Tetrahedron Vol. 38 No. 22 pp. 3299-3308, 1982,
and Johannes Kaulen: Oxidation of diols and secondary alcohols at
the nickel hydroxide electrode. Use for selective oxidation of
hydroxysteroids [in German], dissertation at the University of
Munster 1981, that the electrochemical oxidation of cyclohexanol at
relatively high temperatures proceeds, to some extent, with adipic
acid being formed by ring cleavage. The reaction is effected using
nickel hydroxide electrodes. Yields of adipic acid of 16% and 24%
at 25.degree. C. and of 42% at 80.degree. C. were obtained.
[0011] B. V. Lyalin, V. A. Petrosyan, Electrosynthesis of adipic
acid by undivided cell electrolysis, Russian Chemical Bulletin,
International Edition, Vol. 53 No. 3 pp. 688-692, March, 2004,
likewise addresses electrochemical oxidative ring cleavage of
cyclohexanol to give adipic acid at nickel hydroxide electrodes.
This paper reports a maximum yield of adipic acid of 46.7% at a
simultaneous current yield of 11.5%. By-products in the reaction
are succinic acid and glutaric acid formed in a yield of 6.3% and
11.5%, respectively. These components are formed by oxidative
elimination of CH.sub.2 groups from the C6 core structure of
cyclohexanol.
[0012] Adipic acid is formed as the disodium salt in the above
publications. The salt can be converted into the H acid form by
simple acidification with hydrochloric acid, for example.
[0013] The solubility of cyclohexanol in water is 40 g/l at
20.degree. C. The solubility of the trimethylated cyclohexanol,
TMCol, in water is only 1.8 g/l at 20.degree. C.
BRIEF SUMMARY OF THE INVENTION
[0014] It was found that, surprisingly, TMCol may be converted into
2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic acid (TMAS) by
electrochemical oxidative ring cleavage under alkaline conditions
despite the low solubility in water. The conversion proceeds via
the intermediate 3,3,5-trimethylcyclohexanone (TMCon).
[0015] Advantages of this process compared to the process mentioned
above due to the use of nitric acid being avoided are: avoidance of
corrosivity, no formation of nitrous gases.
[0016] These and other objects are achieved by the present
invention, which electrochemically produces 2,2,4-trimethyladipic
acid and 2,4,4-trimethyladipic acid by electrochemical oxidative
ring cleavage of a mixture of cis- and
trans-3,3,5-trimethylcyclohexanol in an aqueous alkaline
solution.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1: Electrolysis batch apparatus for conversion of TMCol
into TMAS.
[0018] FIG. 2: Electrolysis batch apparatus for conversion of TMCol
into TMAS.
[0019] FIG. 3a: A cross-section of a Swiss-roll continuous flow
electrolytic cell.
[0020] FIG. 3b: Section through sandwich construction of a
Swiss-roll continuous flow electrolytic cell.
[0021] FIG. 3c: Rolled-up sandwich construction of a Swiss-roll
continuous flow electrolytic cell.
[0022] FIG. 4a: An empty electrolytic cell.
[0023] FIG. 4b: An electrolytic cell filled with nickel
pellets.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In this specification, the words "a" and "an" and the like
carry the meaning of "one or more." The phrases "selected from the
group consisting of," "chosen from," and the like include mixtures
of the specified materials. Terms such as "contain(s)" and the like
are open terms meaning `including at least` unless otherwise
specifically noted. Where a numerical limit or range is stated, the
endpoints are included. Also, all values and subranges within a
numerical limit or range are specifically included as if explicitly
written out.
[0025] The invention provides a process for the electrochemical
production of 2,2,4-trimethyladipic acid and 2,4,4-trimethyladipic
acid by electrochemical oxidative ring cleavage of a mixture of
cis- and trans-3,3,5-trimethylcyclohexanol in aqueous alkaline
solution.
[0026] The electrochemical conversion of TMCol into TMAS is
effected in an electrolytic cell. The process is in principle not
limited to a particular type of electrolytic cell.
[0027] The reaction is performed in aqueous alkaline solution.
Useful alkalis include in principle all known inorganic bases.
Alkali metal hydroxides, such as LiOH, NaOH, KOH, and soluble
alkaline earth metal hydroxides are preferred. In accordance with
the invention, it is particularly preferable to use aqueous sodium
hydroxide solution or aqueous potassium hydroxide solution.
[0028] Materials useful in principle as anode material include
transition metals. It is preferable to use nickel.
[0029] Materials useful in principle as cathode material include
transition metals. It is preferable to use stainless steel.
[0030] Preference for use as the anode is given to electrode types
having a large specific surface area. Gauzes, pellet beds, and
foams are particularly preferred.
[0031] The electrolysis may be effected batchwise or
continuously.
[0032] The electrolysis may be carried out in a batch electrolytic
cell and also in a continuous flow electrolytic cell. It is
preferable to carry out the electrolysis in a continuous flow
electrolytic cell.
[0033] The electrolysis is preferably run at an elevated
temperature. A temperature of from 60.degree. C. to 100.degree. C.
is preferred. A temperature of from 70.degree. C. to 90.degree. C.
is particularly preferred.
[0034] Preferred variants of the process are described
hereinbelow.
Variant 1
[0035] The electrochemical conversion of TMCol into TMAS may be
effected in the electrolysis batch apparatus shown in FIG. 1. The
cathode is a stainless steel plunger and the anode is a cylindrical
nickel gauze. The solution introduced into the apparatus is stirred
by a magnetic stirrer bar and heated using a thermostat. A pump
facilitates additional external circulation of the solution in
order to further enhance commixing.
Variant 2
[0036] The electrochemical conversion of TMCol into TMAS may
alternatively be effected in the electrolysis apparatus shown in
FIG. 2. Said apparatus comprises an electrolytic cell, a
temperature-controllable receiver, a pump, and a cooler.
[0037] The electrolytic cell is a continuous flow electrolytic cell
with a stainless steel cathode and a nickel anode.
[0038] Various pump types may be used as pumps for the electrolysis
apparatus shown in FIG. 2. Pumps which in addition to the conveying
effect achieve dispersion of the organic substrate in the alkaline
aqueous solution are particularly suitable, for example peripheral
pumps.
Variant 3
[0039] The continuous flow electrolytic cell employed may
specifically be a Swiss-roll cell (see "Peter. M. Robertson, F.
Schwager, A new cell for electrochemical processes, Journal of
Electroanalytical Chemistry Vol. 65 pp. 883-900, 1975", "Peter
Seiler, Peter M. Robertson, The anodic oxidation of
diacetone-L-sorbose on an industrial scale [in German], Chimia Vol.
36 No. 7/8 pp. 305-312, 1982"). The Swiss-roll cell is shown in
FIG. 3. This electrolytic cell type comprises a nickel gauze and a
stainless steel gauze, one above the other, separated by a
polypropylene fabric and wound around a central nickel rod. Here,
the nickel rod contacts only the nickel gauze. The cell housing
consists of stainless steel which contacts only the stainless steel
gauze.
Variant 4a
[0040] It was found that it is likewise possible to use an
electrolytic cell made of a stainless steel housing, a central
nickel rod and nickel pellets introduced into the cell. The cell
type is shown in FIG. 4. Here, the nickel pellets are in electrical
contact with the central nickel rod.
[0041] The nickel pellets are electrically insulated from the
stainless steel housing by a polypropylene fabric disposed on the
inside of the stainless steel housing.
Variant 4b
[0042] It was further found that the cell type shown in FIG. 4 may
be furnished with a flat-ply nickel foam and a stainless steel
gauze instead of with nickel pellets. Said foam and gauze are wound
around the central nickel rod, one above the other, with a
polypropylene fabric separating them. Here, the nickel rod contacts
only the nickel foam. The cell housing consists of stainless steel
which contacts only the stainless steel gauze.
[0043] Prior to TMAS electrosynthesis, the nickel anode surface may
be conditioned in order to electrochemically deposit a thin
multilayered nickel oxide hydroxide top layer onto the nickel anode
surface.
[0044] This may, for example, be carried out as follows:
[0045] 280 ml of a conditioning solution comprising 0.1 mol/l of
NiSO.sub.4.times.6H.sub.2O, 0.1 mol/l of NaOAc.times.3H.sub.2O, and
0.005 mol/l of NaOH in distilled water was introduced into the
electrolysis. In the case of the electrolysis apparatus of FIG. 2,
the conditioning solution was additionally recirculated. The nickel
gauze was alternately polarised as the anode or the cathode for a
short time (10 s) by automatic electrode polarisation switching
until a black surface layer was formed (current 150 mA, charge 100
C). The conditioning solution was subsequently discharged from the
entire apparatus. The entire apparatus was then thoroughly rinsed
with distilled water. The freshly activated electrolytic cell was
then immediately used for electrolysis.
[0046] To carry out electrosynthesis of TMAS, the electrolytic cell
was filled with water and also sodium hydroxide and TMCol dissolved
therein. The recirculated solution was then brought to the desired
temperature. The electrolysis was carried out by passing electrical
current through the cell galvanostatically for several hours.
[0047] Upon completion of the electrolysis, the solution was
completely discharged from the electrolysis apparatus and the
electrolysis apparatus was then rinsed out with DM water. The
electrolysis apparatus was left dry between experiments. The
combined solution from the electrolysis apparatus was worked up in
order to isolate TMCol, TMCon, TMAS, and any by-products upon
completion of the electrolysis.
EXAMPLES
Example 1
[0048] The electrolysis was carried out as described above in the
electrolysis batch apparatus shown in FIG. 1 using a wound 100 mesh
nickel gauze of 0.1 mm nickel wire having an area of 10 cm*25 cm
and an interiorly disposed round stainless steel plunger of 7 cm in
diameter.
[0049] 260 ml of water, 11.2 g of sodium hydroxide, and 5.73 g of
TMCol were charged to the electrolytic cell.
[0050] The electrolysis was carried out by passing 2 A through the
cell for 6 hours. The temperature was 80.degree. C.
[0051] 2.45 g of TMCol, 2.34 g of TMCon, and 1.06 g of TMAS were
isolated following work-up. The yield of TMAS based on the TMCol
employed was 14%.
Example 2
[0052] The electrolysis was carried out as described above in the
electrolysis apparatus shown in FIG. 2 using a Swiss-roll
electrolytic cell shown in FIG. 3 comprising a wound 100 mesh
nickel gauze of 0.1 mm nickel wire having an area of 6.5 cm*24.5
cm, a polypropylene fabric, and a wound 100 mesh stainless steel
gauze of 0.114 mm stainless steel wire having an area of 6.5
cm*26.5 cm.
[0053] 260 ml of water, 11.2 g of sodium hydroxide, and 5.93 g of
TMCol were charged to the electrolysis apparatus. A peripheral pump
was used.
[0054] The electrolysis was carried out by passing 2 A through the
cell for 24 hours. The temperature was 80.degree. C.
[0055] 0.05 g of TMCol, 0.03 g of TMCon, and 2.70 g of TMAS were
isolated following work-up. The yield of TMAS based on the TMCol
employed was 34%.
Example 3
[0056] The electrolysis was carried out as described above in the
electrolysis apparatus shown in FIG. 2 using an electrolytic cell
shown in FIGS. 4a and 4b comprising nickel pellets (bed volume 60
cm.sup.3).
[0057] 264 ml of water, 11.2 g of sodium hydroxide, and 5.93 g of
TMCol were charged to the electrolytic cell. A peripheral pump was
used.
[0058] The electrolysis was carried out by passing 2 A through the
cell for 24 hours. The temperature was 80.degree. C.
[0059] 0.06 g of TMCol, 0.04 g of TMCon, and 2.52 g of TMAS were
isolated following work-up. The yield of TMAS based on the TMCol
employed was 32%.
Example 4
[0060] The electrolysis was carried out as described above in the
electrolysis apparatus shown in FIG. 2 using an electrolytic cell
shown in FIG. 3a comprising a wound flat-ply nickel foam having an
area of 6.5 cm*19 cm, a polypropylene fabric, and a wound 100 mesh
stainless steel gauze of 0.114 mm stainless steel wire.
[0061] 264 ml of water, 11.2 g of sodium hydroxide, and 5.93 g of
TMCol were charged to the electrolytic cell. A peripheral pump was
used.
[0062] The electrolysis was carried out by passing 2 A through the
cell for 17 hours. The temperature was 80.degree. C.
[0063] 0.09 g of TMCol, 0.14 g of TMCon, and 2.06 g of TMAS were
isolated following work-up. The yield of TMAS based on the TMCol
employed was 26%.
Example Work-Up
[0064] The purpose of the work-up of the electrolysis solution
described hereinbelow was to isolate TMCol, TMCon, TMAS, and any
by-products upon completion of the electrolysis and to subsequently
determine conversion, yield, and selectivity.
[0065] 50 g of sodium chloride were added to the aqueous solution
poured out of the electrolysis apparatus.
[0066] The alkali aqueous phase was extracted with methyl
tert-butyl ether (analytical grade) to remove remaining TMCol and
TMCon by repeated (at least 4-fold) extraction in a separating
funnel.
[0067] The ether phase was dried with anhydrous magnesium sulphate.
To this end, magnesium sulphate was added to the ether phase until
newly added magnesium sulphate remained in the liquid in the form
of fine grains in that clumping no longer occurred. The magnesium
sulphate was subsequently filtered off.
[0068] The ether was removed by rotary evaporation. The rotary
evaporator was initially operated at atmospheric pressure. The
boiling point of the solution increased significantly towards the
end of the distillative removal. Accordingly, a slight vacuum was
applied and the underpressure was increased as the concentration of
MTBE in the solution was reduced in order always to achieve a
sufficient distillation rate (up to 300 mbar at 90.degree. C.). The
distillation at 300 mbar and 90.degree. C. was continued until the
head temperature in the rotary evaporator fell to and remained
constant at room temperature.
[0069] Unreacted TMCol and TMCon were left behind in a residual
amount of MTBE. These compounds were analysed by gas chromatography
to determine purity and quantity.
[0070] TMAS was isolated by perforation. A relatively large liquid
volume was required for the perforator. The mixture was diluted
with water accordingly.
[0071] The alkaline aqueous phase was subsequently acidified with
concentrated hydrochloric acid to a pH of 1.
[0072] The acidified aqueous phase was perforated with MTBE
(analytical grade) for 48 h.
[0073] The ether phase was subsequently dried with anhydrous
magnesium sulphate. To this end, magnesium sulphate was added to
the ether phase until newly added magnesium sulphate remained in
the liquid in the form of fine grains in that clumping no longer
occurred. The magnesium sulphate was subsequently filtered off.
[0074] The MTBE was removed by rotary evaporation. The rotary
evaporator was initially operated at atmospheric pressure. The
boiling point of the solution increased significantly towards the
end of the distillative removal. Accordingly, a slight vacuum was
applied and the underpressure was increased as the concentration of
MTBE in the solution was reduced in order always to achieve a
sufficient distillation rate (up to 300 mbar at 90.degree. C. but
not sufficient for quantitative removal of MTBE). The distillation
at 300 mbar and 90.degree. C. was continued until the head
temperature in the rotary evaporator fell to and remained constant
at room temperature.
[0075] TMAS and by-products were left behind in a residual amount
of MTBE after the distillative removal and were quantitatively
determined by gas chromatography following etherification with
diazomethane.
[0076] The above description is presented to enable a person
skilled in the art to make and use the invention, and is provided
in the context of a particular application and its requirements.
Various modifications to the preferred embodiments will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other embodiments and applications
without departing from the spirit and scope of the invention. Thus,
this invention is not intended to be limited to the embodiments
shown, but is to be accorded the widest scope consistent with the
principles and features disclosed herein. In this regard, certain
embodiments within the invention may not show every benefit of the
invention, considered broadly.
* * * * *