WO2009138368A1 - Method for electrochemically cleaving lignin on a diamond electrode - Google Patents
Method for electrochemically cleaving lignin on a diamond electrode Download PDFInfo
- Publication number
- WO2009138368A1 WO2009138368A1 PCT/EP2009/055638 EP2009055638W WO2009138368A1 WO 2009138368 A1 WO2009138368 A1 WO 2009138368A1 EP 2009055638 W EP2009055638 W EP 2009055638W WO 2009138368 A1 WO2009138368 A1 WO 2009138368A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lignin
- diamond electrode
- vanillin
- derivatives
- electrochemically
- 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.)
- Ceased
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B3/00—Electrolytic production of organic compounds
- C25B3/20—Processes
- C25B3/23—Oxidation
Definitions
- the invention relates to a process for the electrochemical cleavage of lignin by means of a diamond electrode and to a process for the preparation of vanillin and its derivatives by electrochemical cleavage of lignin in solutions having a pH ⁇ 11.
- Lignin is a high molecular weight, aromatic substance that fills the spaces between the cell membranes in woody plants and turns them into wood.
- the lignin content of the dried plant material is about 27 to 33 wt .-% in Conife- ren wood and 22 wt .-% in hardwood.
- Lignin is considered to be a higher molecular weight derivative of phenylpropane. Depending on the type of wood, the phenyl ring is substituted with one to two methoxy groups and the propane units with hydroxy groups. In softwoods the predominantly guaiacyl type is found, in hardwood also the syringyl and coumar type. Lignan and coumarin structures, cyclic ethers and lactones are also formed by various linking possibilities.
- Alkali lignin is used in North America as a binder for wood and cellulosic press plates, as a dispersing agent, for clarifying sugar solutions, stabilizing asphalt emulsions and stabilizing foams.
- the alkali lignin is used as an energy source for the pulp process by burning the black liquors.
- Vanillin is widely used as a flavoring for chocolate, confectionery, liquors, baked goods and other sweet foods, as well as vanillin sugar instead of expensive natural vanilla.
- the vanilla content of wood which has been made into wine barrels, contributes to the flavoring of wine. Smaller amounts are used in deodorants, perfumes, and to improve the taste of pharmaceuticals and vitamin supplements.
- Vanillin is also an intermediate in the synthesis of various drugs, e.g. L-dopa, methyldopa and papaverine.
- EP-B 0 245 418 describes the electrochemical cleavage of lignin for obtaining vanillin and its derivatives, such as guaiacol and acetovanillon (3-methoxy-4-hydroxyacetophenone).
- vanillin and its derivatives such as guaiacol and acetovanillon (3-methoxy-4-hydroxyacetophenone).
- work is carried out in aqueous alkaline solution, wherein heavy metal electrodes are used.
- the work-up is carried out using toxic organohalogen solvents such as chloroform. From the (eco-) toxicological point of view, this is very disadvantageous, as is the use of heavy-metal electrodes.
- EP 0245418 B1 causes vanillin or its derivatives to be used as phenolic compounds. lat or hydroxybenzaldehyde derivatives are present. However, the phenolates or hydroxybenzaldehyde derivatives of vanillin and vanillin derivatives are very sensitive to oxidative processes which are to take place in an alkaline medium. For the workup, a neutralization must therefore be carried out beforehand, so that an increased workup effort is necessary to obtain vanillin.
- This object is achieved by a process for the degradation of lignin with a higher yield than 5 wt .-% of hydroxybenzaldehyde derivatives and / or phenol derivatives, wherein an aqueous solution or suspension of the lignin is electrolyzed on a diamond electrode.
- the process according to the invention is advantageous, the process being carried out in an aqueous solution which has a pH of ⁇ 11.
- the process of the invention is advantageous, in which case an aqueous, acidic solution is used.
- the method according to the invention wherein the diamond electrode used is a boron-doped diamond electrode.
- the inventive method wherein the Ligninabbau area are continuously removed from the electrochemical cell.
- the inventive method wherein the Ligninabbau area be removed by continuous extraction with an organic solvent.
- the process according to the invention is advantageous, the lignin degradation products being selected from the group of guaiacol, vanillin and acetovanillon.
- the lignin used for degradation is any lignin known to those skilled in the art.
- it is lignin contained in products selected from the group of straw, bagasse, black liquor, kraft lignin, lignin sulphonate, organosolv lignin, and related papermaking or fiberwood residues.
- Particularly preferred is the starch lignin and the lignin containing lignin sulphonate.
- the hydroxybenzaldehyde derivatives and / or phenol derivatives resulting from the degradation of lignin can be obtained by the process according to the invention to more than 5% by weight.
- the hydroxybenzaldehyde derivatives and / or phenol derivatives resulting from the degradation of the lignin are selected from the group of guaiacol, vanillin and acetovanillon. Particularly preferred are vanillin or guaiacol.
- the Hydroxybenzaldehydderivate and / or phenol derivatives obtained by the process according to the invention can be continuously removed from the reaction products.
- these Hydroxybenzaldehydderivate and / or phenol derivatives are removed from the reaction mixture by distillation or extraction continuously.
- Particularly preferred is the steam distillation.
- the lignin is in aqueous solution, wherein the aqueous solution is a pH of ⁇ 1 1, preferably ⁇ 9, particularly preferably acidic. Most preferably, the pH is ⁇ 3.
- the pH is adjusted to a pH ⁇ 3 with readily water-soluble inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid or organic acids such as para-toluenesulfonic acid or mixtures of various acids. Particularly preferred is sulfuric acid.
- any electrolysis cells known to those skilled in the art may be used, such as divided or undivided flow cell, capillary gap cell or plate stack cell. Particularly preferred is the undivided flow cell. To achieve optimum space-time yields, a bipolar arrangement of several electrodes is advantageous.
- the anode is a diamond electrode.
- These diademantel electrodes contain a diamond layer applied to a carrier material, wherein the carrier material is selected from the group of niobium, silicon, tungsten, titanium, silicon carbide, tantalum, graphite or ceramic carriers such as titanium suboxide. Particular preference is given to niobium or silicon as support material.
- the diamond layer on the carrier may be doped with other elements. Boron- or nitrogen-doped diamond electrodes are preferred. Particularly preferred are boron-doped diamond electrodes.
- any conventional low oxygen overpotential cathode material selected from the group consisting of RuO x TiO x mixed oxide electrode (DSA), platinized titanium, platinum, nickel, molybdenum or stainless steel may be used.
- DSA RuO x TiO x mixed oxide electrode
- the use of boron- or nitrogen-doped diamond electrodes is particularly preferred. Very particular preference is boron-doped diamond electrodes.
- Diamond electrodes can be used which have been produced by the chemical vapor deposition (CVD) method. Such electrodes are commercially available, such as from the manufacturer: Condias, Itzehoe; Diaccon, Hundth (Germany) or Adamant Technologies, La-Chaux-de-Fonds (Switzerland).
- HTHP-BDD electrodes are commercially available from pro aqua, Niklasdorf (Austria) and their properties are described by A Cieciwa, R. Wüthrich and Ch. Comninellis in Electrochem. Commun. 8 (2006) 375-382.
- the temperature for the process according to the invention is between 20 and 150 ° C., preferably in the range from 90 to 120 ° C.
- the current density is preferably in the range of 5 to 3000 mA / cm 2 , more preferably in the range of 10 to 200 mA / cm 2 .
- the polarity can be changed in short time intervals. The polarity reversal can take place in an interval of 30 seconds to 10 minutes, preferably an interval of 30 seconds and 2 minutes.
- the efficiency of the electrolysis of lignin in aqueous solution at boron-doped diamond electrodes can be increased by the addition of additives such as TiC "2.
- TiC" 2 is preferably used in catalytic amounts.
- a metal-containing or metal-free redox mediator may be added, preferably transition-metal-free mediators, e.g. Nitrosodisulfonates such as Fremy's salt (dipotassium nitrosodisulfonate).
- any mechanical stirrer known to those skilled in the art but also other mixing methods such as the use of Ultraturrax or ultrasound can be used.
- a suspension of 30 g of kraft lignin in an electrolyte consisting of 570 g of dilute sulfuric acid (0.1 M), in an undivided cell, with an electrode stack of boron-doped diamond cathodes (expanded metal, 5 x 10 cm) and boron-doped diamond anodes (expanded metal, 5 x 10 cm) at a distance of 0.5 cm is electrolysed at a current density of 80 mA / cm 2 and a temperature of 30 0 C for 1 hour with stirring at 9500 U / min.
- the resulting cell voltage is in the range of 2-6 V.
- the aqueous phase is extracted with methyl tert-butyl ether (MTBE), the solid is filtered off with suction and washed with MTBE.
- the aqueous phase is extracted several times with MTBE, the organic phases are combined, dried and the solvent is removed.
- the gas chromatographic analysis of the crude organic product shows the following typical composition (GC area percentages): 27% guaacol, 24% vanillin, 24% acetovanillon and 25% other compounds.
- the stationary phase used was a dB1 column from J & W Scientific with a length of 30 m and a diameter of 0.25 mm and a layer thickness of 1 ⁇ m. This column is heated by means of a temperature program of 80 0 C within 5 min in 8 ° C steps to 250 0 C.
- the carrier gas used is helium at a flow rate of 20 to 30 mL / min.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Compounds Of Unknown Constitution (AREA)
Abstract
Description
Verfahren zur elektrochemischen Spaltung von Lignin an einer Diamantelektrode Process for the electrochemical cleavage of lignin on a diamond electrode
Beschreibungdescription
Die Erfindung betrifft ein Verfahren zur elektrochemischen Spaltung von Lignin mittels einer Diamantelektrode sowie ein Verfahren zur Herstellung von Vanillin und seinen Derivaten durch elektrochemische Spaltung von Lignin in Lösungen mit einem pH-Wert < 11.The invention relates to a process for the electrochemical cleavage of lignin by means of a diamond electrode and to a process for the preparation of vanillin and its derivatives by electrochemical cleavage of lignin in solutions having a pH <11.
Lignin ist ein hochmolekularer, aromatischer Stoff, der in verholzenden Pflanzen die Räume zwischen den Zellmembranen ausfüllt und zu Holz werden lässt. Der Lignin Gehalt des getrockneten Pflanzenmaterials beträgt etwa 27 bis 33 Gew.-% im Conife- renholz und 22 Gew.-% im Laubholz.Lignin is a high molecular weight, aromatic substance that fills the spaces between the cell membranes in woody plants and turns them into wood. The lignin content of the dried plant material is about 27 to 33 wt .-% in Conife- ren wood and 22 wt .-% in hardwood.
Lignin ist als höhermolekularer Abkömmling des Phenylpropans aufzufassen. Je nach Holzart ist der Phenylring mit ein bis zwei Methoxygruppen und die Propaneinheiten mit Hydroxygruppen substituiert. Bei Nadelhölzern findet sich überwiegend der Guaja- cyl-Typ, bei Laubholz außerdem der Syringyl- und Cumar-Typ. Durch verschiedene Verknüpfungsmöglichkeiten entstehen unter anderem auch Lignan- und Cumarin- Strukturen, cyclische Ether und Lactone.Lignin is considered to be a higher molecular weight derivative of phenylpropane. Depending on the type of wood, the phenyl ring is substituted with one to two methoxy groups and the propane units with hydroxy groups. In softwoods the predominantly guaiacyl type is found, in hardwood also the syringyl and coumar type. Lignan and coumarin structures, cyclic ethers and lactones are also formed by various linking possibilities.
Alkalilignin wird in Nordamerika als Bindemittel für Pressplatten auf Holz- und CeIIuIo- sebasis, als Dispergiermittel, zur Klärung von Zuckerlösungen, Stabilisierung von Asphaltemulsionen sowie Schaumstabilisierung verwendet. Der weitaus größte Teil des Alkalilignins wird jedoch durch Verbrennung der Schwarzlaugen als Energiespender für den Zellstoffprozess verwendet.Alkali lignin is used in North America as a binder for wood and cellulosic press plates, as a dispersing agent, for clarifying sugar solutions, stabilizing asphalt emulsions and stabilizing foams. However, by far the largest part of the alkali lignin is used as an energy source for the pulp process by burning the black liquors.
Vanillin dient anstelle der teuren natürlichen Vanille in großem Umfang als Aromastoff für Schokolade, Süßwaren, Liköre, Backwaren und andere süße Lebensmittel sowie zur Herstellung von Vanillinzucker. Der Vanillingehalt von Holz, das zu Weinfässern verarbeitet wurde, trägt zur Aromatisierung von Wein bei. Kleinere Mengen werden in Deodorantien, Parfüms, und zur Geschmacksverbesserung von Pharmazeutika und Vitaminpräparaten verwendet. Vanillin ist auch Zwischenprodukt bei der Synthese von verschiedenen Arzneimitteln wie z.B. L-Dopa, Methyldopa und Papaverin.Vanillin is widely used as a flavoring for chocolate, confectionery, liquors, baked goods and other sweet foods, as well as vanillin sugar instead of expensive natural vanilla. The vanilla content of wood, which has been made into wine barrels, contributes to the flavoring of wine. Smaller amounts are used in deodorants, perfumes, and to improve the taste of pharmaceuticals and vitamin supplements. Vanillin is also an intermediate in the synthesis of various drugs, e.g. L-dopa, methyldopa and papaverine.
In EP-B 0 245 418 ist die elektrochemische Spaltung von Lignin zur Gewinnung von Vanillin und seinen Derivaten wie Guajakol und Acetovanillon (3-Methoxy-4-hydroxy- acetophenon) beschrieben. Hierbei wird in wässrig-alkalischer Lösung gearbeitet, wobei Schwermetallelektroden eingesetzt werden. Die Aufarbeitung erfolgt unter Verwen- düng toxischer Organohalogen-Lösungsmittel wie Chloroform. Aus (öko-)toxiko- logischen Gesichtspunkten ist dies wie auch der Einsatz von Schwermetallelektroden sehr nachteilig. Die Verwendung hoher Natriumhydroxid-Konzentrationen, wie inEP-B 0 245 418 describes the electrochemical cleavage of lignin for obtaining vanillin and its derivatives, such as guaiacol and acetovanillon (3-methoxy-4-hydroxyacetophenone). In this case, work is carried out in aqueous alkaline solution, wherein heavy metal electrodes are used. The work-up is carried out using toxic organohalogen solvents such as chloroform. From the (eco-) toxicological point of view, this is very disadvantageous, as is the use of heavy-metal electrodes. The use of high sodium hydroxide concentrations, as in
EP 0245418 B1 beschrieben, führt dazu, dass Vanillin bzw. seine Derivate als Pheno- lat bzw. Hydroxybenzaldehydderivate vorliegen. Die Phenolate bzw. Hydroxybenzalde- hydderivate des Vanillins und der Vanillinderivate sind jedoch gegenüber oxidativen Prozessen, die im alkalischen Milieu ablaufen sollen, sehr empfindlich. Für die Aufarbeitung muss daher zuvor eine Neutralisation erfolgen, so dass zur Gewinnung von Vanillin ein erhöhter Aufarbeitungsaufwand notwendig ist.EP 0245418 B1, causes vanillin or its derivatives to be used as phenolic compounds. lat or hydroxybenzaldehyde derivatives are present. However, the phenolates or hydroxybenzaldehyde derivatives of vanillin and vanillin derivatives are very sensitive to oxidative processes which are to take place in an alkaline medium. For the workup, a neutralization must therefore be carried out beforehand, so that an increased workup effort is necessary to obtain vanillin.
Es besteht daher ein großer Bedarf Lignin oxidativ so abbauen zu können, dass eine Aufarbeitung der erhaltenen Vorprodukte einen geringeren Aufwand erfordert und somit kostengünstiger als die bisher bekannten Verfahren ist.There is therefore a great need to reduce lignin oxidatively so that a workup of the resulting precursors requires less effort and thus is less expensive than the previously known methods.
Diese Aufgabe wird gelöst durch ein Verfahren zum Abbau von Lignin mit einer höheren Ausbeute als 5 Gew.-% an Hydroxybenzaldehydderivaten und/oder Phenolderivate, wobei eine wässrige Lösung oder Suspension des Lignins an einer Diamantelektrode elektrolysiert wird.This object is achieved by a process for the degradation of lignin with a higher yield than 5 wt .-% of hydroxybenzaldehyde derivatives and / or phenol derivatives, wherein an aqueous solution or suspension of the lignin is electrolyzed on a diamond electrode.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei in einer wässrigen Lösung gearbeitet wird, die einen pH-Wert <11 aufweist.The process according to the invention is advantageous, the process being carried out in an aqueous solution which has a pH of <11.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei in einer wässrigen, sauren Lö- sung gearbeitet wird.The process of the invention is advantageous, in which case an aqueous, acidic solution is used.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei die eingesetzte Diamantelektrode eine bordotierte Diamantelektrode ist.Advantageously, the method according to the invention, wherein the diamond electrode used is a boron-doped diamond electrode.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei die Ligninabbauprodukte kontinuierlich aus der elektrochemischen Zelle entfernt werden.Advantageously, the inventive method, wherein the Ligninabbauprodukte are continuously removed from the electrochemical cell.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei die Ligninabbauprodukte durch Wasserdampfdestillation entfernt werden.Advantageously, the process according to the invention, wherein the Ligninabbauprodukte be removed by steam distillation.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei die Ligninabbauprodukte durch kontinuierliche Extraktion mit einem organischen Lösungsmittel entfernt werden.Advantageously, the inventive method, wherein the Ligninabbauprodukte be removed by continuous extraction with an organic solvent.
Vorteilhaft ist das erfindungsgemäße Verfahren, wobei die Ligninabbauprodukte aus- gewählt sind aus der Gruppe von Guajakol, Vanillin und Acetovanillon.The process according to the invention is advantageous, the lignin degradation products being selected from the group of guaiacol, vanillin and acetovanillon.
Das zum Abbau eingesetzte Lignin ist jedes dem Fachmann bekannte Lignin. Bevorzugt ist es Lignin, das in Produkten enthalten ist, die ausgewählt sind aus der Gruppe von Stroh, Bagasse, Schwarzlauge, Kraft-Lignin, Ligninsulphonat, Organosolv-Lignin und entsprechenden Rückständen aus der Papierindustrie oder Faserherstellung. Besonders bevorzugt ist das in Kraft-Lignin und das in Ligninsulphonat enthaltende Lignin. Die beim Abbau von Lignin entstehenden Hydroxybenzaldehydderivate und/oder Phenolderivate können nach dem erfindungsgemäßen Verfahren zu mehr als 5 Gew.-% erhalten werden.The lignin used for degradation is any lignin known to those skilled in the art. Preferably, it is lignin contained in products selected from the group of straw, bagasse, black liquor, kraft lignin, lignin sulphonate, organosolv lignin, and related papermaking or fiberwood residues. Particularly preferred is the starch lignin and the lignin containing lignin sulphonate. The hydroxybenzaldehyde derivatives and / or phenol derivatives resulting from the degradation of lignin can be obtained by the process according to the invention to more than 5% by weight.
Die beim Abbau des Lignins entstehenden Hydroxybenzaldehydderivate und/oder Phenolderivate sind ausgewählt aus der Gruppe von Guajakol, Vanillin und Acetovanillon. Besonders bevorzugt sind Vanillin oder Guajakol.The hydroxybenzaldehyde derivatives and / or phenol derivatives resulting from the degradation of the lignin are selected from the group of guaiacol, vanillin and acetovanillon. Particularly preferred are vanillin or guaiacol.
Die nach dem erfindungsgemäßen Verfahren erhaltenen Hydroxybenzaldehydderivate und/oder Phenolderivate können aus dem Reaktionsprodukte kontinuierlich entzogen werden. Bevorzugt werden diese Hydroxybenzaldehydderivate und/oder Phenolderivate aus dem Reaktionsgemisch durch Destillation oder Extraktion kontinuierlich entzogen. Besonders bevorzugt ist die Wasserdampfdestillation.The Hydroxybenzaldehydderivate and / or phenol derivatives obtained by the process according to the invention can be continuously removed from the reaction products. Preferably, these Hydroxybenzaldehydderivate and / or phenol derivatives are removed from the reaction mixture by distillation or extraction continuously. Particularly preferred is the steam distillation.
Zur Elektrolyse liegt das Lignin in wässriger Lösung vor, wobei die wässrige Lösung einen pH-Wert von < 1 1 , bevorzugt < 9, besonders bevorzugt sauer ist. Ganz besonders bevorzugt liegt der pH-Wert < 3. Bevorzugt wird der pH-Wert mit in Wasser gut löslichen anorganischen Säuren, wie Salzsäure, Schwefelsäure, Salpetersäure oder organischen Säuren wie para-Toluolsulfonsäure oder Mischungen verschiedener Säuren auf einen pH < 3 eingestellt. Besonders bevorzugt ist Schwefelsäure.For electrolysis, the lignin is in aqueous solution, wherein the aqueous solution is a pH of <1 1, preferably <9, particularly preferably acidic. Most preferably, the pH is <3. Preferably, the pH is adjusted to a pH <3 with readily water-soluble inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid or organic acids such as para-toluenesulfonic acid or mixtures of various acids. Particularly preferred is sulfuric acid.
Für die Elektrolyse können jegliche dem Fachmann bekannte Elektrolysezellen eingesetzt werden wie geteilte oder ungeteilte Durchflusszelle, Kapillarspaltzelle oder Plat- tenstapelzelle. Besonders bevorzugt ist die ungeteilte Durchflusszelle. Zur Erzielung optimaler Raum-Zeit-Ausbeuten ist eine bipolare Anordnung mehrerer Elektroden vorteilhaft.For electrolysis, any electrolysis cells known to those skilled in the art may be used, such as divided or undivided flow cell, capillary gap cell or plate stack cell. Particularly preferred is the undivided flow cell. To achieve optimum space-time yields, a bipolar arrangement of several electrodes is advantageous.
Für das erfindungsgemäße Verfahren ist die Anode eine Diamantelektrode. Diese Di- amantelektroden enthält eine auf einen Trägermaterial aufgebrachte Diamantschicht, wobei das Trägermaterial ausgewählt ist aus Gruppe von Niob, Silizium, Wolfram, Titan, Siliziumcarbid, Tantal, Graphit oder keramische Trägern wie Titansuboxid. Besonders bevorzugt ist als Trägermaterial Niob oder Silizium. Die Diamantschicht auf dem Träger kann noch mit weiteren Elementen dotiert sein. Bevorzugt sind bor- oder stick- stoffdotierte Diamantelektroden. Besonders bevorzugt sind bordotierte Diamantelektroden.For the method according to the invention, the anode is a diamond electrode. These diademantel electrodes contain a diamond layer applied to a carrier material, wherein the carrier material is selected from the group of niobium, silicon, tungsten, titanium, silicon carbide, tantalum, graphite or ceramic carriers such as titanium suboxide. Particular preference is given to niobium or silicon as support material. The diamond layer on the carrier may be doped with other elements. Boron- or nitrogen-doped diamond electrodes are preferred. Particularly preferred are boron-doped diamond electrodes.
Als Kathodenmaterial kann jedes herkömmliche Kathodenmaterial mit geringer Sauerstoffüberspannung ausgewählt aus der Gruppe von RuOxTiOx-Mischoxid-Elektrode (DSA), platiniertem Titan, Platin, Nickel, Molybdän oder Edelstahl verwendet werden. Bevorzugt ist die Kombination von bordotierter Diamantkathode mit Edelstahl als Kathode. Besonders bevorzugt ist die Verwendung bor- oder stickstoffdotierte Diamantelektroden. Ganz besonders bevorzugt sind bordotierte Diamantelektroden. Es können Diamantelektroden eingesetzt werden, die nach dem CVD-Verfahren (che- mical vapour deposition) hergestellt worden sind. Solche Elektroden sind kommerziell verfügbar wie zum Beispiel bei Hersteller: Condias, Itzehoe; Diaccon, Fürth (Deutsch- land) bzw. Adamant Technologies, La-Chaux-de-Fonds (Schweiz).As the cathode material, any conventional low oxygen overpotential cathode material selected from the group consisting of RuO x TiO x mixed oxide electrode (DSA), platinized titanium, platinum, nickel, molybdenum or stainless steel may be used. Preference is given to the combination of boron-doped diamond cathode with stainless steel as the cathode. The use of boron- or nitrogen-doped diamond electrodes is particularly preferred. Very particular preference is boron-doped diamond electrodes. Diamond electrodes can be used which have been produced by the chemical vapor deposition (CVD) method. Such electrodes are commercially available, such as from the manufacturer: Condias, Itzehoe; Diaccon, Fürth (Germany) or Adamant Technologies, La-Chaux-de-Fonds (Switzerland).
Preisgünstigere Diamantelektroden, die nach dem HTHP-Verfahren (high temperature high pressure: Industriediamantpulver wird mechanisch in die Oberfläche eines Trägerbleches eingebracht) hergestellt wurden, können ebenfalls eingesetzt werden. HTHP-BDD-Elektroden sind kommerziell von pro aqua, Niklasdorf (Österreich) erhält- lieh, ihre Eigenschaften werden von A Cieciwa, R. Wüthrich und Ch. Comninellis in Electrochem. Commun. 8 (2006) 375-382 beschrieben.Lower-priced diamond electrodes manufactured according to the HTHP method (high-temperature high pressure: industrial diamond powder is mechanically introduced into the surface of a carrier sheet) can also be used. HTHP-BDD electrodes are commercially available from pro aqua, Niklasdorf (Austria) and their properties are described by A Cieciwa, R. Wüthrich and Ch. Comninellis in Electrochem. Commun. 8 (2006) 375-382.
Die Temperatur für das erfindungsgemäße Verfahren liegt zwischen 20 bis 1500C, bevorzugt im Bereich von 90 bis 1200C.The temperature for the process according to the invention is between 20 and 150 ° C., preferably in the range from 90 to 120 ° C.
Für das erfindungsgemäße Verfahren liegt die Stromdichte bevorzugt im Bereich von 5 bis 3000 mA/cm2, besonders bevorzugt im Bereich von 10 bis 200 mA/cm2. Um einen Belag auf den Elektroden zu vermeiden, kann bei der Verwendung von Diamantelektroden als Anoden- und/oder Kathodenmaterial die Polung in kurzen Zeitab- ständen gewechselt werden. Die Umpolung kann in einem Intervall von 30 Sekunden bis 10 Minuten erfolgen, bevorzugt ist ein Intervall von 30 Sekunden und 2 Minuten.For the inventive method, the current density is preferably in the range of 5 to 3000 mA / cm 2 , more preferably in the range of 10 to 200 mA / cm 2 . In order to avoid a coating on the electrodes, when using diamond electrodes as the anode and / or cathode material, the polarity can be changed in short time intervals. The polarity reversal can take place in an interval of 30 seconds to 10 minutes, preferably an interval of 30 seconds and 2 minutes.
Die Effizienz der Elektrolyse von Lignin in wässriger Lösung an bordotierten Diamantelektroden kann durch den Zusatz von Additiven wie TiC"2 gesteigert werden. TiC"2 wird bevorzugt in katalytischen Mengen eingesetzt.The efficiency of the electrolysis of lignin in aqueous solution at boron-doped diamond electrodes can be increased by the addition of additives such as TiC "2. TiC" 2 is preferably used in catalytic amounts.
Zur Elektrolyse von Lignin kann ein metallhaltiger oder metallfreier Redoxmediator zugegeben werden, bevorzugt sind Übergangsmetallfreie Mediatoren, z.B. Nitrosodisulfo- nate wie Fremy's Salz (Dikaliumnitrosodisulfonat).For electrolysis of lignin, a metal-containing or metal-free redox mediator may be added, preferably transition-metal-free mediators, e.g. Nitrosodisulfonates such as Fremy's salt (dipotassium nitrosodisulfonate).
Für die Durchmischung des Zelleninhalts können jegliche dem Fachmann bekannte mechanische Rührer, aber auch andere Durchmischungsmethoden wie der Einsatz von Ultraturrax oder Ultraschall verwendet werden. BeispieleFor the mixing of the cell contents, any mechanical stirrer known to those skilled in the art, but also other mixing methods such as the use of Ultraturrax or ultrasound can be used. Examples
Beispiel 1example 1
Eine Suspension von 30 g Kraft-Lignin in einem Elektrolyten, bestehend aus 570 g verdünnter Schwefelsäure (0.1 M), wird in einer ungeteilten Zelle, die mit einem Elektrodenstack aus bordotierten Diamantkathoden (Streckmetall, 5 x 10 cm) und bordotierten Diamantanoden (Streckmetall, 5 x 10 cm) im Abstand von 0.5 cm versehen ist, bei einer Stromdichte von 80 mA/cm2 und einer Temperatur von 300C für 1 Stunde unter Rühren bei 9500 U/min elektrolysiert. Die sich einstellende Zellspannung liegt im Bereich von 2-6 V. Die wässrige Phase wird mit Methyl-tert-butylether (MTBE) extrahiert, der Feststoff abgesaugt und mit MTBE gewaschen. Die wässrige Phase wird mehrfach mit MTBE extrahiert, die organischen Phasen vereinigt, getrocknet und das Lösungsmittel entfernt. Die gaschromatographische Analyse des organischen Rohpro- duktes ergibt folgende typische Zusammensetzung (GC-Flächenprozente): 27% Gua- jakol, 24% Vanillin, 24% Acetovanillon und 25% andere Verbindungen. Für die GC- Analyse wurde als stationäre Phase eine dB1 Säule von J&W Scientific mit 30 m Länge und 0,25 mm Durchmesser und 1 μm Schichtdicke verwendet. Diese Säule wird mittels Temperaturprogramm von 800C innerhalb von 5 min in 8°C Schritten auf 2500C aufgeheizt. Als Trägergas wird Helium mit einer Durchflussgeschwindigkeit von 20 bis 30 mL/min verwendet.A suspension of 30 g of kraft lignin in an electrolyte consisting of 570 g of dilute sulfuric acid (0.1 M), in an undivided cell, with an electrode stack of boron-doped diamond cathodes (expanded metal, 5 x 10 cm) and boron-doped diamond anodes (expanded metal, 5 x 10 cm) at a distance of 0.5 cm is electrolysed at a current density of 80 mA / cm 2 and a temperature of 30 0 C for 1 hour with stirring at 9500 U / min. The resulting cell voltage is in the range of 2-6 V. The aqueous phase is extracted with methyl tert-butyl ether (MTBE), the solid is filtered off with suction and washed with MTBE. The aqueous phase is extracted several times with MTBE, the organic phases are combined, dried and the solvent is removed. The gas chromatographic analysis of the crude organic product shows the following typical composition (GC area percentages): 27% guaacol, 24% vanillin, 24% acetovanillon and 25% other compounds. For the GC analysis, the stationary phase used was a dB1 column from J & W Scientific with a length of 30 m and a diameter of 0.25 mm and a layer thickness of 1 μm. This column is heated by means of a temperature program of 80 0 C within 5 min in 8 ° C steps to 250 0 C. The carrier gas used is helium at a flow rate of 20 to 30 mL / min.
Beispiel 2Example 2
Durchführung wie Beispiel 1 mit folgender Variation: 6 g Kraft-Lignin, 594 g verdünnte Schwefelsäure (0.1 M), 3 g Fremy's Salz, 30 Minuten Elektrolyse bei 25°C. Typische Zusammensetzung der organischen Extrakte (GC-Flächenprozente): 37% Guajakol, 23% Vanillin, 40% Acetovanillon. Procedure as Example 1 with the following variation: 6 g of kraft lignin, 594 g of dilute sulfuric acid (0.1 M), 3 g of Fremy 's salt, 30 minutes of electrolysis at 25 ° C. Typical composition of organic extracts (GC area percentages): 37% guaiacol, 23% vanillin, 40% acetovanillon.
Claims
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT09745700T ATE532888T1 (en) | 2008-05-14 | 2009-05-11 | METHOD FOR THE ELECTROCHEMICAL CLEAVING OF LIGNIN ON A DIAMOND ELECTRODE |
| US12/992,217 US20110089046A1 (en) | 2008-05-14 | 2009-05-11 | Process for the electrochemical cleavage of lignin at a diamond electrode |
| EP09745700A EP2276877B1 (en) | 2008-05-14 | 2009-05-11 | Method for electrochemically cleaving lignin on a diamond electrode |
| RU2010150834/04A RU2495157C2 (en) | 2008-05-14 | 2009-05-11 | Method for electrochemical splitting of lignin on diamond electrode |
| CN2009801172252A CN102027161B (en) | 2008-05-14 | 2009-05-11 | Method for electrochemically cleaving lignin on a diamond electrode |
| JP2011508877A JP2011521102A (en) | 2008-05-14 | 2009-05-11 | Method for electrochemical decomposition of lignin at a diamond electrode |
| CA2722235A CA2722235A1 (en) | 2008-05-14 | 2009-05-11 | Process for the electrochemical cleavage of lignin at a diamond electrode |
| BRPI0912164A BRPI0912164A2 (en) | 2008-05-14 | 2009-05-11 | process for lignin degradation. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP08156190 | 2008-05-14 | ||
| EP08156190.4 | 2008-05-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2009138368A1 true WO2009138368A1 (en) | 2009-11-19 |
Family
ID=41055312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2009/055638 Ceased WO2009138368A1 (en) | 2008-05-14 | 2009-05-11 | Method for electrochemically cleaving lignin on a diamond electrode |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US20110089046A1 (en) |
| EP (1) | EP2276877B1 (en) |
| JP (1) | JP2011521102A (en) |
| CN (1) | CN102027161B (en) |
| AT (1) | ATE532888T1 (en) |
| BR (1) | BRPI0912164A2 (en) |
| CA (1) | CA2722235A1 (en) |
| RU (1) | RU2495157C2 (en) |
| WO (1) | WO2009138368A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013021040A1 (en) | 2011-08-11 | 2013-02-14 | Basf Se | Method for producing vanillin by electrochemically oxidizing aqueous lignin solutions or suspensions |
| WO2014006108A1 (en) | 2012-07-04 | 2014-01-09 | Basf Se | Method for obtaining vanillin from aqueous basic compositions containing vanillin |
| WO2014006106A1 (en) | 2012-07-04 | 2014-01-09 | Basf Se | Method for producing vanillin |
| US9006494B2 (en) | 2012-07-04 | 2015-04-14 | Basf Se | Process for producing vanillin from vanillin-comprising compositions |
| AT518544A4 (en) * | 2016-04-29 | 2017-11-15 | Pro Aqua Diamantelektroden Produktion Gmbh & Co Kg | Process for the electrochemical conversion of organic compounds contained in residues or obtained as residues and use of a single-cell flow cell designed as an electrolytic cell for the electrochemical conversion of organic compounds contained in residues or as residues in a gaseous fuel |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BRPI0918489A2 (en) | 2008-09-08 | 2015-12-01 | Basf Se | integrated process for producing pulp and at least one low molecular weight value material |
| CN102277591B (en) * | 2011-08-02 | 2014-03-05 | 北京化工大学 | A method for electrochemically degrading lignin |
| CN103074639B (en) * | 2013-02-04 | 2015-04-29 | 河北工业大学 | Method for preparing 2, 6-ditertiary butyl-4-methylphenol by electrochemically degrading lignin |
| CN103469244B (en) * | 2013-08-02 | 2015-10-28 | 河北工业大学 | In copperas solution, electrochemical degradation xylogen prepares the method for dibutyl phthalate |
| CN104532284A (en) * | 2014-12-16 | 2015-04-22 | 广西科技大学 | Converting method and converting device of lignocellulose in ionic solution through electrooxidation-hydrothermal method |
| CN106480472B (en) * | 2015-08-25 | 2019-03-12 | 中国科学院天津工业生物技术研究所 | Convert one step of biological material to method, container and the purposes of solable matter |
| CN106987862B (en) * | 2017-04-12 | 2018-03-09 | 中北大学 | A kind of method of the electrochemical degradation lignin in eutectic solvent |
| KR102737082B1 (en) * | 2022-06-28 | 2024-11-29 | 울산과학기술원 | Device for hydrogen generation |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1666639A1 (en) * | 2003-08-08 | 2006-06-07 | Ebara Corporation | Submerged electrode and material thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US370370A (en) * | 1887-09-27 | Camera-plate holder for holding negative-paper | ||
| US372581A (en) * | 1887-11-01 | And ed | ||
| JPS5121346A (en) * | 1974-08-16 | 1976-02-20 | Sanwa Chemical Co Ltd | Parupukogyohaisuino datsushokujokahoho |
| GB8527960D0 (en) * | 1985-11-13 | 1985-12-18 | Mini Agriculture & Fisheries | Electro chemical treatment of lignins |
| FR2730730B1 (en) * | 1995-02-20 | 1997-04-04 | Rhone Poulenc Chimie | PROCESS FOR THE PREPARATION OF A SUBSTITUTED 4-HYDROXYBENZALDEHYDE |
| US6136186A (en) * | 1997-01-31 | 2000-10-24 | Lynntech, Inc. | Photocatalytic oxidation of organics using a porous titanium dioxide membrane and an efficient oxidant |
| DE69942360D1 (en) * | 1998-04-09 | 2010-06-24 | Suntory Holdings Ltd | METHOD FOR THE PRODUCTION OF ESSENTIAL OILS BY BLEED OILS BY TREATMENT WITH SUPERCRITICAL WATER |
| JP2005060752A (en) * | 2003-08-08 | 2005-03-10 | Ebara Corp | Material for electrode in liquid |
| JP2006068617A (en) * | 2004-09-01 | 2006-03-16 | Ebara Corp | Method and apparatus for treating water medium |
| DE102006034895A1 (en) * | 2006-07-25 | 2008-01-31 | Siemens Ag | Process for the removal of pollutants from liquids and apparatus for carrying out the process |
-
2009
- 2009-05-11 WO PCT/EP2009/055638 patent/WO2009138368A1/en not_active Ceased
- 2009-05-11 US US12/992,217 patent/US20110089046A1/en not_active Abandoned
- 2009-05-11 CN CN2009801172252A patent/CN102027161B/en not_active Expired - Fee Related
- 2009-05-11 EP EP09745700A patent/EP2276877B1/en not_active Not-in-force
- 2009-05-11 RU RU2010150834/04A patent/RU2495157C2/en not_active IP Right Cessation
- 2009-05-11 JP JP2011508877A patent/JP2011521102A/en active Pending
- 2009-05-11 AT AT09745700T patent/ATE532888T1/en active
- 2009-05-11 BR BRPI0912164A patent/BRPI0912164A2/en not_active IP Right Cessation
- 2009-05-11 CA CA2722235A patent/CA2722235A1/en not_active Abandoned
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1666639A1 (en) * | 2003-08-08 | 2006-06-07 | Ebara Corporation | Submerged electrode and material thereof |
Non-Patent Citations (2)
| Title |
|---|
| P. PARPOT ET AL: "Biomass conversion: attempted electrooxidation of lignin for vanillin production", J. APPL. ELECTROCHEM., vol. 30, no. 6, June 2000 (2000-06-01), pages 727 - 731, XP002545692 * |
| WALDVOGEL R. S.: "Electrochemical Conversion of Lignin", FACHAGENTUR NACHWACHSENDE ROHSTOFFE (FNR) VERANSTALTUNGEN, 10 March 2009 (2009-03-10), XP002545693, Retrieved from the Internet <URL:http://www.fnr-server.de/cms35/fileadmin/allgemein/pdf/veranstaltungen/Lignin/Votrag_frei_Waldvogel.pdf> * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013021040A1 (en) | 2011-08-11 | 2013-02-14 | Basf Se | Method for producing vanillin by electrochemically oxidizing aqueous lignin solutions or suspensions |
| US8808781B2 (en) | 2011-08-11 | 2014-08-19 | Basf Se | Method for producing vanillin by electrochemical oxidation of aqueous lignin solutions or suspensions |
| JP2014533326A (en) * | 2011-08-11 | 2014-12-11 | ビーエーエスエフ ソシエタス・ヨーロピアＢａｓｆ Ｓｅ | Method for producing vanillin by electrochemically oxidizing an aqueous lignin solution or suspension |
| WO2014006108A1 (en) | 2012-07-04 | 2014-01-09 | Basf Se | Method for obtaining vanillin from aqueous basic compositions containing vanillin |
| WO2014006106A1 (en) | 2012-07-04 | 2014-01-09 | Basf Se | Method for producing vanillin |
| US9006494B2 (en) | 2012-07-04 | 2015-04-14 | Basf Se | Process for producing vanillin from vanillin-comprising compositions |
| AT518544A4 (en) * | 2016-04-29 | 2017-11-15 | Pro Aqua Diamantelektroden Produktion Gmbh & Co Kg | Process for the electrochemical conversion of organic compounds contained in residues or obtained as residues and use of a single-cell flow cell designed as an electrolytic cell for the electrochemical conversion of organic compounds contained in residues or as residues in a gaseous fuel |
| AT518544B1 (en) * | 2016-04-29 | 2017-11-15 | Pro Aqua Diamantelektroden Produktion Gmbh & Co Kg | Process for the electrochemical conversion of organic compounds contained in residues or obtained as residues and use of a single-cell flow cell designed as an electrolytic cell for the electrochemical conversion of organic compounds contained in residues or as residues in a gaseous fuel |
Also Published As
| Publication number | Publication date |
|---|---|
| BRPI0912164A2 (en) | 2015-10-13 |
| RU2495157C2 (en) | 2013-10-10 |
| US20110089046A1 (en) | 2011-04-21 |
| RU2010150834A (en) | 2012-06-20 |
| CN102027161A (en) | 2011-04-20 |
| ATE532888T1 (en) | 2011-11-15 |
| EP2276877B1 (en) | 2011-11-09 |
| CA2722235A1 (en) | 2009-11-19 |
| JP2011521102A (en) | 2011-07-21 |
| CN102027161B (en) | 2013-01-09 |
| EP2276877A1 (en) | 2011-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2276877B1 (en) | Method for electrochemically cleaving lignin on a diamond electrode | |
| EP2742172B1 (en) | Method for producing vanillin by electrochemically oxidizing aqueous lignin solutions or suspensions | |
| JP2011521102A5 (en) | ||
| Gao et al. | Electro-oxidative depolymerization of lignin for production of value-added chemicals | |
| Zirbes et al. | Electro-conversion as sustainable method for the fine chemical production from the biopolymer lignin | |
| Möhle et al. | Modern electrochemical aspects for the synthesis of value‐added organic products | |
| EP3337801B1 (en) | Method for the preparation of (4s)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1-6-naphthyridine-3-carboxamide and recovery of (4s)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1-6-naphthyridine-3-carboxamide by electrochemical methods | |
| Shiraishi et al. | Studies on electrooxidation of lignin and lignin model compounds. Part 1: Direct electrooxidation of non-phenolic lignin model compounds | |
| JPH0772355B2 (en) | Electrochemical treatment of lignin | |
| US11028235B2 (en) | Polycarboxylated compounds and compositions containing same | |
| CN112831799A (en) | Method for Electrochemical Depolymerization of Lignin | |
| EP4459011A1 (en) | High-throughput electrochemical oxidation process | |
| EP2870275B1 (en) | Method for producing vanillin | |
| WO2002042249A1 (en) | Production of butane tetracarboxylic acid derivatives by means of coupled electrosynthesis | |
| Zhang et al. | Electrocarboxylation of Acetophenone to 2‐Hydroxy‐2‐phenylpropionic Acid in the Presence of CO2 | |
| US9903028B2 (en) | Nitroxyl-mediated oxidation of lignin and polycarboxylated products | |
| Moodley et al. | The electro-oxidation of lignin in Sappi Saiccor dissolving pulp mill effluent | |
| DE602004001782T2 (en) | PROCESS FOR PREPARING A-SUBSTITUTED CARBOXYLIC ACIDS FROM THE SERIES OF A-HYDROXYCARBOXYLIC ACIDS AND N-SUBSTITUTED A-AMINOCARBOXYLIC ACIDS | |
| US4457810A (en) | 4,4'-Diphenyl ether-dialdehyde-bis-dimethylacetal and a process for its preparation | |
| WO2020099350A1 (en) | Process for the oxidation of carbon-containing organic compounds with electrochemically generated oxidizing agents and arrangement for carrying out the process | |
| DE3215095A1 (en) | METHOD FOR PRODUCING 2,3,5-TRIMETHYL-L-P-BENZOQUINONE | |
| Singh et al. | Electrochemical cyclic voltametric and kinetics of vanillin formation over TiMMO electrodes from agroresidue black liquor | |
| DE2331712A1 (en) | PROCESS FOR THE PREPARATION OF 2METHOXY-3,6-DICHLOROBENZOIC ACID | |
| Singha et al. | Electrochemical cyclic voltametric |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WWE | Wipo information: entry into national phase |
Ref document number: 200980117225.2 Country of ref document: CN |
|
| DPE2 | Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101) | ||
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09745700 Country of ref document: EP Kind code of ref document: A1 |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 2722235 Country of ref document: CA |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 12992217 Country of ref document: US |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 2011508877 Country of ref document: JP |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 2009745700 Country of ref document: EP |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 2010150834 Country of ref document: RU |
|
| ENP | Entry into the national phase |
Ref document number: PI0912164 Country of ref document: BR Kind code of ref document: A2 Effective date: 20101110 |