WO2013021040A1 - Verfahren zur herstellung von vanillin durch elektrochemische oxidation von wässrigen lignin-lösungen bzw. suspensionen - Google Patents
Verfahren zur herstellung von vanillin durch elektrochemische oxidation von wässrigen lignin-lösungen bzw. suspensionen Download PDFInfo
- Publication number
- WO2013021040A1 WO2013021040A1 PCT/EP2012/065642 EP2012065642W WO2013021040A1 WO 2013021040 A1 WO2013021040 A1 WO 2013021040A1 EP 2012065642 W EP2012065642 W EP 2012065642W WO 2013021040 A1 WO2013021040 A1 WO 2013021040A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lignin
- aqueous
- solution
- vanillin
- silver
- Prior art date
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
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/042—Electrodes formed of a single material
- C25B11/046—Alloys
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C47/00—Compounds having —CHO groups
- C07C47/52—Compounds having —CHO groups bound to carbon atoms of six—membered aromatic rings
- C07C47/575—Compounds having —CHO groups bound to carbon atoms of six—membered aromatic rings containing ether groups, groups, groups, or groups
- C07C47/58—Vanillin
-
- 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
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
- C25B11/081—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound the element being a noble metal
-
- 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 preparation of vanillin by electrochemical oxidation of an aqueous, lignin-containing suspension or solution.
- Lignins are a group of three-dimensional macromolecules found in the cell wall of plants and composed of various phenolic monomer units such as p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. Lignins are stored in the growth of plants in the plant cell wall and thereby cause the lignification of the cell (lignification). About 20% to 30% of the dry matter of woody plants consists of lignins. In addition to cellulose and chitin, lignins are the most abundant organic compounds in the world.
- Lignin as well as lignin-containing substances such as alkali lignin, lignin sulphate or lignin sulphonate are obtained as a by-product in large quantities in various industrial processes such as papermaking.
- the total production of lignin-containing substances is estimated at about 20 billion tonnes per year. Lignin thus represents a valuable raw material. Parts of this lignin are still used.
- alkali lignin which can be prepared by alkaline treatment of the black liquor obtained in papermaking, used in North America as a binder for wood-based and cellulose-based press plates, as a dispersant, for clarification of sugar solutions, stabilization of asphalt emulsions and foam stabilization.
- lignin is an aromatic valuable material, it is desirable in addition to its energetic utilization lignin to a greater extent to convert further recyclables.
- Vanillin 4-hydroxy-3-methoxybenzaldehyde
- Vanillin sugar instead of expensive natural vanilla. 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 such as L-dopa, methyldopa and papaverine. There is therefore a fundamental interest in new economical processes for the production of vanillin. Due to its structural similarity to the basic building blocks of lignin, the flavoring agent vanillin is suitable as a target molecule for syntheses starting from lignin.
- WO 87/03014 describes a process for the electrochemical oxidation of lignin at temperatures of preferably 170 ° to 190 ° C. in aqueous, strongly alkaline solutions with thorough mixing during the electrolysis. Above all, copper or nickel electrodes are used as anodes.
- a complex mixture which comprises, inter alia, vanillic acid (4-hydroxy-3-methoxybenzoic acid), vanillin, 4-hydroxybenzaldehyde, 4-hydroxyacetophenone and acetovanillon (4-hydroxy-3-methoxyacetophenone) and optionally phenol, sulfonic acid (4-hydroxy-3,5-dimethoxybenzoic acid) and syringaldehyde (4-hydroxy-3,5-dimethoxybenzaldehyde).
- 4-hydroxybenzoic acid is the major product. Only with the use of nickel electrodes is it possible to obtain vanillin as the main product of the electrolysis, although temperatures of 170 ° C.
- the strongly alkaline conditions and the high temperatures cause the low-molecular-weight products formed during the oxidation to undergo degradation reactions such as over-oxidation and disproportionation.
- the aqueous alkaline solutions are highly corrosive under the conditions described in WO 87/03014 and lead to destruction of the electrolysis cell and of the electrode material. These corrosion processes require not inconsiderable heavy metal entry into the products obtained, so that they are no longer suitable for the food industry even after purification.
- the electrolytic cell used is a circulation cell in which the lignosulfate-containing electrolyte is circulated continuously through a cylindrical electrode arrangement with a central cylindrical nickel network as the cathode and a nickel net surrounding the cathode as an anode.
- WO 2009/138368 describes a process for the electrolytic degradation of lignin, in which an aqueous lignin-containing electrolyte is oxidized on a diamond electrode.
- a low molecular weight product is formed which contains about equal parts of vanillin together with other hydroxybenzaldehyde derivatives such as acetovaniline or guaiacol.
- the selectivity of lignin oxidation with respect to vanillin is thus low.
- the diamond electrode is not able to cope with the strongly corrosive conditions at basic pH values during the electrolysis. After a short time, the diamond electrode is strong damaged. It is therefore necessary to carry out the electrolysis in the acidic pH range.
- the method should be feasible under conditions that are less corrosive than the conditions of the prior art and attack the electrodes used less strongly.
- the vanillin should be obtained in a form that does not interfere with use as a flavoring in the food industry.
- the present invention thus relates to a process for the production of vanillin, comprising an electrochemical oxidation of an aqueous, lignin-containing suspension or solution at an anode, wherein a silver electrode is used as the anode.
- Another object of the present invention is the use of vanillin, which was prepared by the process according to the invention, as a flavoring in the food industry.
- the process according to the invention has a number of advantages.
- the electrode materials used lead to a significant increase in selectivity. This high selectivity can surprisingly be achieved even at a comparatively low temperature of up to 100 ° C.
- the anode materials used in the invention prove to be extremely resistant to the corrosive reaction conditions and, unlike the methods of the prior art, no or no appreciable corrosion takes place.
- Lignin-containing aqueous solutions or suspensions are understood here and below to mean an aqueous solution or suspension which contains lignin or lignin derivatives, for example lignin sulfate, lignin sulfonate, kraft lignin, alkali lignin or organosolv lignin or a mixture thereof, as lignin constituent.
- the aqueous solution or suspension may be an aqueous solution or suspension which is obtained as a by-product in a technical process such as pulp, pulp or cellulose production, eg black liquor, and the lignin-containing wastewater.
- the aqueous solution or suspension may be an aqueous solution or suspension which is prepared by dissolving a lignin or lignin derivative, for example lignosulfate, lignosulfonate, kraft lignin, alkali or organosolv lignin, or a lignin in a technical processes such as pulp, pulp or cellulose production, eg lignin from black liquor, from the sulfite process, from the sulfate process, from the organocell or organosolv process, from the ASAM process, from the power plant Method or from the natural-pulping method.
- a lignin or lignin derivative for example lignosulfate, lignosulfonate, kraft lignin, alkali or organosolv lignin, or a lignin in a technical processes such as pulp, pulp or cellulose production, eg lignin from black liquor, from the sulfite process, from the sulf
- an aqueous lignin-containing electrolyte containing lignin or a lignin-containing substance which is in the form of an aqueous suspension or solution, is subjected to electrochemical oxidation, i. subjected to electrolysis.
- electrochemical oxidation i. subjected to electrolysis.
- the oxidation of the lignin contained or the lignin derivative takes place at the anode.
- a reduction of the aqueous electrolyte e.g. with formation of hydrogen.
- any silver electrode known to the person skilled in the art can be used as anode in the process according to the invention.
- This may consist entirely of silver or a silver-containing alloy, or it may be a support electrode comprising a support coated with silver or a silver-containing alloy.
- the electrodes used as the anode may, for example, be electrodes in the form of expanded metals, nets or sheets.
- silver-containing coin alloys known to those skilled in the art can be used.
- these preferably contain copper, nickel, iron or mixtures of these metals.
- Preferred silver alloys typically have a silver content of at least 50% by weight.
- the proportion of the further silver constituents is typically in the range from 1 to 40% by weight, in particular in the range from 5 to 35% by weight.
- Examples of such silver alloys is an alloy of 90% by weight of silver and 10% by weight of nickel, and cuprosilver, which is an alloy of 72.5% by weight of silver and 27.5% by weight of copper ,
- the anode used is a silver electrode in which silver or a silver-containing alloy is arranged as a coating on an electrically conductive carrier other than silver.
- the thickness of the silver layer is generally less than 1 mm, for example 10 to 300 ⁇ , preferably 10 to 100 ⁇ .
- Suitable support materials for such silver-coated electrodes are electrically conductive materials such as niobium, silicon, tungsten, titanium, silicon carbide, tantalum, copper, gold, nickel, iron, graphite, ceramic supports such as titanium suboxide or silver-containing alloys.
- Preferred supports are metals, in particular metals with a lower standard potential than silver, for example iron, copper, nickel or niobium.
- supports in the form of expanded metals, nets or sheets, the supports in particular containing the aforementioned materials.
- these expanded metals or sheets consist of 50% by weight, preferably 75% by weight, in particular 95% by weight, based on the total weight of the support of iron, copper or nickel.
- any electrode known to the person skilled in the art and suitable for the electrolysis of aqueous systems can be used as the cathode. Since reduction processes take place at the cathode and the vanillin is oxidized at the anode, when a heavy metal electrode such as a nickel cathode is used, the loading of vanillin with this heavy metal is so low that the vanillin obtained can be used without problem in the food industry. Nevertheless, it is advantageous not to use cathodes containing nickel or lead.
- the electrode materials exhibit a low hydrogen overvoltage.
- the cathode is a coated noble metal electrode. Coatings of silver or platinum or alloys which essentially, i. E. at least 50 wt .-%, made of silver, platinum or mixtures thereof, into consideration.
- the thickness of the noble metal layer is usually less than 1 mm, e.g. 10 to 300 ⁇ .
- Suitable support materials for such noble-metal-coated electrodes are electrically conductive materials as have been mentioned above in connection with the silver electrode. It is preferred to use supports in the form of expanded metals, nets or sheets, the supports in particular containing the aforementioned materials. In particular, these expanded metals or sheets consist of 50% by weight, preferably 75% by weight, in particular 95% by weight, based on the total weight of the support of iron or copper.
- the arrangement of anode and cathode is not limited and includes, for example, arrangements of planar gratings and / or plates, which are also in the form of several, may be arranged alternately polarized stack and cylindrical arrangements of cylindrically shaped networks, grids or pipes, which may also be arranged in the form of several, alternately polarized cylinder.
- various electrode geometries are known to the person skilled in the art.
- the anode and cathode are separated by a separator.
- the separator is typically a porous sheet placed between the electrodes, e.g. a grid, mesh, woven or nonwoven fabric made of an electrically nonconductive material that is inert under the electrolysis conditions, e.g. a plastic material, in particular a Teflon material or a Teflon-coated plastic material.
- 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. More preferably, the undivided flow cell, e.g. a flow cell with circulation, in which the electrolyte is continuously circulated past the electrodes. The process can be carried out with good success both batchwise and continuously.
- the process according to the invention can likewise be carried out on an industrial scale.
- Corresponding electrolysis cells are known to the person skilled in the art. All embodiments of this invention relate to both the laboratory and the industrial scale.
- the contents of the electrolytic cell is mixed.
- any mechanical stirrer known to those skilled in the art can be used.
- the use of other mixing methods such as the use of Ultraturrax, ultrasound or jet nozzles is also preferred.
- the electrolysis voltage By applying the electrolysis voltage to the anodes and cathodes, electric current is passed through the electrolyte.
- a current density of 1000 mA / cm 2 In particular 100 mA / cm 2 .
- the current densities at which the process is carried out are generally 1 to 1000 mA cm 2 , preferably 1 to 100 mA / cm 2 .
- the process according to the invention is particularly preferably carried out at current densities between 1 and 50 mA / cm 2 .
- the total duration of the electrolysis naturally depends on the electrolytic cell, the electrodes used and the current density. An optimum duration can be determined by the skilled person by routine tests, e.g. by sampling during electrolysis.
- the polarity can be changed at short intervals.
- the polarity reversal can take place in an interval of 30 seconds to 10 minutes, an interval of 30 seconds to 2 minutes is preferred.
- the anode and cathode are made of the same material.
- the electrolysis is carried out according to the inventive method usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90 ° C.
- the electrolysis is usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90 ° C.
- the electrolysis is usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90 ° C.
- the electrolysis is usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90 ° C.
- the electrolysis is usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90 ° C.
- the electrolysis is usually at a temperature in a range of 0 to 100 ° C, preferably 50 to 95 ° C, in particular 75 to 90
- Pressure below 2000 kPa preferably below 1000 kPa, in particular below 150 kPa, e.g. in the range of 50 to 1000 kPa, in particular 80 to 150 kPa performed. It is particularly preferred to carry out the process according to the invention at a pressure in the range of atmospheric pressure (101 ⁇ 20 kPa).
- the inventive method at 80 ° C to 85 ° C and in the range of atmospheric pressure (101 ⁇ 20 kPa) is performed.
- the aqueous, lignin-containing suspension or solution generally contains 0.5 to 30 wt .-%, preferably 1 to 15 wt .-%, in particular 1 to 10 wt .-% lignin based on the total weight of the aqueous, lignin-containing suspension or solution.
- lignin-containing wastewater streams are produced. These can be used as an aqueous, lignin-containing suspension or solution in the process according to the invention.
- the effluent streams of the papermaking sulfite process often contain lignin as lignosulfonic acid.
- Lignin sulfonic acid can be used directly in the process of the invention or first hydrolyzed alkaline.
- lignin-containing wastewater streams occur, for example, in the form of black liquor.
- the lignin falls as Organosolv lignin.
- Ligninsulfonklare restroom or Organosolv lignin-containing wastewater streams and black liquor are particularly suitable as an aqueous, lignin-containing suspension or solution for the process of the invention.
- the aqueous lignin-containing suspensions or solutions may also be prepared by dissolving or suspending at least one lignin-containing material.
- the lignin-containing material preferably contains at least 10% by weight, in particular at least 15% by weight and particularly preferably at least 20% by weight of lignin, based on the total weight of the lignin-containing material.
- the lignin-containing material is preferably selected from straw, bagasse, kraft lignin, lignin sulphonate, oxidized lignin, organosolv lignin or other lignin-containing residues from the paper industry or fiber production, in particular under kraft lignin, lignin sulphonate and oxidized lignin an electrochemical oxidation of unoxidized lignin is obtained.
- oxidized lignin is used which originates from a previous electrolysis cycle. It has proved to be advantageous to use oxidized lignin in at least one further electrolysis cycle, preferably in at least two further electrolysis cycles and in particular in at least three further electrolysis cycles.
- An advantage of this repeated use of the oxidized lignin is that repeated vanillin can be obtained.
- the yield of vanillin is significantly increased based on the amount of lignin originally used and therefore increases the efficiency of the overall process.
- the concentration of the oxidation-sensitive vanillin in the electrolyte per oxidation process can be kept so low that the undesirable side reactions such as overoxidation are effectively reduced. while the overall yield of vanillin increases over the whole process (several electrolysis cycles).
- alkali metal hydroxides such as NaOH or KOH
- ammonium salts such as ammonium hydroxide
- alkali metal carbonates such as sodium carbonate, e.g. in the form of soda.
- the concentration of inorganic bases in the aqueous, lignin-containing suspension or solution should not exceed 5 mol / l and in particular 4 mol / l and is then typically in the range of 0.01 to 5 mol / l, in particular in the range of 0.1 to 4 mol / l. It is particularly preferred to use effluent streams or residues from paper and pulp production, in particular black liquor or kraft lignin.
- the viscosity of the solution or suspension can increase greatly and the solubility of the lignin can be very low.
- the concentration of the alkali metal hydroxide is generally in the range of from 0.1 to 5 mol / l, preferably from 0.5 to 5 mol / l, in particular from 1, 0 to 3.5 mol / l.
- sodium hydroxide or potassium hydroxide is used.
- the lignin-containing alkali metal hydroxide solution is heated to a temperature of 150 to 250 ° C, in particular 170 to 190 ° C and stirred vigorously for 1 to 10 h, preferably for 2 to 4 h.
- the pre-hydrolyzed lignin can be separated from the alkali metal hydroxide solution prior to electrochemical oxidation.
- the process according to the invention makes it possible in principle to work both in the acidic and in the alkaline pH range.
- the aqueous, lignin-containing suspension or solution generally has a pH in the range of pH 0 to 14, frequently in the range of pH 6 to 14, preferably in the range of pH 7 to 13, in particular in the range of pH 8 to 13 on.
- the vanillin formed during electrolysis is susceptible to oxidation and disproportionation processes under alkaline conditions. Therefore, it is basically advantageous for the stability of the vanillin obtained to work at low pH values.
- the aqueous, lignin-containing suspension or solution has a pH of from pH 0 to pH 8, preferably from pH 1 to 5, especially pH 1 to pH 3.
- the pH is adjusted 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.
- the aqueous, lignin-containing suspension or solution has a pH in the range from pH 6 to pH 14, preferably from pH 7 to pH 13, in particular from pH 8 to pH 13.
- the aqueous, lignin-containing suspension or solution has a pH of at least pH 8, in particular at least pH 10 and especially at least pH 12, e.g. a pH in the range of pH 8 to pH 14, preferably from pH 10 to pH 14, in particular from pH 12 to pH 14.
- the aqueous, lignin-containing suspension or solution are thereby to improve the solubility of the lignin as an additive alkali metal hydroxides, in particular NaOH or KOH added.
- the concentration of the alkali metal hydroxides is generally in a range of 0.1 to 5 mol / l, often in the range of 0.5 to 5 mol / l, preferably 1 to 3.5 mol / l, in particular 1, 0 to 3 , 0 mol / l.
- the aqueous, lignin-containing suspension or solution may contain a conductive salt to improve the conductivity.
- a conductive salt to improve the conductivity.
- alkali metal salts such as salts of Li, Na, K or quaternary ammonium salts such as tetra (C 1 -C 6 -alkyl) ammonium or tri (C 1 -C 6 -alkyl) methylammonium salts.
- Suitable counterions are sulfate, bisulfate, alkyl sulfates, aryl sulfates, halides, phosphates, carbonates, alkyl phosphates, alkyl carbonates, nitrate, alcoholates, tetrafluoroborate, hexafluorophosphate, perchlorate or bis-triflate or bis-triflimide.
- suitable conductive salts are ionic liquids ("lonic liquids").
- Suitable electrochemically stable ionic liquids are described in "Lonic Liquids in Synthesis”, ed. Peter Wasserscheid, Tom Welton, Verlag Wiley-VCH 2003, Chap. 1 to 3.
- a metal-containing or metal-free mediator can be added to the aqueous, lignin-containing suspension or solution.
- Mediators are understood as meaning redox pairs which allow indirect electrochemical oxidation.
- the mediator is electrochemically transferred to the higher oxidation state, then acts as an oxidant and then regenerates again by electrochemical oxidation. It is therefore an indirect electrochemical oxidation of the organic compound, since the mediator is the oxidizing agent.
- the oxidation of the organic compound with the mediator in the oxidized form can be carried out in the electrolysis cell in which the mediator was converted into the oxidized form, or in one or more separate reactors ("ex-cell method"). The latter method has the advantage that any remaining traces of the organic compound to be oxidized do not interfere with the production or regeneration of the mediator.
- Suitable mediators are compounds which can be present in two oxidation states, act as oxidants in the higher oxidation state and can be regenerated electrochemically.
- salts or complexes of the following redox couples can be used as mediators: Ce (III / IV), Cr (II / III), Cr (IIIA / I), Ti (II / III), V (II / III), V ( III / IV), V (IV / V), Ag (1 / ll), AgOVAgO " , Cu (1 / ll), Sn (II / IV), Co (II / III), Mn (II / III), Mn (II / IV), Os (IVA / IM), Os (III / IV), Br 2 / Br 7 Br 3 , I- / I 2 , I 3VI 2 10 3 + / I0 4 -, Fremy's salt (dipotassium nitroso disulfonate) or also organic mediators, such as ABTS
- the process according to the invention is carried out without addition of mediators.
- the aqueous, lignin-containing suspension or solution may further contain an inert solvent.
- Suitable solvents are polar-aprotic solvents having high electrochemical stability, such as acetonitrile, propionitrile, adiponitrile, corkerrinitrile, propylene carbonate, ethylene carbonate, dichloromethane, nitromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, Trichlorethylene, tetrachlorethylene, hexafluoroacetone, N-methylpyrrolidone, hexamethylphosphoric triamide, dimethyl sulfoxide and dimethylpropyleneurea (DMPU).
- polar-aprotic solvents having high electrochemical stability, such as acetonitrile, propionitrile, adiponitrile, corkerrinitrile, propylene carbonate, ethylene carbonate, dichloromethane
- inert solvents are generally used in an amount of not more than 60% by weight, preferably not more than 30% by weight, in particular not more than 20% by weight, e.g. 2.5 to 30 wt .-% or 5 to 20 wt .-%, based on the total amount of the aqueous, lignin-containing suspension or solution used.
- the vanillin obtained by the process according to the invention can be removed from the aqueous, lignin-containing solution by methods known to the person skilled in the art.
- the vanillin is removed by distillation or extraction of the aqueous, lignin-containing suspension or solution.
- Suitable distillative methods are distillation processes known to those skilled in the art, e.g. Vacuum distillation, distillation under a protective gas atmosphere or steam distillation.
- An advantage of vanillin separation via distillative processes is that the vanillin is not contacted with potentially hazardous organic solvents.
- Vanillin can also be removed by extraction from the aqueous, lignin-containing suspension or solution. This is particularly advantageous because the sensitive vanillin is not exposed to any further thermal stress. For this purpose, extraction processes known to those skilled in the art are suitable.
- the aqueous, lignin-containing suspension or solution can be mixed with an organic solvent so as to separate the vanillin formed (liquid-liquid extraction).
- Suitable organic solvents are water-immiscible organic solvents such as hydrocarbons having 5 to 12 carbon atoms such as hexane or octane, chlorinated hydrocarbons having 1 to 10 carbon atoms such as dichloromethane or chloroform, aliphatic ethers having 2 to 10 carbon atoms such as diethyl ether or diisopropyl ether, cyclic ethers or aliphatic esters such as ethyl ethanoate. Halogen-free organic solvents are preferred. Furthermore, it is possible to extract vanillin with the aid of supercritical fluids. In particular, supercritical CO2 is suitable for this purpose.
- the formed lignin can also be removed by solid phase extraction from the aqueous, lignin-containing suspension or solution.
- solid phase extractants are added to the aqueous, lignin-containing suspension or solution.
- the adsorbed on the extractant vanillin (vanillate) can then with the
- the vanillin produced is removed by solid-phase extraction from the aqueous, lignin-containing solution or suspension.
- the separation of vanillin can be continuous or discontinuous. It is particularly advantageous to continuously remove the vanillin from the aqueous, lignin-containing suspension or solution during the electrochemical oxidation. In particular, it is preferred to remove the vanillin by continuous (solid phase) extraction or steam distillation from the aqueous, lignin-containing solution. Over-oxidation products of vanillin, which can be formed during the electrolysis, are easily removed. Investigations by the inventors have shown that overoxidation products formed on a silver electrode used according to the invention have a high proportion of carboxyl groups, so that they are more easily known by those skilled in techniques such as use of ion exchanger or extraction from the Reaction product can be removed.
- the vanillin is prepared without the use of a heavy metal anode. Therefore, due to the low Schwermetallbelas- tion of vanillin produced this can be used in the food industry.
- Another object of the invention is thus the use of vanillin, which was prepared by the described method to use as a flavoring in the food industry.
- the aqueous, lignin-containing suspension or solution contains oxidized lignin in addition to the vanillin formed.
- the oxidized lignin can be obtained by drying the aqueous, lignin-containing solution.
- a lignin produced in this way can advantageously be used as an additive in building materials research, for example as a cement or concrete additive.
- the stationary phase used was an HP-5 column from Agilent with a length of 30 m, a diameter of 0.25 mm and a thickness of 1 ⁇ m. This column is heated by means of a temperature program of 50 ° C within 10 min at 10 ° C / min to 290 ° C. This temperature is held for 15 min.
- the carrier gas used was hydrogen at a flow rate of 46.5 mL / min.
- the cell contents were brought to room temperature and filtered through a frit of existing solid.
- the precipitated, gelatinous solid was filtered through kieselguhr and washed with dichloromethane.
- Example 4 523 mg of Kraft lignin were dissolved in an electrolyte from 80 g of 1 M aqueous NaOH, dissolved in a temperature-controlled, undivided cell with stirring.
- the cell had two silver sheet electrodes (2.5 cm by 3.2 cm each) mounted parallel to each other at a distance of 0.5 cm.
- the precipitated, gelatinous solid was filtered through kieselguhr and washed with dichloromethane.
- the organic phase was separated.
- the aqueous phase was extracted three more times with in each case 80 ml of dichloromethane.
- the electrolysis was carried out analogously to Example 4 with the following change:
- the cell had two electrodes made of nickel sheet (2.5 cmx4.0 cm each), which were mounted parallel to each other at a distance of 0.5 cm.
- Examples 7 to 9 524-526 mg of force lignin were dissolved in 80 g of electrolyte in a temperature-controlled, undivided cell with stirring.
- the cell had an Ag / Ni alloy anode
- Example 7 The procedure was analogous to Example 7 with the following variation: 525-526 mg of kraft lignin were dissolved in 85 g of 3 M aqueous NaOH in an undivided cell with stirring.
- the cell is provided with anode and cathode consisting of cuprosilber (3.0x4.0 cm 2 ), which were mounted parallel to each other at a distance of 0.5 cm.
- the maximum cell voltage during the reaction was 2.9 V.
- the yields of the organic extracts, based on lignin (wt .-%) were: 1, 51% vanillin, 0.15% acetovanillon.
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)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Paper (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
Description
Claims
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR112014003265A BR112014003265A2 (pt) | 2011-08-11 | 2012-08-10 | método para produzir vanilina |
EP12744004.8A EP2742172B1 (de) | 2011-08-11 | 2012-08-10 | Verfahren zur herstellung von vanillin durch elektrochemische oxidation von wässrigen lignin-lösungen bzw. suspensionen |
KR1020147003457A KR20140048967A (ko) | 2011-08-11 | 2012-08-10 | 수성 리그닌 용액 또는 현탁액의 전기화학적 산화에 의한 바닐린의 제조 방법 |
CA2844406A CA2844406A1 (en) | 2011-08-11 | 2012-08-10 | Method for producing vanillin by electrochemically oxidizing aqueous lignin solutions or suspensions |
RU2014108709/04A RU2600322C2 (ru) | 2011-08-11 | 2012-08-10 | Способ получения ванилина электрохимическим окислением водных растворов или суспензий лигнина |
JP2014524386A JP6096189B2 (ja) | 2011-08-11 | 2012-08-10 | 水性リグニン溶液又は懸濁液を電気化学的に酸化することによるバニリンの製造方法 |
CN201280049147.9A CN103842555B (zh) | 2011-08-11 | 2012-08-10 | 通过电化学氧化木素水溶液或含水悬浮液制备香草醛的方法 |
ES12744004.8T ES2556467T3 (es) | 2011-08-11 | 2012-08-10 | Procedimiento para la preparación de vainillina por oxidación electroquímica de soluciones o suspensiones acuosas de lignina |
MX2014001650A MX2014001650A (es) | 2011-08-11 | 2012-08-10 | Metodos para producir vainillina por oxidacion electroquimica de soluciones o suspensiones acuosas de lignina. |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11177320 | 2011-08-11 | ||
EP11177320.6 | 2011-08-11 | ||
EP12175005.3 | 2012-07-04 | ||
EP12175005 | 2012-07-04 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013021040A1 true WO2013021040A1 (de) | 2013-02-14 |
Family
ID=46639530
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2012/065642 WO2013021040A1 (de) | 2011-08-11 | 2012-08-10 | Verfahren zur herstellung von vanillin durch elektrochemische oxidation von wässrigen lignin-lösungen bzw. suspensionen |
Country Status (11)
Country | Link |
---|---|
US (1) | US8808781B2 (de) |
EP (1) | EP2742172B1 (de) |
JP (1) | JP6096189B2 (de) |
KR (1) | KR20140048967A (de) |
CN (1) | CN103842555B (de) |
BR (1) | BR112014003265A2 (de) |
CA (1) | CA2844406A1 (de) |
ES (1) | ES2556467T3 (de) |
MX (1) | MX2014001650A (de) |
RU (1) | RU2600322C2 (de) |
WO (1) | WO2013021040A1 (de) |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104603329B (zh) * | 2012-07-04 | 2017-06-27 | 巴斯夫欧洲公司 | 制备香草醛的方法 |
US8969534B2 (en) * | 2013-02-20 | 2015-03-03 | Wisconsin Alumni Research Foundataion | Selective aerobic alcohol oxidation method for conversion of lignin into simple aromatic compounds |
JP6019216B2 (ja) * | 2013-03-21 | 2016-11-02 | 日本たばこ産業株式会社 | 黒液の製造方法および香味成分含有液の製造方法 |
CN104062332A (zh) * | 2014-06-30 | 2014-09-24 | 浙江天能电池(江苏)有限公司 | 木素磺酸钠耐电化学氧化能力的测定方法 |
CN104532284A (zh) * | 2014-12-16 | 2015-04-22 | 广西科技大学 | 一种在离子溶液中的电氧化水热木质纤维素转化方法及其装置 |
WO2017024220A1 (en) * | 2015-08-05 | 2017-02-09 | Ohio University | Electrochemical conversion of lignin to industrial chemicals |
US11154087B2 (en) | 2016-02-02 | 2021-10-26 | R.J. Reynolds Tobacco Company | Method for preparing flavorful compounds isolated from black liquor and products incorporating the flavorful compounds |
US9903028B2 (en) | 2016-05-27 | 2018-02-27 | Wisconsin Alumni Research Foundation | Nitroxyl-mediated oxidation of lignin and polycarboxylated products |
US10336868B2 (en) | 2016-05-27 | 2019-07-02 | Wisconsin Alumni Research Foundation | Polycarboxylated compounds and compositions containing same |
RU2641901C1 (ru) * | 2016-11-22 | 2018-01-23 | федеральное государственное автономное образовательное учреждение высшего образования "Южный федеральный университет" (Южный федеральный университет) | Способ получения окисленного лигнина |
CN106676564B (zh) * | 2017-01-18 | 2019-04-23 | 邓渝林 | 一种直接电解生物质制氢的方法及*** |
CN106939428A (zh) * | 2017-04-18 | 2017-07-11 | 河南科技大学 | 一种电解木质纤维素制备还原糖的方法 |
US10818952B2 (en) * | 2017-11-30 | 2020-10-27 | Northeastern University | Lignin-based electrolytes and flow battery cells and systems |
JP7072778B2 (ja) * | 2018-07-04 | 2022-05-23 | 国立大学法人京都大学 | イミダゾール誘導体の製造方法 |
CN110850015B (zh) * | 2019-11-14 | 2022-02-08 | 中国人民大学 | 一种提高水热液化生物油中可检测组分数量的方法 |
CN114196974B (zh) * | 2021-12-17 | 2023-11-24 | 上海应用技术大学 | 一种香兰素的电化学合成方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1987003014A1 (en) | 1985-11-13 | 1987-05-21 | The Minister Of Agriculture Fisheries And Food In | Electrochemical treatment of lignins |
EP0882814A1 (de) * | 1997-06-06 | 1998-12-09 | Consortium für elektrochemische Industrie GmbH | System und Verfahren zur elektrochemischen Spaltung von Verbindungen |
WO2009138368A1 (de) | 2008-05-14 | 2009-11-19 | Basf Se | Verfahren zur elektrochemischen spaltung von lignin an einer diamantelektrode |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SU694488A1 (ru) * | 1978-05-19 | 1979-10-30 | Ленинградская Ордена Ленина Лесотехническая Академия Им.С.М.Кирова | Способ получени ванилина |
FR2569726B1 (fr) * | 1984-09-04 | 1986-09-19 | Hoechst France | Procede de preparation d'acide glyoxylique par oxydation electrochimique anodique du glyoxal |
JPS61147890A (ja) * | 1984-12-20 | 1986-07-05 | Okamura Seiyu Kk | 不飽和高級脂肪酸の製造方法 |
US5526223A (en) * | 1994-12-01 | 1996-06-11 | Motorola, Inc. | Electrode materials and electrochemical capacitors using same |
CN1205366A (zh) * | 1997-06-06 | 1999-01-20 | 电化学工业有限公司(国际) | 含木素材料的电化学去木质作用体系及其应用 |
-
2012
- 2012-08-08 US US13/569,677 patent/US8808781B2/en not_active Expired - Fee Related
- 2012-08-10 BR BR112014003265A patent/BR112014003265A2/pt unknown
- 2012-08-10 CN CN201280049147.9A patent/CN103842555B/zh not_active Expired - Fee Related
- 2012-08-10 MX MX2014001650A patent/MX2014001650A/es unknown
- 2012-08-10 WO PCT/EP2012/065642 patent/WO2013021040A1/de active Application Filing
- 2012-08-10 EP EP12744004.8A patent/EP2742172B1/de not_active Not-in-force
- 2012-08-10 KR KR1020147003457A patent/KR20140048967A/ko not_active Application Discontinuation
- 2012-08-10 CA CA2844406A patent/CA2844406A1/en active Pending
- 2012-08-10 RU RU2014108709/04A patent/RU2600322C2/ru not_active IP Right Cessation
- 2012-08-10 ES ES12744004.8T patent/ES2556467T3/es active Active
- 2012-08-10 JP JP2014524386A patent/JP6096189B2/ja not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1987003014A1 (en) | 1985-11-13 | 1987-05-21 | The Minister Of Agriculture Fisheries And Food In | Electrochemical treatment of lignins |
EP0882814A1 (de) * | 1997-06-06 | 1998-12-09 | Consortium für elektrochemische Industrie GmbH | System und Verfahren zur elektrochemischen Spaltung von Verbindungen |
WO2009138368A1 (de) | 2008-05-14 | 2009-11-19 | Basf Se | Verfahren zur elektrochemischen spaltung von lignin an einer diamantelektrode |
Non-Patent Citations (10)
Title |
---|
"lonic Liquids in Synthesis", 2003, VERLAG WILEY-VCH |
B MOODLEY ET AL: "The electro-oxidation of lignin in Sappi Saiccor dissolving pulp mill effluent", WATER SA (ONLINE), 37 (1), 31 January 2011 (2011-01-31), http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1816-79502011000100006&lng=en&nrm=iso, pages 33 - 40, XP055044895, ISSN: 1816-7950, Retrieved from the Internet <URL:http://www.ajol.info/index.php/wsa/article/viewFile/64104/51902> [retrieved on 20121120] * |
C.Z. SMITH ET AL., J. APPL. ELECTROCHEM, 2011 |
CARMEN Z. SMITH ET AL: "Electro-organic reactions. Part 60[1]. The electro-oxidative conversion at laboratory scale of a lignosulfonate into vanillin in an FM01 filter press flow reactor: preparative and mechanistic aspects", JOURNAL OF APPLIED ELECTROCHEMISTRY, vol. 41, no. 4, 26 November 2010 (2010-11-26), pages 363 - 375, XP055044214, ISSN: 0021-891X, DOI: 10.1007/s10800-010-0245-0 * |
JOHN C. WOZNIAK: "Preparation and Reactions of Diels-Alder Adducts of Lignin-Derived Quinones, Doctor's Dissertation, June 1988", June 1988 (1988-06-01), The Institute of Paper Chemistry, Appleton, Wisconsin, pages 1 - 173, XP055044921, Retrieved from the Internet <URL:http://smartech.gatech.edu/bitstream/handle/1853/5515/wozniak_jc.pdf?sequence=1> [retrieved on 20121120] * |
KOSUKE IZUTSU: "Electrochemistry in Nonaqueous Solutions", 2002, VERLAG WILEY-VCH |
PARPOT P ET AL: "Biomass conversion: attempted electrooxidation of lignin for vanillin production", JOURNAL OF APPLIED ELECTROCHEMISTRY, KLUWER ACADEMIC PUBLISHERS, DO, vol. 30, no. 6, 1 June 2000 (2000-06-01), pages 727 - 731, XP002545692, ISSN: 1572-8838, DOI: 10.1023/A:1004003613883 * |
PETR ZUMAN AND ELINORE B. RUPP: "Electrochemical Investigations of Alkaline Cleavage of Lignin Under Mild Conditions", COLLECTION OF CZECHOSLOVAK CHEMICAL COMMUNICATIONS, vol. 66, no. 7, 2001, pages 1125 - 1139, XP002687571, Retrieved from the Internet <URL:http://cccc.uochb.cas.cz/66/7/1125/> [retrieved on 20121120], DOI: 10.1135/cccc20011125 * |
TIAN M ET AL: "A novel approach for lignin modification and degradation", ELECTROCHEMISTRY COMMUNICATIONS, ELSEVIER, AMSTERDAM, NL, vol. 12, no. 4, 1 April 2010 (2010-04-01), pages 527 - 530, XP026977282, ISSN: 1388-2481, [retrieved on 20100128], DOI: 10.1016/J.ELECOM.2010.01.035 * |
VERA L. PARDINI ET AL: "Anodic cleavage of lignin model dimers in methanol", TETRAHEDRON, vol. 48, no. 35, 1 January 1992 (1992-01-01), pages 7221 - 7228, XP055044781, ISSN: 0040-4020, DOI: 10.1016/S0040-4020(01)88262-4 * |
Also Published As
Publication number | Publication date |
---|---|
EP2742172B1 (de) | 2015-10-14 |
CN103842555A (zh) | 2014-06-04 |
RU2600322C2 (ru) | 2016-10-20 |
RU2014108709A (ru) | 2015-09-20 |
EP2742172A1 (de) | 2014-06-18 |
ES2556467T3 (es) | 2016-01-18 |
BR112014003265A2 (pt) | 2017-07-18 |
JP2014533326A (ja) | 2014-12-11 |
US20130040031A1 (en) | 2013-02-14 |
CA2844406A1 (en) | 2013-02-14 |
KR20140048967A (ko) | 2014-04-24 |
CN103842555B (zh) | 2017-08-04 |
US8808781B2 (en) | 2014-08-19 |
MX2014001650A (es) | 2014-08-26 |
JP6096189B2 (ja) | 2017-03-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2742172B1 (de) | Verfahren zur herstellung von vanillin durch elektrochemische oxidation von wässrigen lignin-lösungen bzw. suspensionen | |
EP2276877B1 (de) | Verfahren zur elektrochemischen spaltung von lignin an einer diamantelektrode | |
EP0012215B1 (de) | 2-Hydroxybutansulfonsaures Cholin und dessen Verwendung als Leitsalz | |
DE2343054C2 (de) | Verfahren zur elektrochemischen Herstellung von Pinacolen | |
DE2460754C2 (de) | Verfahren zur Herstellung von p-Benzochinondiketalen | |
US20140034508A1 (en) | Process for the preparation of vanillin | |
EP2870275B1 (de) | Verfahren zur herstellung von vanillin | |
DE69701224T2 (de) | Verfahren zur elektrochemischen synthese von n-acetylcystein aus cystein | |
WO2014006108A1 (de) | Verfahren zur gewinnung von vanillin aus wässrigen basischen vanillin-haltigen zusammensetzungen | |
DE60209109T2 (de) | Verfahren zur reinigung einer redox-mediator enthaltenden lösung vor dessen elektrolytischen regenerierung | |
DE2404560B2 (de) | Verfahren zur Herstellung von Sebacinsäure | |
DE3420333C2 (de) | ||
EP0576853B1 (de) | Verfahren zur Herstellung von Perfluorpolyethern | |
EP3802917A1 (de) | Anolytfraktion-katalysierte hmf-herstellung | |
DE602004001782T2 (de) | Verfahren zur herstellung a-substituierter carbonsäuren aus der reihe der a-hydroxycarbonsäuren und n-substituierten a-aminocarbonsäuren | |
DE3028758C2 (de) | Verfahren zur Herstellung von Anisaldehyd | |
DE68905443T2 (de) | Verfahren zur herstellung von chinon aus hydrochinon durch elektrolyse. | |
DE3152459C2 (de) | ||
EP0040331B1 (de) | Verfahren zur Herstellung von Diacetonketogulonsäure | |
DE2460156C2 (de) | Verfahren zur Herstellung von Diaceton-2-ketogulonsäure | |
DE3504144A1 (de) | Bis(ethylendithiolo)-tetrathiofulvalen-derivat und seine herstellung | |
DE1518027A1 (de) | Verfahren zur Herstellung von quartaeren Ammoniumhydroxyden | |
DE2065514A1 (de) | Verfahren zur herstellung von olefinoxyden |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12744004 Country of ref document: EP Kind code of ref document: A1 |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) | ||
ENP | Entry into the national phase |
Ref document number: 2844406 Country of ref document: CA |
|
ENP | Entry into the national phase |
Ref document number: 2014524386 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20147003457 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2014/001650 Country of ref document: MX |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012744004 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2014108709 Country of ref document: RU Kind code of ref document: A |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112014003265 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112014003265 Country of ref document: BR Kind code of ref document: A2 Effective date: 20140211 |