METHOD FOR THE PREPARATION OF SUBSTITUTED OR UNSUBSTITUTED PHENOL AND CATALYSTS THEREFOR

Abstract: The invention relates to a method for the preparation of a substituted or unsubstituted phenol by oxidation of the cor­ responding substituted or unsubstituted benzoic acid in the gas phase in the presence of a copper and vanadium and/or silver and lithium and/or sodium and/or magnesium contain­ ing catalyst and catalysts therefor. The invention particularly relates to the gas phase oxidation of unsubstituted benzoic acid to unsubstituted phenol.

Description: METHOD FOR THE PREPARATION OF SUBSTITUTED OR UNSUBSTITUTED PHENOL AND CATALYSTS THEREFOR The invention relates to a method for the preparation of a substituted or unsubstituted phenol by oxidation of the corresponding substituted or unsubstituted benzoic acid in the gas phase in the presence of a copper containing catalyst and catalysts therefor. The invention particularly relates to the gas phase oxidation of unsubstituted benzoic acid to unsubstituted phenol. Such a method and catalyst are known from the Dutch patent specification 107,561. This patent specification describes such a method and catalyst, in which the catalyst consists of copper oxide on a magnesium oxide carrier. The disadvantage of such a catalyst is that the activity and/or selectivity of it will strongly decrease after a very short time, for instance already after a few hours, so that the application of such a method for the preparation of phenols was economically unattainable. So far all kinds of attempts have been made to come to an improved catalyst for the above-mentioned method. Thus it was suggested to replace a large part, often even far more than half, of the copper oxide. Such catalysts, however, show faults all of them. Thus no catalyst has so far been known to combine a good activity and selectivity with a long economic life. The purpose of the invention is to provide a catalyst which does combine these properties. A method according to the invention is characterized in that, in addition to copper and/or one or more copper compounds, particularly copper oxide, vanadium and/or one or more vanadium compounds and/or silver and/or one or more silver compounds and lithium and/or one or more lithium compounds and/or sodium and or one or more sodium compounds and/or magnesium and or one or more magnesium compounds are applied as catalyst compounds with an atom ratio between vanadium and copper of at most 1 : 2 and preferably of between 1 : 250 and 1 : 10, between copper and silver of at most 1 : 2 and preferably between 1 : 500 and 1 : 4, between lithium and copper of at most 5 : 1 and preferably of between 1 : 200 and 2 : 1, between sodium and copper of at most 5 : 1 and preferably of between 1 : 200 and 2 : 1 and between magnesium and copper of at most 5 : 1 and preferably of between 1 : 200 and 2 : 1 and if both vanadium and silver are present an atom ratio between vanadium and silver preferably of between 1 : 2 and 25 : 1, more in particular of between 2 : 1 and 10 : 1. In addition to vanadium and/or silver and lithium and/or sodium and/or magnesium other catalyst compounds may be used as well, c.q. potassium, barium, calcium, cesium, rubidium, strontium, mercury, lead, thallium, arsenic, antimony, chromium, molybdenum, manganese, technetium, rhenium, uranium, the noble metals of group VIII of the Periodic Table of the Elements, the rare earths and one or more compounds containing one or more of these metals. The catalyst used according to the invention preferably consists of an intimate mixture of CuO and V205 and/or Ag20 and Li20 andjor Na20 and/or MgO and, optionally, one or more other compounds. In addition the catalyst¯preferably contains 0-95 % by weight of carrier material, more specifically 20-80 % by weight of carrier material. Preferably a silicon-containing carrier material is applied. A suitable method of preparation for the catalyst according to the invention is as follows. The carrier material is suspended in distilled water. Subsequently, at virtually room temperature, for instance 280-320 K, a solution of copper nitrate, a solution of ammonium metavanadate and/or a solution of silvernitrate and, optionally, one-or more solutions of one or more cocatalyst metal-containing compounds are added to this suspension. During firm stirring the metals are precipitated as hydroxide or oxide by adding, in drops, an equivalent quantity of a solution and/or a suspension of lithium and/or sodium and/or magnesium hydroxide. Subsequently the suspension is filtered. The filter cake is broken, dried and, for a certain length of time, for instance 1-50 hours and preferably for 10-25 hours, calcined at a temperature of, for instance, 500-1000 K and preferable of 500-750 K. Finally, the catalyst thus obtained is reduced in size, if necessary, with mechani cal means and optionally sieved. The desired catalyst particle size depends on the kind and the size of the particular reactor in which the catalyst particles are applied. The method according to the invention is carried out as follows. I mol part of substituted or unsubstituted benzoic acid, with 1-100 mol parts of water, for instance in the form of steam, and preferably 5-25 mol parts of water, and 0.05-5 mol parts of oxygen and preferably 0.1-2 mol parts of oxygen, for instance in the form of air, is brought into contact in the gas phase with a catalyst according to the invention at a temperature of 450-700 K, preferably 500-650 K, and at a pressure of preferably 50-2000 kPa, at which higher and lower pressures are not excluded as long as the gas phase is maintained in the reaction medium. Preferably a catalyst load of 0.05-5 parts by weight of substituted or unsubstituted benzoic acid per part by weight of catalyst is applied per hour, specifically 0.1-2 parts by weight of substituted or unsubstituted benzoic acid per part by weight of catalyst per hour. Higher and lower catalyst loads can also be applied, but are, for economic reasons, less attractive. The gas phase oxidation according to the invention can be effected in all kinds of reactors. Very well applicable are fixed-bed reactors and particularly fluid bed reactors. In a fixed-bed reactor preference is given to the use of catalyst particles with a diameter of between 1 and 10 mm. In a fluid bed reactor preference is given to the use of catalyst particles containing a carrier with a high specific surface, preferably larger than 100 m2/g, more specifically larger than 200 m2/g, and which particles preferably have a diameter of between 20 and 500 e m. A very suitable method to carry out the gas phase oxidation according to the invention in a fluid bed reactor is as follows. The fluidization of the catalyst particles is effected by the supply of oxidizing gas and steam. Thus a fluid bed is formed with a height h. The subsituted or unsubstituted benzoic acid to be oxidized is fed, in gaseous state, into the fluid bed at a place separate from the oxidizing gas supply, at a height preferably between 1/4 and 3/4 h. The reaction mixture formed during the gas phase oxidation can be received and condensed. The liquid reaction mixture thus formed can then be separated, as known in the art, into the various components, for instance by distillation. Moreover, instead of ordinary condensation of the reaction gases, fractional condensation can be applied. Thus a separation by distillation can afterwards become superfluous. The invention also includes catalysts for the catalysis of the gas phase oxidation of substituted or unsubstituted bezoic acid to the corresponding substituted or unsubstituted phenol. These catalysts contain 1000 parts of copper and/or one or more copper compounds, particularly copper oxide, (calculated as Cu atoms) together with 4-100 parts of vanadium and/or one or more vanadium compounds (calculated as V atoms) and/or 2-250 parts of silver and/or one or more silver compounds (calculated as Ag atoms) and 5-2000 parts of lithium and/or one or more lithium compounds (calculated as Li atoms) and/or 5-2000 parts of sodium and/or one or more sodium compounds (calculated as Na atoms) and/or 5-2000 parts of magnesium and/or one or more magnesium compounds (calculated as Mg atoms). These catalysts preferably contain 0-95 % by weight of carrier material, more specifically 20-80 % by weight of carrier material. Preferably a silicon-containing carrier material is applied. By preference does this carrier material have a specific surface larger than 100 m2/g, more particularly larger than 200 m2/g. The invention is furhter elucidated by means of the following non-restrictive examples and comparative experiments. Examples and comparative experiments In the table below examples 1 up to and including 21 and comparative experiments A up to and including G are given. Examples 1 up to and including 20 and comparative experiments A up to and including F have been carried out in a fluid bed reactor as described above, into which reactor the benzoic acid was fed at about i h at virtually atmospheric pressure. The example 21 and comparative experiment G have been carried out in a fixed-bed reactor as described above, again at virtually atmospheric pressure. The load during the experiments was each time about 0.4 g benzoic acid per g catalyst per hour, the molar ratio H20 : benzoic acid about 10 : 1 to 20 : 1 and 02 : benzoic acid about 0.2. After 1 hour, 24 hours, 96 hours and 120 hours samples of the reactor gases released were cooled, homogenized with dimethylformamide and analyzed. The results of these analyses are given in the table. The catalyst used in the gas phase oxidation process had been prepared as described above. In this preparation a calcination time of 16 hours was observed. Besides the metal compounds, the catalyst consisted of Aerosil, a silicon-containing carrier material with a specific surface larger than 200 m2/g. The table below shows the following: Column I number of example or comparative experiment II % by weight of Cu in catalyst III % by weight of V in catalyst IV % by weight of Ag in catalyst V % by weight of Li in catalyst VI % by weight of Na in catalyst VII % by weight of Mg in catalyst VIII duration of the experiment till the measurement in hours IX conversion in moles % X phenol selectivity in moles % XI benzene selectivity in moles % XII diphenylether selectivity in moles % XIII calcination temperature in K XIV reaction temperature in K The remainder of the reaction gas consisted of combustion products. I II III IV V VI VII VIII IX X XI XII XIII XIV 1 28,3 1,2 1,5 1 35,1 79,8 6,3 1,7 585 570 24 35,1 86,4 4,8 1,4 96 34,9 82,3 6,2 1,8 120 34,1 80,1 7,1 1,9 2 28,7 4,0 1,2 1 20,5 75,3 5,3 5,2 700 540 24 20,8 74,1 5,5 7,2 96 21,0 73,4 5,7 8,8 120 20,1 72,5 6,0 9,3 3 34,0 1,8 0,9 1 20,9 72,1 4,4 5,9 700 540 24 21,9 72,1'5,9 8,9 96 23,5 71,8 6,3 11,0 120 20,9 70,7 7,8 13,8 4 30,1 0,6 ---9,8 - 1 44,7 77,9 8,1 8,2 575 540 24 39,2 76,1 8,1 8,0 96 31,0 74,8 8,2 8,5 120 26,8 73,8 9,0 10,1 5 33,6 1,8 0,8 1 25,2 77,1 5,8 6,7 575 540 24 24,7 76,0 7,4 8,2 96 24,1 73,5 6,5 10,2 120 23,9 72,1 8,0 11,3 6 31,2 2,0 5,8 1 15,3 73,1 8,5 3,1 580 570 24 14,9 72,1 9,3 4,0 96 14,6 71,8 10,1 5,9 120 14,1 72,0 11,0 4,9 7 27,4 0,4 1,7 1 50,5 81,1 8,5 3,0 580 575 24 48,1 80,2 8,9 3,2 96 45,0 78,9 9,1 5,0 120 43,7 78,1 9,5 4,8 III III IV V VI VII VIII IX X XI XII XIII XIV 8 27,6 9,3 4,5 1 33,1 73,8 7,6 5,6 700 555 24 33,0 73,7 7,9 6,0 96 32,9 73,4 8,9 6,2 120 32,0 73,2 9,0 6,3 9 27,6 9,3 4,5 1 40,6 80,1 6,9 5,0 575 555 24 37,8 78,2 6,9 6,0 96 35,7 77,1 6,2 6,7 120 35,1 76,9 6,3 6,9 10 32,0 0,1 3,4 1 42,5 81,9 5,4 6,9 700 575 24 32,7 71,0 13,7 6,2 96 24,8 71,1 15,1 6,3 120 23,2 70,1 15,3 5,8 11 31,2 0,3 6,0 1 18,1 80,0-8,-S 5,1 580 570 24 17,3 79,1 9,1 6,0 96 16,3 78,0 10,0 6,1 120 16,1 77,1 11,0 7,0 12 31,2 1,2 0,5 3,8 1 43,7 88,6 4,0 -1,9 585 570 24 46,1 86,8 3,8 1,5 96 45,0 84,1 5,1 2,2 120 44,2 83,2 6,2 3,0 13 30,0 1,3 0,4 1,9 1 48,5 84,7 6,4 1,5 590 570 24 47,2 87,9 4,8 1,3 96 47,8 83,5 6,1 2,0 120 46,1 84,1 7,0 2,5 14 31,8 1,1 0,3 1,2 1 21,7 80,8 4,2 7,2 575 540 24 19,3 79,8 4,5 8,3 96 19,7 79,5 4,6 8,3 120 21,4 75,8 6,2 10,1 I II III IV V VI VII- VIII IX X XI XII XIII XIV 15 31,8 1,1 0,3 1,2 1 47,5 78,8 4,3 7,0 575 590 24 52,4 79,3 4,6 -8,0 96 45,4 80,4 5,1 4,9 120 39,5 79,3 3,9 3,0 16 33,5 0,7 0,2 0,9 1 22,3 76,1 7,6 8,0 575 565 24 21,9 75,2 10,8 7,7 96 21,7 74,1 12,9 7,4 120 21,0 72,4 14,8 6,7 17 31,1 0,4 1,1 1,1 1 15,2 75,4 3,7 8,0 575 540 24 16,2 74,9 5,2 7,8 96 15,1 74,7 6,1 7,6 120 14,9 74,3 7,1 7,2 18 31,1 0,4 1,1 1,1 1 37,1 7521387,5 575 565 24 -35,7-73,6 16,1 6,8 96 36,9 74,7 14,7 6,2 120 35,0 74,6 15,7 6,6 19 32,0 1,1 0,4 2,0 1 30,1 77,1 10,5 8,0 575 590 24 30,2 78,0 11,0 7,5 96 29,8 77,5 10,8 8,9 120 27,5 77,0 10,9 9,5 20 30,6 1,3 0,4 1,2 4,3 1 46,7 84,4 6,6 3,3 585 575 24 41,6 86,3 4,6 3,3 96 38,1 86,4 4,5 3,4 120 37,7 85,9 5,1 3,3 21 30,6 1,3 0,4 1,2 4,3 1 32,1 81,3 4,1 5,1 585 575 24 31,6 80,1 3,6 6,0 96 30,5 81,2 3,9 5,9 120 29,8 79,5 4,2 4,8 I II III IV V VI VII VIII IX X XI XII XIII XIV A 30,1 1 10,0 48,4 7,4 1,6 585 540 24 5,2 36,8 7,9 5,7 96 3,6 30,1 8,0 10,9 120 3,0 25,9 8,1 12,8 B 28,8 1,8 1 40,3 77,6 11,3 3,1 585 575 24 31,5 75,3 13,0 2,5 96 25,7 70,1 18,1 3,7 120 20,8 61,9 22,0 5,6 C 33,7 3,9 1 20,2 70,8 22,3 2,8 575 540 24 20,1 60,3 28,5 3,9 96 19,8 51,2 35,1 5,8 120 19,7 35,9 40,7 8,9 D 31,2 6,0 1 25,0 72,8 15,1 3,9 580 565 24 21,0 67,9 17,9 4,1 96 18,1 60,1 25,1 5,9 120: 17,0 55,1 30,7 8,7 E 9,9 15,8 4,0 1 6,9 43,0 6,5 0,6 700 540 24 6,1 35,1 6,4 1,3 96 5,4 29,7 6,6 1,9 120 4,8 25,1 6,7 2,6 F 10,9 18,8 4,0 1 31,9 46,5 27,4 8,4 590 570 24 28,1 34,9 33,2 6,6 96 28,4 33,7 35,6 5,7 120 27,5 31,6 36,4 7,8 G 33,7 3,9 1 16,2 72,3 23,1 3,7 575 540 24 15,9 61,2 29,0 4,8 96 14,3 44,9 35,6 5,8 120 13,9 31,0 45,9 5,8

Claims: CLAIMS 1. Method for the preparation of substituted or unsubstituted phenol by oxidation of the corresponding substituted or unsubstituted benzoic acid in the gas phase in the presence of a copper con taining catalyst, characterized in that, in addition to copper and/or one or more copper compounds, vanadium and/or one or more vanadium compounds and/or silver and/or one or more silver com pounds and lithium and/or one or more lithium compounds and/or sodium and/or one or more sodium compounds and/or magnesium and/or one or more magnesium compounds are applied as catalyst compounds with an atom ratio between vanadium and copper of at most 1 : 2 between silver and copper of at most 1 : 2, between lithium and copper of at most 5 : 1, between sodium and copper of at most 5 : 1 and between magnesium and copper of at most 5 : 1. 2. Method according to claim 1, characterized in that a vanadium copper atom ratio of between 1 : 250 and 1 : 10 is applied. 3. Method according to claim 1 or 2, characterized in that a silver copper atom ratio of between : 500¯-and¯¯-1--: 4 is applied. 4. Method according to any one of the claims 1-3, characterized in that a lithium-copper atom ratio of between 1 : 200 and 2 : 1 is applied. 5. Method according to any one of the claims 1-4, characterized in that a sodium-copper an atom ratio of between 1 : 200 and 2 : 1 is applied. 6. Method according to any one of the claims 1-5, characterized in that a magnesium-copper atom ratio of between 1 : 200 and 2 : 1 is applied 7. Method according to any one of the claims 1-6, characterized in that the said gas phase oxidation is carried out in a fluid bed reactor. 8. Method according to claim 7, characterized in that the substituted or unsubstituted benzoic acid to be oxidized is fed to the fluid bed separately from the supply for oxygen-containing gas at a height of between 1/4 and 3/4 parts of the total height of the bed. 9. Catalyst for the catalysis of the gas phase oxidation of substi tuted and unsubstituted benzoic acid to the corresponding substi tuted or unsubstituted phenol, characterized in that this catalyst contains 1000 parts of copper and/or one or more copper compounds (calculated as Cu atoms) together with 4-100 parts of vanadium and/or one of more vanadium compounds (calculated as V atoms) and/or 2-250 parts of silver and/or one or more silver compounds (calculated as Ag atoms) and 5-2000 parts of lithium and/or one or more lithium compounds (calculated as Li atoms) and/or 5-2000 parts of sodium and/or one or more sodium compounds (calculated as Na atoms) and/or 5-2000 parts of magnesium and/or one or more magnesium compounds (calculated as Mg atom). 10. Method for the gas phase oxidation of substituted or unsubstituted benzoic acid in substance as described above and elucidated by means of the examples. 11. Catalyst for the gas phase oxidation of substituted or unsubsti tuted benzoic acid in substance as described above and prepared in -a manner as described above and elucidated by means of the examples. - - ¯ 12. Substituted or unsubstituted phenol prepared by gas phase oxida tion of the corresponding substituted or unsubstituted benzoic acid according to a method according to any one of the claims 1-8 and 10 catalyzed with a catalyst according to any one of the claims 9 and 11.

Inventors: TEUNISSEN, ANTONIUS JACOBUS, VAN GEEM, PAUL CHRISTIAAN
Applicants: STAMICARBON B.V.
Application year: 1981
Main classification: C07C37
IPC codes: C07C37