METHOD FOR RECOVERING THE OXYGENATED COMPOUNDS CONTAINED IN AQUEOUS FRACTIONS DERIVED FROM BIOMASS
20190367816 ยท 2019-12-05
Inventors
- Marcelo Eduardo DOMINE (Valencia, ES)
- Jose Manuel Lopez Nieto (Valencia, ES)
- Daniel Delgado Munoz (Valencia, ES)
- Alberto Fernandez-Arroyo Naranjo (Valencia, ES)
Cpc classification
B01J2523/00
PERFORMING OPERATIONS; TRANSPORTING
B01J37/0236
PERFORMING OPERATIONS; TRANSPORTING
B01J2523/00
PERFORMING OPERATIONS; TRANSPORTING
B01J35/30
PERFORMING OPERATIONS; TRANSPORTING
Y02P30/20
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B01J37/03
PERFORMING OPERATIONS; TRANSPORTING
B01J37/10
PERFORMING OPERATIONS; TRANSPORTING
B01J23/002
PERFORMING OPERATIONS; TRANSPORTING
International classification
C10G3/00
CHEMISTRY; METALLURGY
Abstract
The present invention relates to a method for producing mixtures of hydrocarbons and aromatic compounds for subsequent use as fuel components (preferably in the C5-C16 range) by catalytic conversion of the oxygenated compounds contained in aqueous fractions derived from primary biomass treatments, which can comprise at least the following steps: (i) bringing the aqueous mixture containing the oxygenated compounds derived from biomass in contact with a catalyst comprising at least W and/or Nb, and combinations of Nb and W with other elements, (ii) reacting the mixture with the catalyst in a catalytic reactor at temperatures between 50 C. and 450 C. and under pressures of 1 to 120 bar; and (iii) recovering the products obtained by a liquid/liquid separation process of the aqueous and organic phases.
Claims
1. A method for producing mixtures of hydrocarbons and aromatic compounds, characterised in that it comprises, at least, the following stages: (a) bringing an aqueous mixture containing oxygenated compounds derived from primary biomass treatments in contact with a catalyst, comprising at least W and/or Nb and that, in its calcined form, has at least one material ordered along one of the crystallographic axes and an X-ray diffractogram wherein at least diffraction lines corresponding to angles 2 to 22.70.4 and 46.60.4 are observed; (b) reacting the mixture with the catalyst in a catalytic reactor at temperatures between 50 C. and 450 C. and pressures of 1 to 120 bar; and (c) recovering the products obtained in stage (b) by means of a liquid/liquid separation process of the aqueous and organic phases.
2. The method, according to claim 1, characterised in that the catalyst has the empirical formula:
W.sub.aNb.sub.bA.sub.cH.sub.dO.sub.e wherein: A is a metal of the group of alkaline and alkaline earth metals, B is a chemical element of the group of transition metals, rare earth or elements of groups III, a and b are comprised between 0 and 12.0, with a+b other than zero (a+b0), c is comprised between 0 and 2.0, d is comprised between 0 and 4.0, and e has a value depending on the state of oxidation of the elements W, Nb and the element B.
3. The method, according to claim 2, characterised in that d is zero and the catalyst has the empirical formula:
W.sub.aNb.sub.bA.sub.cO.sub.e wherein: A is a metal of the group of alkaline or alkaline earth metals a and b are comprised between 0 and 12.0, with a+b other than zero (a+b0), c is comprised between 0.0001 and 1.0 and e has a value depending on the state of oxidation of the elements W, Nb and A.
4. The method, according to claim 2, characterised in that c is zero and the catalyst has the empirical formula:
W.sub.aNb.sub.bB.sub.dO.sub.e wherein: B is a chemical element of the group of transition metals, rare earth or elements of groups III, IV and V a and b are comprised between 0 and 12.0, with a+b other than zero (a+b0), d is comprised between 0.0001 and 4.0, and e has a value depending on the state of oxidation of the elements W, Nb and the element B.
5. The method, according to claim 2, characterised in that c and d are zero and the catalyst has the empirical formula:
W.sub.aNb.sub.bO.sub.e wherein: a and b are comprised between 0 and 12, with a+b other than zero (a+b0) and e has a value depending on the state of oxidation of the elements W and Nb.
6. The method, according to claim 2, characterised in that A is at least one alkaline metal or alkaline earth metal selected from Li, Na, K, Cs, Be, Mg, Ca, Sr, Ba, and combinations thereof.
7. The method, according to claim 6, characterised in that the metal is selected from Na, K, Cs, Mg, Ca and combinations thereof.
8. The method, according to claim 2, characterised in that the element B is selected from the group of transition metals, rare earth, or elements of group III, IV and V.
9. The method, according to claim 8, characterised in that the element B is a transition metal selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ta, Tl, Re and combinations thereof.
10. The method, according to claim 8, characterised in that the element B is a rare earth selected from La, Ce and combinations thereof.
11. The method, according to claim 8, characterised in that the element B is an element of group III, IV and V selected from B, Al, Ga, Si, Sn, Sb, and combinations thereof.
12. The method, according to claim 8, characterised in that the element B is selected from Ti, V, Mn, Cu, Zn, Zr, La, Ce, Al, Si, and combinations thereof.
13. The method, according to claim 1, characterised in that mixtures of hydrocarbons and aromatic compounds containing between 5 and 16 carbon atoms are obtained.
14. The method, according to claim 13, characterised in that the products obtained are selected from linear, branched, cyclical aliphatic hydrocarbons containing between 5 and 16 carbon atoms, containing between 0 and 4 oxygen atoms.
15. The method, according to claim 13, characterised in that the products obtained are aromatic compounds containing between 5 and 16 carbon atoms, containing between 0 and 4 oxygen atoms.
16. The method, according to claim 1, characterised in that the aqueous mixture derived from biomass contains oxygenated compounds containing between 1 and 12 carbon atoms, and also contain between 1 and 9 oxygen atoms.
17. The method, according to claim 1, characterised in that the total concentration of the oxygenated compounds contained in the aqueous mixture derived from biomass is in the range comprised between 0.5% and 99.5% by weight.
18. The method, according to claim 17, characterised in that the total concentration of the oxygenated compounds contained in the aqueous mixture derived from biomass is in the range comprised between 1.0% and 70.0% by weight.
19. The method, according to claim 1, characterised in that the contact between the aqueous mixture and the catalyst is carried out in a reactor selected from a discontinuous reactor, a continuous stirred-tank reactor, a continuous fixed-bed reactor and a continuous fluidised-bed reactor.
20. The method, according to claim 19, characterised in that the reactor is a discontinuous reactor and the reaction is carried out in the liquid phase.
21. The method, according to claim 20, characterised in that the process is carried out at a pressure of 1 to 120 bar.
22. The method, according to claim 20, characterised in that the process is carried out at a temperature comprised between 50 C. and 350 C.
23. The method, according to claim 20, characterised in that the contact between the aqueous mixture containing the oxygenated compounds derived from biomass and the catalyst is carried out in a time interval ranging between 2 minutes and 200 hours.
24. The method, according to claim 20, characterised in that the weight ratio between the aqueous mixture containing the oxygenated compounds derived from biomass and the catalyst ranges between 1 and 200.
25. The method, according to claim 19, characterised in that the reactor is a fixed-bed reactor or a fluidised-bed reactor.
26. The method, according to claim 25, characterised in that the reaction temperature is comprised between 50 C. and 450 C.; the contact time is comprised between 0.001 and 200 s; and the working pressure is between 1 and 100 bar.
27. The method, according to claim 1, characterised in that the contact between the aqueous fraction containing oxygenated compounds and the catalyst is carried out in a nitrogen, argon, hydrogen, air, nitrogen-enriched air or argon-enriched air atmosphere, or combinations thereof.
28. The method, according to claim 27, characterised in that it is carried out in a nitrogen atmosphere.
Description
BRIEF DESCRIPTION OF THE FIGURES
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EXAMPLES
[0165] Next, the inventors will illustrate the invention by means of different tests performed by the inventors that demonstrate the preparation of the catalysts and their application to the method of the invention.
Example 1. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium Oxide [WO] and Treated in Nitrogen
[0166] 31.7 g of ammonium wolframium, 2.0 g of oxalic acid and 2.45 g of 37% hydrochloric acid are added to 134.8 g of water at 80 C. and stirred for 30 minutes. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is heated at 450 C. for 2 hours under a nitrogen flow to obtain the catalyst. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 2. Preparation of a Catalyst Similar to that of Example 1, but Thermally Activated in Air
[0167] 31.7 g of ammonium wolframium, 2.0 g of oxalic acid and 2.45 g of 37% hydrochloric acid are added to 134.8 g of water at 80 C. and stirred for 30 minutes. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is heated at 600 C. for 2 hours under an air flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 3. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=1.8 [WNbO (1.8)] and Treated in Nitrogen
[0168] 44.0 g of ammonium metawolframate and 5.88 g of 96% sulfuric acid are added to 235.7 g of water at 80 C. Furthermore, and after heating at 40 C., a solution is prepared with 65.9 g of deionised water and 27.2 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is heated at 550 C. for 2 hours under a nitrogen flow to obtain the catalyst. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 4. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=1.8 [WNbO (1.8)] and Treated in Air
[0169] 25.7 g of ammonium metawolframate and 2.5 g of 37% hydrochloric acid are added to 136.5 g of water at 80 C. Furthermore, and after heating at 40 C., a solution is prepared with 38.7 g of deionised water and 26.2 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is thermally treated at 550 C. for 2 hours under an air flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 5. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=1.0 [WNbO (1.0)] and Treated in Nitrogen
[0170] 25.87 g of ammonium metawolframate and 1.90 g of 96% sulfuric acid are added to 134.5 g of water at 80 C. Furthermore, and after heating at 80 C., a solution is prepared with 71.5 g of deionised water and 48.5 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 hours and the solid obtained is dried at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 6. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=0.7 [WNbO (0.7)] and Treated in Nitrogen
[0171] 10.35 g of ammonium metawolframate and 0.76 g of 96% sulfuric acid are added to 53.8 g of water at 80 C. Furthermore, and after heating at 40 C., a solution is prepared with 28.6 g of deionised water and 19.26 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is heated at 550 C. for 2 hours under a nitrogen flow to obtain the catalyst. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 7. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=0.3 [WNbO (0.3)] and Treated in Nitrogen
[0172] 4.07 g of ammonium metawolframate and 1.1 g of 37% hydrochloric acid are added to 54.9 g of water at 80 C. and stirred for 30 minutes. Simultaneously, a solution of 30.6 g of niobium oxalate is prepared in 29.9 g of water, which is slowly added to the first. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is treated at 100 C. for 16 hours and finally heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 8. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=1.0 [WNbO (1.0)] and Treated in Nitrogen at 300 C.
[0173] 25.87 g of ammonium metawolframate and 1.90 g of 96% sulfuric acid are added to 134.5 g of water at 80 C. Furthermore, and after heating at 80 C., a solution is prepared with 71.5 g of deionised water and 48.5 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days and the solid obtained is dried at 100 C. for 16 hours. Lastly, the material is heated at 300 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 9. Preparation of a Catalyst Using the Hydrothermal Method, Based on Wolframium and Niobium Oxides with a W/Nb Molar Ratio=1.0 [WNbO (1.0)] and Treated in Nitrogen at 800 C.
[0174] 25.87 g of ammonium metawolframate and 1.90 g of 96% sulfuric acid are added to 134.5 g of water at 80 C. Furthermore, and after heating at 80 C., a solution is prepared with 71.5 g of deionised water and 48.5 g of niobium oxalate, which is added to the previous solution. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days and the solid obtained is dried at 100 C. for 16 hours. Lastly, the material is heated at 800 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 10. Preparation of a Catalyst by the Hydrothermal Method, Based on Niobium Oxide [NbO Hydrot.] and Treated in Nitrogen
[0175] 30.6 g of niobium oxalate are dissolved in 63.2 g of deionised water at 80 C. and stirred. Stirring is maintained for 10 minutes. The mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C. in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 11. Preparation of a Catalyst Similar to that of Example 10, but Thermally Activated in Air
[0176] 30.6 g of niobium oxalate are dissolved in 63.2 g of deionised water at 80 C. and stirred. Stirring is maintained for 10 minutes. The mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C. in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 12. Preparation of a Catalyst Based on Mixed Ce and Zr Oxides [CeZrO] Using the Co-Precipitation Method
[0177] This catalyst is synthesised to illustrate catalysts of the mixed CeZr type commonly used in literature for this type of condensation reactions [A. Gangadharan et al., Appl. CataL A: Gral., 385 (2010) 80]. Various catalysts were synthesised with different CeZr ratios and the catalyst that provided the best results in terms of yield to organics and conversion was selected for comparison to the catalysts of the present invention.
[0178] The catalyst was prepared using the synthesis method by co-precipitation of the mixed CeZr oxide adapting the method published by Serrano-Ruiz et al. [J. Catal., 241 (2006) 45-55].
[0179] In order to synthesise the catalyst Ce.sub.0.5Zr.sub.0.5O.sub.2, an aqueous solution of the salts of both metals is prepared in an equimolar proportion. Ce(NO.sub.3).sub.3.6H.sub.2O and ZrO(NO.sub.3).sub.2.H.sub.2O are used as precursors of both metals. In a beaker, 11.76 g of Ce(NO.sub.3).sub.3.6H.sub.2O and 6.70 g of ZrO(NO.sub.3).sub.2.H.sub.2O are weighed and dissolved in 120 ml of distilled water. Next, a solution of 28% NH.sub.4OH is added one drop at a time until reaching a pH of 10. Then, the solution is transferred to a sealed 250 ml cylinder and stirred, wherein the mixture is allowed aging at room temperature for 65 hours. Afterwards, the catalyst is washed with distilled water by means of vacuum filtration until reaching a pH of 7. The catalyst is allowed drying over night at 100 C. and, lastly, is subjected to an activation process by calcination in air at 450 C. for 4.5 hours. The amounts of Ce and Zr measured by ICP match those of the formula Ce.sub.0.5Zr.sub.0.5O.sub.2, and the X-ray diffractogram obtained for this sample indicates the presence of mixed Ce and Zr oxides (
Example 13. Preparation of a Catalyst Based on Mixed W and Nb Oxides [WNbO Impreg.] Using the Wet Impregnation Method
[0180] This catalyst is synthesised to illustrate catalysts of the mixed WNb type commonly used in literature [C. Yue et al., Appl. Catal. B: Environ., 163 (2015) 370-381]. A catalyst of the mixed oxide type is synthesised with a WNb ratio similar to that used for the catalyst of Example 6, in order to be compared in terms of catalytic activity with the catalysts of the present invention.
[0181] The catalyst was prepared using the synthesis method by wet impregnation of the mixed CeZr oxide adapting the method published by C. Yue et al. [Appl. Catal. B: Environ., 163 (2015) 370-381].
[0182] In order to synthesise the catalyst W.sub.12Nb.sub.6.5O.sub.x, an aqueous solution of the salts of the two metals is prepared in the desired proportion. (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40.H.sub.2O and C.sub.4H.sub.4NNbO.sub.9.H.sub.2O are used as precursors of both metals. In a beaker, 3.84 g of (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40.H.sub.2O and 2.36 g of C.sub.4H.sub.4NNbO.sub.9.H.sub.2O are weighed and dissolved in 15 ml of distilled water. The mixture is stirred at a temperature of 70 C. and the solvent is slowly evaporated. After 10 hours drying at a temperature of 100 C., the catalyst is subjected to an activation process by calcination in air at 450 C. for 3.5 hours. The X-ray diffractogram obtained for this sample indicates the presence of mixed W and Nb oxides (
Example 14. Preparation of a Catalyst Based on Mixed W and Nb Oxides [WNbO Co-Precip.] Using the Co-Precipitation Method
[0183] This catalyst is synthesised to illustrate catalysts of the mixed WNb type commonly used in literature [D. Stosic et al., Catal. Today, 192 (2012) 160-168]. A catalyst of the mixed oxide type is synthesised with a WNb ratio similar to that used for the catalyst of Example 6, in order to be compared in terms of catalytic activity with the catalysts of the present invention.
[0184] In this case, a method similar to that used in the preparation of a catalyst of the CeZr mixed oxide type (Example 11) to prepare a mixed WNb oxide using the co-precipitation method. To this end, the synthesis method published by D. Stosic et al. [Catal. Today, 192 (2012) 160-168] is adapted.
[0185] In order to synthesise the catalyst W.sub.12Nb.sub.18O.sub.x, an aqueous solution of the salts of the two metals is prepared in the desired proportion. (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40.H.sub.2O and C.sub.4H.sub.4NNbO.sub.9.H.sub.2O are used as precursors of both metals. In a beaker, 2.96 g of (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40.H.sub.2O and 5.4536 g of C.sub.4H.sub.4NNbO.sub.9.H.sub.2O are weighed and dissolved in 50 ml of distilled water. Next, a solution of 28% NH.sub.4OH is added one drop at a time until reaching a pH of 9. Then, the mixture is allowed aging at room temperature for 24 hours. Next, the catalyst is washed with distilled water by means of vacuum filtration until reaching a pH of 7.
[0186] The catalyst is allowed drying over night at 100 C. and, lastly, is subjected to an activation process by calcination in nitrogen at 550 C. for 5 hours. The X-ray diffractogram obtained for this sample indicates the presence of mixed W and Nb oxides (
Example 15: Modification of the Catalyst of Example 6 by Treatment with Potassium Salt
[0187] A solution of 0.13 g of potassium bicarbonate is prepared in 100 g of water to which 8.0 g of the catalyst obtained in Example 6 is added. The mixture is stirred at room temperature for 4 hours. Next, the solid is separated from the solution and treated at 280 C. for 2 hours under an air flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 16. Preparation of a Catalyst Based on Mixed WVNbO Oxide with a V/W Molar Ratio=0.33 Using the Hydrothermal Method and Thermally Treated in Nitrogen
[0188] 31.0 g of ammonium metawolframate and 3.0 g of 37% hydrochloric acid are added to 163.5 g of water, and the mixture is heated at 80 C. and stirred for 30 minutes. Simultaneously, a solution of 13.7 g of vanadyl sulphate is prepared in 62.1 g of water at room temperature, which is slowly added to the first. Next, a solution of 12.0 g of niobium oxalate is prepared in 29.1 g of water at 80 C., which is slowly added to the previous mixture. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 17. Preparation of a Catalyst Similar to that of Example 15, with a Lower V/W Molar Ratio (V/W=0.17) and Thermally Treated in Nitrogen
[0189] 12.9 g of ammonium wolframate and 1.29 g of 98% sulfuric acid are added to 68.1 g of water, and the mixture is maintained at 80 C. and stirred for 30 minutes. Simultaneously, a solution of 6.7 g of vanadyl sulphate is prepared in 30.1 g of water, which is added to the first. Next, a solution of 37.5 g of niobium oxalate is prepared in 90.4 g of water at 80 C., which is slowly added to the previous mixture. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 18. Preparation of a Catalyst Based on Mixed WCeNbO Oxide Using the Hydrothermal Method and Thermally Treated in Nitrogen
[0190] 7.0 g of ammonium metawolframate, 5.4 g of cerium trichloride and 0.52 g of 37% hydrochloric acid are added to 54.1 g of water at 80 C., which is stirred for 30 minutes. Simultaneously, a solution of 28.7 g of niobium oxalate is prepared in 29.4 g of water at 80 C., which is slowly added to the first, stirring for 10 minutes. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode for 2 days and the solid obtained is treated at 100 C. for 16 hours. Lastly, the material is heated at 550 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 19. Preparation of a Catalyst Based on Wolframium and Zirconium Oxides [WZrO] Using the Hydrothermal Method and Thermally Treated in Nitrogen
[0191] 20.4 g of ammonium metawolframate, 1.28 g of oxalic acid and 1.75 g of 37% hydrochloric acid are added to 105.7 g of water at 80 C. and stirred for 30 minutes. Simultaneously, a solution of 8.9 g of zirconium chloride is prepared in 31.0 g of water, which is slowly added to the first. The resulting mixture is transferred to a Teflon-lined steel autoclave. The autoclave is maintained at 175 C., in static mode, for 2 days. The solid obtained is treated at 100 C. for 16 hours and finally heated at 450 C. for 2 hours under a nitrogen flow. This catalyst is characterised by the fact that it presents an X-ray diffractogram such as that shown in
Example 20. Comparative Catalytic Activity of the Catalysts of the WNb Series of Examples 1, 3, 6, 7 and 10
[0192] The catalytic activity experiments are carried out in the liquid phase using 12 ml stainless steel autoclave-type reactors with PEEK (polyether ether ketone) reinforced interior and equipped with a magnetic stirrer, pressure gauge and gas and liquid sample input/output valve. The reactors are disposed on a steel-lined individual support with closed-loop temperature control.
[0193] The initial feed consists of a model aqueous mixture containing oxygenated compounds simulating the residual aqueous flows obtained after a phase separation process, subsequent to biomass pyrolysis. The composition of the model aqueous mixture is detailed below (Table 1):
TABLE-US-00001 TABLE 1 Composition of the model aqueous mixture used as initial feed in the autoclave-type reactor. Component Content (wt %) Water 30 Propionaldehyde 25 Hydroxy-acetone 5 Acetic acid 30 Ethanol 10
[0194] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 1-xx were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0195] The quantification of the products was carried out based on the response factors calculated using an internal standard (solution of 2 wt % chlorobenzene in methanol) and species with more than 5 carbon atoms are classified and quantified in intervals, whose response factors were calculated based on molecules representative thereof. In addition to the main primary condensation reaction products, such as acetone, ethyl acetate, 3-pentanone and 2-methyl-2-pentenal, groups of molecules containing 5, 6, 7, 8, 9, 10 or more than 10 carbon atoms can be distinguished. In order to simplify the quantification of these reaction products, these molecules are grouped into two major groups of compounds, namely: C5-C8 Products and C9-C10+ Products.
[0196] In the illustrated Examples of catalytic activity, the following parameters are used to analyse the results obtained:
[0197] The conversion (in molar percentage) for each of the oxygenated compounds contained in the model aqueous mixture, is calculated using the following formula:
Conversion (%)=(initial moles of oxygenated comp.final moles of oxygenated comp./initial moles of oxygenated comp.)*100
[0198] The final yield (as a percentage by weight) to each of the products obtained, is calculated using the following formula:
[0199] Product yield (%)=grams of product, in the reactor/total grams in the reactor
[0200] Yield to Total Organics (as a percentage by weight), is calculated using the following formula:
Total Organics (%)=(Yield.sub.Acetone+Yield.sub.3-pentanone+Yield.sub.2-methyl-2-pentenal+Yield.sub.C5-C8+Yield.sub.C9-C10+)
[0201] In this manner, the following results were obtained for the catalytic activity experiments with the catalysts based on W and Nb of Examples 1, 3, 6, 7 and 10:
TABLE-US-00002 TABLE 2 Catalytic activity in the conversion of oxygenated compounds contained in a model aqueous mixture of catalysts based on W and/or NB of Examples 1, 3, 6, 7 and 10. Example 1 3 6 7 10 Catalyst WNbO WNbO WNbO NbO WO (1.8) (0.7) (0.3) hydrot. Conversion Acetic acid 0.00% 8.04% 9.76% 10.14% 9.99% (%) Propionaldehyde 86.57% 90.13% 89.02% 91.03% 92.34% Ethanol 49.83% 47.11% 51.30% 52.79% 57.57% Hydroxy-acetone 100.00% 100.00% 100.00% 100.00% 100.00% Final Yield Acetone 0.22% 0.06% 0.06% 0.15% 0.37% (%) Ethyl acetate 6.69% 7.08% 5.75% 6.15% 5.00% 3-pentanone 0.18% 0.18% 0.18% 0.16% 0.19% 2-methyl-2-pentenal 8.78% 8.81% 10.67% 10.61% 11.57% C5-C8 3.32% 3.92% 3.31% 2.57% 2.76% C9-C10+ 3.37% 4.81% 5.12% 5.69% 5.61% Total Organics 15.87% 17.78% 19.34% 19.18% 20.50%
[0202] From the comparison shown in Table 2, it can be observed that hydroxy-acetone conversion is in all cases 100%, while the conversion of acetic acid and propionaldehyde increases upon increasing the amount of niobium present in the catalysts used.
[0203] Acetone (acetic acid condensation product) is present in the final mixture in amounts smaller than 0.5%, due to the fact that it is a highly reactive compound that can give rise to condensation products of higher molecular weight.
[0204] In addition, upon increasing the amount of Nb in the catalysts, the intermediate condensation products (C5-C8) decrease until giving rise to products of higher molecular weight in subsequent condensation stages.
[0205] Moreover, the increased conversion of propionaldehyde gives rise to an increase in the amount of 2-methyl-2-pentenal (product of the first self-condensation of propionaldehyde). The condensation products in the C9-C10+ interval and Yield to Total Organics have the same behaviour.
[0206] These results show that the combination of W and Nb oxides in the structure of these catalysts produce higher condensation product yields and, in general, higher yield to products in the C9-C10+ range than its analogous WO catalyst without niobium (Example 1). Additionally, the catalyst NbO without wolframium (Example 9) also shows an improved catalytic activity (both in the conversion of oxygenated compounds and in the Yield to Total Organics, >20%), even when there are small amounts of W present in the catalyst (see result with small concentrations of W, catalyst of Example 7). This indicates the existence of an optimum range in the W/Nb ratio (between Examples 6 and 10) in the structure of the catalyst to obtain the maximum yields in the conversion of oxygenated compounds contained in aqueous mixtures derived from biomass.
Example 21. Comparative Catalytic Activity of the Catalysts of the WNb Series (Examples 3, 6 and 10) Compared to Conventional WNb Oxides (Examples 13 and 14) and Commercial Nb.SUB.2.O.SUB.5 .(Sigma-Aldrich, CAS 1313-96-8)
[0207] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 3, 6, 10, 13, 14 and of commercial Nb.sub.2O.sub.5 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0208] The following results were obtained:
TABLE-US-00003 TABLE 3 Catalytic activity in the conversion of oxygenated compounds contained in a model aqueous mixture of catalysts based on W and/or Nb, hydrothermally prepared, Examples 3, 6 and 10, compared to the results obtained with other catalysts based on WNb prepared using more conventional methods (Examples 13 and 14) or with commercial Nb.sub.2O.sub.5. Example 13 3 14 6 10 Catalyst WNb WNbO WNbO WNbO commercial NbO impreg. (1.8) co-precip. (0.7) Nb.sub.2O.sub.5 hydrot. Conversion Acetic acid 11.13% 8.04% 13.04% 9.76% 8.66% 9.99% (%) Propionaldehyde 72.86% 90.13% 71.69% 89.02% 76.36% 92.34% Ethanol 51.63% 47.11% 46.46% 51.30% 53.47% 57.57% Hydroxy-acetone 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% Final Yield Acetone 0.25% 0.06% 0.20% 0.06% 0.40% 0.37% (%) Ethyl acetate 6.51% 7.08% 7.01% 5.75% 6.15% 5.00% 3-pentanone 0.14% 0.18% 0.20% 0.18% 0.13% 0.19% 2-methyl-2-pentenal 7.97% 8.81% 8.14% 10.67% 8.07% 11.57% C5-C8 3.08% 3.92% 3.27% 3.31% 1.73% 2.76% C9-C10+ 2.88% 4.81% 4.16% 5.12% 5.40% 5.61% Total Organics 14.33% 17.78% 15.97% 19.34% 15.74% 20.50%
[0209] In Table 3, the catalytic results of the catalysts based on structures containing WNbO and NbO, hydrothermally prepared and described earlier (Examples 3, 6 and 10) are compared to other catalysts based on mixed oxides of both metals and prepared using more conventional methods, and whose preparation is described in Examples 13 and 14. A commercial Nb.sub.2O.sub.5 catalyst acquired from Sigma-Aldrich, analogously activated prior to use, is also used to compare the NbO catalyst without W (Example 10).
[0210] From the results shown in Table 3, the total conversion of hydroxy-acetone in all cases is observed, while the conversion of acetic acid is similar in all the cases studied (close to 10-11%).
[0211] The conversion of propionaldehyde is the greatest difference between one type of catalysts and others. While catalysts based on combined WNb structures have conversions >90%, the commercial niobium catalyst and the mixed oxides prepared in Examples 13 and 14 have much lower conversions (72%-75%). This gives rise to a reduction in the formation of first condensation products such as 2-methyl-2-pentenal and some C5-C8 products, as well as products with higher molecular weight originated by second condensation reactions. In such cases, the Yield to Total Organics is reduced to 14%-16%, which means that the use of catalysts based on specific WNb structures such as that of Examples 3, 6 and 10 increases the products obtained in the final mixture of the condensation reaction of oxygenated compounds contained in aqueous mixtures derived from biomass by 25%. Said products are potentially usable as additives in gasoline and refining fractions in general.
[0212] These results show that the catalysts of the method of the present invention obtain better results than those obtained using catalysts prepared using conventional methods or commercial materials of similar composition.
Example 22. Comparative Catalytic Activity of the Catalysts of the WNbO Series, Prepared Using the Hydrothermal Method and Treated in Nitrogen at Different Temperatures (Examples 5, 8 and 9)
[0213] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 5, 8 and 9 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0214] The following results were obtained:
TABLE-US-00004 TABLE 4 Catalytic activity in the conversion of oxygenated compounds contained in a model aqueous mixture of catalysts based on W and/or Nb, hydrothermally prepared and treated in nitrogen at different temperatures, Examples 5, 8 and 9. Example 9 5 8 Catalyst [Treatment temperature] WNbO WNbO WNbO (1.0) (1.0) (1.0) [800 C.] [550 C.] [300 C.] Conversion Acetic acid 8.73% 9.19% 5.84% (%) Propion- 83.66% 90.34% 94.49% aldehyde Ethanol 43.55% 55.56% 52.32% Hydroxy- 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.19% 0.36% 0.32% (%) Ethyl acetate 7.36% 4.50% 5.73% 3-pentanone 0.14% 0.22% 0.19% 2-methyl-2- 8.90% 8.96% 9.90% pentenal C5-C8 4.31% 3.08% 2.53% C9-C10+ 3.55% 5.00% 6.36% Total Organics 17.09% 17.62% 19.30%
[0215] Table 4 shows a comparison of the catalytic results of the previously described catalysts based on structures containing WNbO (with a W/Nb molar ratio=1.0) hydrothermally prepared and then thermally treated under a N.sub.2 atmosphere at different temperatures.
[0216] From the results shown in Table 4, the total conversion of hydroxy-acetone is observed in all cases, while the conversion of acetic acid is similar in all the catalysts treated at high temperatures, i.e. at 550 C. and 800 C. (Examples 9 and 5, respectively); being slightly lower in the material treated at lower temperature (300 C., Example 8).
[0217] However, the distribution of products observed is the greatest difference between these catalysts. Therefore, as the temperature at which the catalysts have been treated decreases (from 800 C. to 500 C., and then 300 C.), a reduction in the production of C5-C8 compounds is observed, from 4.31% to 3.08%, finally reaching 2.57%, respectively. At the same time, an increase in the generation of C9->C10 products is observed, from 3.55% to 5.00% (with treatments at high temperatures), reaching 6.36% (with the treatment at 300 C.). This same upward trend of the observed values is evidenced in the Yields to Total Organics, which increase from 17.09% and 17.62% for the catalysts of Examples 9 and 5, to 19.30% for the catalyst of Example 8. This means that the Yield to Total Organics, and particularly the production of the compound C9->C10, can be controlled and even increased by means of the adequate thermal treatment of the catalysts based on specific WNb structures such as that of Examples 5, 8 and 9.
Example 23. Comparative Catalytic Activity of the Catalysts of the WNbO and NbO Series, Prepared Using the Hydrothermal Method (Examples 6 and 10), Compared to a Conventional CeZr Catalyst (Example 12)
[0218] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 6, 10 and 12 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0219] The following results were obtained:
TABLE-US-00005 TABLE 5 Comparative catalytic activity of the catalysts based on W and Nb of Examples 6 and 10 in the conversion of oxygenated compounds contained in a model aqueous mixture compared to a conventional CeZr catalyst (Example 12). Example 6 10 12 Catalyst WNbO NbO (0.7) hydrot. CeZrO Conversion Acetic acid 9.76% 9.99% 17.36% (%) Propionaldehyde 89.02% 92.34% 93.82% Ethanol 51.30% 57.57% 47.81% Hydroxyacetone 100.00% 100.00% 100.00% Final Yield Acetone 0.06% 0.37% 0.21% (%) Ethyl acetate 5.75% 5.00% 5.81% 3-pentanone 0.18% 0.19% 0.15% 2-methyl-2- 10.67% 11.57% 11.03% pentenal C5-C8 3.31% 2.76% 1.61% C9-C10+ 5.12% 5.61% 7.57% Total Organics 19.34% 20.50% 20.56%
[0220] Propionaldehyde and hydroxyacetone conversions are very similar in the catalysts of Examples 6, 10 and 12, while the catalyst of Example 12 has greater conversion of acetic acid and lower conversion of ethanol (results shown in Table 5). However, both the global conversion of reagents and the the Yield to Total Organics observed are very similar in the three examples studied. The only observable difference between the catalysts based on WNb oxides (Examples 6 and 10) and mixed CeZr oxide (Example 12) is that the first two have a higher production of organic compounds in the C5-C8 interval, while the mixed oxide prepared in Example 12 is capable of more easily catalysing second condensation reactions, increasing the amount of compounds in the C9-C10+ interval.
[0221] In general, catalysts based on structures combining W and Nb obtain results similar to those shown by a catalyst such as Ce.sub.0.5Zr.sub.0.5O.sub.2 traditionally used in literature for this type of reactions.
[0222] The catalysts of Examples 6 and 12, once used, are recovered after the reaction, washed with methanol and dried at 100 C. over night. They are then characterised by means of Elemental Analysis (EA) and Thermogravimetry (TG).
[0223] The EA study shows that the CeZr-type catalyst of Example 12 presents 3.46 wt % of carbon (organic products deposited in the catalyst) after washing. The catalyst based on WNb of Example 6 presents only 1.42 wt % of carbon, demonstrating that a smaller amount of carbonaceous substances are deposited during the reactive process and, therefore, that it is less sensitive to the deactivation caused by the deposition of coke.
[0224] These characterisation data are confirmed by the TG analyses. The CeZr-type catalyst of Example 12 presents a mass loss of 11.5% at a temperature close to 300 C. corresponding to the desorption of the organic products absorbed. However, the catalyst of Example 6 presents a mass loss of only 3.5% at said temperature. This catalyst also presents a mass loss of 3.4% at a temperature close to 100 C. corresponding to the water absorbed in the channels of the crystalline structure. This amount of absorbed water is also observed in the TG analysis of the catalyst prior to use, due to which the presence of water in the reaction medium is not detrimental to catalyst activity or stability.
Example 24. Comparative Catalytic Activity During Reuse of the WNbO (0.7) (Example 6) and CeZrO Catalysts (Example 12)
[0225] A series of consecutive reactions were carried out using the catalysts prepared in Examples 6 and 12 to compare their activity after several uses. To this end, the initial reaction (R0) and three subsequent reuses (R1, R2 and R3) were carried out, all of them under the same reaction conditions. The catalysts used are recovered after each reaction, washed with methanol and dried at 100 C. over night. They are then characterised by means of Elemental Analysis (EA) and Thermogravimetry (TG).
[0226] In each case (R0, R1, R2 and R3), 3,000 mg of the model aqueous mixture and 150 mg of one of the catalytic materials of Examples 6 and 12 (fresh or used) were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0227] The results obtained are shown in Tables 6 and 7, and in
TABLE-US-00006 TABLE 6 Catalytic activity during reuse of the WNbO catalyst (0.7) of Example 6. R0 R1 R2 R3 Conversion Acetic 9.76% 7.56% 4.92% 0.00% (%) acid Propion- 89.02% 86.12% 86.44% 80.37% aldehyde Ethanol 51.30% 51.10% 51.26% 49.12% Hydroxy- 100.00% 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.06% 0.17% 0.33% 0.27% (%) Ethyl 5.75% 6.14% 6.04% 6.49% acetate 3-penta- 0.18% 0.14% 0.14% 0.18% none 2-methyl- 10.67% 10.00% 9.83% 9.25% 2-pentenal C5-C8 3.31% 2.76% 2.44% 2.44% C9-C10+ 5.12% 5.45% 5.37% 5.70% Total 19.34% 18.52% 18.10% 17.84% Organics
TABLE-US-00007 TABLE 7 Catalytic activity during reuse of the CeZrO catalyst of Example 12. R0 R1 R2 R3 Conversion Acetic 17.36% 13.37% 3.84% 0.00% (%) acid Propion- 93.82% 87.81% 84.82% 81.21% aldehyde Ethanol 47.81% 49.73% 50.13% 55.28% Hydroxy- 100.00% 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.21% 0.20% 0.09% 0.11% (%) Ethyl 5.81% 6.05% 5.99% 6.27% acetate 3-penta- 0.15% 0.14% 0.13% 0.15% none 2-methyl- 11.03% 10.23% 9.50% 8.37% 2-pentenal C5-C8 1.61% 1.89% 2.11% 2.12% C9-C10+ 7.57% 7.51% 7.55% 6.52% Total 20.56% 19.98% 19.38% 17.28% Organics
[0228] In both catalysts, the same behaviour can be observed in the conversion of the reagents contained in the initial aqueous mixture. Acetic acid and propionaldehyde conversions decrease with the number of reactions carried out. However, the conversion of ethanol increases in the case of the CeZrO catalyst (Example 12) and remains constant in the case of the WNbO catalyst (0.7) (Example 6). Consequently, the Yield to Total Organics decreases slightly with the number of reuses in both catalysts, but the drop in percentage is sharper in the case of the CeZrO catalyst of Example 12, with a percentage loss of catalytic activity with respect to the initial activity of 16%, while the WNbO catalyst prepared in Example 6 has greater stability with a decrease in catalytic activity of only 7.7% (see
[0229] It should be noted that in the case of the CeZrO catalyst of Example 12, at the end of the reuses only 80 mg of the 150 mg initially added are recovered, while 135 mg are recovered in the case of the WNbO catalyst (0.7) of Example 6. The smaller amount of solid catalyst recovered can be due to a lower stability of the CeZrO catalyst and to the possible formation of cerium acetate, which causes extraction of cerium oxide from the catalyst structure.
[0230] At the same time, the Elementary and Thermogravimetric analyses carried out confirm the greater stability of the WNb catalyst of Example 6 compared to the mixed CeZr oxide prepared in Example 12. Therefore, in the WNb material (Example 6), only 1.5% by weight of carbon is determined by EA after the third reuse (R3); while the amount of carbon detected in the CeZr catalyst (Example 12) after the same number of reuses reached 4.8 wt %. In addition, it was observed by TG analysis that the WNb catalyst (Example 6) suffers a mass loss of 4.0% at temperatures close to 300 C.-350 C. corresponding to absorbed organic products, while the mixed CeZr oxide (Example 12) presents a mass loss of only 9.5% at those temperatures, plus another additional mass loss of 3.3% at temperatures close to 450 C., the latter corresponding to heavier reaction products absorbed in the catalyst.
Example 25. Comparative Catalytic Activity of Catalysts Based on WNbO (Examples 3 and 6) and WNbO with the Addition of an Alkaline Metal, WNbKO (Example 15)
[0231] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 3, 6 and 15 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0232] The following results were obtained:
TABLE-US-00008 TABLE 8 Comparative catalytic activity for converting oxygenated compounds contained in a model aqueous mixture of catalysts based on W and Nb, of Examples 3, 6 and 15, thermally activated in a nitrogen atmosphere. Example 3 6 15 Catalyst WNbO WNbO (1.8) (0.7) WNbKO Conversion Acetic 8.04% 9.76% 11.45% (%) acid Propion- 90.13% 89.02% 94.22% aldehyde Ethanol 47.11% 51.30% 47.18% Hydroxy- 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.06% 0.06% 0.18% (%) Ethyl 7.08% 5.75% 7.10% acetate 3-penta- 0.18% 0.18% 0.16% none 2-methyl- 8.81% 10.67% 11.97% 2-pentenal C5-C8 3.92% 3.31% 3.20% C9-C10+ 4.81% 5.12% 4.81% Total 17.78% 19.34% 20.32% Organics
[0233] From the results of Table 8 it can be inferred that the addition of low concentrations of potassium to the WNbO materials (maintaining a constant W/Nb molar ratio in the composition of the material), generally favours the obtainment of catalytic activities slightly greater than those observed with the WNbO materials of Examples 3 and 6. It should be noted that the presence of K, in these conditions, increases the conversion of acetic acid and the formation of intermediates such as 2-methyl-2-pentenal, maintaining the formation of products in the C5-C8 and C9-C10+ range practically constant, due to which the Yield to Total Organics is slightly increased (>20%) on using this WNbKO material (Example 15).
Example 26. Comparative Catalytic Activity of Catalysts Based on WNbO (Examples 3 and 6) and WNbVO, with the Addition of V as a Third Metallic Element (Examples 16 and 17)
[0234] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 3, 6, 16 and 17 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0235] The results obtained using catalysts based on WNb to which a certain amount of vanadium was added (Examples 16 and 17) are shown below, and the results are compared to WNb catalysts of similar composition:
TABLE-US-00009 TABLE 9 Catalytic activity in the conversion of oxygenated compounds contained in a model aqueous mixture of catalysts based on W and Nb of Examples 3 and 6 compared to the results of WNbVO catalysts (Examples 16 and 17). Example 15 3 16 6 Catalyst WNbVO WNbO WNbVO WN bO (V/W = 0.33) (1.8) (V/W = 0.17) (0.7) Conv. (%) Acetic acid 12.18% 8.04% 7.88% 9.76% Propionaldehyde 81.60% 86.31% 90.38% 89.02% Ethanol 48.57% 47.11% 45.31% 51.30% Hydroxyacetone 100.00% 100.00% 100.00% 100.00% Final Yield Acetone 0.14% 0.06% 0.42% 0.42% (%) Ethyl acetate 6.46% 7.08% 6.63% 5.75% 3-pentanone 0.17% 0.18% 0.20% 0.18% 2-methyl-2- 9.77% 8.81% 10.69% 10.67% pentenal C5-C8 2.80% 3.92% 2.77% 3.31% C9-C10+ 4.30% 4.81% 4.89% 5.12% Total Organics 17.28% 17.77% 18.97% 19.34%
[0236] Based on the results of Table 9 it can be concluded that the catalytic activity of the samples containing V (Examples 16 and 17) is similar to its analogue without V and with the same composition (Examples 3 and 6); although in both cases, by adding vanadium to the structure a slight decrease in the Yield to Total Organics is observed, due mainly to the decrease in the production of compounds in the C9-C10+ range.
Example 27. Comparative Catalytic Activity of Catalysts Based on WNb (Examples 3 and 6) and WNbCeO with the Addition of Ce as a Third Metallic Element (Example 18)
[0237] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 3, 6 and 18 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0238] The following results were obtained:
TABLE-US-00010 TABLE 10 Comparative catalytic activity of the catalysts based on W and Nb of Examples 3 and 6 in the conversion of oxygenated compounds contained in a model aqueous mixture compared to a conventional WNbCeO catalyst (Example 18). Example 3 18 6 Catalyst WNbO WNbO (1.8) WNbCeO (0.7) Conversion Acetic 8.04% 13.77% 9.76% (%) acid Propion- 86.31% 85.05% 89.02% aldehyde Ethanol 47.11% 47.85% 51.30% Hydroxy- 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.06% 0.03% 0.42% (%) Ethyl acetate 7.08% 6.32% 5.75% 3-penta- 0.18% 0.15% 0.18% none 2-methyl- 8.81% 10.59% 10.67% 2-pentenal C5-C8 3.92% 1.85% 3.31% C9-C10+ 4.81% 7.22% 5.12% Total 17.77% 19.83% 19.34% Organics
[0239] From the results of Table 10 it can be inferred that the partial substitution of W by Ce atoms in WNbO materials (maintaining a constant composition ratio), favours the obtainment of similar catalytic activities. It should be noted that the presence of Ce, in these conditions, favours the consecutive condensation reactions and decreases the number of intermediates situated in the C5-C8 product range, while the amount of products generated in the C9-C10+ range increases.
Example 28. Comparative Catalytic Activity of Catalysts Based on WNb (Examples 3 and 6) and WZrO (Example 19)
[0240] 3,000 mg of model aqueous mixture and 150 mg of one of the catalytic materials of Examples 3, 6 and 19 were introduced in the previously described autoclave reactor. The reactor was hermetically sealed, initially pressurized with 13 bar of N.sub.2, and heated to 220 C. under continuous stirring. Liquid samples were taken (50-100 l) at different time intervals up to 7 hours of reaction. The samples were filtered and diluted in a standard solution of 2 wt % chlorobenzene in methanol and analysed by means of gas chromatography in a GC-Bruker 430 equipped with a FID detector and a TRB-624 capillary column of 60 m. The identification of the products was carried out using an Agilent 6890N gas chromatograph coupled to an Agilent 5973N (GC-MS) mass detector and equipped with a HP-5MS 30 m capillary column.
[0241] The following results were obtained:
TABLE-US-00011 TABLE 11 Comparative catalytic activity of catalysts based on W and Nb of Examples 3 and 6 in the conversion of oxygenated compounds contained in a model aqueous mixture compared to a WZrO catalyst (Example 19). Example 3 19 6 Catalyst WNbO WNbO (1.8) WZrO (0.7) Conversion Acetic acid 8.04% 1.06% 9.76% (%) Propion- 86.31% 89.82% 89.02% aldehyde Ethanol 47.11% 44.98% 51.30% Hydroxy- 100.00% 100.00% 100.00% acetone Final Yield Acetone 0.06% 0.05% 0.42% (%) Ethyl acetate 7.08% 7.43% 5.75% 3-pentanone 0.18% 0.22% 0.18% 2-methyl-2- 8.81% 10.65% 10.67% pentenal C5-C8 3.92% 3.30% 3.31% C9-C10+ 4.81% 4.88% 5.12% Total Organics 17.77% 19.09% 19.34%
[0242] From the results of Table 11, it can be inferred that the substitution of Nb for Zr in the W-Metal-O materials leads to results in terms of the formation of products and catalytic activities very similar in general to those observed with WNbO catalysts (Examples 3 and 6). It should be noted that the WZr combination of the catalyst of Example 19, under these conditions, significantly reduces the conversion of acetic acid, while the amount of products generated in the C5-C8 and C9-C10+ range are similar to those obtained with the WNbO materials (Examples 3 and 6).