CATALYSTS FOR ISOBUTANOL SYNTHESIS

Abstract

M/M.sup.2+M.sup.4+ oxide catalysts have been developed for use in producing isobutanol in propanol-methanol, ethanol-methanol and propanol/ethanol mixture-methanol reactions. The catalysts can also be used in making n-butanol in ethanol-ethanol reactions. M may comprise one or more metals from Groups 3-12 of the Periodic Table. M.sup.2+ may comprise divalent magnesium, calcium, strontium, barium, or combinations thereof. M.sup.4+ may comprise tetravalent silicon, titanium, zirconium, or combinations thereof. Catalysts, and methods of using the catalysts are described.

Claims

1. An alcohol condensation catalyst for the synthesis of isobutanol comprising: a M/M.sup.2+M.sup.4+ oxide catalyst; wherein M comprises a metal from Groups 3-12 of the Periodic Table, or combinations thereof; wherein M.sup.2+ comprises divalent magnesium, calcium, strontium, barium, or combinations thereof; and wherein M.sup.4+ comprises tetravalent silicon, titanium, zirconium, or combinations thereof; with the proviso that when M.sup.2+ is magnesium, M.sup.4+ is not titanium or zirconium.

2. The catalyst of claim 1 wherein M comprises Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au, or combinations thereof.

3. The catalyst of claim 1 wherein M comprises Cu.

4. The catalyst of claim 1 wherein M is present in an amount of 0.01 wt % to 50 wt %.

5. The catalyst of claim 1 wherein M.sup.2+ comprises divalent magnesium.

6. The catalyst of claim 1 wherein M.sup.2+ O is present in an amount of 1 wt % to 98 wt %.

7. The catalyst of claim 1 wherein M.sup.4+ comprises silicon.

8. The catalyst of claim 1 wherein M.sup.4+O.sub.2 is present in an amount of 1 wt % to 98 wt %.

9. The catalyst of claim 1 further comprising: a salt or oxide of a metal from Group 1 of the Periodic Table, or combinations thereof.

10. The catalyst of claim 9 wherein the Group 1 metal comprises Li, Na, K, Rb, Cs, or combinations thereof.

11. The catalyst of claim 9 wherein the Group 1 metal is present in an amount of 0.01 wt % to 10 wt %.

12. A method of producing isobutanol comprising: reacting ethanol or propanol with methanol in the presence of an alcohol condensation catalyst under reaction conditions to produce isobutanol; wherein the alcohol condensation catalyst comprises a M/M.sup.2+M.sup.4+ oxide catalyst; wherein M comprises metals from Groups 3-12 of the Periodic Table, or combinations thereof; wherein M.sup.2+ comprises divalent magnesium, calcium, strontium, barium, or combinations thereof; wherein M.sup.4+ comprises tetravalent silicon, titanium, zirconium, or combinations thereof.

13. The method of claim 12 wherein the reaction conditions comprise one or more of: a temperature in a range of 100 C. to 500 C.; or a pressure in a range of 5 kPa to 30,000 kPa.

14. The catalyst of claim 12 wherein M comprises Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au, or combinations thereof.

15. The catalyst of claim 12 wherein M is present in an amount of 0.01 wt % to 50 wt %.

16. The catalyst of claim 12 wherein M.sup.2+ O is present in an amount of 1 wt % to 98 wt %.

17. The catalyst of claim 12 wherein M.sup.4+O.sub.2 is present in an amount of 1 wt % to 98 wt %.

18. The catalyst of claim 12 further comprising: a salt or oxide of a metal from Group 1 of the Periodic Table, or combinations thereof.

19. The catalyst of claim 18 wherein the Group 1 metal is present in an amount of 0.01 wt % to 10 wt %.

Description

DETAILED DESCRIPTION

[0009] M/M.sup.2+M.sup.4+ oxide catalysts have been developed which exhibit good isobutanol yield in propanol-methanol, ethanol-methanol and propanol/ethanol mixture-methanol reactions. They also exhibit good n-butanol yield in ethanol-ethanol reactions. Methanol and ethanol can be reacted to form propanol, which can then react with methanol to form isobutanol using the M/M.sup.2+M.sup.4+ oxide catalysts. Alternatively, methanol and propanol can be reacted directly to produce isobutanol using the M/M.sup.2+M.sup.4+ oxide catalysts. Mixtures of propanol and ethanol can be reacted with methanol. Ethanol can also be reacted with ethanol to form n-butanol.

[0010] One aspect of the invention is an alcohol condensation catalyst for the synthesis of isobutanol. In one embodiment, the catalyst comprises a M/M.sup.2+M.sup.4+ oxide catalyst. M may comprise one or more metals from Groups 3-12 of the Periodic Table. M.sup.2+ may comprise divalent magnesium, calcium, strontium, barium, or combinations thereof. M.sup.2+ may consist essentially of divalent magnesium, calcium, strontium, barium, or combinations thereof. M.sup.2+ may be selected from the group consisting of divalent magnesium, calcium, strontium, barium, or combinations thereof. M.sup.4+ may comprise tetravalent silicon, titanium, zirconium, or combinations thereof. M.sup.4+ may consist essentially of tetravalent silicon, titanium, zirconium, or combinations thereof. M.sup.4+ may be selected from the group consisting of tetravalent silicon, titanium, zirconium, or combinations thereof.

[0011] In some embodiments, M comprises Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au, or combinations thereof. In some embodiments, M is Cu.

[0012] In some embodiments M is present in the catalyst in an amount of 0.01 wt % to 50 wt %, or 0.01 wt % to 40 wt %, or 0.01 wt % to 30 wt %, or, 0.01 wt % to 25 wt %, or 0.01 wt % to 20 wt %, or 0.01 wt % to 15 wt %, or 0.01 wt % to 10 wt %, or 0.1 wt % to 50 wt %, or 0.1 wt % to 40 wt %, or 0.1 wt % to 30 wt %, or, 0.1 wt % to 25 wt %, or 0.1 wt % to 20 wt %, or 0. 1 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.5 wt % to 50 wt %, or 0.5 wt % to 40 wt %, or 0.5 wt % to 30 wt %, or, 0.5 wt % to 25 wt %, or 0.5 wt % to 20 wt %, or 0.5 wt % to 15 wt %, or 0.5 wt % to 10 wt %, or 1 wt % to 50 wt %, or 1 wt % to 40 wt %, or 1 wt % to 30 wt %, or, 1 wt % to 25 wt %, or 1 wt % to 20 wt %, or 1 wt % to 15 wt %, or 1 wt % to 10 wt %, or 2 wt % to 50 wt %, or 2 wt % to 40 wt %, or 2 wt % to 30 wt %, or, 2 wt % to 25 wt %, or 2 wt % to 20 wt %, or 2 wt % to 15 wt %, or 2 wt % to 10 wt %, or 5 wt % to 50 wt %, or 5 wt % to 40 wt %, or 5 wt % to 30 wt %, or, 5 wt % to 25 wt %, or 5 wt % to 20 wt %, or 5 wt % to 15 wt %, or 5 wt % to 10 wt %, or 10 wt % to 50 wt %, or 10 wt % to 40 wt %, or 10 wt % to 30 wt %, or, 10 wt % to 25 wt %, or 10 wt % to 20 wt %, or 10 wt % to 15 wt %, or 15 wt % to 50 wt %, or 15 wt % to 40 wt %, or 15 wt % to 30 wt %, or, 15 wt % to 25 wt %, or 15 wt % to 20 wt %, or 20 wt % to 50 wt %, or 20 wt % to 40 wt %, or 20 wt % to 30 wt %, or 20 wt % to 25 wt %, or 25 wt % to 50 wt %, or 25 wt % to 40 wt %, or 25 wt % to 30 wt %, or 30 wt % to 50 wt %, or 30 wt % to 40 wt %, or 35 wt % to 50 wt %, or 35 wt % to 40 wt %, or 40 wt % to 50 wt %.

[0013] In some embodiments, M2+O is present in the catalyst in an amount of 1 wt % to 50 wt %, or 1 wt % to 75 wt %, or 1 wt % to 70 wt %, or 1 wt % to 65 wt %, or 1 wt % to 60 wt %, or 2 wt % to 98 wt %, or 2 wt % to 75 wt %, or 2 wt % to 70 wt %, or 2 wt % to 65 wt %, or 2 wt % to 60 wt %, or 5 wt % to 98 wt %, or 5 wt % to 75 wt %, or 5 wt % to 70 wt %, or 5 wt % to 65 wt %, or 5 wt % to 60 wt %, or 10 wt % to 98 wt %, or 10 wt % to 75 wt %, or 10 wt % to 70 wt %, or 10 wt % to 65 wt %, or 10 wt % to 60 wt %, or 15 wt % to 98 wt %, or 15 wt % to 75 wt %, or 15 wt % to 70 wt %, or 15 wt % to 65 wt %, or 15 wt % to 60 wt %, or 20 wt % to 98 wt %, or 20 wt % to 75 wt %, or 20 wt % to 70 wt %, or 20 wt % to 65 wt %, or 20 wt % to 60 wt %, or 25 wt % to 98 wt %, or 25 wt % to 75 wt %, or 25 wt % to 70 wt %, or 25 wt % to 65 wt %, or 25 wt % to 60 wt %, or 30 wt % to 98 wt %, or 30 wt % to 75 wt %, or 30 wt % to 70 wt %, or 30 wt % to 65 wt %, or 30 wt % to 60 wt %, or 35 wt % to 98 wt %, or 35 wt % to 75 wt %, or 35 wt % to 70 wt %, or 35 wt % to 65 wt %, or 35 wt % to 60 wt %, or, 40 wt % to 98 wt %, or 40 wt % to 75 wt %, or 40 wt % to 70 wt %, or 40 wt % to 65 wt %, or 40 wt % to 60 wt %, or 45 wt % to 98 wt %, or 45 wt % to 75 wt %, or 45 wt % to 70 wt %, or 45 wt % to 65 wt %, or 45 wt % to 60 wt %, or 50 wt % to 98 wt %, or 50 wt % to 75 wt %, or 50 wt % to 70 wt %, or 50 wt % to 65 wt %, or 50 wt % to 60 wt %, or 55 wt % to 98 wt %, or 55 wt % to 75 wt %, or 55 wt % to 70 wt %, or 55 wt % to 65 wt %, or 55 wt % to 60 wt % 5 wt % to 98 wt %, or 5 wt % to 75 wt %, or 5 wt % to 70 wt %, or 5 wt % to 65 wt %, or 5 wt % to 60 wt %, or 10 wt % to 98 wt %, or 10 wt % to 75 wt %, or 10 wt % to 70 wt %, or 10 wt % to 65 wt %, or 10 wt % to 60 wt %, or 15 wt % to 98 wt %, or 15 wt % to 75 wt %, or 15 wt % to 70 wt %, or 15 wt % to 65 wt %, or 15 wt % to 60 wt %, or 20 wt % to 98 wt %, or 20 wt % to 75 wt %, or 20 wt % to 70 wt %, or 20 wt % to 65 wt %, or 20 wt % to 60 wt %, or 25 wt % to 98 wt %, or 25 wt % to 75 wt %, or 25 wt % to 70 wt %, or 25 wt % to 65 wt %, or 25 wt % to 60 wt %, or 30 wt % to 98 wt %, or 30 wt % to 75 wt %, or 30 wt % to 70 wt %, or 30 wt % to 65 wt %, or 30 wt % to 60 wt %, or 35 wt % to 98 wt %, or 35 wt % to 75 wt %, or 35 wt % to 70 wt %, or 35 wt % to 65 wt %, or 35 wt % to 60 wt %, or, 40 wt % to 98 wt %, or 40 wt % to 75 wt %, or 40 wt % to 70 wt %, or 40 wt % to 65 wt %, or 40 wt % to 60 wt %, or 45 wt % to 98 wt %, or 45 wt % to 75 wt %, or 45 wt % to 70 wt %, or 45 wt % to 65 wt %, or 45 wt % to 60 wt %, or 50 wt % to 98 wt %, or 50 wt % to 75 wt %, or 50 wt % to 70 wt %, or 50 wt % to 65 wt %, or 50 wt % to 60 wt %, or 55 wt % to 98 wt %, or 55 wt % to 75 wt %, or 55 wt % to 70 wt %, or 55 wt % to 65 wt %, or 55 wt % to 60 wt %.

[0014] In some embodiments, M.sup.4+O.sub.2 is present in the catalyst in an amount of 1 wt % to 98 wt %, or 1 wt % to 75 wt %, or 1 wt % to 70 wt %, or 1 wt % to 65 wt %, or 1 wt % to 60 wt %, or 2 wt % to 98 wt %, or 2 wt % to 75 wt %, or 2 wt % to 70 wt %, or 2 wt % to 65 wt %, or 2 wt % to 60 wt %, or 5 wt % to 98 wt %, or 5 wt % to 75 wt %, or 5 wt % to 70 wt %, or 5 wt % to 65 wt %, or 5 wt % to 60 wt %, or 10 wt % to 98 wt %, or 10 wt % to 75 wt %, or 10 wt % to 70 wt %, or 10 wt % to 65 wt %, or 10 wt % to 60 wt %, or 15 wt % to 98 wt %, or 15 wt % to 75 wt %, or 15 wt % to 70 wt %, or 15 wt % to 65 wt %, or 15 wt % to 60 wt %, or 20 wt % to 98 wt %, or 20 wt % to 75 wt %, or 20 wt % to 70 wt %, or 20 wt % to 65 wt %, or 20 wt % to 60 wt %, or 25 wt % to 98 wt %, or 25 wt % to 75 wt %, or 25 wt % to 70 wt %, or 25 wt % to 65 wt %, or 25 wt % to 60 wt %, or 30 wt % to 98 wt %, or 30 wt % to 75 wt %, or 30 wt % to 70 wt %, or 30 wt % to 65 wt %, or 30 wt % to 60 wt %, or 35 wt % to 98 wt %, or 35 wt % to 75 wt %, or 35 wt % to 70 wt %, or 35 wt % to 65 wt %, or 35 wt % to 60 wt %, or, 40 wt % to 98 wt %, or 40 wt % to 75 wt %, or 40 wt % to 70 wt %, or 40 wt % to 65 wt %, or 40 wt % to 60 wt %, or 45 wt % to 98 wt %, or 45 wt % to 75 wt %, or 45 wt % to 70 wt %, or 45 wt % to 65 wt %, or 45 wt % to 60 wt %, or 50 wt % to 98 wt %, or 50 wt % to 75 wt %, or 50 wt % to 70 wt %, or 50 wt % to 65 wt %, or 50 wt % to 60 wt %, or 55 wt % to 98 wt %, or 55 wt % to 75 wt %, or 55 wt % to 70 wt %, or 55 wt % to 65 wt %, or 55 wt % to 60 wt %.

[0015] In some embodiments, M.sup.2+ comprises divalent magnesium.

[0016] In some embodiments, M.sup.4+ comprises silicon.

[0017] In some embodiments, the catalyst further comprises a salt or oxide of a metal from Group 1 of the Periodic Table, or combinations thereof. In some embodiments, the Group 1 metal comprises Li, Na, K, Rb, Cs, or combinations thereof. The Group 1 metal may be present in an amount of 0.01 wt % to 10 wt %, or 0.05 wt % to 10 wt %, or 0.1 wt % to 10 wt %, or 0.5 wt % to 10 wt %, or 1 wt % to 10 wt %, or 2 wt % to 10 wt %, or 3 wt % to 10 wt %, or 4 wt % to 10 wt %, or 5 wt % to 10 wt %, or 6 wt % to 10 wt %, or 7 wt % to 10 wt %, or 8 wt % to 10 wt %, or 9 wt % to 10 wt %, or 0.01 wt % to 8 wt %, or 0.01 wt % to 5 wt %, or 0.01 wt % to 2 wt %, or 0.01 wt % to 1 wt %, or 0.01 wt % to 0.5 wt %, or 0.05 wt % to 8 wt %, or 0.05 wt % to 5 wt %, or 0.05 wt % to 2 wt %, or 0.05 wt % to 1 wt %, or 0.05 wt % to 0.5 wt %, or 0.1 wt % to 8 wt %, or 0.1 wt % to 5 wt %, or 0.1 wt % to 2 wt %, or 0.1 wt % to 1 wt %, or 0.1 wt % to 0.5 wt %, or or 0.5 wt % to 8 wt %, or 0.5 wt % to 5 wt %, or 0.5 wt % to 2 wt %, or 0.5 wt % to 1 wt %, or 1 wt % to 8 wt %, or 1 wt % to 5 wt %, or 1 wt % to 2 wt %, or 2 wt % to 8 wt %, or 2 wt % to 5 wt %, or 3 wt % to 5 wt %, or 4 wt % to 8 wt %, or 4 wt % to 5 wt %.

[0018] Another aspect of the invention is a method of producing isobutanol or n-butanol. In one embodiment, the method comprises: reacting ethanol or propanol with methanol in the presence of an alcohol condensation catalyst under reaction conditions to produce isobutanol or reacting ethanol with ethanol in the presence of an alcohol condensation catalyst under reaction conditions to produce n-butanol; wherein the alcohol condensation catalyst comprises a M/M.sup.2+M.sup.4+ oxide catalyst: wherein M comprises metals from Groups 3-12 of the Periodic Table, or combinations thereof: wherein M.sup.2+ comprises divalent magnesium, calcium, strontium, barium, or combinations thereof: wherein M.sup.4+ comprises tetravalent silicon, titanium, zirconium, or combinations thereof.

[0019] The M/M.sup.2+M.sup.4+ oxide catalyst is described above.

[0020] In some embodiments, the reaction conditions comprise one or more of: a temperature in a range of 100 C. to 500 C.: or a pressure in a range of 5 kPa to 30,000 kPa.

[0021] The method of producing isobutanol or n-butanol with the M/M.sup.2+M.sup.4+ oxide catalyst allows good methanol, ethanol or propanol conversion, as well as good isobutanol or n-butanol selectivity and productivity.

EXAMPLES

Example 1

[0022] Mg.sub.2SiO.sub.4 was prepared by reacting Mg(NO.sub.3).sub.2.Math.6H.sub.2O (dissolved in ethanol) with a Na.sub.2SiO.sub.3.Math.9H.sub.2O aqueous solution at 170 C. in autoclave for 24 hours, followed by filtering, washing, drying, and calcination at 450 C. for 4 hours. Cu was impregnated on the Mg.sub.2SiO.sub.4 surface by incipient wetness impregnation. This produced 5% Cu/Mg.sub.2SiO.sub.4 catalyst with a BET surface area of 203 m.sup.2/g and a pore volume of 0.21 cm.sup.3/g.

[0023] The catalyst performance testing was conducted in a micro-reactor under the conditions of 289-337 C., 600 psi, 11.4% propanol, 22.8% methanol, balance N.sub.2 and a GHSV of 3000 ml/g-h. The testing results are summarized in Table 1. The methanol conversions were 28-42%, the propanol conversions were 43-66%, the isobutanol selectivities were 30-46%, and the isobutanol productivities were 154-361 g/kg-h under the testing conditions.

[0024] The above results indicate that Cu doped Mg.sub.2SiO.sub.4 catalyst is a good catalyst for converting propanol and methanol to isobutanol through Guerbet reaction.

Example 2

[0025] Cu.sub.0.19Ca.sub.1.81ZrO.sub.4 catalyst was prepared with a conventional co-precipitation method.

[0026] 3.65 g Cu(NO.sub.3).sub.2.Math.2.5H.sub.2O, 36.05 g Ca(NO.sub.3).sub.2.Math.4H.sub.2O and 31.41 g ZrO(NO.sub.3).sub.2.Math.xH.sub.2O were dissolved in 167 g deionized water in a beaker.

[0027] In a separate beaker, 52.39 g K.sub.2CO.sub.3 were dissolved in 188 g deionized water.

[0028] The two solutions were pumped to a third beaker containing 200 g deionized water at 70 C. with stirring. The pH value of the mixture was maintained at 7.0. After the co-precipitation process was complete, the mixture was stirred for an additional one hour.

[0029] Subsequently, the slurry was filtered and washed with deionized water three times. The obtained paste was dried at 120 C. for 12 hours and calcined at 600 C. for 4 hours.

[0030] 1.00 g sample was loaded into a catalyst basket and placed in a stainless steel autoclave along with 29 g solution with 2:1 CH.sub.3OH-C.sub.3H.sub.7OH molar ratio. The autoclave was sealed, charged with 2200 psi of ultra-high purity N.sub.2, and vented after two hours to give a sealed system with an N.sub.2 headspace. The autoclave was heated to 325 C. at a 2 C./min ramp rate with stirring and held at 325 C. for 15 hours before cooling to room temperature. The liquid, catalyst basket, and autoclave weights were recorded. The liquid was analyzed by GC to provide information about methanol and propanol conversions and isobutanol productivity. 55% methanol conversion, 46% propanol conversion, 28% isobutanol selectivity and 148 g/kg-h isobutanol productivity were achieved.

Example 3

[0031] 5% Cu/Mg3Si.sub.4O.sub.11 was prepared with precipitation followed by impregnation. 25.6 g Mg(NO.sub.3).sub.2.Math.6H.sub.2O and 3.81 g acetic acid were dissolved in 50 ml deionized water in a 500 ml Nalgene bottle. 37.9 g Na.sub.2SiO.sub.3.Math.9H.sub.2O was dissolved in 300 ml deionized water and then added rapidly to the Mg(NO.sub.3).sub.2 solution with stirring. The mixture was stirred vigorously for 30 min and then allowed to stand sealed for four days at room temperature. Next the slurry was filtered, washed with deionized water, and dried at 120 C. The dried solid was mixed with 100 ml H.sub.2O in a 200 ml Teflon lined autoclave and heated for 24 h at 200 C. The solid was filtered and washed with 500 ml H.sub.2O, dried, and calcined at 500 C. for 4 h.

[0032] 8 g of the calcined material (Mg.sub.3Si.sub.4O.sub.11) was impregnated with a solution of 0.541 g Cu(NO.sub.3).sub.2.Math.2.5 H.sub.2O in 2.8 ml H.sub.2O, and the material was calcined at 400 C. for 8 h.

[0033] 1.00 g sample was loaded into a catalyst basket and placed in a stainless steel autoclave along with 29 g solution with 2:1 CH.sub.3OH-C.sub.3H.sub.7OH molar ratio. The autoclave was sealed, charged with 2200 psi of ultra-high purity N.sub.2, and vented after two hours to give a sealed system with an N.sub.2 headspace. The autoclave was heated to 325 C. at a 2 C./min ramp rate with stirring and held at 325 C. for 15 hours before cooling to room temperature. The liquid, catalyst basket, and autoclave weights were recorded. The liquid was analyzed by GC to provide information about methanol and propanol conversions and isobutanol productivity. 55% methanol conversion, 60% propanol conversion, 30% isobutanol selectivity, and 206 g/kg-h isobutanol productivity were achieved.

Example 4

[0034] 1.0 g 5% Cu/Mg.sub.3Si.sub.4O.sub.11 sample from EXAMPLE 3 was loaded into a catalyst basket and placed in a stainless steel autoclave along with 31.3 g ethanol solution. The autoclave was sealed, charged with 2200 psi of ultra-high purity N.sub.2, and vented after two hours to give a sealed system with an N.sub.2 headspace. The autoclave was heated to 325 C. at a 2 C./min ramp rate with stirring and held at 325 C. for 15 hours before cooling to room temperature. The liquid, catalyst basket, and autoclave weights were recorded. The liquid was analyzed by GC to provide information about ethanol conversion and n-butanol productivity. 72% ethanol conversion, 22% n-butanol selectivity and 263 g/kg-h n-butanol productivity were achieved.

TABLE-US-00001 TABLE 1 Isobutanol synthesis from propanol-methanol reaction on the catalyst in Example 1 Isobutanol Methanol Propanol Isobutanol productivity T ( C.) conversion conversion selectivity (g/kg-h) 289 28% 43% 30% 154 313 36% 53% 43% 269 337 42% 66% 46% 361

[0035] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.