WO2021133383A1

WO2021133383A1 - Catalysts for mixed alcohols synthesis from co and h2

Info

Publication number: WO2021133383A1
Application number: PCT/US2019/068393
Authority: WO
Inventors: Richard Long; Tian Ruan
Original assignee: Uop Llc; China Petroleum & Chemical Corporation
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-07-01

Abstract

Precious metal promoted CuCoZnMn based catalysts are described. The catalysts consists essentially of copper, cobalt, zinc, manganese, chromium or zirconium or a combination thereof, a noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; optionally a metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof; and optionally a metal from group 1 of the periodic table, or combinations thereof. The catalyst is aluminum-free. The catalysts can be used in the production of mixed alcohols from synthesis gas.

Description

CATALYSTS FOR MIXED ALCOHOLS SYNTHESIS FROM CO and H₂

BACKGROUND

Synthesis of mixed alcohols from synthesis gas is an important energy conversion process. By integration with gasification or reforming, solid coal and biomass and natural gas can be converted to liquid fuels and value-added chemicals. The mixed alcohols can be used as gasoline additive (for example, ethanol) and organic solvents (for example, propanol and butanol). They can also further be converted to valuable light olefins, such as ethylene and propylene, through methanol-to-olefms process and dehydration of ethanol and propanol. Consequently, syngas conversion to mixed alcohols has been extensively investigated in the world.

According to the disclosed information in the literature, there are mainly four types catalysts: Cu-Co catalysts, Cu-Fe catalysts, Rh-based catalysts and supported Mo catalysts (M0S2, M02C and MoP) (H.T. Luk et al, Chem. Soc. Rev., 2017, 46, 1358-1426). Among them, Cu-Co catalysts and Rh-based catalysts exhibit better performance than supported Mo catalysts. However, Rh is very expensive, and its source is limited. In comparison, the low-cost Cu-Co catalysts are more commercially viable and have attracted strong interest. For instance, US patent No. 4,562,174 disclosed a catalyst comprising of an alkali metal salt, a mixture of copper oxide, zinc oxide and cobalt oxide and optionally manganese oxide, and a stabilizer selected from aluminum, chromium, alkaline earths, lanthanides, tantalum, niobium, silica, zirconium, titanium, thorium, uranium and yttrium. US patent No. 4,659,742 described a process for manufacturing methanol and higher alcohols by reacting carbon oxides with hydrogen on a catalyst containing copper, cobalt, aluminum and alkali or alkaline-earth metal. US Patent No. 4,791,141 disclosed a process for manufacturing primary alcohols by reacting CO and H2 on a catalyst containing copper, zinc, cobalt and aluminum. US patent No. 4,780,481 disclosed catalysts formed of copper, cobalt, zinc, alkali metals and alkaline earth metals. The catalysts might optionally have zirconium and/or one metal from scandium, yttrium and rare earth metals and one metal from noble metals, but were essentially free of aluminum, chromium, iron, vanadium and manganese. US patent No. 8,450,536 disclosed conversion of synthesis gas to mixed alcohols and then use Guerbet reaction to convert methanol and ethanol to isobutanol. The catalyst had five metals: copper, zinc, potassium, cobalt, and manganese on supports. The supports were AI2O3, S1O2 and carbon nanotubes.

Although many catalysts have been investigated, there is still a need for improved catalysts for conversion of synthesis gas to mixed alcohols.

DESCRIPTION

The present invention describes a precious metal promoted CuCoZnMn based catalyst that exhibits excellent mixed alcohols synthesis performance from synthesis gas.

The catalyst consists essentially of copper, cobalt, zinc, manganese, chromium or zirconium or a combination thereof, a noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; optionally a metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof; optionally a metal from group 1 of the periodic table, or combinations thereof. The catalyst is aluminum-free. By “aluminum-free,” we mean that there is no added aluminum; the only aluminum present is due to impurities as a result of the manufacturing process.

The catalyst contains 5-70 wt% copper, or 10-50 wt%.

The catalyst contains 2-50 wt% cobalt, or 5-30 wt%.

In some embodiments, the catalyst has more copper than cobalt.

The catalyst contains 0.01-40 wt% zinc, or 2-20 wt%.

The catalyst contains 0.01-40 wt% manganese, or 2-20 wt%.

The catalyst contains 2-60 wt% chromium, or zirconium, or combinations thereof, or 5-50 wt%.

The catalyst contain 0.001-10 wt% of the noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof, or 0.01-1 wt%. Suitable noble metals include, but are not limited to, Pt, Pd, Rh, Ru, Ir, Re, or combinations thereof.

The cobalt sites act as the sites for CO dissociation, C-C chain growth and hydrogenation, while the copper sites may adsorb CO molecules and insert the CO to the formed alkyl group on the cobalt sites. The ZnO and Mn sites may be used as promoters for stabilizing the copper and cobalt. The addition of noble metals may help CO and H2 activation as well as cobalt oxide reduction. The catalyst may optionally contain 0-60 wt% of the metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof, or 5-50 wt%. Suitable metals from groups 4, 6, 13, or 14 include, but are not limited to, Ga, Sn, Si, Ti, or combinations thereof.

The catalyst may contain 0-20 wt% of the metal from group 1 of the periodic table, or combinations thereof, or 0-10 wt%, or 0-5 wt%. When the catalyst is zirconium-free (i.e., there is no added zirconium; the only zirconium present is due to impurities as a result of the manufacturing process), the group 1 metal is present. Suitable metals from group 1 include, but are not limited to, Li, Na, K, Rb, Cs, or combinations thereof. In some embodiments, the catalyst is alkali-free. By “alkali-free,” we mean that there are no added metals from group 1; the only metals present from group 1 are due to impurities as a result of the manufacturing process.

The catalyst may be formed using any suitable process including, but not limited to, co-precipitation, impregnation, deposition-precipitation, sol-gel and fuel combustion.

The copper, cobalt, zinc, manganese, chromium and/or zirconium are present in the catalyst as oxides. The noble metals are present as either oxides or metals. The metals from groups 4, 6, 13, or 14 of the periodic table are present as oxides. The metals from group 1 of the periodic table are present as either oxides or salts, such as hydroxides, carbonates or bicarbonates.

The catalyst may be used in the manufacture of mixed alcohols from synthesis gas. The synthesis gas is contacted with the catalyst described above in a reaction zone. This results in the formation of a mixture of alcohols. The mixture of alcohols may contain alcohols having from 1 to 12 carbon atoms.

The reaction conditions include, but are not limited to, one or more of: a temperature in a range of 200°C to 500°C, or 250°C to 450°C; or a pressure in a range of 1.0 to 30 MPa, or 1.0 to 20 MPa. The molar ratio of Th to CO in the synthesis gas may be in the range of 5: 1 to 0.2:1, or 3:1 to 0.5:1. The gas hourly space velocity may be in the range of 500 to 50,000 ml/g-h (or ml/ml-h), or 1,000 to 30,000 ml/g-h (or ml/ml-h).

The synthesis gas may be obtained from gasification of coal and biomass, reforming of natural gas, shale gas, biogas, and refinery gas.

The mixed alcohols may be sent to distillation process to separate to different fractions. Most of the alcohols may be directly used as solvents, such as methanol, ethanol, propanol, butanol and hexanol. Methanol may also be further converted to valuable light olefins, such as ethylene and propylene through methanol-to-olefms process. Ethanol may also be used as gasoline additive to improve engine combustion efficiency. Ethanol, propanol and butanol may be further converted to corresponding light olefins, through dehydration process.

The noble metal promoted catalyst has been shown to provide significantly increased C2-C4 alcohol production compared with a corresponding unpromoted catalyst, as well as increased CO conversion in some cases. The noble metal promoted chromium containing catalyst has been shown to provide significantly increased C2-C4 alcohol production compared with a similar noble metal promoted catalyst containing aluminum, as well as increased CO conversion in some cases. The noble metal promoted zirconium containing catalyst has been shown to provide significantly increased C2-C4 alcohol production compared with a similar noble metal promoted catalyst containing aluminum in some cases, as well as significantly increased CO conversion.

EXAMPLES

Example 1 (reference)

A CuCoZnCrOx based catalyst was prepared using the co-precipitation method. In the experiment, 13. Og Cu(N03)2 2.5H20, 16.6g Co(N03)2 6H2O, 16.8gZn(N03)2-6H20 and 8.2g Cr(N03)3-9H20 were dissolved in 188g deionized water with stirring in a beaker. In a separate beaker, 38.6g K2CO3 was dissolved in 277g deionized water. The solution of metal nitrates was pumped to the K2CO3 solution at 70°C with stirring. After all of the solution of metal nitrates was added to the K2CO3 solution, the mixture was stirred for an additional one hour at 70°C. Subsequently, the slurry was filtered and washed with deionized water three times. The paste obtained was dried at 120°C for 12 hours and then calcined at 350°C for 4 hours.

Example 2 (reference)

A CuCoZnMnCrOx based catalyst was prepared using the co-precipitation method. In the experiment, 32.2g Cu(N03)2 2.5H2O, 20.6g Co(N03)2 6H2O, 10.4g Zh(Nq3)2 6H2O, 14. lg Cr(N03)3 9H2O and 12.4g Mn(N03)2 (50 wt%) were dissolved in 31 lg deionized water in a beaker with stirring. In a separate beaker, 64.2g K2CO3 was dissolved in 460g deionized water. The solution of metal nitrates was pumped to the K2CO3 solution at room temperature with stirring. After all of the solution of metal nitrates was added to the K2CO3 solution, the mixture was stirred for an additional one hour. Subsequently, the slurry was filtered and washed with deionized water three times. The paste obtained was dried at 120°C for 12 hours and then calcined at 400°C for 4 hours.

Example 3 (reference)

A Ru/CuCoZnMnAlOx catalyst was prepared using the co-precipitation method followed by impregnation. In the experiment, 32.4g Cu(NC>3)2 2.5H2O, 13.84g

Co(N0₃)₂ 6H20, 14. Og Zn(N0₃)₂ · 6H20, 17.8g A1(N03)3-9H₂0 and 16.6gMn(N03)₂ (50 wt%) were dissolved in 325g deionized water in a beaker with stirring. In a separate beaker, 68. lg K2CO3 was dissolved in 488g deionized water. The solution of metal nitrates was pumped to the K2CO3 solution at room temperature with stirring. After all of the solution of metal nitrates was added to the K2CO3 solution, the mixture was stirred for an additional one hour. Subsequently, the slurry was filtered and washed with deionized water three times. The paste obtained was dried at 120°C for 12 hours and then calcined at 400°C for 4 hours. Next, 0.67g RU(N0)(N0₃)3 solution (1.5 wt% Ru) was dissolved in 3.8g deionized water and impregnated on 5.0g of the mixed oxides. The catalyst was finally dried at 120°C for 4 hours and calcined at 250°C for 4 hours.

Example 4

A Ru/CuCoZnMnCrOx catalyst was prepared using the co-precipitation method followed by impregnation. In the experiment, 32.2g Cu(NC>3)2 2.5H2O, 20.6g Co(NC>3)2 6H2O, 10.4g Zh(Nq3)2 6H2O, 14. lg Cr(N03)3 9H2O and 12.4g Mn(NCb)2 (50 wt%) were dissolved in 31 lg deionized water in a beaker with stirring. In a separate beaker, 64.2g K2CO3 was dissolved in 460g deionized water. The solution of metal nitrates was pumped to the K2CO3 solution at room temperature with stirring. After all of the solution of metal nitrates was added to the K2CO3 solution, the mixture was stirred for an additional one hour. Subsequently, the slurry was filtered and washed with deionized water three times. The paste obtained was dried at 120°C for 12 hours and then calcined at 400°C for 4 hours. Next, 0.67g Ru(N0)(N03)3 solution (1.5 wt% Ru) was dissolved in 1.9g deionized water and impregnated on 5.0g of the mixed oxides. The catalyst was finally dried at 120°C for 4 hours and calcined at 250°C for 4 hours. Example 5

A Ru/CuCoZnMnZrOx catalyst was prepared using the co-precipitation method followed by impregnation. In the experiment, 30.2gCu(NO3)2-2.5EhO, 19.3g Co(NC>3)2 6H2O, 9.8g Zn(N03)2-6Eh0, 8.7g Zr0(N03)2 xEhO and 11.6g Mn(N03)2 (50 wt%) were dissolved in 292g deionized water in a beaker with stirring. In a separate beaker, 60.3g K2CO3 was dissolved in 432g deionized water. The solution of metal nitrates was pumped to the K2CO3 solution at room temperature with stirring. After all of the solution of metal nitrates was added to the K2CO3 solution, the mixture was stirred for an additional one hour. Subsequently, the slurry was filtered and washed with deionized water three times. The paste obtained was dried at 120°C for 12 hours and then calcined at 400°C for 4 hours. Next, 0.67g Ru(N0)(N03)3 solution (1.5 wt% Ru) was dissolved in 1.9g deionized water and impregnated on 5.0g of the mixed oxides. The catalyst was finally dried at 120°C for 4 hours and calcined at 250°C for 4 hours.

Examples 6-10

The catalysts from Examples 1-5 were tested in a tubular reactor under the conditions of 275-375°C, 100 atm (10.1 MPa), 45% Eh, 45% CO, 10% N2, and gas hourly space velocity of 8,000-16,000 ml/g-h. The testing results are summarized in Table 1. It can be seen clearly that the Ru promoted CuCoZnMnCrOx catalyst (Example 4) exhibited higher total C2-C4 alcohols yields than unpromoted CuCoZnCrOx (Example 1) and CuCoZnMnCrOx catalyst (Example 2), indicating promoting role from Ru. The Ru promoted CuCoZnMnCrOx catalyst (Example 4) and Ru promoted CuCoZnMnZrOx catalyst (Example 5) exhibited higher total C2-C4 alcohols yields than Ru promoted CuCoZnMnAlOx catalyst (Example 3), indicating Cr and Zr are better than A1 for the C2-C4 alcohols formation.

Table 1. Synthesis gas conversion to mixed alcohols performance

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.

Claims

What is claimed is:

1. An aluminum-free catalyst for synthesis of mixed alcohols consisting essentially of: copper; cobalt; zinc; manganese; chromium, or zirconium, or a combination thereof; a noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; optionally a metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof; and optionally a metal from group 1 of the periodic table, or combinations thereof, with the proviso that if the catalyst is zirconium-free, the metal from group 1 is present.

2. The catalyst of claim 1 wherein the catalyst consists essentially of: 5-70 wt% copper;

2-50 wt% cobalt;

0.01-40 wt% zinc;

0.01-40 wt% manganese;

2-60 wt% chromium, or zirconium, or a combination thereof;

0.001-10 wt% of the noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; and

0-60 wt% of the metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof; and

0-10 wt% of the metal from group 1 of the periodic table, or combinations thereof, with the proviso that if the catalyst is zirconium-free, the metal from group 1 is present.

3. The catalyst of any one of claims 1-2 wherein the catalyst consists essentially of:

10-50 wt% copper;

5-30 wt% cobalt; 2-20 wt% zinc;

2-20 wt% manganese;

5-50 wt% chromium, or zirconium, or a combination thereof;

0.01-1 wt% of the noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; and

5-50 wt% of the metal from groups 4, 6, 13, or 14 of the periodic table, or combinations thereof; and

0-5 wt% of the metal from group 1 of the periodic table, or combinations thereof, with the proviso that if the catalyst is zirconium-free, the metal from group 1 is present.

4. The catalyst of any one of claims 1-3 wherein the noble metal comprises Pt, Pd, Rh, Ru, Ir, Re, or combinations thereof.

5. The catalyst of any one of claims 1-4 wherein the metal from groups 4, 6, 13, or 14 is present and comprises Ga, Sn, Si, Ti, or combinations thereof.

6. The catalyst of any one of claims 1-5 wherein the metal from group 1 is present and comprises Li, Na, K, Rb, Cs, or combinations thereof.

7. The catalyst of any one of claims 1-5 wherein catalyst is alkali-free.

8. A method of making mixed alcohols comprising: contacting a synthesis gas with an aluminum-free catalyst in a reaction zone under reaction conditions to form a mixture of alcohols, wherein the catalyst consisting essentially of: copper; cobalt; zinc; manganese; chromium, or zirconium, or a combination thereof; noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof; optionally a metal from groups 4, 6, 13, or 14, of the periodic table, or combinations thereof; and optionally a metal from group 1 of the periodic table, or combinations thereof, with the proviso that if the catalyst is zirconium-free, the metal from group 1 is present.

9. The method of claim 8 wherein the catalyst consists essentially of:

5-70 wt% copper;

2-50 wt% cobalt;

0.01-40 wt% zinc;

0.01-40 wt% manganese;

2-60 wt% chromium, or zirconium, or a combination thereof;

0.001-10 wt% of the noble metal from groups 7, 8, 9, or 10 of the periodic table, or combinations thereof;; and

10. The catalyst of any one of claims 8-9 wherein the catalyst consists essentially of:

10-50 wt% copper;

5-30 wt% cobalt;

2-20 wt% zinc;

2-20 wt% manganese;

5-50 wt% chromium, or zirconium, or a combination thereof;

11. The method of any one of claims 8-10 wherein the noble metal comprises Pt, Pd, Rh, Ru, Ir, Re, or combinations thereof.

12. The method of any one of claims 8-11 wherein the metal from groups 4, 6, 13, or 14 of the periodic table is present and comprises Ga, Sn, Si, Ti, or combinations thereof.

13. The catalyst of any one of claims 8-12 wherein the metal from group 1 is present and comprises Li, Na, K, Rb, Cs, or combinations thereof.

14. The catalyst of any one of claims 8-12 wherein catalyst is alkali-free.

15. The method of any one of claims 8-14 wherein the reaction conditions comprise one or more of: a temperature in a range of 200°C to 500°C; or a pressure in a range of 1.0 to 30 MPa; or a molar ratio of Th to CO in the synthesis gas is in a range of 5: 1 to 0.2:1.