Catalyst Selection
A number of catalyst systems are currently under investigation for conversion of syngas to ethanol, but low conversion and poor ethanol yield are still major issues in this route. So far, Rh-based and MoS2-based catalysts have shown much promise and a comparison of some leading Rh-based and MoS2-based catalysts are shown in Table 13.9. A Rh-Mn/SiO2 catalyst reported by Pacific Northwest National Laboratory (PNNL) of the United States at two operating conditions [31] are in the first two columns. Two patented KCoMoS2 catalysts by Dow Chemical [67] and Abengoa Bioenergy New Technologies (ABNT) [68] are in the third and fourth columns. Catalysts were selected under the criteria of the highest ethanol yield per pass found in the literature. The presented sample includes the performance of catalysts in terms of conversion and selectivity to products. For each catalyst, higher selectivity to ethanol can be achieved at the cost of lower CO conversion, although this does not necessarily lead to a higher ethanol yield.
Total selectivity to alcohols is in the 46-50% range for most catalysts except for PNNL’s catalyst number 1, which is 60%. A significant difference between these types of catalysts is that carbon selectivity is shifted to CO2 in the MoS2 catalysts while it is shifted to hydrocarbons for the rhodium catalyst. The CO2 in the syngas tends to inhibit the activity of both types of catalyst but it is not clear what level of CO2 concentration is allowable to prevent this effect [1]. In addition, MoS2 catalysts require 50-100 ppm of sulfur in the form of H2S in the syngas to maintain the sulfidity of the catalyst [1], while H2S is a poison for the rhodium catalyst.
|
Table 13.9 A comparison of Rh-based and MoS2-based catalysts [69].
a CO to ethanol per CO fed to reactor (%) b Reported selectivity to C2+ and higher oxygenates has been ascribed to C2H4 for the sake of simplicity (%) |
c Measured at standard temperature and pressure
PNNL — Pacific Northwest National Laboratory of the Unite States
1. V. Subramani and S. K. Gangwal, A review of recent literature to search for an efficient catalytic process for the conversion of syngas to ethanol. Energy and Fuels, 2008. 22(2): p. 814-839.
2. P. M. Maitlis, Metal catalysed CO hydrogenation: hetero — or homo-, what is the difference? Journal of Molecular Catalysis A: Chemical, 2003. 204-205(0): p. 54-61.
3. J. He and W. N. Zhang, Research on ethanol synthesis from syngas. Journal of Zhejiang University: Science A, 2008. 9(5): p. 714-719.
4. B. K. Warren and B. D. Dombek, Ethanol from H2 and CO via homogeneous ruthenium catalysis. Journal of Catalysis, 1983. 79(2): p. 334-347.
5. H. Ono, K. Fujiwara, M. Hashimoto, H. Watanabe, and K. Yoshida, Hydrogenation of carbon monoxide with homogeneous ruthenium catalysts: novel effect of phosphoric acid on ethanol synthesis. Journal of Molecular Catalysis, 1990. 58(3): p. 289-297.
6. M. Tanaka, Y. Kiso, and K. Saeki, Hydrogenation of carbon monoxide by homogeneous ruthenium-rhenium bimetallic catalysts: effects of rhenium carbonyl as a promoter for ethylene glycol formation. Journal of Organometallic Chemistry, 1980. 329(1): p. 99-104.
7. J.-J. Lin and J. F. Knifton, Synthesis of ethanol by homologation of methanol. U. S. Patent 1983: p. 4,374,285.
8. J. W. Rathke, M. J. Chen, R. J. Klinger, R. E. Gerald, C. L. Marshall, and J. L. Rodgers, Catalysis and Chemical Transformations Program, Cambridge, MD, May21-24,. Proceedings of the 2006 Meetings of the DOE/BES 2006.
9. J. J. Spivey and A. Egbebi, Heterogeneous catalytic synthesis of ethanol from biomass-derived syngas. Chemical Society Reviews, 2007. 36(9): p. 1514-1528.
10. K. R. Jegannathan, E. S. Chan, and P. Ravindra, Harnessing biofuels: A global Renaissance in energy production? Renewable and Sustainable Energy Reviews, 2009. 13(8): p. 2163-2168.
11. M. Gupta, M. L. Smith, and J. J. Spivey, Heterogeneous catalytic conversion of dry syngas to ethanol and higher alcohols on Cu-based catalysts. ACS Catalysis, 2011. 1(6): p. 641-656.
12. P. Becker, J. Schroder, R. Ahmad, M. Zimmermann, T. Otto, M. Doring, and U. Arnold, Recent patents on the conversion of biomass to fuels via synthesis gas. Recent Patents on Chemical Engineering, 2012. 5(2): p. 75-86.
13. M. M. Bhasin, W. J. Bartley, P. C. Ellgen, and T. P. Wilson, Synthesis gas conversion over supported rhodium and rhodium-iron catalysts. Journal of Catalysis, 1978. 54(2): p. 120-128.
14. P. C. Ellgen, W. J. Bartley, M. M. Bhasin, and T. P. Wilson, Rhodium-based catalysts for the conversion of synthesis gas to two-carbon chemicals. Preprints, 1978. 23(2): p. 616-623.
15. P. Forzatti, E. Tronconi, and I. Pasquon, Higher alcohol synthesis. Catalysis Reviews — Science and Engineering, 1991. 33(1-2): p. 109-168.
16. M. L. Poutsma, L. F. Elek, P. A. Ibarbia, A. P. Risch, and J. A. Rabo, Selective formation of methanol from synthesis gas over palladium catalysts. Journal of Catalysis, 1978. 52(1): p. 157-168.
17. M. Ichikawa and T. Fukushima, Mechanism of syngas conversion into C2-oxygenates such as ethanol catalysed on a SiO2-supported Rh-Ti catalyst. Journal of the Chemical Society, Chemical Communications, 1985(6): p. 321-323.
18. A. Takeuchi and J. R. Katzer, Ethanol formation mechanism from CO + H2. Journal of Physical Chemistry, 1982. 86(13): p. 2438-2441.
19. A. Takeuchi and J. R. Katzer, Mechanism of methanol formation. The Journal of Physical Chemistry, 1981. 85(8): p. 937-939.
20. E. Guglielminotti, E. Giamello, F. Pinna, G. Strukul, S. Martinengo,
and L. Zanderighi, Elementary Steps in CO Hydrogenation on Rh Catalysts Supported on ZrO2 and Mo/ZrO2. Journal of Catalysis, 1994. 146(2): p. 422-436. 2 2
21. T. Iizuka and Y. Tanaka, Dissociative adsorption of CO2 on supported rhodium catalyst: Comment on surface interaction between H2 and CO2 on RhAl2O3. Journal of Catalysis, 1981. 70(2): p. 449-450.
22. K. K. Bando, K. Soga, K. Kunimori, and H. Arakawa, Effect of Li additive on CO2 hydrogenation reactivity of zeolite supported Rh catalysts. Applied Catalysis A: General, 1998. 175(1-2): p. 67-81.
23. T. Iizuka, Y. Tanaka, and K. Tanabe, Hydrogenation of CO and CO2 over rhodium catalysts supported on various metal oxides. Journal of Catalysis, 1982. 76(1): p. 1-8.
24. M. F.H. van Tol, A. Gielbert, and B. E. Nieuwenhuys, The adsorption and dissociation of CO2 on Rh. Applied Surface Science, 1993. 67(1-4): p. 166-178.
25. S. C. Chuang, J. G. Goodwin Jr, and I. Wender, The effect of alkali promotion on CO hydrogenation over Rh TiO2. Journal of Catalysis, 1985. 95(2): p. 435-446.
26. D. Yu-Hua, C. De-An, and T. Khi-Rui, Promoter action of rare earth oxides in rhodium/silica catalysts for the conversion of syngas to ethanol. Applied Catalysis, 1987. 35(1): p. 77-92.
27. A. Egbebi, V. Schwartz, S. H. Overbury, and J. J. Spivey, Effect of Li Promoter on titania-supported Rh catalyst for ethanol formation from CO hydrogenation. Catalysis Today, 2010. 149(1-2): p. 91-97.
28. S. F. Zaman and K. J. Smith, Synthesis gas conversion over a Rh-K — MoP/SiO2 catalyst. Catalysis Today, 2011. 171(1): p. 266-274.
29. W. Chen, Y. Ding, X. Song, T. Wang, and H. Luo, Promotion effect of support calcination on ethanol production from CO hydrogenation over Rh/Fe/Al2O3 catalysts. Applied Catalysis A: General, 2011. 407(1-2): p. 231-237.
30. G. Chen, C. Y. Guo, Z. Huang, and G. Yuan, Synthesis of ethanol from syngas over iron-promoted Rh immobilized on modified SBA-15 molecular sieve: Effect of iron loading. Chemical Engineering Research and Design, 2011. 89(3): p. 249-253.
31. J. Hu, Y. Wang, C. Cao, D. C. Elliott, D. J. Stevens, and J. F. White, Conversion of biomass-derived syngas to alcohols and C2 oxygenates using supported Rh catalysts in a microchannel reactor. Catalysis Today, 2007. 120(1): p. 90-95.
32. X. Song, Y. Ding, W. Chen, W. Dong, Y. Pei, J. Zang, L. Yan, and Y. Lu, Bimetal modified ordered mesoporous carbon as a support of Rh catalyst for ethanol synthesis from syngas. Catalysis Communications, 2012. 19: p. 100-104.
33. V. R. Surisetty, A. K. Dalai, and J. Kozinski, Alkali-promoted trimetallic Co-Rh-Mo sulfide catalysts for higher alcohols synthesis from synthesis gas: Comparison of MWCNT and activated carbon supports. Industrial and Engineering Chemistry Research, 2010. 49(15): p. 6956-6963.
34. H. Yin, Y. Ding, H. Luo, D. He, W. Chen, Z. Ao, and L. Lin, A Kinetic Study of Selective Hydrogenation of Carbon Monoxide to C2 Oxygenates on Rh-Mn-Li-Fe/SiO2 Catalyst. Journal of Natural Gas Chemistry, 2003. 12(4): p. 233-236.
35. N. D. Subramanian, J. Gao, X. Mo, J. G. Goodwin Jr, W. Torres, and J. J. Spivey, La and/or v oxide promoted Rh/SiO2 catalysts: Effect of temperature, H2/CO ratio, space velocity, and pressure on ethanol selectivity from syngas. Journal of Catalysis, 2010. 272(2): p. 204-209.
36. Y. Liu, K. Murata, M. Inaba, I. Takahara, and K. Okabe, Synthesis of ethanol from syngas over Rh/Ce 1-xZr xO2 catalysts. Catalysis Today, 2011. 164(1): p. 308-314.
37. H. Y. Luo, W. Zhang, H. W. Zhou, S. Y. Huang, P. Z. Lin, Y. J. Ding, and L. W. Lin, A study of Rh-Sm-V/SiO2 catalysts for the preparation of C2-oxygenates from syngas. Applied Catalysis A: General, 2001. 214(2):
p. 161-166.
38. G. Prieto, P. Concepcion, A. Martinez, and E. Mendoza, New insights into the role of the electronic properties of oxide promoters in Rh-catalyzed selective synthesis of oxygenates from synthesis gas. Journal of Catalysis, 2011. 280(2): p. 274-288.
39. T. Iizuka, Y. Tanaka, and K. Tanabe, Hydrogenation of carbon monoxide and carbon dioxide over supported rhodium catalysts. Journal of Molecular Catalysis, 1982. 17(2-3): p. 381-389.
40. F. Solymosi, I. Tombacz, and M. Kocsis, Hydrogenation of CO on supported Rh catalysts. Journal of Catalysis, 1982. 75(1): p. 78-93.
41. S. H. Chai, J. Y. Howe, X. Wang, M. Kidder, V. Schwartz, M. L. Golden,
S. H. Overbury, S. Dai, and D. E. Jiang, Graphitic mesoporous carbon as a support of promoted Rh catalysts for hydrogenation of carbon monoxide to ethanol. Carbon, 2012. 50(4): p. 1574-1582.
42. Y. Huang, W. Deng, E. Guo, P. W. Chung, S. Chen, B. G. Trewyn, R. C. Brown, and V. S.Y. Lin, Mesoporous Silica Nanoparticle-Stabilized and Manganese-Modified Rhodium Nanoparticles as Catalysts for Highly Selective Synthesis of Ethanol and Acetaldehyde from Syngas. ChemCatChem, 2012. 4(5): p. 674-680.
43. S. Gangwal. Catalytic conversion of syngas to alcohols. 2008.
44. K. J. Smith and R. B. Anderson, Higher alcohol synthesis over promoted Cu/ZnO catalysts. Canadian Journal of Chemical Engineering, 1983. 61(1): p. 40-45.
45. J. G. Nunan, R. G. Herman, and K. Klier, Higher alcohol and oxygenate synthesis over Cs/Cu/ZnO/M2O3 (M Al, Cr) catalysts. Journal of Catalysis, 1989. 116(1): p. 222-229.
46. G. A. Vedage, P. B. Himelfarb, G. W. Simmons, and K. Klier. Alkali — promoted copper-zinc oxide catalysts for low alcohol synthesis. 1985.
47. N. Tien-Thao, M. Hassan Zahedi-Niaki, H. Alamdari, and S. Kaliaguine, Effect of alkali additives over nanocrystalline Co-Cu — based perovskites as catalysts for higher-alcohol synthesis. Journal of Catalysis, 2007. 245(2): p. 348-357.
48. P. Courty, D. Durand, E. Freund, and A. Sugier, C1-C6 alcohols from synthesis gas on copper-cobalt catalysts. Journal of Molecular Catalysis, 1982. 17(2-3): p. 241-254.
49. E. Iglesia, Carbon-carbon bond formation pathways in CO hydrogenation to higher alcohols. Journal of Catalysis, 1999. 188(1): p. 125-131.
50. S. Goodarznia and K. J. Smith, Properties of alkali-promoted Cu-MgO catalysts and their activity for methanol decomposition and C2-oxygenate formation. Journal of Molecular Catalysis A: Chemical, 2010. 320(1-2): p. 1-13.
51. G. Yang, X. San, N. Jiang, Y. Tanaka, X. Li, Q. Jin, K. Tao, F. Meng, and N. Tsubaki, A new method of ethanol synthesis from dimethyl ether and syngas in a sequential dual bed reactor with the modified zeolite and Cu/ZnO catalysts. Catalysis Today, 2011. 164(1): p. 425-428.
52. N. D. Subramanian, G. Balaji, C. S.S. R. Kumar, and J. J. Spivey, Development of cobalt-copper nanoparticles as catalysts for higher alcohol synthesis from syngas. Catalysis Today, 2009. 147(2): p. 100-106.
53. M. Gupta and J. J. Spivey, Electrodeposited Cu-ZnO and Mn-Cu-ZnO nanowire/tube catalysts for higher alcohols from syngas. Catalysis Today, 2009. 147(2): p. 126-132.
54. S. A. Hedrick, S. S.C. Chuang, A. Pant, and A. G. Dastidar, Activity and selectivity of Group VIII, alkali-promoted Mn-Ni, and Mo-based catalysts for C2+ oxygenate synthesis from the CO hydrogenation and CO/H2/C2H4 reactions. Catalysis Today, 2000. 55(3): p. 247-257.
55. T. Inui, Highly effective conversion of carbon dioxide to valuable compounds on composite catalysts. Catalysis Today, 1996. 29(1-4): p. 329-337.
56. T. Inui and T. Yamamoto, Effective synthesis of ethanol from CO2 on polyfunctional composite catalysts. Catalysis Today, 1998. 45(1-4): p. 209-214.
57. T. Yamamoto and T. Inui, Highly effective synthesis of ethanol from CO2 on Fe, Cu-based novel catalysts, 1998. p. 513-516.
58. S. N. Khadzhiev, A. Y. Krylova, A. S. Lyadov, and M. V. Kulikova, Formation of alcohols on nanosized iron catalysts under Fischer- Tropsch synthesis conditions. Petroleum Chemistry, 2012. 52(4): p. 240-244.
59. T. Tatsumi, A. Muramatsu, T. Fukunaga, and H. o. Tominaga, Effects of Mo precursors on the activity of alkali-promoted Mo catalysts for alcohol synthesis from COH2. Polyhedron, 1986. 5(1-2): p. 257-260.
60. T. Tatsumi, A. Muramatsu, and H. o. Tominaga, Influence of support and potassium on CO hydrogenation catalyzed by molybdenum. Applied Catalysis, 1986. 27(1): p. 69-82.
61. T. Tatsumi, a. Muramatsu, and H. o. Tominaga, Importance of sequence
of impregnation in the activity development of alkali-promoted mo catalysts for alcohol synthesis from COH2. Journal of Catalysis, 1986. 101(2): p. 553-556. 2
62. M. Xiang, D. Li, H. Xiao, J. Zhang, H. Qi, W. Li, B. Zhong, and Y. Sun, Synthesis of higher alcohols from syngas over Fischer-Tropsch elements modified K/^-Mo2C catalysts. Fuel, 2008. 87(4-5): p. 599-603.
63. Y. Yang, Y. Wang, S. Liu, Q. Song, Z. Xie, and Z. Gao, Mo-Co-K Sulfide-Based Catalysts Promoted by Rare Earth Salts for Selective Synthesis of Ethanol and Mixed Alcohols from Syngas. Chinese Journal of Catalysis, 2007. 28(12): p. 1028-1030.
64. X. Ma, G. Lin, and H. Zhang, Co-Mo-K Sulfide-Based Catalyst Promoted by Multiwalled Carbon Nanotubes for Higher Alcohol Synthesis from Syngas. Chinese Journal of Catalysis, 2006. 27(11): p. 1019-1027.
65. E. C. Alyea, D. He, and J. Wang, Alcohol synthesis from syngas: I. Performance of alkali-promoted Ni-Mo(MOVS) catalysts. Applied Catalysis A: General, 1993. 104(1): p. 77-85.
66. G.-z. Bian, L. Fan, Y.-l. Fu, and K. Fujimoto, High temperature calcined K-MoO3/y-Al2O3 catalysts for mixed alcohols synthesis from syngas: Effects of Mo loadings. Applied Catalysis A: General, 1998. 170(2): p. 255-268.
67. R. Stevens, Dow Chemical Company, assignee. Process forproducing alcohols from synthesis gas. patent Nov. 21., 1989: United States.
68. S. J. G Prieto, Martinez A, Sanz JL, Caraballo J, Arjona R, Abengoa Bioenergias Nuevas Tecnologias S. A, assigneee. Method for obtaining a multimetallic sulfureous catalyst and use thereof in a method for producing higher alcohols by catalytic conversion of synthesis gas. Spanish Patent. International publication number: ; 2011 March, 2011, Abengoa Bioenergias Nuevas Tecnologias.
69. A. L. Villanueva Perales, C. Reyes Valle, P. Ollero, and A. Gomez-Barea, Technoeconomic assessment of ethanol production via thermochemical conversion of biomass by entrained flow gasification. Energy, 2011. 36(7): p. 4097-4108.