Chemical and technical aspects of propene oxide production via hydrogen peroxide (HPPO process)

Industrial and Engineering Chemistry Research

Volumn 52, Issue 3, 2013, Pages 1168-1178

  Russo, V ^a   Tesser, R ^a   Santacesaria, E ^a   Di Serio, M ^a  

^a UNIVERSITY OF NAPLES FEDERICO II   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

KINETIC ASPECTS; PRODUCTION TECHNOLOGY; PROPENE OXIDE; SCIENTIFIC KNOWLEDGE; STATE OF THE ART; TECHNICAL ASPECTS; TITANIUM SILICALITE-1; TS-1 CATALYSTS;

CHEMICAL PLANTS; HYDROGEN PEROXIDE; PATENTS AND INVENTIONS; PROPYLENE; SILICATE MINERALS; TITANIUM;

TITANIUM OXIDES;

EID: 84872908714     PISSN: 08885885     EISSN: 15205045     Source Type: Journal    
DOI: 10.1021/ie3023862     Document Type: Review

References (122)

1. Nijhuis, T. A.; Makkee, M.; Moulijn, J. A.; Weckhuysen, B. M. The Production of Propene Oxide: Catalytic Processes and Recent Developments Ind. Eng. Chem. Res. 2006, 45 (10) 3447-3459
2. Bassler, P.; Weidenbach, M.; Goebbel, H. The new HPPO Process for Propylene Oxide: From Joint Development to worldscale Production Chem. Eng. Trans. 2010, 21, 571-576
3. Ishino, M. Development of New Propylene Oxide Process. 16th Saudi Arabia-Japan Joint Symposium; Dhahran, Saudi Arabia, November 5-6, 2006.
4. Lee, W. S.; Akatay, M. C.; Stach, E. A.; Ribeiro, F. H.; Delgass, W. N. Reproducible preparation of Au/TS-1 with high reaction rate for gas phase epoxidation of propylene J. Catal. 2012, 287, 178-189
5. 2 over Au/Ti-MWW catalysts Pure Appl. Chem. 2012, 84 (3) 561-578
6. Zheng, X.; Zhang, Q.; Guo, Y.; Zhan, W.; Guo, Y.; Wang, Y.; Lu, G. Epoxidation of propylene by molecular oxygen over supported Ag-Cu bimetallic catalysts with low Ag loading J. Mol. Catal A: Chem. 2012, 357, 106-111
7. Pulido, A.; Concepción, P.; Boronat, M.; Corma, A. Aerobic epoxidation of propene over silver (111) and (100) facet catalysts J. Catal. 2012, 292, 138-147
8. Duma, V.; Hönicke, D. Gas Phase Epoxidation of Propene by Nitrous Oxide over Silica-Supported Iron Oxide Catalysts J. Catal. 2000, 191, 93-104
9. Thömmes, T.; Gräf, I.; Reitzmann, A.; Kraushaar-Czarnetzki, B. Catalytic Vapor Phase Epoxidation of Propene with Nitrous Oxide as an Oxidant: Investigations on Catalyst Composition and Reaction Conditions Ind. Eng. Chem. Res. 2010, 49, 2624-2637
10. Lines, E. L.; Fairbrother, R. J.; Herbst, J. A. Catalytic epoxidation of alkylene compounds. US 4157346, Olin Corporation; 1979.
11. Rameswaran, M.; Cochran, R. N. Epoxidation process. US 5081267, Arco Chemical Technology, L.P.; 1992.
12. Zajacek, J. G.; Pa, D.; Crocco, G. L. Integrated process for epoxide production. US 5214168, Arco Chemical Technology, L.P.; 1993.
13. http://www.sumitomo-chem.co.jp/english/rd/report/theses/docs/ 20060100-ely.pdf (accessed Jan 2013).
14. Prescher., G.; Schreyer, G.; Weiberg, O.; Wirthwein, R.; Waldmann, H.; Seifert, H.; Schwerdtel, W.; Swodenk, W. Process for the preparation of propylene oxide. US 4137242, Bayer Aktiengesellschaft, Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler; 1979.
15. Prescher., G.; Schreyer, G.; Weiberg, O.; Wirthwein, R.; Waldmann, H.; Seifert, H.; Schwerdtel, W.; Swodenk, W. Process for the preparation of propylene oxide. US 4113747,. Bayer Aktiengesellschaft, Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler; 1978.
16. Weissermel, K.;; Arpe, H.-J. Industrielle Organische Chemie; Wiley: New York, 1994; p 295.
17. Saxton, R. J.; Zajecek, J. G.; Crocco, G. L. Epoxidation process and catalyst therefore. US 5374747, Arco Chemical Technology, L.P.; 1994.
18. Saxton, R. J.; Zajecek, J. G.; Crocco, G. L. Epoxidation process. US 5412122, Arco Chemical Technology, L.P.; 1995.
19. Saxton, R. J.; Zajecek, J. G.; Crocco, G. L. Epoxidation process. US 5684170, Arco Chemical Technology, L.P.; 1997.
20. Buchler, J.; Schmidt, M.; Prescher, G. Method for the catalytic epoxidation of olefins with hydrogen peroxide. US 4973718, Degussa Aktiengesellschaft; 1990.
21. Clerici, M. G. TS-1 and Propylene Oxide, 20 Years Later Erdöl, Erdgas, Kohle 2006, 122 (6) OG77-OG82
22. Weissermel, K.; Arpe, H. J. Industrial Organic Chemistry, third completely revised ed.; Wiley: New York, 1997; p 273.
23. Taramasso, M.; Perego, G.; Notari, B. Preparation of porous crystalline synthetic material comprised of silicon and titanium oxides. US 4410501, Snamprogetti S.p.A.; 1983.
24. Neri, C.; Anfossi, B.; Esposito, A.; Buonomo, F. Process for the epoxidation of olefinic compounds. IT 22608, ANIC S.p.A.; 1982.
25. Neri, C.; Anfossi, B.; Esposito, A.; Buonomo, F. Process for the epoxidation of olefinic compounds. EP 100119, ANIC S.p.A.; 1986.
26. Clerici, M. G.; Bellussi, G.; Romano, U. Synthesis of Propylene Oxide from Propylene and Hydrogen Peroxide Catalyzed by Titanium Silicalite J. Catal. 1991, 129, 159-167
27. Clerici, M. G.; Ingallina, P. Epoxidation of lower olefins with Hydrogen-Peroxide and Titanium Silicalite J. Catal. 1993, 140, 71-83
28. http://corporate.evonik.com/en/media/archive/pages/news-details.aspx? newsid=15734 (accessed Jan 2013).
29. Short, P. L. BASF, Dow Open Novel Propylene Oxide Plant Chem. Eng. News 2009, 87 (11) 21
30. EPA, The Presidential Green Chemistry Challenge Awards Program: Summary of 2010 Award Entries and Recipients. http://www.epa.gov/greenchemistry (accessed Jan 2013).
31. http://corporate.evonik.com/en/media/search/Pages/news-details.aspx? newsid=26719 (accessed Jan 2013).
32. http://www.dow.com/polyurethane/news/2012/20120104a.htm (accessed Jan 2013).
33. Nexant Chemsystems PERP Program; Propylene Oxide, Process Technology; 2009; PERP07/08-6.
34. http://www.ihs.com/products/chemical/planning/ceh/propylene-oxide.aspx (accessed Jan 2013).
35. Shin, S. B.; Chadwick, D. Kinetics of Heterogeneous Catalytic Epoxidation of Propene with Hydrogen Peroxide over Titanium Silicalite (TS-1) Ind. Eng. Chem. Res. 2010, 49, 8125-8134
36. Wang, Q.; Wang, L.; Chen, J.; Wu, Y.; Mi, Z. Deactivation and regeneration of titanium silicalite catalyst for epoxidation of propylene J. Mol. Catal. A: Chem. 2007, 273, 73-80
37. To, J.; Sherwood, P.; Sokol, A. A.; Bush, I. J.; Richard, C.; Catlow, A.; van Dam, H. J. J.; French, S. A.; Guest, M. F. QM/MM modelling of the TS-1 catalyst using HPCx J. Mater. Chem. 2006, 16, 1919-1926
38. 3) and Comparison with Ultraviolet-Visible and IR Results Phys. Chem. 1994, 98 (15) 4125-4132
39. Neri, C.; Anfossi, B.; Esposito, A.; Buonomo, F. Process for the epoxidation of olefinic compounds. US 4833260, ANIC S.p.A.; 1989.
40. Van der Pol, A. J. H. P.; Van Hooff, J. H. C. Parameters Affecting the Synthesis of Titanium Silicalite-1 Appl. Catal. A: Gen. 1992, 92 (2) 93-111
41. Van der Pol, A. J. H. P.; Verduyn, A. J.; Van Hooff, J. H. C. Why Are Some Titanium Silicalite-1 Samples Active and Others Not Appl. Catal. A: Gen. 1992, 92 (2) 113-130
42. Tatsumi, T.; Nakamura, M.; Yuasa, K.; Tominaga, H. Shape selectivity as a function of pore size in epoxidation of alkenes with supported titanium catalysts Catal. Lett. 1991, 10, 259-262
43. Perego, C.; Carati, A.; Ingallina, P.; Mantegaza, M. A.; Bellussi, G. Production of titanium containing molecular sieves and their application in catalysis Appl. Catal. A: Gen. 2001, 221, 63-72
44. Carati, A.; Flego, C.; Berti, D.; Millini, R.; Stocchi, B.; Perego, C. Influence of synthesis media on the TS-1 Characteristics Stud. Surf. Sci. Catal. 1999, 125, 45-52
45. Millini, R.; Previde Massara, E.; Perego, G.; Bellussi, G. Framework composition of titanium silicalite-1 J. Catal. 1992, 137, 497-503
46. Scarano, D.; Zecchina, A.; Bordiga, S.; Geobaldo, F.; Spoto, G.; Petrini, G.; Leofanti, G.; Padovan, M.; Tozzola, G. Fourier-transform infrared and Raman spectra of pure and Al-, B-, Ti- and Fe-substituted silicalites: stretching-mode region J. Chem. Soc., Faraday Trans. 1993, 89, 4123
47. Geobaldo, F.; Bordiga, S.; Zecchina, A.; Giamello, E.; Leofanti, G.; Petrini, G. DRS UV-Vis and EPR spectroscopy of hydroperoxo and superoxo complexes in titanium silicalite Catal. Lett. 1992, 16, 109-115
48. Park, S.; Cho, K. M.; Youn, M. H.; Seo, J. G.; Jung, J. C.; Baeck, S. H.; Kim, T. J.; Chung, Y. M.; Oh, S. H.; Song, I. K. Direct Epoxidation of Propylene with Hydrogen Peroxide over TS-1 Catalysts: Effect of Hydrophobicity of the Catalysts Catal. Commun. 2008, 9 (15) 2485-2488
49. Fan, W. B.; Duan, R. G.; Yokoi, T.; Wu, P.; Kubota, Y.; Tatsumi, T. Synthesis, Crystallization Mechanism, and Catalytic Properties of Titanium-Rich TS-1 Free of Extraframework Titanium Species J. Am. Chem. Soc. 2008, 130 (31) 10150-10164
50. Belussi, G.; Buonomo, F.; Esposito, A.; Clerici, M. G.; Romano, U.; Notari, B. Catalyst of silicon and titanium having high mechanical strength and a process for its preparation. US 4701428, 1987.
51. Li, G.; Wang, X.; Yan, H.; Liu, Y.; Liu, X. Epoxidation of propylene using supported titanium silicalite catalyst Appl. Catal. A: Gen. 2002, 236, 1-7
52. Clerici, M. G. Oxidation of saturated-hydrocarbons with Hydrogen-Peroxide, catalyzed by Titanium Silicalite Appl. Catal. 1991, 68, 249-261
53. Clerici, M. G. The role of the solvent in TS-1 chemistry: active or passive? An early study revisited Top. Catal. 2001, 15, 257-263
54. 2 catalyzed by Titanium Silicalite-1 J. Catal. 1994, 146, 476-482
55. Clerici, M. G.; Ingallina, P.; Millini, R. Titanium Silicate-1 Peroxides. Proceedings of 9th International Zeolite Conference, Montreal, 1992; Butterworth-Heinemann: Boston, 1993, p 445.
56. Paparatto, G.; Forlin, A.; De Alberti, G.; D'Alosio, R.; Tegon, P. Integrated process for the preparation of epoxides. US 6541648 B1, Polimeri Europa S.r.l.; 2003.
57. Santacesaria, E.; Tesser, R.; Di Serio, M.; Russo, V.; Turco, R. A New Simple Microchannel Device To Test Process Intensification Ind. Eng. Chem. Res. 2011, 50 (5) 2569-2575
58. Teles, J. H.; Rehfinger, A.; Bassler, P.; Wenzel, A. Method for the production of propylene oxide. US 6756503 B2, BASF Aktiengesellschaft; 2004.
59. Thiele, G. F.; Roland, E. Propylene epoxidation with hydrogen peroxide and titanium silicalite catalyst: Activity, deactivation and regeneration of the catalyst J. Mol. Catal. A 1997, 117, 351
60. Crocco, G. L.; Zajacek, J. G. Regeneration of a titanium-containing molecular sieve. US 5741749, Arco Chemical Technology, L.P.; 1998.
61. Catinat, J. P.; Strebelle, M. Process for regeneration of catalysts of titanium silicalite type. US 6169050, Solvay; 2001.
62. Mantegazza, M. A.; Balducci, L.; Rivetti, L. Process for the regeneration of zeolitic catalysts containing titanium. US 6403514, Enichem S.p.A.; 2002.
63. Sun, B.; Wu, W.; Wang, E.; Li, Y.; Zhang, S.; Hu, L. Process for regenerating titanium-containing catalysts. US 2003/0228970, China Petroleum & Chemical Corporation, Research Institute of Petroleum Processing Sinopec; 2003.
64. Han, H. Z.; Carrol, K. M. Heterogeneous catalyst regeneration. US 6872679, 2005. Arco Chemical Technology, L.P.
65. Muller, U.; Teles, J. H.; Wenzel, A.; Harder, W.; Rudolf, P.; Rehfinger, A.; Reiber, N. Method for regenerating a zeolite catalyst. US 6790969, BASF Aktiengesellschaft; 2004.
66. Grosh, G. H.; Muller, U.; Walch, Q.; Reiber, N.; Harder, W. Method for regenerating a zeolitic catalyst. US 6710002, BASF Aktiengesellschaft; 2004.
67. Thiele, G. Method for the regeneration of a catalyst. US 5620935, Degussa Aktiengesellschaft; 1997.
68. Gilbeau, P. Method for regenerating catalysts. WO 9818555, Solvay; 1998.
69. Zuo, Y.; Wang, M.; Song, W.; Wang, X.; Guo, X. Characterization and Catalytic Performance of Deactivated and Regenerated TS-1 Extrudates in a Pilot Plant of Propene Epoxidation Ind. Eng. Chem. Res. 2012, 51 (32) 10586-10594
70. Carrol, K. M.; Morales, H. E.; Han, Y. Z. Heterogeneous catalyst regeneration. US 5916835, Arco Chemical Technology, L.P.; 1999.
71. Chang, T. Process for epoxidation of propylene. WO 9901445, Lyondell Chemical Technology; 1999.
72. Chang, T. Process for regenerating epoxidation catalysts. EP 1190770, Lyondell Chemical Technology; 2002.
73. Thiele, G. Process for the production of epoxides from olefins. US 5675026, Degussa Aktiengesellschaft; 1997.
74. 2 with titanium silicalite Chem. Commun. 1996, 1133-1134
75. Sinclair, P. E.; Catlow, C. R. A. Computational and EXAFS study of the nature of the Ti(IV) active sites in mesoporous titanosilicate catalysts J. Phys. Chem. B 1997, 101 (21) 4232-4237
76. Liang, X.; Mi, Z.; Wu, Y.; Wang, L.; Xing, E. Kinetics of epoxidation of propilene over TS-1 in isopropanol React. Kinet. Catal. Lett. 2003, 80 (2) 207-215
77. Haas, T.; Hofen, W.; Sauer, J.; Thiele, G. P rocess for the epoxidation of olefins. US 6600055 B2, Degussa AG, Uhde GmbH; 2003.
78. Haas, T.; Hofen, W.; Pilz, S.; Thiele, G.; Woell, W. Process for the epoxidation of olefins. WO 02/085874 A1, Degussa AG, Uhde GmbH; 2002.
79. Hofen, W.; Thiele, G. Process for the epoxidation of olefins. WO 03/016296 A2, Degussa AG, Uhde GmbH; 2003.
80. Haas, T.; Hofen, W.; Thiele, G.; Pilz, S.; Woell, W. Process for the epoxidation of olefins. US 6608219 B2, Degussa AG, Uhde GmbH; 2003.
81. Corma, A.; Esteve, P.; Martinez, A. Solvent effects during the oxidation of olefins and alcohols with hydrogen peroxide on Ti-beta catalyst: The influence of the hydrophilicity-hydrophobicity of the zeolite J. Catal. 1996, 161 (1) 11-19
82. Van der Wall, J. C.; Van Bekkum, H. Zeolite titanium beta: A versatile epoxidation catalyst. Solvent effects J. Mol. Catal. A 1997, 124, 137
83. Liu, X. W.; Wang, X. S.; Guo, X. W.; Li, G. Effect of solvent on propylene epoxidation over TS-1 catalyst Catal. Today 2004, 93, 505
84. Jappar, N.; Xia, Q. H.; Tatsumi, T. Oxidation activity of Ti-beta synthesized by a dry-gel conversion method J. Catal. 1998, 180, 132
85. Miyano, Y.; Fukuchi, K. Henry's Constants of Propane, Propene, Trans-2-butene and 1,3-Butadiene in Methanol at 255-320 K Fluid Phase Equilib. 2004, 226, 183-187
86. Perry, R. H.; Green, D. W. Perry's Chemical Engineers' Handbook; McGraw-Hill: New York, 2007.
87. Crocco, G. L.; Zajacek, J. G. Process for titanium silicalite-catalyzed epoxidation. US 5646314, ARCO Chemical Technology, L.P.; 1997.
88. Grey, R. A. Epoxidation process. US 6037484, Arco Chemical Technology, L.P.; 2000.
89. Thiele, G. Process for the preparation of epoxides from olefins. US 6372924 B2, Degussa-Huls AG; 2002.
90. Haas, T.; Brasse, C.; Stochniol, G.; Hofen, W.; Wöll, W.; Thiele, G. US 6838572 B2, Degussa AG, Uhde GmbH; 2005.
91. Haas, T.; Hofen, W.; Wöll, W.; Brasse, C.; Stochniol, G.; Ullrich, N. Process for the epoxidation of olefins. US 7169945 B2, Degussa AG, Uhde GmbH; 2007.
92. Paparatto, G.; Forlin, A.; De Alberti, G.; D'Alosio, R.; Tegon, P. Integrated process for the preparation of olefin oxides. US 6888013 B2, Polimeri Europa S.p.A.; 2005.
93. Arca, V.; Buzzoni, R.; Furlan, P. Process for the preparation of olefinic epoxides. EP0930308 B1, Dow Global Technologies Inc; 1998.
94. Clerici, M. G.; Romano, U. Process for the epoxidation of olefinic compounds and catalysts used therein. US4824976, Eniricerche, S.p.A., Enichem Sintesi, S.p.A.; 1988.
95. Clerici, M. G.; Ingallina, P. Process for producing olefin oxides. US5221795, Eniricerche, S.p.A., Enichem Sintesi, S.p.A.; 1993.
96. Clerici, M. G.; Ingallina, P. Process for oxidizing organic compounds. US5252758, Eniricerche, S.p.A., Enichem Sintesi, S.p.A.; 1992.
97. Crocco, G. L.; Zajacek, J. G. Regeneration of a titanium-containing molecular sieve. US5753576, ARCO Chemical Technology, L.P.; 1995.
98. Catinat, J. P.; Strebelle, M. Method for making an oxirane. US6380407, Solvay; 2002.
99. Paparatto, G.; D'Aloisio, R.; De Alberti, G.; Furlan, P.; Arca, V.; Buzzoni, R.; Meda, L. Catalyst, process for the production of hydrogen peroxide and its use in oxidation processes. US6284213, Enichem S.p.A.; 1999.
100. Muller, U.; Brocker, F. J.; Grosch, G. H.; Putter, H.; Schulz, M.; Rieber, N.; Harder, W. Gauze catalyst based on titanium or vanadium zeolites and inert gauze fabrics for accelerating oxidation reactions. US6106797, BASF Aktiengesellschaft; 2000.
101. Bassler, P.; Harder, W.; Resch, P.; Rieber, N.; Ruppel, W.; Teles, J. H.; Walch, A.; Wenzel, A.; Zehner, P. Method for reacting an organic compound with a hydroperoxide. US6479680, BASF Aktiengesellschaft; 2002.
102. Grosch, G. H.; Mller, U.; Walch, A.; Rieber, N.; Fischer, M.; Quaiser, S.; Harder, W.; Eller, K.; Bassler, P.; Wenzel, A.; Kaibel, G.; Stammer, A.; Henkelmann, J.; Battcher, A.; Teles, J. H.; Schulz, M.; Treiber, G. Method for oxidizing an organic compound containing at least one C-C double bond. US6518441, BASF Aktiengesellschaft; 2003.
103. Schindler, G. P.; Walsdorff, C.; Korner, R.; Gobbel, H. G. Process for producing propylene oxide. US 2007/0004926 A1, BASF Aktiengesellschaft, The Dow Chemical Company; 2007.
104. Haas, T.; Hofen, W.; Thiele, G.; Pilz, S.; Woell, W. Process for the epoxidation of olefins. US6608219, Degussa AG, Uhde GmbH; 2002.
105. Catinat, J. P.; Strebelle, M. Method for making an oxirane. US6429322, Solvay; 2002.
106. Strebelle, M. Process for manufacturing an oxirane. US2008/0132718, Solvay; 2008.
107. Catinat, J. P.; Strebelle, M. Process for manufacturing an oxirane. US7323578, Solvay; 2008.
108. Strickler, G. R.; Quarderer, G. J., Jr.; Lindner, J. P. Process of preparing an olefin oxide from olefin and organic hydroperoxide. US 7273941 B2, Dow Global Technologies Inc.; 2007.
109. Jubin, J. C., Jr. Catalytic converter and method for highly exothermic reactions. US 5466836, ARCO Chemical Technology, L.P.; 1995.
110. Ullmann's Encyclopedia of Industrial Chemistry, 5 th ed.; Wiley-VCH: New York, 1999; Vol. 13, 447-456.
111. Samanta, C. Direct synthesis of hydrogen peroxide from hydrogen and oxygen: An overview of recent developments in the process Appl. Catal. A: Gen. 2008, 350, 133-149
112. Santacesaria, E.; Di Serio, M.; Russo, A.; Leone, U.; Velotti, R. Kinetic and catalytic aspects in the hydrogen peroxide production via anthraquinone Chem. Eng. Sci. 1999, 54, 2799-2806
113. http://www.chemicals-technology.com/projects/basf-hppo/ (accessed Jan 2013).
114. Clerici, M. G.; Ingallina, P. Oxidation reactions with in-situ generated oxidants Catal. Today 1998, 41, 351-364
115. Muller, U.; Lingelbach, P.; Bassler, P.; Harder, W.; Eller, K.; Kohl, W.; Kohl, V.; Dembowski, J.; Rieber, N.; Fischer, M. Oxidation catalyst, its preparation and oxidation using the oxidation catalyst. US 5859265, BASF Aktiengesellschaft; 1999.
116. Bowman, G. R.; Womack, L. J.; Clark, W. H. Process for the direct oxidation of olefins to olefin oxides. WO 98/00413 A1, The Dow Chemical Company; 1998.
117. Kaminsky, M. P.; Grey, R. A. Direct epoxidation process using a mixed catalyst system. US 7671222, Lyondell Chemical Technology, L. P.; 2010.
118. Romano, U.; Occhiello, E.; Paludetto, R. Integrated Process for the production of olefin oxides. WO 02/085875 A1, Polimeri Europa S.p.A.; 2002.
119. Gobbel, H. G.; Bassler, P.; Teles, J. H.; Rudolf, P.; Müller, U.; Forlin, A.; Schultz, M.; Weidenbach, M. A process for epoxidizing propene. WO 2007/074101 A1, BASF SE, The DOW Chemical Company; 2007.
120. Gobbel, H. G.; Schultz, H.; Schultz, P.; Petrascu, R.; Schultz, M.; Weidenbach, M. Separation of propylene oxide from a mixture comprising propylene oxide and methanol. US 2006/0009648 A1, BASF Aktiengesellschaft, The Dow Chemical Company; 2006.
121. http://www.knak.jp/big/evonik-hppo.htm (accessed Jan 2013).
122. http://www.uhde.eu/fileadmin/documents/brochures/uhde-brochures-pdf-en- 10000032.pdf (accessed Jan 2013).