High-temperature parallel screening of catalysts for the oxidative coupling of methane

The oxidative coupling of methane (OCM) was investigated with a specifically designed multi-channel device operating fixed-bed reactors at high temperature and atmospheric pressure. The device allows precise temperature measurement in each channel selected for analysis and possesses a quench cooling unit right after the reaction zone. Analysis is based on a mass spectrometer allowing a time resolution of only 3 s per analysis and 30 s per reactor channel. Successful screening is demonstrated using a reactant feed of O 2 and CH 4 diluted in Ar at flows between 100 and 166 mL/min per reactor channel. As expected, Li/MgO-based catalysts showed good initial performance, but rapid deactivation at 800 °C excludes their use in high-temperature applications. Good C 2 selectivity up to 80% and high yields up to 20% were observed for La/Sr/CaO catalysts. Even more interesting, no decline in performance was observed for those formulations identifying 10% La/20% Sr/CaO as best catalyst in an initial library. Screening of various La and Sr loadings at different operating conditions identified a optimal content of 5-10% for La and 20% for Sr. The exploration of operating conditions showed increasing C 2 productivities with increasing reactant partial pressure, reaching at 800 °C values up to 1.3 × 10 -5 mol (C 2 ) s -1 g(cat) -1 .

[1]  Huanling Song,et al.  Comparative study on oxidation of methane to ethane and ethylene over Na2WO4–Mn/SiO2 catalysts prepared by different methods , 2006 .

[2]  Qiming Zhu,et al.  Low temperature catalysts for oxidative coupling of methane , 1996 .

[3]  Y. S. Lin,et al.  Controlled Oxidative Coupling of Methane by Ionic Conducting Ceramic Membrane , 2002 .

[4]  Y. S. Lin,et al.  Oxygen permeation through fluorite-type bismuth-yttrium-copper oxide membranes , 1997 .

[5]  S. Lacombe,et al.  Oxidative Coupling of Methane over Lanthana Catalysts: II. A Mechanistic Study Using Isotope Transient Kinetics , 1995 .

[6]  Yi Hua Ma,et al.  Oxidative coupling of methane in a modified γ-alumina membrane reactor , 2000 .

[7]  M. Hatano,et al.  The oxidative coupling of methane on lithium nickelate(III) , 1989 .

[8]  C. Au,et al.  An ab initio study of methane activation on lanthanide oxide , 1997 .

[9]  J. Rocha,et al.  Oxidation of Dry Methane on the Surface of Oxygen Ion-Conducting Membranes , 2003 .

[10]  C. Mirodatos,et al.  Oxidative coupling of methane over lanthana catalysts. I: Identification and role of specific active sites , 1995 .

[11]  H. Wan,et al.  The performance and structure of rare earth oxides modified by strontium fluoride for methane oxidative coupling , 1996 .

[12]  J. Ross,et al.  Lithium chemistry of lithium doped magnesium oxide catalysts used in the oxidative coupling of methane , 1990 .

[13]  J. Lunsford,et al.  Gas phase coupling of methyl radicals during the catalytic partial oxidation of methane , 1987 .

[14]  H. Verweij,et al.  Oxidative coupling of methane in a mixed-conducting perovskite membrane reactor , 1995 .

[15]  S. Tsang,et al.  Oxidative coupling of methane over chloride catalysts , 1989 .

[16]  Y. S. Lin,et al.  Catalytic properties of yttria doped bismuth oxide ceramics for oxidative coupling of methane , 1997 .

[17]  C. Mirodatos,et al.  Morphological Aspects of Catalysts for Oxidative Coupling of Methane , 1992 .

[18]  A. Veen,et al.  Influence of oxygen supply rates on performances of catalytic membrane reactors , 2007 .

[19]  Pm Pieter Couwenberg,et al.  The oxidative coupling of methane with cofeeding of ethane , 1994 .

[20]  H. Wan,et al.  Oxidative coupling of methane over BaF2-promoted rare earth oxides with variable valence , 1997 .

[21]  E. Wolf.  Methane Conversion by Oxidative Processes , 1992 .

[22]  A. M. Maitra.  Critical performance evaluation of catalysts and mechanistic implications for oxidative coupling of methane , 1993 .

[23]  M. Baerns,et al.  OCM in a fixed-bed reactor: limits and perspectives , 1994 .

[24]  Zhen Kaiji,et al.  Catalytic oxidative coupling of methane over alkali, alkaline earth and rare earth metal oxides , 1988 .

[25]  Jack H. Lunsford.  The Catalytic Oxidative Coupling of Methane , 1995 .

[26]  Yong Rok Kim,et al.  Effect of altervalent cation-doping on catalytic activity of neodymium sesquioxide for oxidative coupling of methane , 1997 .

[27]  A. Julbe,et al.  Catalytic membrane reactor for oxidative coupling of methane. Part II —Catalytic properties of LaOCl membranes , 1995 .

[28]  H. Wan,et al.  Promoting effect of F- on Sr/La oxide catalysts for the oxidative coupling of methane , 1995 .

[29]  Haihui Wang,et al.  Oxidative coupling of methane in Ba0.5Sr0.5Co0.8Fe0.2O3−δ tubular membrane reactors , 2005 .

[30]  K. Yoon,et al.  Oxidative coupling of methane over sodium-chloride-promoted zirconia supported on sodium-preimpregnated silica , 1997 .

[31]  Claude Mirodatos,et al.  High-throughput gas phase transient reactor for catalytic material characterization and kinetic studies , 2008 .

[32]  Yuehe Lin,et al.  Perovskite-type ceramic membrane: synthesis, oxygen permeation and membrane reactor performance for oxidative coupling of methane , 1998 .

[33]  K. Seshan,et al.  Oxidative coupling of methane over doped Li/MgO catalysts , 1994 .

[34]  K. Otsuka,et al.  Oxidative coupling of methane over ternary metal oxide catalysts consisting of Groups I, III and V elements in the Periodic Table , 1995 .

[35]  Yaping Lu,et al.  Oxygen-permeable dense membrane reactor for the oxidative coupling of methane. , 2000 .

[36]  Y. S. Lin,et al.  Oxidative coupling of methane in dense ceramic membrane reactor with high yields , 2002 .

[37]  Qiming Zhu,et al.  Catalytic contribution of reactor wall materials on oxidative coupling of methane , 1996 .

[38]  J. Rocha,et al.  Characterization of mixed-conducting La2Ni0.9Co0.1O4+δ membranes for dry methane oxidation , 2004 .

[39]  Xuejia Ding,et al.  Investigation of the catalytic performance of MgO/ BaCO3 catalyst for the oxidative coupling of methane , 1994 .

[40]  V. Basevich,et al.  The role of initiation in oxidative coupling of methane , 1995 .

[41]  Zongping Shao,et al.  Performance of a mixed-conducting ceramic membrane reactor with high oxygen permeability for methane conversion , 2001 .

[42]  A. Dalai,et al.  Critical Influence of Mn on Low-Temperature Catalytic Activity of Mn/Na2WO4/SiO2 Catalyst for Oxidative Coupling of Methane , 2002 .

[43]  P. Claus,et al.  Parallel synthesis and fast catalytic testing of catalyst libraries for oxidation reactions , 2000 .

[44]  V. Choudhary,et al.  Oxidative coupling of methane over alkaline earth oxides deposited on commercial support precoated with rare earth oxides , 1999 .

[45]  Kevin J. Smith,et al.  Oxidative coupling of methane over cobalt—magnesium and manganese—magnesium mixed oxide catalysts , 1990 .