Hydrogen production by the catalytic steam reforming of methanol: Part 2: Kinetics of methanol decomposition using girdler G66B catalyst

Abstract

The rate of catalytic decomposition of methanol in the presence of steam has been studied using a commercial Girdler G66B CuO-ZnO low temperature shift catalyst from IS0 to 250°C at atmospheric pressure. The mole ratio of steam to methanol was varied from 0 to 1.5, and the feed rates covered the range from 300 to 1400 kg s/mol. The data were successfully correlated using a simple reaction network involving CH30H, HzO, CO and Hz. A conventional reversible reaction rate equation was used which included a resistance term for site blockage by a CO surface complex. The methanol decomposition rate constants showed satisfactory Arrhenius behaviour with an activation energy of about 96 kJ/mole. On a Ctudit la vitesse de dCcomposition catalytique du mCthanol en prksence de vapeur d'eau, en employant un catalyseur commercial de la rkaction du gaz h I'eau B basse tempkrature (150 ii 250°C B la pression atmosphCrique) Girdler G66B CuO-ZnO. On a fait varier le rapport molaire vapeur d'eau/mCthanol de 0 a 1,s et les vitesses d'alimentation ont variC de 300 a 1400 kg s/mol. On a obtenu une bonne corrklation des rksultats obtenus, en employant une sCrie simple d'ttapes rkactionnelles impliquant CH,OH, H 2 0 , CO et Hz. On a employ6 une Cquation classique pour la vitesse des rkactions rkversibles qui inclut un terme de rksistance pour le blocage des sites par un complexe de surface du CO. Les constantes de vitesse de decomposition du mCthanol suivent bien la loi d'ArrhCnius avec une Cnergie d'activation d'environ 96 kJ/mole. n Part 1 of this paper (Amphlett et al., 1981), the

Redox Behavior of Copper Oxide/Zinc Oxide Catalysts in the Steam Reforming of Methanol Studied by in Situ X-Ray Diffraction and Absorption Spectroscopy

“…Structural investigations of the copper phase under reduction conditions based on XRD have been reported by Himelfarb et al (17) and Vong et al (18). Himelfarb et al and Porta et al ( 19) described an intermediary Cu 2 O phase, whereas this phase was not observed by Vong et al However, the detection of Cu 2 O is based on ex situ investigations which may not represent the "real" state of the Cu phase under reduction conditions. Als-Nielsen et.…”

“…Cu/ZnO catalysts can be used to produce hydrogen by steam reforming of methanol with high selectivity and activity (1,2). Thus, methanol often is considered as an alternative "automotive" fuel and could serve as a potential hydrogen source for fuel cell applications (3).…”

“…al. reported on an in situ detection of Cu 2 O by time-resolved QEXAFS without further anal yzing the growth kinetics of this phase ( 20). Reitz et.…”

Production of hydrogen from methanol over Cu/ZnO catalysts promoted by ZrO2 and Al2O3

“…In the literature, copper-based catalysts have received considerable attention for production of H 2 by SRM [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Recent papers have discussed the POM reaction [22][23][24], as well as the combined process for production of H 2 [25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

SMSI-like behavior and Ni promotion effect on NiZnAl catalysts in steam reforming of methanol

“…Cu-based catalysts have been the most extensively studied SRM catalysts, and have been shown to be active as binary or ternary systems, in the presence of ZnO and Al 2 O 3 [5][6][7][8], and/or zirconia [9][10][11][12][13], ceria [14], and manganese oxide [15]. However, instability of this catalyst under fuel processing conditions at elevated temperature has been a recurring problem.…”