Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-III-13PREPARATION AND PERFORMANCE OF WALL TUBE REACTORIN THE REFORMING OF METHANOLToshimitsu Suzuki, Fumihiko Nakao, Na-oki Ikenaga, and Takanori MiyakeIntroductionDepartment of Chemical Engineering, Kansai University, Suita Osaka 564-8680FAX: +81-6-6368-8869, E-mail: tsuzuki@ipcku.kansai-u.ac.jpThe steam-reforming reaction of methanol (SRM) has attracted much attention as apromising method for a compact hydrogen production system for a fuel cell. Due to the largeendothermicity of this type of reaction, 1 use of a wall tube reactor is proposed. 2 The formationof a porous alumina thin layer on an aluminum plate by anodic oxidation is an establishedtechnique. 3 However, until now, there have been no reports on the anodic oxidation of theinner wall of a thin aluminum tube. This paper provides a first report on the anodic oxidationof a thin aluminum tube and its application to the SMR.ExperimentalAnodic oxidation of the inner wall of the pretreated tube was carried out by inserting aTeflon-coated 0.56-mm copper wire, with the Teflon coat partially stripped off, into the tube,and this was used as a cathode electrode (fig. 1). The anodic oxidation was carried out byfollowing the literature. 4 Pre-oxidation wasachieved by circulating the electrolyte (0.6M oxalic acid) inside the tube at a flow rateCopper cathodePower source−of 25 ml/min, and an electric potential of30 V DC was applied between the cathode+2 mmand aluminum tube. After the firstElectrolytePorous aluminaCirculatingoxidation, the inner surface was exposed toa mixture of 6.0 wt% H 3 PO 4 and 1.8 wt%H 2 CrO 4 at 60 °C for 15 min to remove theoxidized alumina layer The second anodicoxidation was carried out under the samealuminum tubeFig. 1. New method for anodic oxidation of aluminumtube of inner diameter of 2.0 mm.condition as above for 1-9 h. The obtained tube was washed with distilled water, and calcined at350 °C under flowing air.ResultsFigure 2 shows scanning electron micrograph (SEM) images of the cross section and theinner surface of the oxidized aluminum tube. Relatively uniform pores sized 20 to 30 nm wereobserved, and the surface area (BET, N 2 ) of oxidized inner wall was ca. 20 m 2 / m-tube.115