Washcoating Copper Catalyst with Zirconia Sol onto Microchannel Reactor for Steam Reforming of Methanol

• Main Authors: Cheng-Yu Pan, 潘承煜
• Other Authors: Kuen-Song Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/60438109841889964588

碩士 === 元智大學 === 化學工程與材料科學學系 === 97 === Steam reforming of methanol (SRM) is a reaction which may produce hydrogen for fuel cell application. In this study, micro-channel reactors (MCR) for SRM reaction are under developing. The micro-channel reactor generally has advantages of low pressure drop, low probability of explosion, and fast in thermal and mass transfer. The heart of micro-channel reactors is active plates which were fabricated in the literature by washcoating powders of active catalyst onto stainless steel plates (SSP) with metal oxide sols. The present study intended to mix SRM catalyst (Cu/ZnO/Al2O3) with a commercial ZrO2 sol into slurries and brush them onto SSP for active plates. The binding strength of slurries on SSP was estimated by fraction of weight loss (FL) in an ultrasonic vibration test. The performance of assembles MCR was estimated from temperature required for 95% methanol conversion (T95) in SRM reaction. Experimentally, FL was found low at pH ≦ 5 but increased drastically on increasing the basicity of prepared slurries. Viscosity characterization revealed that the FL increase was resulted from a formation of gel upon storage. Therefore, the slurry prepared in the acidic condition is necessary to exhibit the adhesive ability. Unfortunately, a significant dissolution of catalyst was found in slurries with pH ≦ 5 and active plates coated in such condition required a high reaction temperature of T95 ~ 300oC from the SRM test. In order to improve SRM activity of MCR, a none-acidic binder was prepared by dissolving zirconia alkoxide in 1-propanol. The SRM test revealed that active plates coated by this binder indeed exhibited much better catalytic activity than those coated with the commercial ZrO2 sol. Consequently, T95 was significantly decreased to 240oC.