Hydrogen production from steam reforming of acetic acid over Cu–Zn supported calcium aluminate

Abstract

Hydrogen can be produced by catalytic steam reforming (CSR) of biomass-derived oil. Typically bio oil contains 12–14% acetic acid; therefore, this acid was chosen as model compound for reforming of biooil with the help of a Cu–Zn/Ca–Al catalyst for high yield of H2 with low CH4 and CO content. Calcium aluminate support was prepared by solid–solid reaction at 1350°C. X-ray diffraction indicates 12CaO·7Al2O3 as major, CaAl4O7 and Ca5Al6O14 as minor phases. Cu and Zn were loaded onto the support by wet-impregnation at 10 and 1wt.%, respectively. The catalysts were characterized by Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy TEM and the surface area for both support and Cu–Zn were 10.5 and 5.8m2/g, respectively. CSR was carried out in a tubular fixed bed reactor (I.D.=19mm) at temperatures between 600 and 800°C with 3-g loadings and (H2O/acetic acid) wt. ratio of 9:1. Significantly high (80%) yield of hydrogen was obtained over Cu–Zn/Ca–Al catalyst, as incorporation of Zn enhanced the H2 yield by reducing deactivation of the catalyst. The coke formation on the support (Ca-12/Al-7) surface was negligible due to the presence of excess oxygen in the 12CaO·7Al2O3 phase.