We have evaluated the long-term stability of activities and physicochemical properties for nickel nanoparticles supported on Mg-promoted γ-Al2O3 (MgAl2O4-Al2O3), α-Al2O3, and multi-wall carbon nanotubes (CNTs) for supercritical water gasification (SCWG) in a continuous flow reactor at 425 °C, 25.2 MPa, using 9 wt.% glycerol as the feed. Ni/CNT achieved the lowest H2 yields but produced consistent carbon gasification efficiencies (CGEs) ∼80% during 48 h of operation at steady state, whereas the CGEs from Ni/α-Al2O3 and Ni/MgAl2O4-Al2O3 decreased to <80% when the gasification was extended to 48 h. Characterization results indicated that CNTs showed stable pore structures and Ni/CNT showed the best dissolution resistance of Ni in SCW. Persistent loss of Al into SCW probably contributed to the deactivation of Al2O3-supported Ni catalyst beds. Results also suggest that enhanced interaction of Ni and the supports may be beneficial for reducing dissolution of Ni in SCW.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Condensed Matter Physics
- Physical and Theoretical Chemistry