NAMS 2002 Workshop - ICOM 2008

Inorganic Membranes III – 4
Friday July 18, 11:15 AM-11:45 AM, O’ahu/Waialua
Micro-structured Inorganic Membrane Reactor
W. Liu (Speaker), Pacific Northwest National Lab, Richland, Washington, USA - wei.liu@pnl.gov
Y. Wang, Pacific Northwest National Lab, Richland, Washington, USA
D. Elliott, Pacific Northwest National Lab, Richland, Washington, USA
X. Li, Pacific Northwest National Lab, Richland, Washington, USA
B. Johnson, Pacific Northwest Naitonal Lab, Richland, Washington, USA
R. Zheng, Pacific Northwest National Lab, Richland, Washington, USA
Many catalytic reactions are limited by mass transfer or thermodynamic
equilibrium. Membranes can be used for in situ regulation of mass transfer rate of
reactants or products during a catalytic reaction process to enhance the
productivity and/or product yield. Inorganic membranes are suitable for
fabrication of membrane reactors due to its high thermal and chemical stability.
However, the conventional inorganic membranes made in a single tube or planar
disk form has low surface area packing density and is associated with challenges
of high cost per unit membrane surface area and low productivity per unit reactor
volume. Micro-structured membrane reactor design concepts and prototypes will
be discussed in this presentation. In the proposed design, small reaction
channels (0.5~3mm) are formed in macro-porous support matrix with the
membrane and/or catalyst layer being deposited on the channel wall. The porous
matrix plus membrane layer allows selective introduction of reactants from the
exterior of the reactor module into the reaction channel or selective withdrawal of
products from the reaction channel to the exterior of the reactor module. The
small channel enables efficient mixing of the reactants inside the channel and
rapid mass transport between the membrane surface and bulk channel fluid. Use
of the small channel also provides high membrane surface area packing density.
Performance benefits of the novel design will be illustrated with two different
types of reaction applications, gas-phase steam reforming for hydrogen
production, gas/liquid multiphase hydrogenation for biomass conversion.