Res. Chem. Intermed.
, Vol. 34, Nos 5–7, pp. 467–474 (2008)
Koninklijke Brill NV, Leiden, 2008.
Also available online - www.brill.nl/rci
Separation of CO
by a DDR membrane
JOHAN VAN DEN BERGH
, WEIDONG ZHU
, FREEK KAPTEIJN
JACOB A. MOULIJN
, KENJI YAJIMA
, KUNIO NAKAYAMA
and SHUICHI YOSHIDA
Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136,
2628 BL Delft, The Netherlands
New Products Development Center, NGK Insulators, Ltd., 2-56 Suda-cho, Mizuho-ku,
Nagoya 467-8530, Japan
Received 11 September 2006; accepted 27 December 2006
Abstract—The permeation of CO
and their binary mixtures through a DDR membrane has
been investigated over a wide range of temperatures and pressures. The synthesized DDR membrane
exhibits a high permeance and maintains a very high selectivity for CO
. At a total pressure of
101 kPa, the highest selectivity for CO
in a 50:50 feed mixture was found to be over 4000 at 225 K.
This is ascribed to the higher adsorption afﬁnity, as well as to the higher mobility for the smaller CO
molecules in the zeolite, preventing the bypassing of the CH
through the membrane. An engineering
model, based on the generalized Maxwell–Stefan equations, has been used to interpret the transport
phenomena in the membrane. The feasibility of DDR membranes as applied to CO
natural gas or biogas is anticipated.
Keywords: DDR membrane; CO
removal; permeation; zeolite.
Maxwell–Stefan diffusivity component i (m
diffusivity activation energy (J/mol)
enthalpy of adsorption (J/mol)
adsorption equilibrium constant component i (Pa
ﬂux of component i through membrane (mol s
partial pressure component i (Pa)
Present address: Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004,
Zhejiang, P. R. China.
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