NAMS 2002 Workshop - ICOM 2008

Gas Separation IV – 7
Thursday July 17, 12:00 PM-12:30 PM, Kaua’i
Novel Semi-IPN Carbon Membranes Fabricated by a Low-Temperature
Pyrolysis for C3H6/C3H8 Separation
M. Chng (Speaker), National University of Singapore, Singapore
Y. Xiao, National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore- chencts@nus.edu.sg
M. Toriida, Mitsui Chemicals, Inc., Japan
S. Tamai, Mitsui Chemicals, Inc., Japan
One of the most important processes in petrochemical industries and petroleum
refining is the separation of hydrocarbon mixtures with close boiling points, such
as olefins and paraffins. At present, the separation of olefin and paraffin mixture
is mostly carried out using low temperature distillation which requires enormous
capital and large energy consumption. Membrane technology, which has the
advantages of both low cost and reduced energy consumption as compared to
the conventional separation processes, is potentially an attractive option,
although it is the largest challenge to find suitable membrane materials with both
high permeability and propylene/propane separation performance. Carbon
membranes are chemically strong materials and have tailorable gas transport
properties with high separation performance for gas pairs with very similar
molecular dimensions such as C3H6/C3H8 through a molecular sieving
mechanism. We will report a carbon membrane derived from Poly (aryl ether
ketone). Interpenetrating polymer networks (IPNs) are a unique polymer blend,
which is defined as a combination of two or more polymers in the form of network
with at least one of which is crosslinked in the immediate presence of the other.
IPNs successfully created polymeric nano-scale blends having new extraordinary
properties. Carbon membranes display superior permeabilities- selectivity
combination than polymeric membranes. Low pyrolysis temperature not only
keeps the membrane flexibility and toughness, but also tends to avoid excessive
closure of the main selective ultramicropores and hence increase the
permeability and selectivity. As a result, the newly developed carbon membranes
show a significantly enhanced olefin/paraffin separation performance due to the
molecular sieving mechanism.