NAMS 2002 Workshop - ICOM 2008

Gas Separation V – 3
Friday July 18, 10:45 AM-11:15 AM, Kaua’i
Kinetic Sorption and Permeation Behavior of Water Vapor in Polymeric
Membranes
H. Sybesma, University of Twente, The Netherlands
J. Potreck, University of Twente, The Netherlands
K. Nymeijer (Speaker), University of Twente, The Netherlands - d.c.nijmeijer@utwente.nl
R. van Marwijk, KEMA, The Netherlands
R. Heijboer, KEMA, The Netherlands
M. Wessling, University of Twente, The Netherlands
Objective
Coal-fired power plants produce electricity and in addition to that large volume
flows of flue gas, which mainly contains N2, O2, CO2 and water vapor, but also
pollutants such as nitric oxides (NOx), sulfur dioxide (SO2), and fly ash. As a
consequence of gas cleaning steps, the temperature of the flue gas decreases
and the gas stream becomes saturated with water vapor. This can easily lead to
condensation of water vapor in the stack of the power plant, which causes
corrosion. To prevent condensation, traditionally reheating of the flue gas is
required, resulting in extra energy consumption and additional costs.
Membrane technology is an attractive technology to remove part of the water
vapor to prevent condensation. The application of membranes for this separation
is especially attractive due to the possibility of re-use of the water and the
additional energy savings.
In the present work we present such a membrane system with extremely high
separation factors and fluxes for the removal of water vapor from flue gasses.
The work combines fundamental understanding of the kinetic sorption and
transport behavior of water vapor in macromolecular structures with more applied
knowledge to show the potential of the developed membranes for industrial flue
gas dehydration [1-3].
Kinetic sorption analysis
An economically viable membrane process for the dehydration of flue gasses
requires membranes with extremely high water vapor fluxes combined with a
very low non-condensable flux. Several materials were investigated and the
results clearly show the superior performance of sulfonated poly(ether ether
ketone) (SPEEK), especially at higher water vapor activities. Sorption isotherms
of water vapour in this glassy polymer were determined experimentally and the