WAVAR WATER VAPOR ADSORPTION REACTOR FOR MARS INSITU RESOURCE UTILIZATION.
"Water is present on Mars as ice in the
polar caps, adsorbed in the regolith, and possibly
in subsurface deposits, but the atmosphere of
Mars is the most highly characterized and
globally distributed water source on the planet.
The desire to utilize this atmospheric water led to
the development of the Water Vapor Adsorption
Reactor (WAVAR).
WAVAR is conceptually very simple.
Martian atmosphere
is brought into the system through a filter by an
axial-flow fan. The filtered atmosphere is passed
over the adsorbent bed where the water vapor is
removed from the flow by the zeolite 3A
molecular sieve. The disk-shaped bed is divided
into sectors by insulative separators. Once a
sector has reached saturation, it is rotated into a
chamber and sealed off from the outside. A
microwave emitter is engaged, heating the
adsorbent bed sector and driving off the water
vapor. The desorbed water vapor is condensed
and piped to storage, where it is available for
utilization by a S/E propellant production plant
or for use by a manned Mars base.
The Water Vapor Adsorption Reactor is
an energy efficient method of extracting water
from the Martian atmosphere.
For the assumed conditions,
(253K, 800 Pa, 0.06% humidity) 2
WAVAR uses 4.9 kW-hr for every kilogram of
water it extracts. In comparison, an optimized
compression-refrigeration cycle operating under
the same conditions requires 70 kW-hr per
kilogram water."
You can read about WAVAR here --->
http://www.lpi.usra.edu/meetings/isru97/PDF/COONS.PDF and here --->
http://ralph.open-aerospace.org/solar/ares/report/sumrep.htm 
