NAMS 2002 Workshop - ICOM 2008

Inorganic Membranes I – 2
Tuesday July 15, 3:00 PM-3:30 PM, Moloka’i
Synthesis and Characterization of SAPO-34 Zeolite Crystals and
Membranes Employing Crystal Growth Inhibitors
S. Venna, University of Louisville, Louisville, Kentucky, USA
M. Carreon (Speaker), University of Louisville, Louisville, Kentucky, USA -
macarr15@louisville.edu
The separation of CO2 from natural gas is an important environmental and
energy issue. Improved membranes for separating CO2 from CH4 would reduce
considerably the costs of natural gas purification. Since polymeric membranes
have limitations based on operating temperature and high pressures that cause
their degradation, small pore zeolites such as SAPO-34 with pore size ~0.38 nm
are preferred to effectively separate CO2/CH4 mixtures. Here, we present the
hydrothermal synthesis of SAPO- 34 employing crystal growth inhibitors (CGI)
such as polyoxyethylene lauryl ether, polyethylene glycol, and methylene blue for
both crystal and membrane preparation. The incorporation of these CGI during
gel synthesis resulted in 1-2.5 ¼m seeds with narrow crystal size distribution and
unprecedented high surface areas (up to 700 m2/g). CO2 and CH4 adsorption
isotherms indicated improved CO2/CH4 selectivities for the crystals prepared with
CGI. Membranes were grown by in-situ crystallization on ±-alumina porous tubes
and evaluated for CO2/CH4 gas separation.