Amino-Functionalized SAPO-34 Membranes for CO2/CH4 and CO2/N2 Separation

• Published in: Langmuir Vol. 27; no. 6; pp. 2888 - 2894
• Main Authors: Venna, Surendar R, Carreon, Moises A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.03.2011
• Subjects: Amines - chemistry; Carbon Dioxide - isolation & purification; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Materials: Nano-and Mesostructured Materials, Polymers, Gels, Liquid Crystals, Composites; Membranes; Methane - isolation & purification; Models, Molecular; Nitrogen - isolation & purification; Particle Size; Surface Properties; Zeolites - chemical synthesis; Zeolites - chemistry; Methane; Infrared spectrometry; Incorporation; Organic cation; Gas mixture; Separation; Amino group; Membrane; Photoelectron spectrometry; Hexylamine; X ray; Selectivity
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la105037n

SAPO-34 seeds and membranes were functionalized with several organic amino cations, such as ethylenediamine, hexylamine, and octylamine. The successful incorporation of the amino groups in the SAPO-34 framework was confirmed by Fourier transform infrared (FTIR) and X-ray photoemission (XPS) spectroscopies. The resultant SAPO-34 membranes were evaluated for the separation of CO2/CH4 and CO2/N2 gas mixtures. CO2/CH4 selectivities as high as 245, with CO2 permeances of ∼5 × 10−7 mol m−2 s−1 Pa−1 at 295K and 138 kPa, were observed for an optimum ethylenediamine-functionalized membrane, which corresponded to a ∼40% increase in the separation index, as compared to the nonfunctionalized SAPO-34 membrane. Similarly, the CO2/N2 separation performance was highly improved with the incorporation of ethylenediamine. CO2/N2 selectivities as high as 39, with CO2 permeances of ∼2.1 × 10−7 mol m−2 s−1 Pa−1 at 295K and 138 kPa, were observed for an optimum ethylenediamine-functionalized membrane, which corresponded to a ∼167% increase in the separation index, as compared to the nonfunctionalized SAPO-34 membrane.