Hybrid Membranes for Selective Carbon Dioxide Separation from Fuel Gas
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- 作者：David Luebke ; Christina Myers ; Henry Pennline
- 刊名：Energy & Fuels
- 出版年：2006
- 出版时间：September 2006
- 年：2006
- 卷：20
- 期：5
- 页码：1906 - 1913
- 全文大小：104K
- 年卷期：v.20,no.5(September 2006)
- ISSN：1520-5029
文摘
The potential of hybrid membranes as a CO2 capture technology for integrated gasification combined cycleapplications was evaluated. Commercial 
-alumina supports were modified with a variety of trichlorosilanesintended to enhance the surface adsorption of CO2. The resulting hybrids were characterized using X-rayphotoelectric spectroscopy and Fourier transform infrared spectroscopy and tested for performance in theseparation of He and CO2. The silanization temperature was determined to be important because membranesfabricated at 273 K had substantially different performance properties than those fabricated at room temperature.Specifically, the permeances of membranes modified with alkyltrichlorosilanes at reduced temperatures were1-2 orders of magnitude higher than those of membranes fabricated at room temperature, and the selectivitiesof these low-temperature silanized membranes were relatively similar to those expected from Knudsen diffusion.Supports modified with silanes containing one of a variety of functionalities were tested for CO2/He selectivity.Membranes modified with 2-acetoxyethyl, 2-carbomethoxyethyl, and 3-aminopropyl groups exhibited CO2selectivity, with the highest values approaching 7 for 2-carbomethoxyethyl-silated membranes at 50 
C.Temperature dependences resulted in selectivity maxima for the 2-acetoxyethyl and 2-carbomethoxyethylmembranes. Mixed-gas selectivities were slightly higher than pure-gas selectivities because of a decrease inHe permeance with a relatively minor reduction in CO2 permeance. Transport in the selective membranes isbelieved to occur by a combination of activated and solution diffusion for He and a combination of activatedand surface diffusion for CO2.
-alumina supports were modified with a variety of trichlorosilanesintended to enhance the surface adsorption of CO2. The resulting hybrids were characterized using X-rayphotoelectric spectroscopy and Fourier transform infrared spectroscopy and tested for performance in theseparation of He and CO2. The silanization temperature was determined to be important because membranesfabricated at 273 K had substantially different performance properties than those fabricated at room temperature.Specifically, the permeances of membranes modified with alkyltrichlorosilanes at reduced temperatures were1-2 orders of magnitude higher than those of membranes fabricated at room temperature, and the selectivitiesof these low-temperature silanized membranes were relatively similar to those expected from Knudsen diffusion.Supports modified with silanes containing one of a variety of functionalities were tested for CO2/He selectivity.Membranes modified with 2-acetoxyethyl, 2-carbomethoxyethyl, and 3-aminopropyl groups exhibited CO2selectivity, with the highest values approaching 7 for 2-carbomethoxyethyl-silated membranes at 50 C.Temperature dependences resulted in selectivity maxima for the 2-acetoxyethyl and 2-carbomethoxyethylmembranes. Mixed-gas selectivities were slightly higher than pure-gas selectivities because of a decrease inHe permeance with a relatively minor reduction in CO2 permeance. Transport in the selective membranes isbelieved to occur by a combination of activated and solution diffusion for He and a combination of activatedand surface diffusion for CO2.