Separation of supercritical CO2 and ethanol mixtures with an asymmetric polyimide membrane

Semenova, Svetlana I.; Ohya, Haruhiko; Higashijima, Takeshi; Negishi, Youichi

doi:10.1016/0376-7388(92)87078-c

Cited by 43 publications

(11 citation statements)

References 7 publications

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“…In the interest of clarity, this concept is depicted as a two-step process; however, it is important to note that the steps actually occur concurrently. 20 years (Afrane and Chimowitz, 1996;Chiu and Tan, 2001;Higashijima et al, 1994;Kulcke, 2001;Nakamura et al, 1993;Ohya et al, 1993;Sarrade et al, 2001;Semenova et al, 1992b). Much of the emphasis has been on ultrafiltration or nanofiltration membranes, which are either used in dense form or supported by a ceramic support.…”

Section: Introductionmentioning

confidence: 99%

“Sorp‐vection”: An unusual membrane‐based separation

Damle

Koros

2005

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com). A nonstandard membrane process is described that involves highly selective sorption of a compound "A" at a large absolute weight fraction A , coupled with a significant diffusionally induced flux of a second component "B." The flux of B convectively moves A from a dilute external mass fraction relative to component B upstream to an enriched mass fraction downstream. The general form of the process has potential applications involving dilute feeds where current membranes processes perform poorly for such removal as a result of excessive solubility of the smaller component B. The most important IntroductionSeparations of condensables from effluent streams can be achieved by low-temperature condensation or pressure swing adsorption. These technologies have the disadvantage that they are energy intensive and tend to have large footprints. Membranes, on the other hand, are compact, simple to operate, and economical. Development of membranes for separation of condensable components from effluent streams is being pursued and provides a potentially attractive separation avenue (Baker et al., 2002(Baker et al., , 1994(Baker et al., , 1998. If properly supported against mechanical deformation, polymer membranes can be used to separate dilute concentrations of highly condensable bulky components from smaller, less condensable components such as air. The highly condensable nature of heavier and polar hydrocarbons tends to make them sorb easily into rubbery or glassy polymers, whereas highly supercritical components such as N 2 exhibit low sorption uptakes, even at relatively high pressures of 10 bars or so (Mark et al., 1984). On the other hand, for rubbery polymers, the intrinsically higher diffusion coefficient for smaller vs. larger molecules tends to be much less extreme than that in glassy materials. Therefore, rubbery polymers are the preferred materials for such solubility-based separations where the sorption level of the small molecule is sufficiently low. An increasingly important class of systems, however, constitutes a sufficiently high intrinsic sorption coefficient that may prevent effective application of this simple solubility-controlled sorption-diffusion permeation mechanism of separation. This type of application is the focus of this article.Separations involving supercritical carbon dioxide are of great interest, and development of CO 2 technology for use in industrial processing has become a research focal point. Worldwide, billions of pounds of organic solvents are used as processing tools, cleaning agents, and dispersants. Concern for workers' safety and a drive to protect the environment have prompted industrial and academic research efforts to develop acceptable solvent alternatives (DeSimone 1998 and has a broad range of dissolving power, especially in the supercritical region (Kazarian et al., 1999;McHugh and Krukonis, 1986). For the CO 2 to be recycled and reused in processing applications, separation of the CO 2 from bulkier organic solutes wil...

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Section: Introductionmentioning

confidence: 99%

“Sorp‐vection”: An unusual membrane‐based separation

Damle

Koros

2005

AIChE Journal

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“…The initial coupling of membranes with supercritical fluid extraction and fractionations in the 1980s and 1990s was not intended to study the fractionation of product mixtures in SC-CO 2 but to recover excess carbon dioxide for sequestration and recycle (Schell et al 1983;Semenova et al 1992;Hsu & Tan 1993). Probably the first use of membrane technology in supercritical fluid processing of functional food components was by Robinson and Sims (1996), who devised a method employing microporous membranes to increase the fractionation efficiency of flavor and aroma components from fruit berry substrates using critical fluids.…”

Section: Critical Fluids Coupled With Membrane Technologiesmentioning

confidence: 99%

Supercritical Carbon Dioxide and Subcritical Water: Complementary Agents in the Processing of Functional Foods

Srinivas

King

2010

Functional Food Product Development

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“…Semenova et al [4] studied the separation of SC CO 2 and ethanol mixtures with an asymmetric polyimide membrane and obtained a separation factor (α ethanol /CO 2 ) of 8.7. For the separation of SC CO 2 /iso-octane mixtures, a separation factor of 12.8 was obtained by Ohya et al [5].…”

Section: Introductionmentioning

confidence: 98%