Membranes separation with

In gas separation with membranes, a gas mixture at an elevated pressure is passed across the surface of a membrane that is selectively permeable to one component of the mixture. The basic process is illustrated in Figure 16.4. Major current applications of gas separation membranes include the separation of hydrogen from nitrogen, argon and methane in ammonia plants the production of nitrogen from ah and the separation of carbon dioxide from methane in natural gas operations. Membrane gas separation is an area of considerable research interest and the number of applications is expanding rapidly. 

It is therefore not surprising that it was only when suitable methods for catalyst separation from the substrates and reaction products of homogeneous catalysis were developed that the importance of this type of process grew. The successful developments (thermal separation or chemical reaction (e. g., [26]), immobilization by means of supports and thus heterogenization (e. g., [44]), phase transfer catalysis [45], biphasic processes (e. g., [46, 47]) or separation with membrane modules [48, 49]) are described in the relevant sections of this book (cf. [50]). 

The ability to separate cells from a high molecular weight extracellular product is one of the touted advantages of using microporous membranes over ultrafiltration membranes. Microporous membranes compete with centrifuges and rotary vacuum filters for this type of recovery. High yield protein/cell separations with membranes, however, have not been well established in the literature. Rejection coefficients for extracellular proteins in bacterial cell broth have been reported to vary widely from 5 to 100% for microporous membranes of 0.1 to 0.6 micron... 

K.W. Boddeker, Liquid Separations with Membranes, An Introduction to Barrier Interference, Springer-Verlag, Berlin, 2008. 

During the 1970s, considerable research and developmental work was devoted to membranes. Many potential applications were identified, but commercialization was slow. In 1977, Monsanto demonstrated its first full scale membrane separator at Texas City, Texas, in a hydrogen/carbon monoxide ratio adjustment application (Burmaster and Carter, 1983). In 1979, Monsanto commercialized its hollow fiber membrane module as the Prism separator. From 1979 to 1982 Prism separators were evaluated in several refinery hydrogen purification applications (Bollinger et al., 1982). The success of these pilot tests established the commercial viability of gas separation with membranes. The first large scale commercial CO2 membrane separation project was the installation of two membrane separation facilities at the Sacroc tertiary oil recovery project in West Texas in 1983. Up to 80 MMscfd of gas has been processed in these facilities (Parro, 1984). 

Figure 1 Gas separation with membrane. The feed mixture flows along the membrane and the feed components diffuse into and through the membrane at different rates. (Reproduced from Ref 36, MDPI AG (Basel, Switzerland) 2012.)...

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