Gas separation membrane-based

Polymer membranes are the most common commercial membranes for separations [1]. They have proven to operate successfully in many gas and liquid separations. For example, polymer membrane-based gas separation processes have undergone a major evolution since the introduction of the first polymer membrane-based industrial hydrogen separation process about two decades ago. The... 

Table 1.1 shows two developing industrial membrane separation processes gas separation with polymer membranes (Chapter 8) and pervaporation (Chapter 9). Gas separation with membranes is the more advanced of the two techniques at least 20 companies worldwide offer industrial, membrane-based gas separation systems for a variety of applications. Only a handful of companies currently offer industrial pervaporation systems. In gas separation, a gas mixture at an elevated pressure is passed across the surface of a membrane that is selectively permeable to one component of the feed mixture the membrane permeate is enriched in this species. The basic process is illustrated in Figure 1.4. Major current applications... 

Koros, W.J. and Fleming, G.K. (1993) Membrane-based gas separation. Journal of Membrane Science, 83, 1. 

The major membrane-based gas separation applications are shown in Table V. The diverse needs of these separations call for a somewhat wider range of membrane properties and module designs than is the case with liquid separations. To reflect this market and technical seg-... 

Koros WJ and Fleming GK. Membrane-based gas separation. Review. J. Membr. Sci. 1993 83 1-80. 

Koros, W. J. "Membrane-Based Gas Separations Data Base and Models for Glassy Polymers", paper presented at Sunriver Membrane Conference, Sunriver, Oregon, September 1983. 

Koros, W. J. "Membrane-based Gas Separations" paper presented at the conference Membrane Technology In the 1980 s Sunriver, Oregon, Sept. 1983. 

Applications of membrane-based gas separation technology tend to fall into three major categories ... 

Membrane-Based Gas Separations, ACS Symposium Series 269. Materials Science of Synthetic Membranes, D. R. Uoyd (Ed.). American Chemical Society, Washington, DC, 1985. 

The study of gas transport in membranes has been actively pursued for over 100 years. This extensive research resulted in the development of good theories on single gas transport in polymers and other membranes. The practical use of membranes to separate gas mixtures is, however, much more recent. One well-known application has been the separation of uranium isotopes for nuclear weapon production. With few exceptions, no new, large scale applications were introduced until the late 1970 s when polymer membranes were developed of sufficient permeability and selectivity to enable their economical industrial use. Since this development is so recent, gas separations by membranes are still less well-known and their use less widespread than other membrane applications such as reverse osmosis, ultrafiltration and microfiltration. In excellent reviews on gas transport in polymers as recent as 1983, no mention was made of the important developments of the last few years. For this reason, this chapter will concentrate on the more recent aspects of gas separation by membranes. Naturally, many of the examples cited will be from our own experience, but the general underlying principles are applicable to many membrane based gas separating systems. 

The key commercial membrane-based gas-separations and suppliers are listed in Table 9 in Part I. The key features of these applications are discussed below. 

The first company to produce a successful membrane-based gas-separation process was Permea, now a division of Air Products, which introduced hollow-fme-fiber polysulfone membranes for the separation of hydrogen from ammonia reactor purge gas in 1980. This application was an immediate success the feed gas was clean and free of condensable components that might damage the membranes, and the value of the recovered hydrogen provided short payback times. Within a few years, many ammonia plants worldwide had installed these units. Several hundred hydrogen-separating systems have now been installed by Permea and its competitors. 

Other membrane-based gas-separation applications that developed in the late 1980s and the 1990s include the separation of carbon dioxide from natural gas, separation of organic vapors from air and nitrogen, and dehydration of air. Table 7.3 lists the major companies involved in the industry and their principal markets. Currently, total industry sales are estimated to be about US 200 million. Of all the industrial membrane-separation processes, gas separation is... 

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