Carbon molecular sieve air separation

By far the most fully developed application for carbon molecular sieves is in the separation of small gas molecules. A large number of patents describe claims for materials and processes that include carbon-based sieves. Separations that have been accomplished include oxygen and nitrogen, hydrogen and coke gases, methane and carbon dioxide, methane and xenon, ethylene and ethane, propylene and propane. A number of companies in Europe and the United States have recently offered commercial systems for the separation of nitrogen from air. A review of the use of carbon molecular sieves in separation technology is well beyond the scope of this article and the interested reader is referred to recent reviews and references sited therein (12,18.). ... 

KURASEP [Kuraray Separation] A process for separating nitrogen from air by a variant of the PSA process, using carbon molecular sieve as the adsorbent. Developed by Kuraray Chemical Company. 

Suggested method) Alternatively air drawn through a cartridge packed with carbon molecular sieve (0.5 g) cartridge heated at 350°C under He purge analyte transported to the front of a precooled GC column, temperature programmed cumene separated on the column and determined by a PID, FID, or a mass spectrometer recommended air flow rate 0.5 L/min sample volume 50 L. 

Air separation G Carbon molecular sieve Kinetic Pressure swing... 

Villar-Rodil S, Martfnez-Alonso A, and Tascdn JMD. Carbon molecular sieves for air separation from Nomex aramid fibers. J. Colloid Interface Sci., 2002 254(2) 414-416. 

Porous carbonaceous materials are important in many application areas because of their remarkable properties, such as high surface areas, chemical inertness, and good mechanical stability. Carbon molecular sieves that are amorphous and microporous are commercially important for the separation of nitrogen from air, and activated carbons with a wide pore size distribution are also useful adsorbents for various applications. 

Carbon molecular sieve (CMS) is useful in air separation processes because of its ability to selectively discriminate on the basis of molecular size and hence adsorb the smaller oxygen molecule over nitrogen. The difference in the adsorption kinetics of various gases allows the separation of gas mixtures into pure components using pressure swing adsorption (PSA). 

Reid, C.R., and Thomas K.M., Adsorption of Gases on a Carbon Molecular Sieve Used for Air Separation Linear Adsorptives as Probes for Kinetic Selectivity, Langmuir, 15, 3206 (1999). 

Figure 22.4 Air separation by carbon molecular sieve (CMS) (a) uptakes of O2 and Nj from air on a CMS sample, (b) schematic drawing of a Nj pressure swing adsorption (PSA) system, (c) performance of a Nj PSA process.

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