Separations of carbon dioxide from nitrogen

Kusakabe K, Kuroda T, and Morooka S. Separation of carbon dioxide from nitrogen using ion-exchanged faujasite-type zeolite membranes formed on porous support tubes. J Membr Sci 1998 148(l) 13-23. 

L. Liu, A. Chakma, X. Feng, Preparation of hollow fiber poly(ether block amide)/polysulfone composite membranes for separation of carbon dioxide from nitrogen, Chem. Eng. J., 105,... 

Figure 2.7 Robeson plot illustrating the tradeoff between selectivity (a, ALPHA) and permeability (P) for the separation of carbon dioxide from nitrogen with polymer membranes [47]. The circles indicate all literature data considered relevant. The upper bound line is an empirical judgment of the outermost range of reliable data. Reprinted from Robeson IM. The upper bound revisited. J Membr Sci 2008 320(1—2) 390—400. Copyright (2008), with permission from Elsevier.

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. 

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... 

Recently, Ekiner and Simmons reported on membranes for the production of oxygen-enriched air, nitrogen-enriched air, for the separation of carbon dioxide from hydrocarbons, and the separation of hydrogen from various petrochemical and oil refining streams [82]. The membranes are made with blends of PAs, Pis and PI-PAs. They show high strength, chemical resistance, and are suitable for high pressure and temperature applications. 

The phenylarsenous oxide solution is most conveniently prepared from phenyl-dichloroarsine, which is readily available from phenylarsonic acid. Crude phenylarsonic aoid (404 g., 2 moles) is dissolved in concentrated hydrochlorio aoid (700 cc.) and treated with a stream of sulfur dioxide. From time to time a trace of potassium iodide solution is added (0.2-0.5 g. of potassium iodide is usually sufficient to complete the reduction). When the hydrochloric acid solution becomes clear and the addition of more potassium iodide does not form a permanent cloudiness the reaction is complete. Two to three hours is usually required for this reaction. The crude phenyldichloroarsine separates as a heavy oil. The oil is removed, dried with calcium chloride, and fractionally distilled at reduced pressure in a stream of carbon dioxide or nitrogen. The nearly colorless product boiling at 140-143°/40 mm. is collected it weighs 334-400 g. (75-90%), depending on the purity of the original phenylarsonic acid. 

Apphcations of SLM, ELM, and BOHLM configurations for gas separations are reviewed. These are production of oxygen enriched air carbon dioxide separation from various gas streams, including carbon dioxide from nitrogen, unsaturated hydrocarbons, and sugars from aqueous solutions olefin, sulfur dioxide separation from various gas streams hydrogen production and separation. Author presents state-of-the-art information for both the novice and practitioner. 

Fig. 7.7. Chromatogram of separation of benzene (1) and pyridine (2) [142]. The larger peaks corre- ond to the concentration of carbon dioxide and nitrogen (oxidation products) in the carrier gas the small peak (3) relates to the concentration in the carrier gas of nitrogen formed from pyridine.

Post-combustion capture involves separating the carbon dioxide from other exhaust gases after combustion of the fossil fuel. Post-combustion capture systems are similar to those that already remove pollutants such as particulates, sulfur oxides, and nitrogen oxides from many power plants. 

A perfectly mixed gas permeation module is separating carbon dioxide from nitrogen using a poly (2,6 - dimethylphenylene oxide) membrane. The feed is 20.0 mol% carbon dioxide and is at 25 °C. The module has 50.0 m of membrane. The module is operated with a retentate pressure of 5.5 atm and a permeate pressure of 1.01 atm. We desire a permeate that is 40.0 mol% carbon dioxide. The... 

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