Carbon dioxide separation from nitrogen

Carbon dioxide separation from nitrogen using Y-type zeolite membranes... 

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. 

Cadmium(II) transport, over Hg(II) and Zn(II). 102-104 Carbon dioxide facilitated transport, 111 separated from nitrogen in ILMs, 146,150 Carbon monoxide facilitated transport, 112 reversible binding, 30-32 Carboxylate ionophore antibiotics, metal ion transport, 86 Carrier molecule effect on solute flux, 4 function in facilitated transport, 124 Carrier-facilitated transport—... 

Other examples of buffer gas selectivity include the resolution of arginine from phenylalanine in carbon dioxide but not in nitrogen the separation of lorazepam from diazepam in both helium and carbon dioxide but not in argon and nitrogen " the resolution of carbohydrate isomers such as methyl-P-D-mannopyranoside from methyl-a-D-mannopyranoside in carbon dioxide but not nitrogen and the resolution of heroin from THC (tetrahydrocannabinol) using nitrous oxide as the buffer gas in a commercial IMS instrument. ... 

MFl has been extensively studied in zeolite membranes preparation due to its pore size suitable for several industrially important separations." " Using MFl supported membranes it was demonstrated that the CO2/N2 separation factor increases with CO2 feed composition because of the higher CO2 adsorption on the zeolite wall, which consequently limits the N2 transport in zeolitic channels." The selectivity of this gas species reaehes the value of 20 at 180 °C when the carbon dioxide composition is higher than 60% in the feed. Other researchers using membranes with the same topology found the same effect of the CO2 feed concentration on its separation from nitrogen." ... 

Initiators, usually from 0.02 to 2.0 wt % of the monomer of organic peroxides or azo compounds, are dissolved in the reaction solvents and fed separately to the kettie. Since oxygen is often an inhibitor of acryUc polymerizations, its presence is undesirable. When the polymerization is carried out below reflux temperatures, low oxygen levels are obtained by an initial purge with an inert gas such as carbon dioxide or nitrogen. A blanket of the inert gas is then maintained over the polymerization mixture. The duration of the polymerization is usually 24 h (95). 

The separation of nitrogen from natural gas reHes on the differences between the boiling points of nitrogen (77.4 K) and methane (91.7 K) and involves the cryogenic distillation of a feed stream that has been preconditioned to very low levels of carbon dioxide, water vapor, and other constituents that would form soHds at the low processing temperatures. 

The ethylene oxide recovered in the desorber contains some carbon dioxide, nitrogen, aldehydes, and traces of ethylene and ethane. In the stripper the light gases are separated overhead and vented, and the partially purified ethylene oxide is sent from the bottom of the stripper to the mid-section of a final refining column. The ethylene oxide from the refining section should have a purity of >99.5 mol %. The final product is usually stored as a Hquid under an inert atmosphere. 

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. 

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