Nitrogen production using membranes

General Procedure A (esterification of amine) 1 A 50 wt% methanol solution of methyl acrylate (17 g, 0.2 mol) was added to the methanolic solution of Jeffamine T-3000 (100 g, 0.033 mol). This reaction was allowed to stir at room temperature under a nitrogen atmosphere for 48 h. The reaction was then heated to 50°C for 1 h. methanol and excess methyl aerylate were removed by rotary evaporator. After the dialysis using membrane filter with a MWCO of 3 D in methanol, the product was obtained as a yellow viscous oil (6 g, 98%). H NMR (CDCl, 5),... 

Capillary membrane modules very similar to those used for nitrogen production are also used to produce dry air. The water molecule is smaller and more condensable than oxygen and nitrogen, so many membrane materials are available with water/air selectivities of several hundred. 

Membrane configurations used in gas separations include flat sheet, spiral wound and hollow fiber designs. A detailed discussion of the various designs and their attributes is given in Chapter 3. The configuration used in commercial nitrogen production is the hollow fiber design. 

Nitrogen was used as a sweep gas and its effect on hydrogen production was studied. As the sweep gas flow increases, the hydrogen production is unproved, as the permeation of hydrogen through the membranes is enhanced. 

Several methods of helium purification from nitrogen are used. The washing the concentrate with liquid hydrocarbons, particularly with propane, is based on abnormal helium solubility in liquid propane. There are also continued intensive studies and implementation works on helium purification using membranes [19,20]. The purification by washing does not, however give a product of a sufficient purity and efficiency of the diffusive separation on membranes is still too low. For these reasons, the basic process of helium denitrification is adsorption on solid adsorbents, mainly on active carbon. 

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