Cryogenic nitrogen separation

Cryogenic bearing lubrication, 75 254 Cryogenic distillation, nitrogen separation via, 77 274... 

Depending on volume and purity requirements, nitrogen can be supplied by several different production systems or delivery systems. Figure 1.1 illustrates some of these systems159. Liquid refers to delivery by trucks or in cylinders Permeation refers to a membrane system Adsorption refers to a PSA system and Distillation refers to a cryogenic air separation plant. 

A flowsheet for a plant that produces nitrogen in a cryogenic air separation plant is shown in Figure 1.2150. 

Nitrogen usually is produced by cryogenic air separation, liquefaction of atmospheric air, and removal of the nitrogen by distillation, as described earlier. Noncryogenic adsorption technology, including PSA and VSA systems, economically provides nitrogen for requirements between 4,000 and 30,000 standard cubic feet per hour (SCFH).9... 

Even though the combined production of cryogenic nitrogen and oxygen exceeds the production of any other chemical in the United States, the cryogenic industry does not appear to warrant a separate product line of instruments for diagnostic and control purposes. Low-temperature thermometry is the one exception. The general approach... 

Cryogenic air separation processes combine the principles of refrigeration and distillation in a single process to carry out the separation of oxygen, nitrogen and sometimes argon and other rare gases present in atmospheric air. 

Lokhandwala K. 1997. Memhrane-augmented cryogenic methane/nitrogen separation. US Patent 5,647,227. 

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