Abstract: A method for fabricating a distillation column in a remote location away from a permanent manufacturing facility is provided. In one embodiment, the method can include the steps of: forming a plurality of column sections each having a diameter D, each column section comprising a plurality of courses that have been horizontally welded together, wherein each course is comprised of two or more partial shells that have been vertically welded together, wherein each of the two or more partial shells was created by vertically rolling a rectangular plate having a length of at least ( 1 N ? ? · D ) , wherein N is the number of partial shells used to form the course; installing a distributor and packing in each column section to form a plurality of packed column sections; and stacking the plurality of packed column sections to form a column.

Abstract: A process for the separation of a gas mixture containing oxygen and nitrogen, including bringing the mixture into contact in an adsorption zone with a first selective adsorbent for nitrogen of faujasite type exchanged to at least 80% with lithium, in which the Si/Al ratio is lower than 1.5 and a second selective adsorbent for nitrogen of zeolite type exchanged with divalent cations such as the alkaline-earth metal or transition metal cations. The second adsorbent is characterized by a nitrogen adsorptivity C.sub.2 lower than the nitrogen adsorptivity C.sub.1 characterizing the first adsorbent, and an adsorption selectivity for nitrogen in relation to oxygen (1.times.10.sup.5 Pa, 20.degree. C.) higher than or equal to 3.