Isotope exchange process

1,149,729. Deuterium exchange. HOUILLERES DU BASSIN DU NORD ET DU PAS - DE - CALAIS, COMMISSARIAT A L'ENERGIE ATOMIQUE, L'AIR LIQUIDE SOC. POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE and COMPAGNIE DE CONSTRUCTION MECANIQUE PROCEDES SULZER. 27 July, 1967 [27 July, 1966, 16 June, 1967], No. 34506/67. Heading C1A. In a process for deuterium exchange between NH 3 and H 2 wherein liquid NH 3 is enriched in D by countercurrent contact with gaseous N 2 + H 2 in 2 towers (T 1 and T 2 ) then cracked (at C) to give N 2 + H 2 for passing through T 2 , and the gases from T 1 are synthesized (at S) to give NH 3 for passing to T 1 , product low-D NH 3 being withdrawn after S and high-D NH 3 after T 2 , and N 2 + H 2 feed being introduced between T 1 and T 2 ; T 2 and optionally also T 1 is operated at a pressure at most equal to that of the gases leaving C. Where only T 2 is at a low pressure, the gases may leave C at 50-60 bars, leave T 2 at 40- 50 bars, be compressed to 360-410 bars between T 2 and T 1 , and leave T 1 at 350-400 bars; then after synthesis, the NH 3 is expanded between T 1 and T 2 (Fig. 2). Where T 1 and T 2 are both at a low pressure, the gases may leave T 1 at 30-10 bars and be compressed to 350-400 bars between T 1 and S. Alternatively, T 1 , T 2 and C may each operate at 100 bars and part of the gases leaving T 1 may be synthesized at 100 bars (in S 1 ) and recycled to T 1 , the remainder being compressed to 250-500 bars, synthesized (in S 2 ) and withdrawn (Fig. 4). S 1 and C may operate in heat exchange relationship (Fig. 5). The use of an amide catalyst is referred to.