GB1273463A - Deuterium-hydrogen exchange using diamines - Google Patents

Abstract

1,273,463. Deuteration of amines. ATOMIC ENERGY OF CANADA Ltd. 23 March, 1970 [8 April, 1969], No. 13928/70. Heading C2C. [Also in Division Cl] A mono- or bi-thermal process of concentrating deuterium in a gaseous, hydrogen containing stream, e.g. ammonia synthesis gas, comprises passing the stream through an exchange liquid comprising a diamine having up to five carbon atoms per molecule, e.g. 1,2-diaminoethane, 1,2- diaminopropane or 1,3-diaminopropane, or a mixture of the diamine with a liquid selected from the group consisting of another similar diamine, a monoamine and ammonia. The exchange liquid may contain a catalyst e.g. an alkyl amide of lithium, sodium, potassium, rubidium or cesium. In the bi-thermal process shown in Fig. 1 a stream 1 of nitrogen and hydrogen and a stream 2 of exchange liquid countercurrently engage in upper cold tower Cu where deuterium passes to the exchange liquid. A portion 1a of the emergent gaseous stream passes to an ammonia synthesis plant, whereas a portion 1b is fed upwardly through hot tower H and lower cold tower C L before joining the feed stream 1. In the lower cold tower C L deuterium passes from the gaseous stream 1c to the exchange liquid 2a whereas in the hot tower H deuterium passes from the exchange liquid 2b to the gaseous stream 1b Streams 1d and 2d of gas and exchange liquid respectively are taken off from points of highest deuterium concentration. In the monothermal process shown in Fig. 2, ammonia synthesis gas stream 12 passes from exchange tower T to synthesis plant S. A portion of the ammonia product 13 is taken off in stream 14 which then passes upwardly through exchange tower E. The emergent ammonia stream 14a is then cracked at stage C and returned to the exchange tower T. A stream 16a of exchange liquid cycles between the two exchange towers. Deuterium transfers from the synthesis gas to the exchange liquid in the tower T, and from the exchange liquid to the ammonia gas stream 14 in the exchange tower E. Portions 14b and 16b of the gas and exchange liquid are withdrawn.