EXTRACTION OF DEUTERIUM FROM AMMONIA SYNTHESIS GAS

摘要

1,273,462. Deuteration of amines. ATOMIC ENERGY OF CANADA Ltd. 18 March, 1970 [8 April, 1969], No. 13022/70. Heading C2C. [Also in Division C1] A process of extracting deuterium from a gas stream also containing hydrogen and nitrogen e.g. ammonia synthesis gas stream, comprises using two upper cold towers C U1 , C U2 the gas stream only passing through cold tower C U1 , where it loses deuterium to an exchange liquid 2. The exchange liquid 2 is divided into two streams 21, 211 which recombine beneath C U2 to pass through lower cold tower C L and hot tower H and to respectively take and give deuterium from and to a hydrogen stream passing in path 3, 3b, 3a. Deuterium concentrated streams 2c, 3c are tapped off. Any nitrogen which passes into the exchange liquid in C U1 , is stripped in stripper 5 by countercurrently contacting with a stream of hydrogen 4 tapped from the main stream and which then flows to the synthesis gas. The hydrogen is replenished by stream 5. Alternatively the nitrogen may be removed by flashing or by using a different hydrogen source. The exchange liquid is an amine e.g. having up to five carbon atoms/molecule, water or any mixture thereof with ammonia and may contain a catalyst e.g. potassium amide. Amines specified are 1,2-diaminoethane and 1,2- and 1,3-diaminopropanes.