Ammoniaksyntesekonvertere og ammoniaksynteseenheder, i hvilke syntesegassen (nitrogen og hydrogen) trækkes ud af en ammoniak/hydrogen højtryksudvekslingskolonne, og den syntetiserede ammoniak returneres til den nævnte kolonne.
Ammonia synthesis converters or ammonia synthesis units, in which the synthesis gas (nitrogen and hydrogen) is withdrawn from an ammonia/hydrogen high-pressure exchange column and the synthesized ammonia is returned to said column.