DIFF Subgroup
C01C 1/0494 Full Title
Ammonia; Compounds thereof > Preparation, or separation of ammonia > Preparation of ammonia by synthesis (preparation or purification of gas mixtures for ammonia synthesis C01B3/025)
C01C 1/0494 Ammonia; Compounds thereof > Preparation, or separation of ammonia > Preparation of ammonia by synthesis (preparation or purification of gas mixtures for ammonia synthesis C01B3/025)