METHOD OF PRODUCING NITRIC ACID Russian patent published in 2020 - IPC C01B21/40 C01C1/04 C01B21/26 C01B3/02 C01B3/38 B01D53/47 B01D53/94 

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. Method of combined synthesis of ammonia and nitric acid involves synthesis of nitric acid, during which an ammonia stream is subjected to oxidation to obtain a gas stream containing nitrogen oxides. Obtained gas stream is subjected to absorption of nitrogen oxides to obtain nitric acid and a first tail gas containing nitrogen and residual nitrogen oxides. Oxides of nitrogen are removed from at least a portion of the first tail gas to produce a second tail gas containing nitrogen and having a lower content of nitrogen oxides than the first tail gas. Synthesis of ammonia is carried out by means of catalytic conversion of make-up gas containing hydrogen and nitrogen in ammonia synthesis circuit. At least part of the second tail gas serves as nitrogen source for make-up gas. At that, another part of the second tail gas is subjected to expansion with performance of work.

EFFECT: invention allows to reduce emission of exhaust gases of nitric acid production into atmosphere and reduce total power consumption of ammonia and nitric acid production processes.

11 cl, 4 dwg, 1 tbl, 1 ex