公开(公告)号：DE2831941A1

公开(公告)日：1980-02-07

申请号：DE2831941

申请日：1978-07-20

Applicant: BASF AG

Inventor： BLANCK KLAUS DIPL CHEM DR ,  LEUTNER BERND DIPL CHEM DR ,  BACK WOLF-DIETER DIPL ING DR

IPC: C01B17/94

Abstract: The elimination of nitrous acid and/or nitric acid from waste sulphuric acid, partic. that arising from nitration processes, involves treatment of the waste sulphuric acid with monomeric or polymeric cpds. of carbonic, formic, acetic and/or sulphuric acids contg. NH2 gps. (i.e. acid amides), and/or hydroxylamine, and/or treatment with ammonium salts. Treatment is pref. at 30-150 degrees C and 0.5-60 mn. Partic. the cpd. used to treat the waste sulphuric acid is urea or one of its condensn. prods. The cpd. can be added in an excess up to 10% above the stoichiometric amt. required.

公开(公告)号：DE3041324A1

公开(公告)日：1982-06-16

申请号：DE3041324

申请日：1980-11-03

Applicant: BASF AG

Inventor： BLANCK KLAUS DIPL CHEM DR ,  DETHLEFSEN WINFRIED DIPL CHEM ,  JUNGBAUER ANTON DIPL CHEM DR ,  LEUTNER BERND DIPL CHEM DR ,  SCHIER ERNST-JUERGEN DIPL CHEM ,  SCHLIMPER HANS-ULRICH DIPL CHE ,  SCHNEEHAGE HANS DIPL CHEM DR

IPC: C07D251/60 ,  B01D53/86 ,  B01J23/00 ,  B01J23/72 ,  B01J23/745 ,  C01C1/12 ,  C07B61/00 ,  B01D53/36

Abstract: The reaction off-gas from the synthesis of melamine consists, after separating off the melamine, mainly of ammonia and carbon dioxide, with traces of hydrogen cyanide, isocyanic acid, urea and residual melamine. To remove these trace components, the off-gas is passed over a catalyst, containing copper oxide and/or iron oxide, in the presence of steam at from 100 DEG to 500 DEG C.