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US 5,955,050 AGranted
No.sub.x destruction in sulphuric acid
AssigneeMarsulex Inc.
InventorDrew John Drexler
Life of this patent
Estimating the term…
Abstract
A process is provided for the destruction of nitrogen oxides in sulfuric acid by adding a reducing agent, such as hydrazine, sulfamic acid or urea, and an oxidizing agent, such as hydrogen peroxide or persulfates, into the nitrogen oxides contaminated sulfuric acid. The nitrogen oxides contaminated sulfuric acid is treated at a temperature between 15.degree. C. and 100.degree. C.
Claims13
A process for the removal NO.sub.x (oxides of nitrogen) from sulphuric acid comprising treating an NO.sub.x -containing sulphuric acid of acid strength greater than 75% at a temperature of between 15.degree. C. and 100.degree. C. by:
- i) mixing a reducing agent selected from the group consisting of hydrazine, sulfamic acid and urea with said sulphuric acid in an amount of between 1 and 2 times the stoichiometric amount necessary to reduce all of the NO.sub.x species, expressed in equivalents of nitrylsulphuric acid, to nitrogen or to a volatile oxide of nitrogen;
- and
- ii) subsequently adding an oxidizing agent selected from the group consisting of hydrogen peroxide and persulfates to said sulphuric acid in an amount of between 1 and 2 times the stoichiometric amount necessary to oxidize all of the NO.sub.x species, expressed in equivalents of nitrososulphuric acid, to nitrylsulphuric acid.
Dependencies are inferred from the claim text.