Method of nitric acid formation using a catalytic solution
US6284212A · kind A · utility
Inventor
Key dates
| Filing date | Nov 10, 1998 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Nov 10, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/26
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Methods for concentrating nitric acid in aqueous solution are known wherein reduction of some nitric acid initially present in the solution oxidizes nitric oxide obtained for example from exhaust vapors of heterogneously catalytically combusted ammonia, but gas effluence and solution dilution associated with such methods have necessitated recirculation piping to convey fluids of varying content to and fro between separated reactor units adapted to conduct different sub-reactions subsumed under an overall process which is inherently unworkable in batch mode operations. Herein the invention features joint execution of all necessary reactions in a single reactive solution body, and resorts to a liquid phase homogeneous catalysis involving nitrate and/or nitrosyl ions, in a process which is effective whether in continuous or batch processing. Problems with low gas solubilities and diffusivities are resolved when a high enough Hatta Number is attained due to fast free radical-ion reactions in the vicinity of gas-liquid interfaces provided by gas-filled bubbles. Reaction control means include varying the proportion and/or concentration of sulfuric acid blended with nitric acid to constit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.