Method of oxidation using nitric acid
US7692041B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2007 |
| Grant date | Apr 6, 2010 |
| Priority date | — |
| Expiry date | Aug 6, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A controlled nitric acid process employing oxygen and nitric acid as co-oxidants is used to oxidize organic compounds subject to nitric acid oxidation, to their corresponding carboxylic acids. Oxidation of some carbohydrates by this process can produce one or more of their corresponding acid forms. The process is carried out at moderate temperatures, typically in the range of 20° C. to 45° C. in a closed reactor, with oxygen gas being introduced into the reaction chamber as needed in order to sustain the reaction. Computer controlled reactors allow for careful and reproducible control of reaction parameters. Nitric acid can be recovered by a distillation/evaporation process, or by diffusion dialysis, the aqueous solution made basic with inorganic hydroxide, and the residual inorganic nitrate removed using a filtration (nanofiltration) device. The method eliminates issues of thermal control of the oxidation, release of nitrogen into the atmosphere, and post-reaction difficulties in the removal of nitric acid and inorganic nitrates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.