Washing system for nitroaromatic compounds
US9012701B2 · kind B2 · utility
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11References
35Claims
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Key dates
| Filing date | Aug 18, 2009 |
| Grant date | Apr 21, 2015 |
| Priority date | — |
| Expiry date | Dec 8, 2030 |
Classification
- Technology area (CPC —)General
Abstract
A method of removing alkalinity and salt from a nitroaromatic product downstream of water washing to remove mineral acids and alkaline washing to remove salts of organic acids, comprises washing the product stream with an acidic aqueous solution, prior to the step of removing excess organic reactant, by steam stripping or distillation. Acid removed from the stripper or column is recycled back for use in the acidic washing. The acidic washing is done instead of the neutral washing step of the prior art. It removes residual salt and decreases the level of entrained colloidal water in the nitroaromatic product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.