Continuous process for preparing N-phosphonomethyl glycine
AssigneeDow AgroSciences LLC
InventorsDaniel A. Hickman, James W. Ringer
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Abstract
In general the present invention relates to a continuous process for manufacturing (N-phosphonomethyl) glycine, glyphosate, by the catalyzed oxidation of N-phosphonomethyliminodiacetic acid. Glyphosate can be provided in high yield and in a cost efficient process by minimizing the competing side reactions and by-products. The process includes conducting the oxidation reaction and selecting an appropriate catalyst to maximize the rate of the oxidation of N-phosphonomethyliminodiacetic acid while at the same time minimizing the rate of oxidation of glyphosate in the same reaction.
Claims16
A continuous process for the production of glyphosate, said process comprising:
- contacting N-phosphonomethyliminodiacetic acid with molecular oxygen in the presence of a carbon catalyst supported in a fixed bed reactor under conditions which oxidize N-phosphonomethyliminodiacetic acid to glyphosate and oxidize glyphosate to (aminomethyl)phosphonic acid;
- and
- selecting a carbon catalyst for use in the process whereby a ratio of a rate constant of reaction of glyphosate with molecular oxygen to a rate constant of reaction of N-phosphonomethyliminodiacetic acid with molecular oxygen is less than about 0.017.
Dependencies are inferred from the claim text.