Patent ID: 9409935
Filing Date: 2016-08-09
CPC Classification: C07F,G01N,Y10T

Claim Text:
1. A method for monitoring or detecting a conversion of N-(phosphonomethyl)iminodiacetic acid to N-(phosphonomethyl)glycine in the course of a catalytic oxidation of N-(phosphonomethyl)iminodiacetic acid in an aqueous medium, the method comprising: introducing an aqueous medium containing N-(phosphonomethyl)iminodiacetic acid into an oxidation reaction zone; contacting N-(phosphonomethyl)iminodiacetic acid with an oxidizing agent in the aqueous medium within said oxidation reaction zone in the presence of an oxidation catalyst, thereby effecting oxidation of N-(phosphonomethyl)iminodiacetic acid and producing N-(phosphonomethyl)glycine; measuring the generation of carbon dioxide in said reaction zone; identifying a transition point after which the rate of oxidation of N-(phosphonomethyl)iminodiacetic acid is non-zero order; estimating residual N-(phosphonomethyl)iminodiacetic acid concentration at a base point during non-zero order oxidation; identifying an end point subsequent to the base point from a correlation of carbon dioxide generation with residual N-(phosphonomethyl)iminodiacetic acid in the reaction zone during non-zero order oxidation; wherein the measured generation of carbon dioxide is adjusted to account for an estimate of carbon dioxide generated by oxidation of formaldehyde and formic acid in said reaction zone to provide an estimated conversion of N-(phosphonomethyl)iminodiacetic acid to N-(phosphonomethyl)glycine.