Process for making iminodiacetic acid compounds from monoethanolamine substrates
AssigneeMonsanto Technology LLC
InventorsHoward C. Berk, Thaddeus S. Franczyk, II, Robert B. Weisenfeld, David A. Morgenstern, Juan P. Arhancet, William L. Moench, Jr., James C. Peterson
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Abstract
This invention is directed to a process for making an iminodiacetic acid compound from a monoethanolamine substrate having the formula: wherein R1 is hydrogen, hydrocarbyl, or substituted hydrocarbyl. The process includes a series of reactions comprising a cyanomethylation, a hydrolysis and a dehydrogenation. In a particular embodiment, the iminodiacetic acid produced is disodium iminodiacetic acid and the monoethanolamine substrate used is 2-aminoethanol.
Claims79
A process for making an iminodiacetic acid compound from a monoethanolamine substrate, the process comprising:
- continuously or intermittently introducing said monoethanolamine substrate into a dehydrogenation reaction zone;
- contacting said monoethanolamine substrate with a metal-containing catalyst in said dehydrogenation zone to form a dehydrogenation product comprising a glycine intermediate;
- continuously or intermittently introducing at least a portion of said glycine intermediate from said dehydrogenation product into a cyanomethylation reaction zone;
- contacting said glycine intermediate with a cyanide source and a formaldehyde source in said cyanomethylation reaction zone to form a cyanomethylation product comprising an N-cyanomethylated glycine intermediate;
- introducing an acid into said cyanomethylation reaction zone before and/or as the reaction between said glycine intermediate, cyanide and formaldehyde proceeds to control the pH in said cyanomethylation reaction zone;
- continuously or intermittently introducing at least a portion of said N-cyanomethylated glycine intermediate from said cyanomethylation product into a hydrolysis reaction zone;
- and
- contacting said N-cyanomethylated glycine intermediate with a hydroxide source in said hydrolysis reaction zone to form a hydrolysis product comprising an iminodiacetic acid compound,
- wherein said monoethanolamine substrate has the formula:
- and
- R1 is hydrogen, hydrocarbyl, or substituted hydrocarbyl.
A process for making disodium iminodiacetic acid from 2-aminoethanol, the process comprising:
- continuously or intermittently introducing said 2-aminoethanol into a dehydrogenation reaction zone;
- contacting said 2-aminoethanol with a metal-containing catalyst in said dehydrogenation zone to form a dehydrogenation product comprising sodium glycinate;
- continuously or intermittently introducing at least a portion of said sodium glycinate from said dehydrogenat ion product into a cyanomethylation reaction zone;
- contacting said sodium glycinate with a cyanide source and a formaldehyde source in said cyanomethylation reaction zone to form a cyanomethylation product comprising sodium N-cyanomethylglycinate;
- introducing an acid into said cyanomethylation reaction zone before and/or as the reaction between said sodium glycinate, cyanide and formaldehyde proceeds to control the PH in said cyanomethylation reaction zone;
- continuously or intermittently introducing at least a portion of said sodium N-cyanomethylglycinate from said cyanomethylation product into a hydrolysis reaction zone;
- and
- contacting said sodium N-cyanomethylglycinate with a hydroxide source in said hydrolysis reaction zone to form a hydrolysis product comprising disodium iminodiacetic acid.
A process for making an iminodiacetic acid compound, the process comprising:
- continuously or intermittently introducing glycine or a salt thereof into a cyanomethylation reaction zone;
- contacting said glycine or said glycine salt with a cyanide source and a formaldehyde source in said cyanomethylation reaction zone to form a cyanomethylation product comprising an N-cyanomethylated glycine intermediate;
- introducing an acid into said cyanomethylation reaction zone before and/or as the reaction between said glycine or a salt thereof, cyanide and formaldehyde proceeds to control the pH in said cyanomethylation reaction zone;
- continuously or intermittently introducing at least a portion of said N-cyanomethylated glycine intermediate from said cyanomethylation product into a hydrolysis reaction zone;
- and
- contacting said N-cyanomethylated glycine intermediate with a hydroxide source in said hydrolysis reaction zone to form a hydrolysis product comprising an iminodiacetic acid compound.
Dependencies are inferred from the claim text.