Method for the production of acrylic acid or its derivatives

摘要

Methods for catalytically dehydrating hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof to acrylic acid, acrylic acid derivatives, or mixtures thereof with high yield and selectivity and without significant conversion to undesired side products, such as, acetaldehyde, propionic acid, and acetic acid, are provided. The catalysts are mixed monophosphates.

主权项

1. A method of making acrylic acid, acrylic acid derivatives, or mixtures thereof comprising contacting a stream comprising hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof with a catalyst comprising:
a. monohydrogen monophosphate anion described by formula (I):
[HPO4]2−  (I), b. and dihydrogen monophosphate anions described by formula (II):
[H2PO4]−  (II), and c. at least two different cations, wherein the catalyst is essentially neutrally charged; and further, wherein the molar ratio of said monohydrogen monophosphate anion to said dihydrogen monophosphate anion in said catalyst is between about 0.1 and about 10, and further, wherein said acrylic acid derivatives are selected from the group consisting of metal or ammonium salts of acrylic acid, alkyl esters of acrylic acid, acrylic acid oligomers, and mixtures thereof; and said hydroxypropionic acid derivatives are selected from the group consisting of metal or ammonium salts of hydroxypropionic acid, alkyl esters of hydroxypropionic acid, hydroxypropionic acid oligomers, cyclic di-esters of hydroxypropionic acid, hydroxypropionic acid anhydride, and mixtures thereof.