Bio-based methacrylic acid via catalytic decarboxylation of itaconic and citric acids

Authors: Moser, Bryan

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2018
Publication Date: 3/18/2018
Citation: Moser, B.R. 2018. Bio-based methacrylic acid via catalytic decarboxylation of itaconic and citric acids [abstract]. American Chemical Society National Meeting, March 18-22, 2018, New Orleans, LA. Paper No. AGFD 49.

Interpretive Summary:

Technical Abstract: Methacrylic acid is an important commodity monomer for the plastics industry that is produced industrially from acetone, hydrogen cyanide and concentrated sulfuric acid via the acetone cyanohydrin (ACH) process. Disadvantages to the ACH process include nonrenewable starting materials, stoichiometric amounts of harmful and corrosive reagents, generation of toxic intermediates, and production of low-value byproducts. Herein is reported a bio-based route to methacrylic acid via selective decarboxylation of itaconic and citric acids utilizing catalytic ruthenium (I) dicarbonyl propionate (RDP) in an aqueous solvent system. Itaconic and citric acids are produced from fermentation of simple sugars, thereby representing renewable sources for methacrylic acid. Numerous metal catalysts were initially screened for production of methacrylic acid, with RDP ultimately identified as the most efficient. High selectivity (>90%) was achieved at low catalyst loading (0.1 mol % ruthenium) with high substrate concentration (5.5 M) at low temperatures (210–225°C) and pressures (less than or equal to 425 psig). In combination, these findings represent improvements over existing methodologies that may facilitate sustainable production of methacrylic acid, an important petrochemically-based monomer for the plastics industry.