Biobased Methacrylic Acid via Selective Catalytic Decarboxylation of Itaconic Acid

Abstract

We report a biobased route to methacrylic acid via selective decarboxylation of itaconic acid utilizing catalytic ruthenium carbonyl propionate in an aqueous solvent system. High selectivity (>90%) was achieved at low catalyst loading (0.1 mol %) with high substrate concentration (5.5 M) at low temperature (200−225 °C) and pressure (≤425 psig) relative to previous contributions in this area. Direct decarboxylation of itaconic acid was achieved as opposed to the conjugate base reported previously, thereby avoiding basification and acidification steps. Also investigated was catalytic manganese(II) oxalate (5 mol %), but low yield (4.8%) and evolution of carbon monoxide via oxalate decomposition was problematic. Attempts at stabilization of the catalyst with triphenylphosphine were unsuccessful, but it exhibited greater catalytic efficacy (14.0% yield) than the manganese catalyst (4.8% yield) at 5 mol %. Neither carbon monoxide nor propylene (excessive decarboxylation) were detected during ruthenium-catalyzed decarboxylation. In addition, cosolvents such as tetraglyme lowered vapor pressures within the reaction vessel by >100 psig while minimizing decomposition of starting acids. 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.

Combining Reclaimed PET with Bio-based Monomers Enables Plastics Upcycling

“…[54][55][56] In the present work, methacrylic acid and acrylic acid were used as reactive diluents to enable the use of the rPET-polymer backbones in the FRPs and to improve material properties. Methacrylic acid can be produced via decarboxylation of itaconic acid, 57,58 which can be obtained biologically in high yields. [59][60][61] Acrylic acid, which is prepared from propylene industrially, can be renewably sourced from a variety of 3-hydoxypropyl functionalized monomers (e.g., 3-hydroxypropionic acid [3-HP] and 3-hydroxypropionaldehyde, etc.)…”

Production and Polymerization of Biobased Acrylates and Analogs

“…Moser and co‐workers later converted IA into MAA using a homogeneous ruthenium carbonyl propionate catalyst with a high selectivity (90%), at high concentration (5.5 m for increased throughput), moderate temperature, and pressure (200–225 °C and 30 bars), without the use of a base. [ 74,75 ]…”

A Review of the Biotechnological Production of Methacrylic Acid

“…In addition, the chemical decarboxylation of itaconic acid to MA has been demonstrated via several different catalytic routes, mostly reliant on metal catalysts. Some of these processes have demonstrated conversion yields as high as 40% at over 90% selectivity (Le Nôtre et al, 2014;Lansing et al, 2017;Bohre et al, 2019). However, the current cost of itaconic acid ranges from $1.80 to $2.00/kg (Kuenz and Krull, 2018), which is similar to the price of MMA.…”