Solvent-Free Production of Triacetin from Glycerol through Complementary Mechanochemical, Biphasic, and Catalytic Approaches Using ICHeM Technology

Impact in Continuous Flow Heated Mechanochemistry (ICHeM) was utilized for the biphasic acetylation of glycerol with immiscible acetic anhydride in the presence of homogeneous acid catalysts. This innovative technology combines efficient phase dispersion with continuous flow, offering the following benefits: (i) improved mixing of the two immiscible components (liquid glycerol and highly reactive acetic anhydride); (ii) mechanochemical energy generated by bead impact in continuous flow, eliminating the need for additional heating energy; and (iii) an alternative to single- and double-screw extruders, which are ineffective with liquid reaction media. Under our optimized conditions, triacetin “t” can be obtained with a 99% yield (100% conversion and 99% selectivity) in a solvent-free biphasic continuous flow process with a residence time of 15–30 min, using efficient homogeneous Lewis acids like iron triflate II or Brönsted acids like sulfuric acid.