The conversion of the extracted glycerol fermentation products into value-added chemicals by employing chemocatalysis has been targeted. The glycerol fermentation product 1,3-propanediol has been investigated as the chemical platform.
QUB has shown that the hydrogen transfer initiated deydration (HTID) of 1,3-propanediol in ionic liquids catalysed by recyclable Cp*IrCl2(NHC) (Cp* = pentamethylcyclopentadienyl; NHC = carbene ligand) complexes allows the successful production of a range of C3 and C6 aldehydes as the value-added chemicals. Both propionaldehyde and 2-methyl-pentenal were produced with high conversions, yields and selectivities.In addition, the HTID of 1,3-propanediol in ionic liquids is successful also when significant volumes of water are involved in the reaction. The catalytic system has been proven to be recyclable. The successful synthesis and isolation of value-added chemicals out of the ionic liquid solutions of 1,3-propanediol (mimicking the product of extraction of aqueous glycerol fermentation broth) proves that the combination of Cp*IrX2(NHC) catalysed HTID of 1,3-propanediol in ionic liquids with bio-catalysis has, ultimately, the potential to allow the transformation of waste glycerol into valuable chemicals. This valorisation of waste to chemicals would add significant value and improve the economics of biomass waste utilization. The mono- or multi-step, one-pot, bio- chemo-catalytic process to produce value-added chemicals directly from glycerol will be ultimately tested.