Hydrogen transfer initiated dehydration (HTID) of 1,3-propanediol (1,3-PDO), in ionic liquids, catalysed by a fluorinated Cp*IrCl2(NHC) (Cp* = pentamethylcyclopentadienyl; NHC = carbene ligand) complex, allows selective production of propionaldehyde in high yields, under air. Isolation of the product is facilitated by the use of an ionic liquid as the solvent, enabling the reaction to be performed under reduced pressure. The Ir(III) catalyst in ionic liquid was proven to be highly recyclable. Removal of H and F atoms bound to the ortho-C atoms of the benzyl arm of the carbene ligand inhibits the catalytic activity of complexes Cp*IrCl2(NHC), suggesting a crucial role played by the ortho-C-X grouping in HTID. The reaction of 1,3-PDO solutions in ionic liquid mimics that of the product of extraction of aqueous glycerol fermentation broths: the successful synthesis and isolation of a value-added chemical proves that valorisation of glycerol waste can be achieved. The combination of Cp*IrX2(NHC) - catalysed HTID of 1,3-PDO in ionic liquids with bio-catalysis has then, ultimately, the potential to allow the transformation of waste glycerol into valuable chemicals that can be simply isolated.