Adipic Acid (AA) is produced at a rate of 2.5 million tons per year; 60% of it for the production of nylon. A mixture of cyclohexanol and cyclohexanone called “KA oil” (ketone-alcohol oil) is oxidized with nitric acid to give adipic acid, via a multi-step pathway.
One of the by-products is N2O – a potent greenhouse gas, that contributes to ozone depletion.
DSM has taken upon itself to find a suitable pathway that can be turned into profitable bio-based alternative.
Behind the cute acronym LA2AA hides a serious project: Levulinic Acid (LA) to Adipic Acid (AA).Read on
Levulinic acid can be produced from any organic source, as long as it produces C6-sugars. But that is not the concern of DSM. That is left to others, such as the GFBiochemicals company at Brightlands Campus of Chemelot, which already produces levulinic acid at commercial scale directly from biomass. So levulinic acid is the starting point. After considering many possible alternatives a four-step route was chosen, consisting of hydrogenation to convert levulinic acid into gamma-valeroactone, followed by a ring-opening reaction on this molecule to obtain methyl pentanoate. This is converted into dimethyl adipate, and that in turn is converted into adipic acid.
The results on laboratory scale are promising. A pilot with a capacity of between 3 and 10 kiloton is now being planned.