The earliest attempts at manufacturing synthetic vanillin used renewable feedstock. The first route used oil of cloves, containing eugenol, as the starting point. The oil was usually extracted from cloves using steam distillation.

image: cloves

Its manufacture from lignin contained in waste from the paper industry relies on trees, a constantly renewable resource. For a process to be sustainable, however, it is not sufficient simply to use a renewable resource. The chemicals used in making vanillin from the lignin in spent liquor result in a waste management problem. The lignin route is still used by some manufacturers.

Feedstock

image: paper bag
image: forest

The majority of vanillin is currently produced using petrochemical feedstock. Although in the long term this is not sustainable, the process has a much better atom economy, is therefore less wasteful and more energy efficient than the lignin route.
One of the intermediates in this method, catechol, can also be made through a biosynthetic route, allowing for the possibility of moving back to using renewable feedstock.


image: petrochemical industry


Recent and current research suggests that agricultural waste could be the next source of vanillin, using biosynthetic methods modelled on bacteria and fungi.

 


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