Algal residue: Alternative carbon resource for pharmaceuticals and polyesters

Two molecules of lactic acid can be dehydrated to lactone lactide and subsequently polymerized to either atactic or syndiotactic polylactide, which are biodegradable polyesters. Levulinic acid, on the other hand, is used as a precursor for pharmaceuticals and additives like plasticizers, as well as a starting material for a wide number of compounds. The researchers found that using homogeneous Sn(OTf)2 led to an increase in the yield of alkyl levulinate, while using SnBr4 allowed for the selective production of alkyl lactate. Their results show that algae can be utilized not only as a biofuel source, but also as a carbon resource for chemicals that are applied in a wide range of industries. This could lead to algae biomass becoming a new alternative carbon resource to fossil fuels.

Yamaguchi and colleagues examined various homogeneous catalysts to optimize the selective production of methyl levulinate and methyl lactate. They state, however, that further development of heterogeneous catalysts is needed before the process can be put to practical use. Additionally, they recognize the importance in understanding the underlying mechanisms of starch production in algae, as doing so could lead to further advances in algal biomass production.