Potential lactic acid production from crude glycerol as the precursor of polylactic acid analog : literature review

Biodiesel has gained a significant amount of attention over the past decade as an environmentally friendly fuel. However, the biodiesel production process generates glycerol-containing waste streams which have become a disposal issue for biodiesel plants and generated an abundant of crude glycerol, a low-value byproduct of biodiesel manufacturing. Conversion crude glycerol to valuable chemical such as lactic acid, a precursor of polylactic acid (PLA), has a great potential to substitute traditional feedstocks of PLA, i.e., carbohydrate or sugar sources. Some of the process perspectives and the potential of glycerol to produce lactic acid by chemical transformation or microbial conversion are discussed in this paper, as well as the possibility of extending lactic acid to polylactic acid (PLA).