Potential of macroalgae-based biorefinery for lactic acid production from exergy aspect

The increasing production of plastics has raised concerns over the depletion of fossil fuels. In addition, the environmental issues associated with the improper management of plastic waste are increasingly alarming. Therefore, there is a sharp rise of researches conducted on one of the most promising biopolymers for the production of biodegradable plastics, which is known as polylactic acid (PLA). Subsequently, this has led to an increased interest in the production of its monomer, lactic acid (LA). However, the high production cost of LA has been limiting its large-scale manufacturing. The utilization of expensive raw materials and complicated downstream processes have led to the high overall production cost of LA. This review explores the potential of 3G feedstock, specifically macroalgae biomass, as a substrate for LA production. Then, the recent technological advancements for LA production and the challenges currently faced in the LA industry are addressed. Lastly, the sustainability aspect of macroalgae biomass is evaluated economically and environmentally by utilizing engineering tools such as life cycle assessment and exergy analysis, which represent the highlights of this review paper.