An Energy Analysis of Polylactic Acid (PLA) Produced from Corn Grain and Corn Stover Integrated System

Polylactic acid (PLA) has been identified as one of the most promising biobased plastics for various applications. The nonrenewable energy use of 1 kg PLA produced in an integrated system where both corn grain and corn stover are harvested and used for lactic acid production has been assessed through life cycle assessment. The overall findings are that PLA produced from integrated system does not show advantages compared with current corn starch based system. Feedstock consumption of producing 1 kg PLA is about 1.62 kg corn grain and 0.81 kg corn stover. Nonrenewable energy use associated with PLA resin produced in the integrated system is about 58.9 MJ/kg. In order to facilitate future large scale biobased PLA production, and also reduce its dependence on corn grain which increase food costs, more efforts are needed to focus on choosing appropriate lignocellulosic raw materials and developing more efficient technologies.