Evaluation of 1,3-propanediol and lactic acid production via the biotechnological route: Technoeconomic and environmental analysis

Abstract

1,3-Propanediol (1,3-PDO) and lactic acid (LA) are valuable chemical products that can be used as monomers for synthesizing important polymers such as polytrimethylene terephthalate and poly(lactic acid), respectively. In this study, a new integrated process for the production of 1,3-PDO and LA from renewable feedstocks is proposed and analyzed using modeling and simulation tools. Limosilactobacillus reuteri was selected for this application due to its capability to co-ferment both glycerol and glucose, resulting in the production of 1,3-PDO, LA, and other byproducts. A conceptual process was developed and simulated using Aspen Plus software, focusing on the bioreactor, multistage evaporation, and vacuum distillation for separation. The bioreactor was designed using a kinetic model that had been developed previously, which was validated with experimental data. A technoeconomic and environmental analysis was conducted, along with a multi-criteria analysis using the GREENSCOPE methodology. The proposed process was compared with a study from the literature that reproduced metrics of a commercial 1,3-PDO production process, providing a benchmark for evaluation. The results of the economic assessment, particularly in the Brazilian market, estimate the minimal selling prices at US$6.70/kg for 1,3-PDO and US$5.49/kg for LA. Overall, the proposed process presents a potential technical solution for integrated LA and 1,3-PDO production; however, further studies should focus on increasing L. reuteri tolerance to higher substrate concentrations and developing low-cost culture media to ensure process sustainability.