Techno-Economic and Environmental Assessments of 1,3-Propanediol and Xylooligosaccharide Production Annexed to a Typical Sugar Mill

This study presents the economic and environmental assessment of biorefinery scenarios producing 1,3-propanediol (PDO) and xylooligosaccharides (XOS). Five biorefinery scenarios were simulated and assessed, annexed to an existing sugar mill with self-sufficient energy supply. PDO production was investigated in three scenarios, namely, PDO-D and PDO-I (direct and indirect fermentation processes of PDO production from A-molasses) and PDO-1G2G, which utilizes A-molasses and sugar cane bagasse/trash as the feedstock. Both XOS production from lignocelluloses (XOS-2G) and PDO production from A-molasses combined with lignocelluloses (PDO-XOS) are the other two studied scenarios. Internal rates of return (IRRs) of 11.1, 75.4, and 33.5% were obtained for PDO-I, PDO-D, and PDO-1G2G, respectively, for an assumed market price of USD3.38/kg. Scenario PDO-D was found to be energy efficient, while indirect production via glycerol as intermediate (PDO-I) was energy intensive due to the aerobic fermentation. A high market price of USD 25/kg for XOS led to a high IRR (87.9%) for XOS-2G. Consequently, the PDO-XOS scenario improved the energy efficiency of the biorefinery and resulted in a high probability of financial feasibility. Both PDO-D and PDO-XOS scenarios had low greenhouse gas emissions based on the Roundtable on Sustainable Biomaterials methodology, along with the excellent economic outlook.

Automated summary

This study presents the economic and environmental assessment of biorefinery scenarios producing 1,3-propanediol and xylooligosaccharides. Different production methods and feedstock types have significant impacts on economic feasibility and energy efficiency. Meanwhile, high market prices positively affect the economic viability.