Process design and economic evaluation of integrated, multi‐product biorefineries for the co‐production of bio‐energy, succinic acid, and polyhydroxybutyrate (PHB) from sugarcane bagasse and trash lignocelluloses

This study investigates whether a biorefinery, annexed to an existing sugar mill and co‐producing succinic acid, polyhydroxybutyrate (PHB), and electricity from sugarcane bagasse and trash lignocelluloses, will be a viable investment opportunity for existing sugarcane mills. Four scenarios were simulated in Aspen Plus® and were included in the economic analysis. Scenario A involved the production of PHB and electricity; Scenario B the production of PHB, succinic acid, and electricity; Scenario C the production of succinic acid and electricity; and Scenario D involved the production of electricity only. The most favorable configuration was found for Scenario B where PHB was produced from 25% of the fermentable glucose stream, and succinic acid from the hemicellulose hydrolysate together with 75% of the glucose, resulting in an internal rate of return (IRR) of 24.1% with a net present value of US$477.2 million. Alternatively, Scenario D could be selected if low capital (130.1 million US$) and operational costs (US$13.2 million) are desired, although weak returns (IRR 10.3% and net present value of US$6.08 million) were observed for an electricity price of 0.08 US$ kWh −1 . © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd