With the simulation complete, the methodology for exergy analysis in accordance with aim 28 simulated a lactic acid biorefinery using sugarcane bagasse as the substrate, and steam explosion as the pretreatment process. Although the organosolv process was not explored, unlike in other studies, a boiler unit with fuel combustion for hot utilities was included. An exergy analysis revealed the lowest exergy efficiency of all studies, less than 50 %, with most exergy destruction traced to the boiler unit.