Thermochemical conversion of defatted microalgae Scenedesmus obliquus into levulinic and formic acids.

Microalgae are potential alternative resources that can replace fossil resources for the production of biofuels and chemicals. Levulinic acid (LA) and formic acid (FA) were produced from defatted Scenedesmus obliquus (a green microalga) via sulfuric acid-catalyzed thermochemical conversion using Box-Behnken design. Following optimization, 39.93% LA and 25.82% FA yields were obtained with 5 wt% biomass concentration and 0.8 M H 2 SO 4 as the catalyst at 180 °C for 40 min. Furthermore, LA and FA yields matched well with a non-linear sigmoidal equation with the combined severity factor (CSF). High LA and FA yields were achieved at a CSF > 10.4. The results demonstrated the potential of microalgae as a biomass and Brönsted acid as a catalyst for producing platform chemicals. [ABSTRACT FROM AUTHOR]