Microwave irradiation pretreated fermentation of bioethanol production from Chlorella vulgaris Biomasses: Comparative analysis of response surface methodology and artificial neural network techniques.

[Display omitted] • Chlorella vulgaris biomass was hydrolyzed by microwave irradiation with H 2 SO 4. • Maximum reducing sugar was achieved at 3% of H 2 SO 4 for 5 min. • RSM and ANN tools were utilized to model and optimize for bioethanol production. • ANN developed a good fit model compared to the RSM model. • Leftover biomass was characterized after the hydrolysis process completion. Bioethanol is a promising biofuel for replacing gasoline due to its sustainability. This work uses microwave irradiation and acid hydrolysis to produce bioethanol from Chlorella vulgaris. The hydrolysis procedure used 1%–3% sulfuric acid (H 2 SO 4). The maximum output of reducing sugar was 6.773 g/L after 5 min of irradiation. This study used RSM and ANN to optimize bioethanol production. The study predicted bioethanol yield using three factors: fermentation duration (12–36 h), temperature (28–32 °C), and inoculum concentration (0.5–1.5 g/L). The highest bioethanol yield was achieved using fermentation conditions of 36 h, 30 °C temperature, and 1.5 g/L inoculum concentration. The ANN model predicted the best ethanol output compared to the RSM model. The leftover biomass from biofuel synthesis was characterized for its potential for other energy production. The current study examined the feasibility of employing biomass in an environmentally sustainable manner to enhance the production of biofuels. [ABSTRACT FROM AUTHOR]