Sustainable energy enhancement strategy from Chlorella vulgaris microalgae biomass resource

ABSTRACT

Growing demand for renewable and sustainable energy sources has prompted research into bioethanol production as a viable alternative to hydrocarbon fuel for automobile engines. Based on their high carbohydrate content, Chlorella vulgaris microalgae were chosen for this study as a feasible biomass for bioethanol synthesis. After conducting microwave-based acid hydrolysis with varying acid concentrations of sulfuric acid (H₂SO₄) for 1–15 min, this study found that 3% H₂SO₄ for 5 min yielded the highest yield of reducing sugar (6.77 g/L). In this work, the RSM approach of central composite design (CCD) was utilized for modeling and optimization of ethanol fermentation and the MATLAB Simulink approach was employed for the simulation of ethanol fermentation. This study compared the effects of using Saccharomyces cerevisiae yeast for fermentation at different fermentation times (12 to 48 h), temperatures (28 to 32°C), and size of inoculum (0.5–1.5 g/L). Based on the actual and predicted results, the best conditions for fermentation were 36 h of time, 30°C of temperature, and 1.5 g/L of inoculum size. This gave the maximum ethanol concentration of 3.31 g/L. Furthermore, the RSM method provides minimum error and maximum R² value results for ethanol production compared to MATLAB simulation prediction (MSP). In addition, residue biomass from biofuel production is evaluated for its suitability for a further form of biofuel production. This research explores the opportunities for zero-waste biomass utilization in the development of biofuels.

KEYWORDS:

• Microalgae
• microwave
• RSM
• MATLAB simulation
• residue biomass

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

V. Shenbagamuthuraman

V. Shenbagamuthuram is currently a research scholar working in sustainable energy development from micro algae, municipal solid wastes and mathematical modelling etc.

Nanthagopal Kasianantham

Nanthagopal Kasianantham is a Professor in School of Mechanical Engineering, Vellore Institute of Technology, Vellore, Tamilnadu, India. He predominantly working in the field of Electric Vehicles, Evaporative Cooling, Sustainable Energy Development etc.