Lab-scale production of biodiesel from soybean acid oil using immobilized whole cells as catalyst

Abstract

The study demonstrates the lab-scale production of biodiesel from soybean acid oil (SAO) in a 5 L lab-scale bioreactor using immobilized whole cells as a catalyst. The maximum lipase activity 2.89 ± 0.6 U/mL of immobilized whole cells was achieved at optimum conditions viz; pH (7.1), temperature (31 °C), peptone (1.2% w/v) and immobilized pieces (10) in 100 mL growth medium. The esterification approach was fit to Michaelis–Menten model, based on concentration-time profile with 75 gL⁻¹ Michaelis constant (K_M) and 78 gL⁻¹h⁻¹ maximum velocities (V_max) resulting in a maximum yield of up to 95.4% over 24 h of reaction. A 5% decrease in the catalytic potential of immobilized whole cells from 1^st to 5^th recycle of immobilized support. The fuel properties of resulted biodiesel were noted to meet the specifications of major international biodiesel standards such as ASTM D6751 to a significant extent. The study reveals the potential use of immobilized whole-cell catalyst and acid oil as an alternative, low-cost bearing and quality feedstock for the generation of biodiesel for a diverse variety of industrial/commercial use.

Keywords:

• Biodiesel
• acid oil
• whole-cell catalysis
• immobilization
• fuel properties

Acknowledgements

Mr. Sharma acknowledges the help provided by Mr. Gulshan Kumar, School of Chemistry & Biochemistry, Thapar University for interpretation of the data.

Disclosure statement

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

Additional information

Funding

The authors acknowledge the research grant provided by BRNS [2010/35/12/BRNS/2560], India for carrying out the study. The NMR and other analytical facilities provided by SAI Labs, Thapar University are duly acknowledged. Mr. Sharma acknowledges CSIR, India for the Senior Research Fellowship [09/677/(0022)/2014-EMR-1].