Biodiesel production from sunflower oil using a combined atmospheric cold plasma jet-hydrodynamic reactor

Abstract

Conventional transesterification processes are time-consuming and costly. New methods, such as non-thermal plasma technology, reduce the reaction time and temperature. Therefore, this study aims to evaluate the use of a combined plasma jet–hydrodynamic reactor for transesterification. The plasma jet used in this research comprised a ceramic tube with a central high-voltage electrode and a ring outer electrode, into which argon gas was fed. The hydrodynamic reactor consisted of a rotor with holes in its environment that rotated in a fixed stator. In this study, the operating parameters for plasma jet evaluation include the molar ratio of methanol to oil (4:1, 6:1, 8:1), catalyst concentration (0.75, 1, 1.25 wt.%), and reaction time (30, 60, and 90 s). The operating parameters for evaluating the hydrodynamic reactor included reaction time (30, 60, and 90 s), reaction temperature (40, 50, and 60 °C), and rotor–stator distance (10, 20, and 30 mm). The response surface method (RSM) and Box–Behnken design were used to analyze and optimize the results. According to the results, using a plasma jet alone produces a conversion percentage of 83%. Finally, the product’s physical and chemical characteristics were evaluated, and it was found to be insufficiently compliant with international standards.

Keywords:

• Plasma jet
• hydrodynamic
• biodiesel production
• optimization
• response surface methodology
• sunflower oil
• transesterification

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The Research Council of Shahrekord University is thankfully acknowledged for the financial support to carry out the work (Grant No: 99GRN1M1796).