Two-Step Esterification Process of Palm Fatty Acid Distillate Using Soaking Coupled with Ultrasound: Process...

Area of Science:

• Chemical Engineering
• Sustainable Chemistry
• Catalysis

Background:

• Palm fatty acid distillate (PFAD) is a byproduct rich in free fatty acids (FFAs).
• Converting FFAs to methyl esters (MEs) is crucial for biodiesel production.
• Heterogeneous catalysts offer environmental benefits and reusability compared to homogeneous catalysts.

Purpose of the Study:

• To optimize the esterification of FFAs in PFAD to MEs using ultrasound and a heterogeneous acid catalyst.
• To investigate the efficiency and reusability of Amberlyst-15 for biodiesel production.
• To determine the optimal reaction conditions for maximizing ME purity.

Main Methods:

• High-intensity ultrasound (1000 W, 18 kHz) was applied to PFAD esterification.
• Amberlyst-15, a heterogeneous acid catalyst, was used in the process.
• Reaction parameters including methanol content, catalyst loading, soaking time, and sonication time were varied to optimize ME purity.

Main Results:

• Optimal conditions yielded 89.44 wt % ME purity.
• Optimal conditions: 36.73 wt % methanol, 60 wt % Amberlyst-15, 130 min soaking, 505 s sonication at 60 °C.
• Recovered Amberlyst-15 demonstrated reusability for at least two cycles, achieving over 80 wt % ME purity.

Conclusions:

• Ultrasound-assisted esterification with Amberlyst-15 is an effective method for reducing FFA content in PFAD.
• The heterogeneous catalyst Amberlyst-15 is reusable, offering a sustainable approach to biodiesel production.
• Optimized conditions significantly enhance methyl ester yield and purity.