Utilizing an ultra-sonication process to optimize a two-step biodiesel production from Karanja oil

Area of Science:

• Chemical Engineering
• Renewable Energy
• Green Chemistry

Background:

• Biodiesel offers a sustainable alternative to petro-diesel, but production from non-edible oils faces challenges due to impurities.
• Karanja oil (Pongamia pinnata oil) is a non-edible feedstock rich in free fatty acids (FFA), requiring efficient processing for biodiesel production.
• Ultrasound (US) process intensification (PI) offers a novel approach to enhance reaction rates and efficiency in biodiesel synthesis.

Purpose of the Study:

• To optimize a two-step biodiesel production process (esterification and transesterification) from high FFA Karanja oil.
• To investigate the effectiveness of ultrasound (US) process intensification (PI) in optimizing esterification and transesterification parameters.
• To achieve high biodiesel yield and quality suitable for blending with petro-diesel.

Main Methods:

• A two-step process involving esterification followed by transesterification was employed.
• Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to optimize the esterification step, reducing FFA content.
• RSM with Box-Behnken Design (BBD) was applied to optimize the transesterification of esterified oil, maximizing biodiesel yield.

Main Results:

• Esterification optimized with RSM-CCD reduced FFA from 11.06% to 1.56% under specific conditions (32.8 min, 1.14 w/w% H2SO4).
• Transesterification optimized with RSM-BBD achieved a maximum biodiesel yield of 98.16% under optimal conditions (7.6:1 molar ratio, 0.98 w/w% CH3OK, 20.6 min).
• The optimized US-PI process demonstrated superior results compared to conventional stirring methods, producing biodiesel meeting ASTM standards.

Conclusions:

• The ultrasound-assisted two-step process effectively optimizes biodiesel production from high FFA Karanja oil.
• RSM-based optimization significantly enhances both FFA reduction and biodiesel yield.
• The resulting biodiesel is suitable for blending with diesel fuel, contributing to sustainable energy solutions.