Reactive Extraction for Fatty Acid Methyl Ester Production from Castor Seeds Using a Heterogeneous Base Catalyst:...

Area of Science:

• Chemical Engineering
• Biomass Conversion
• Renewable Energy

Background:

• Conventional biodiesel production involves multiple steps: oil extraction followed by esterification or transesterification.
• This multi-step process can be inefficient and costly for certain feedstocks like castor kernel oil (CKO).
• Developing a streamlined, single-step process is crucial for improving the economic viability of biodiesel production.

Purpose of the Study:

• To investigate a novel single-step reactive extraction method for producing fatty acid methyl ester (FAME) from CKO.
• To optimize process parameters for maximizing CKO FAME yield and purity.
• To compare the efficiency of different heterogeneous catalysts (BaO, CaO, ZnO) for this process.

Main Methods:

• Investigated non-reactive extraction parameters (solvent type, ratio, time) to maximize CKO yield.
• Employed reactive extraction with heterogeneous catalysts (BaO, CaO, ZnO) for simultaneous oil extraction and transesterification.
• Utilized Response Surface Methodology (RSM) with Central Composite Design (CCD) to optimize temperature, catalyst concentration, and methanol-to-oil ratio.

Main Results:

• Identified optimal non-reactive extraction conditions: methanol solvent, 6.25:1 methanol-to-seed ratio, 6-hour duration.
• Achieved a maximum CKO FAME yield of 96.13 wt % with 94.4% purity under optimized reactive extraction conditions (4.09 wt % BaO, 330.9:1 methanol-to-oil ratio, 64 °C, 6 hours).
• BaO demonstrated superior performance compared to CaO and ZnO catalysts in terms of CKO FAME yield.

Conclusions:

• A single-step reactive extraction process effectively converts castor seed oil triglycerides directly into FAME with high yield and purity.
• The optimized process offers a more efficient alternative to conventional multi-step biodiesel production methods.
• The rheological properties of castor kernel oil and its methyl ester are influenced by triglyceride content and temperature.