Microwave-assisted biodiesel production using -SO

Area of Science:

• Sustainable Chemistry
• Catalysis
• Renewable Energy

Background:

• Biodiesel synthesis offers a sustainable energy alternative.
• Developing efficient and reusable catalysts is crucial for cost-effective biodiesel production.
• Agro-waste valorization presents an opportunity for green chemistry.

Purpose of the Study:

• To synthesize a reusable heterogeneous catalyst from walnut shell powder.
• To investigate the catalyst's efficacy in oleic acid esterification for biodiesel production.
• To optimize reaction conditions for maximum biodiesel yield.

Main Methods:

• Low-temperature hydrothermal carbonization of walnut shell powder to create WNS-SO3H catalyst.
• Microwave-assisted esterification of oleic acid with methanol using the WNS-SO3H catalyst.
• Characterization of the catalyst using EDS, XPS, and FTIR.
• Optimization of catalyst loading, molar ratio, temperature, and reaction time.
• Analysis of biodiesel product using 13C and 1H NMR, and gas chromatography.

Main Results:

• A reusable -SO3H functionalized heterogeneous catalyst (WNS-SO3H) with high acid density (2.06 mmol/g) was successfully prepared.
• EDS, XPS, and FTIR analyses confirmed the catalyst's composition and functional groups (-SO3H).
• Optimized conditions yielded a 99.01% conversion of oleic acid to methyl oleate (biodiesel).
• The catalyst demonstrated reusability for five reaction cycles with consistent performance.

Conclusions:

• The WNS-SO3H catalyst derived from walnut shells is a sustainable and effective material for biodiesel production.
• The high lignin content in walnut shells contributes to catalyst stability and efficiency.
• This method offers a cost-effective and environmentally friendly route to biodiesel synthesis using agro-waste.