Conversion of lipids from wet microalgae into biodiesel using sulfonated graphene oxide catalysts

Area of Science:

• Catalysis
• Biomass Conversion
• Green Chemistry

Background:

• Biodiesel production from microalgae is a sustainable alternative to fossil fuels.
• Solid acid catalysts offer advantages over liquid acids in biodiesel production.
• Graphene-based materials show promise as efficient solid acid catalysts.

Purpose of the Study:

• To evaluate the efficacy of various solid acid catalysts for converting microalgae lipids into biodiesel.
• To investigate the relationship between catalyst properties and biodiesel conversion efficiency.
• To identify the optimal catalyst for high-yield biodiesel production from wet microalgae.

Main Methods:

• Characterization of graphene oxide (GO), sulfonated graphene oxide (SGO), sulfonated graphene (SG), and sulfonated active carbon (SAC) using SEM, XRD, and TGA.
• Catalytic conversion of wet microalgae lipids into fatty acid methyl esters (FAME) using the prepared catalysts.
• Analysis of catalyst properties (e.g., hydrophilic hydroxyl content, SO3H groups) using FTIR, XPS, and elemental analysis.

Main Results:

• SGO exhibited the highest biodiesel conversion efficiency at 84.6%.
• SAC showed low conversion efficiency, while GO and SG demonstrated moderate efficiencies (73.1% and 48.6%, respectively).
• Higher hydrophilic hydroxyl content in SGO correlated with increased FAME yield compared to SG, despite lower SO3H group density.

Conclusions:

• Sulfonated graphene oxide (SGO) is a highly effective catalyst for microalgae lipid conversion to biodiesel.
• Hydrophilic hydroxyl groups play a crucial role in enhancing catalytic activity for FAME production.
• Graphene-based solid acid catalysts offer a promising route for sustainable biodiesel generation.