Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol...

Area of Science:

• Biomass energy
• Green chemistry
• Biotechnology

Background:

• Microalgae are a promising source for biodiesel due to their lipid content.
• A significant challenge is the robust microalgae cell wall, hindering lipid extraction.
• Direct or in situ supercritical transesterification offers a potential solution to overcome this barrier.

Purpose of the Study:

• To optimize direct supercritical transesterification for biodiesel production from microalgae.
• To investigate the influence of key process parameters on biodiesel yield.
• To analyze the impact of the supercritical process on microalgae cell wall structure.

Main Methods:

• Response surface methodology (RSM) with a central composite design (CCD) was employed.
• Experiments were conducted in a batch reactor, varying temperature, time, methanol ratio, hexane ratio, and moisture content.
• Biodiesel yield was quantified, and statistical analysis (ANOVA) was used to evaluate parameter significance.

Main Results:

• Biodiesel efficiency ranged from 0.44% to 99.32% across 32 experimental runs.
• A quadratic model accurately described the fatty acid methyl ester (FAME) yields.
• Analysis revealed the significant effects of single and interactive parameters on biodiesel production.

Conclusions:

• Direct supercritical transesterification is a highly effective method for microalgae biodiesel production.
• Optimization of process parameters is crucial for maximizing biodiesel yield.
• The supercritical process effectively disrupts microalgae cell walls, facilitating lipid conversion.