Pyrolysis of microalgae residues--A kinetic study

Area of Science:

• Biomass valorization
• Thermochemical conversion
• Microalgae processing

Background:

• Microalgae are a sustainable source of biomass for energy and chemical production.
• Pyrolysis converts biomass into bio-oil, biochar, and syngas.
• Understanding pyrolysis kinetics is crucial for optimizing bio-oil yield and quality.

Purpose of the Study:

• To investigate the pyrolysis kinetics of oil extraction residues from Chlamydomonas (C. sp. JSC4) and Chlorella sorokiniana (C. Sorokiniana CY1).
• To apply a five pseudo-component kinetic model for analyzing pyrolysis data.
• To determine the activation energies for key pseudo-components during pyrolysis.

Main Methods:

• Thermogravimetric analysis (TGA) was used to study the pyrolysis process.
• A five pseudo-component model (hemicellulose, cellulose, lignin, lipid, protein) was applied for kinetic analysis.
• Two kinetic models (n=1 and n≠1) were compared for their fit quality.

Main Results:

• The kinetic model with n≠1 demonstrated a slightly better fit and provided reasonable kinetic parameters.
• Calculated activation energies for C. sp. JSC4 ranged from 61.74–198.30 kJ/mol for different components.
• Calculated activation energies for C. Sorokiniana CY1 ranged from 64.77–218.79 kJ/mol for different components.

Conclusions:

• The n≠1 kinetic model is suitable for describing the pyrolysis of these microalgae residues.
• The study provides valuable kinetic data for optimizing microalgae pyrolysis processes.
• The findings contribute to the efficient valorization of microalgae waste streams.