Computational Study and Detailed Kinetic Model of C₁-C₃ Aldehyde Formation from Cellulose-Based Anhydroglucose via...

Area of Science:

• Chemical Engineering
• Combustion Science
• Computational Chemistry

Background:

• Cellulose combustion produces hazardous C1-C3 aldehydes.
• 5,6-anhydroglucopyranose (AHGlu) is a key cellulose fragment.
• Its role in aldehyde formation needs detailed elucidation.

Purpose of the Study:

• To elucidate elementary reaction pathways for C1-C3 aldehyde formation from AHGlu during pyrolysis.
• To quantify activation barriers and reaction rates using computational methods.
• To validate the proposed mechanism against experimental data.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Transition State Theory (TST) for reaction rates.
• Kinetic pathway analysis and reactor simulations.

Main Results:

• Identified distinct pathways for formaldehyde, acetaldehyde, glyoxal, and methylglyoxal formation from AHGlu.
• Determined rate-limiting activation barriers for each pathway (177.2–205.2 kJ/mol).
• Simulations showed <20% deviation from experimental data at 1 atm.

Conclusions:

• The proposed mechanism accurately describes AHGlu pyrolysis and C1-C3 aldehyde formation.
• Pyrolysis pressure <0.1 atm or promoting specific intermediate conversion can suppress aldehyde formation.
• Findings provide a foundation for understanding cellulose thermal decomposition and mitigating emissions.