Thermal Degradation of Lignin: Researchers Unveil New Insights

Researchers in Iasi, Romania have made significant discoveries about the thermal degradation of lignin, a complex organic polymer found in plant cell walls. The study, published in Cellulose Chemistry and Technology, provides fresh insights into the thermal behavior of various types of lignin, including aspen lignin, lignosulfonate, and cellolignin. The researchers employed TG-FTIR/MSD analysis and pyrolysis followed by GC-MSD analysis to study the thermal degradation of these lignins.

Key Takeaways:

Thermal degradation of aspen lignin starts above 200 degrees C, with the formation of acetic acid, methanol, and methylacetate at a maximum rate around 340 degrees C.
Lignosulfonate degrades around 250 degrees C, producing ammonia and sulfur dioxide, followed by derivatives of structural compounds in lignin.
Cellolignin decomposes at a fast rate within a narrow temperature range, with the formation of particular compounds difficult to distinguish.
Furfural and its derivatives were found in degradation products of cellolignin, but not in other lignins studied.
The researchers identified nitrogen- and sulfur-containing compounds in the light fraction of pyrolysis oils from lignosulfonate.

Statistics:

Thermal degradation of aspen lignin starts above 200 degrees C.
Maximum degradation rate of aspen lignin occurs around 340 degrees C.
Lignosulfonate degrades around 250 degrees C, producing ammonia and sulfur dioxide.
Cellolignin decomposes within a narrow temperature range, with a fast degradation rate.
Furfural and its derivatives were found in 100% of cellolignin degradation products.

Sources:

Cellulose Chemistry and Technology, Pyrolysis Of Lignin - A Potential Method For Obtaining Chemicals And/or Fuels. Cellulose Chemistry and Technology, 2011;45(1-2):43-50.
Petru Poni Institute Macromolecular Chemical, M. Brebu, Grigore Ghica Voda Alley, Iasi 700487, ROMANIA.
Editura Acad Romane, Calea 13 Septembrie NR 13, Sector 5, Bucuresti 050711, Romania.