Lignin containing micro and nano-fibrillated cellulose obtained by steam explosion: Comparative study between...

Area of Science:

• Materials Science
• Biomass Processing
• Cellulose Nanotechnology

Background:

• Lignin-containing micro- and nanofibrillated cellulose (L-MNFC) isolation is a complex, multi-step process.
• Conventional pulping methods can be energy-intensive and may reduce lignin content.

Purpose of the Study:

• To evaluate steam explosion (SE) as an alternative pre-treatment for L-MNFC production.
• To compare SE with conventional cooking (SC) in terms of lignin content, fiber morphology, and energy consumption.
• To investigate the effect of bleaching on SE-treated pulp.

Main Methods:

• Beech wood pre-treatment using steam explosion (SE) and conventional cooking (SC).
• Refining and ultrafine grinding of SE-treated wood to achieve gel formation.
• Chemical composition analysis and fiber morphology assessment of pulps.
• Evaluation of quality index and energy consumption during production.

Main Results:

• SE pre-treatment allows for the production of pulps with significantly higher lignin content (8-12% wt.) compared to SC (3% wt.).
• The resulting gels consist of micro/nanofibrillated cellulose, residual fibers, lignin nanoparticles, and nanocrystals.
• Optimization of ultrafine grinding is crucial for minimizing energy consumption.

Conclusions:

• Steam explosion is a viable alternative to conventional cooking for producing L-MNFC with enhanced lignin content.
• Further optimization of the grinding step is necessary to improve the overall energy efficiency of the L-MNFC production process.
• The study provides insights into tailoring L-MNFC properties through different pre-treatment and processing strategies.