Processing of Citrus Nanostructured Cellulose: A Rigorous Design-of-Experiment Study of the Hydrothermal...

Area of Science:

• Biomass Processing
• Materials Science
• Chemical Engineering

Background:

• Citrus cellulosic matter is an abundant, underutilized biomass resource.
• Developing sustainable methods for cellulose extraction is crucial for biorefineries.
• Acid-free microwave-assisted processing offers a green alternative for cellulose modification.

Purpose of the Study:

• To investigate the effects of temperature, holding time, and concentration on citrus cellulosic matter processing using Hy-MASS.
• To optimize process variables for enhanced cellulose properties.
• To characterize the resulting cellulosic materials and their water holding capacity.

Main Methods:

• Design-of-experiment (DoE) study with varying temperature (120-200°C), holding time (0-30 min), and concentration (1.4-5.0 wt%).
• Analysis of Variance (ANOVA) to determine variable significance.
• Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) for material morphology.
• Water holding capacity, decomposition temperature, and crystallinity index measurements.

Main Results:

• Temperature was the most significant factor affecting yield (25-72%), decomposition temperature (345-373°C), and crystallinity index (34-67%).
• Low temperatures yielded microfibrillated cellulose (MFC); high temperatures produced cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs).
• Water holding capacity increased to 15-27 gH2O g⁻¹, and molecular weight decreased significantly above 180°C.

Conclusions:

• The Hy-MASS process effectively modifies citrus cellulosic matter, with temperature being a critical control parameter.
• Process conditions influence the morphology and properties of the extracted cellulose, enabling tunable material characteristics.
• Optimized Hy-MASS processing yields cellulose with enhanced water holding capacity, suitable for various applications.