Purification and Characterization Methods for Lignin Biomass as a Potential Precursor for Carbon Materials

Abstract

A purification process has been optimized for eucalyptus and sugarcane lignins in order to meet the specification requirements for obtaining high-quality carbon materials free of contaminants. Fluorescence XR was used to determine the inorganic content, comprising Ca, Fe, Al, Si and Na. The ash content after the purification process met the minimum requirements for use as a precursor of carbon materials. Elemental analyses were used to determine the contents of C, N, H, S and O. Fourier transform infrared (FTIR) spectroscopy and the second derivative analysis were used to determine the levels of guaiacyl, syringyl and intramolecular hydrogen interactions. FTIR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that sugarcane lignin has higher thermal stability and intermolecular interactions than kraft lignin. Carbon-13 nuclear magnetic resonance (13 C NMR) spectroscopy was used for the quantitative determination of structural chemical groups and contaminants. The results indicated a large potential for the application of the obtained lignins as precursors for carbon materials.

Fabrication, Modification, and Characterization of Lignin-Based Electrospun Fibers Derived from Distinctive Biomass Sources

“…The structure of lignin is primarily reliant on wood's nature and handling conditions, but the chemical composition and properties depend on the plant source, extraction process, and post-treatment [54].…”

Evaluation of lignin as potential green filler in an optimally designed solution grade styrene–butadiene rubber (SSBR) based tyre tread compound

“…DSC analysis of lignin reveals a distinct endothermic peak near 80°C (Figure S1b) which may be assigned to the moisture loss from lignin. Lignin is moderately stable at elevated temperatures due to the cross-linking and self-polymerization of highly aromatic backbone [34]. This loss of moisture at an early stage has not initiated any cure-related defects while the samples were cured.…”

Strategies for the Removal of Polysaccharides from Biorefinery Lignins: Process Optimization and Techno Economic Evaluation

“…The alkaline hydrolysis-acid precipitation treatment was previously described in literature for the purification of Kraft and Organosolv lignin. As a result of the treatment, ash, sulfur, carbohydrate content, and the average molecular weight (M w ) of lignins were considerably reduced [12,18,29,32] and their solubility in organic solvents were improved [33].…”

“…Despite the challenges, which are (i) the structural complexity and heterogeneity of lignin, (ii) the variability of biomass sources and treatment processes, and (iii) the presence of impurities [11], the number of publications about lignin isolation, purification, fractionation, chemical modification, and potential applications has grown exponentially in the recent years [4,12,13]. These applications include binders [14], surfactants [15], dispersants for cement [16], carbon fibers [17,18], epoxy, polyurethane and phenol formaldehyde resins [19][20][21][22], thermoplastic elastomers [23], and fire retardants [13] among others. Given the applicability in diverse segments, lignin valorization could play an essential role in the bio-based economy and will contribute to the mitigation of climate change [24].…”