SEED FUND 2.0 perspective project LIFT

Lignin fractionation and separation to produce different technical lignins

Results

The SEED FUND 2.0 project LIFT further investigated the application of anti-solvent precipitation using n-pentane to fractionate OrganoCat lignin from different plant sources. In a first evaluation, lignins from ten different plant materials were extracted using the OrganoCat process and characterized. Sida and Szarvasi lignins were particularly interesting due to their contrasting properties in molecular size distribution, β-O-4-linkage content and lignin monomer ratio (S/G/H). The lignin from both sources showed different precipitation profiles in the applied anti-solvent/lignin feed solution (A/F) ratios. Lignin extracted from Sida exhibited a better fractionation in regards to yield of each fraction at low A/F ratios than Szarvasi lignin. In general, the average molecular size distribution and β-O-4-linkage content of the lignin fractions declined with the addition of more n-pentane. Lignin monomer ratios throughout the fractions at different A/F ratios did not change significantly, independent of the S/G/H-ratio of lignin extracted from the different plants. This indicates that the extracted lignins have a statistical distribution of S/G/H ratio – depending on the plant biomass - throughout the lignin extracted with OrganoCat.

In summary, the established technology for lignin fractionation exhibits a robust method to precipitate and fractionate lignin from pretreatment processes like OrganoCat. Lignin of different structure and composition can be successfully fractionated according to molecular size distribution and β-O-4 linkage content. This opens the possibility to produce tailor-made lignin fractions giving useful insights into options for further lignin applications.

SEED FUND 2.0 Coordinator

Dr. Holger Klose
Head of Research | Alternative Biomasss
Institute of Bio- and Geosciences - Plant Sciences
Forschungszentrum Jülich GmbH
phone: +49 2461 61334
email: h.klose@fz-juelich.de

Partners

Prof. Dr. U. Schurr, Dr. P.M. Grande, D. Weidener MSc, IBG-2, Forschungszentrum Jülich
Prof. Dr. A. Jupke, Arne Holtz MSc, AVT – Fluid Process Engineering, RWTH Aachen University

Funding period

01.07.2020 - 31.06.2021

Funding

LIFT is is part of the NRW-Strategieprojekt BioSC and thus funded by the Ministry of Culture and Science of the German State of North Rhine-Westphalia.

Publications

Weidener D, Klose H, Graf von Westarp W, Jupke  A, Leitner W, Domínguez de María P, Grande PM (2021). Selective lignin fractionation using CO2-expanded 2-methyltetrahydrofuran (2-MTHF). Green Chemistry 23, 6330-6336.