Subcritical water de-polymerization of Kraft lignin: A process for future biorefineries. Structural characterization of bio-oil and solids
Paper in proceedings, 2015

A 2D-NMR analysis was carried out on fractionated bio-oil in order to investigate the result of the subcritical water base catalysed de-polymerization of LignoBoost Kraft lignin (350 °C, 25 MPa). It was confirmed that the signals from aliphatic lignin inter-unit linkages, i.e. ß-O-4’, ß-ß’, ß-1’ and ß-5’, had disappeared in all bio-oil fractions (light oil, heavy oil and suspended solids). This means that both aliphatic carbon-oxygen (C-O) and carbon-carbon (C-C) bonds in LignoBoost Kraft lignin have been broken and an effective de-polymerization has occurred. However, re-polymerization to higher molecular weight (Mw) fractions take place simultaneously. These higher Mw fractions (heavy oil and suspended solids) were found to be re-polymerized macromolecules (Mw distribution 5.4 kDa and 19.5 kDa resp.) with new structural networks based on guaiacol/disubstituted aromatic ethers and polyaromatic hydrocarbon structures tightly bound together. In this work it has been demonstrated that the subcritical water de-polymerization process of LignoBoost Kraft lignin does function; an effective de-oxygenation of LignoBoost Kraft lignin takes place, generating a bio-oil with a low content of atomic oxygen (15 wt.%) suitable for further processing at fossil-based oil refineries.

Author

Cecilia Mattsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

Sven-Ingvar Andersson

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Tallal Belkheiri

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Lars-Erik Åmand

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

L. Olausson

Valmet Oy

Lennart Vamling

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Hans Theliander

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

NWBC 2015 - 6th Nordic Wood Biorefinery Conference

112-119

6th Nordic Wood Biorefinery Conference, NWBC 2015
Helsinki, Finland,

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Polymer Chemistry

Polymer Technologies

Other Chemistry Topics

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9/15/2020