Lignins derived from abundant and renewable resources are nontoxic and extremely versatile in performance, qualities that have made them increasingly important in many industrial applications. We have shown recently that liquefaction of lignin extracted from aspen wood resulted in a 90% yield of liquid. In this paper, the hydrothermal treatment of five types of lignin and biomass residues was studied: Kraft pine lignin provided by MeadWestvaco, Kraft pine lignin from Sigma-Aldrich, organosolv lignin extracted from oat hull, the residues of mixed southern hardwoods, and switchgrass after hydrolysis. The yields were found dependent on the composition or structure of the raw materials, which may result from different pretreatment processes. We propose a kinetic model to describe the hydrothermal treatment of Kraft pine lignin and compare it with another model from the literature. The kinetic parameters of the presented model were estimated, including the reaction constants, the pre-exponential factor, and the activation energy of the Arrhenius equations. Results show that the presented model is well in agreement with the experiments.
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Acknowledgements The University of Minnesota Initiative for Renewable Energy and the Environment (IREE) is gratefully acknowledged for its financial support. The authors would like to thank MeadWestvaco and Dr. Kwok-Choi Patrick Lee (Tennessee Valley Authority) for providing lignin, and our collaborators, Dr. Marc von Keitz, Dr. Kenneth Valentas, Dr. Ulrike W Tschirner, Dr. Vernon R Eidman, Dr. Steve Polasky, and Dr. Waleed Wafa Al-Dajani.
Copyright 2008 Elsevier B.V., All rights reserved.
- Biomass residue
- Hydrothermal treatment
- Kinetic model
- Kraft lignin