Assessment of the thermal behavior of lignins from softwood and hardwood species
Keywords:
Activation energy, degradation mechanism, lignin, TGA, thermal stability.Abstract
The thermal behavior of lignins from softwood and hardwood species has been investigated using thermogravimetry and differential scanning calorimetry. Klason Lignin from Pinus taeda and Klason lignin from Eucalyptus grandis were studied. The differential scanning calorimetry results showed that both Klason lignins studied presented similar glass transition temperature. Thermogravimetric results showed that the lignin degradation occurs in three stages. The Klason lignin of Pinus taeda is more thermally stable than Eucalyptus grandis, probably because of the higher thermal stability of the guaiacyl units in softwood lignin. The degradation of both lignins initiate by a diffusion process. However when the conversion values are higher than 0,1 the lignin degradation mechanism is a complex procedure and involves the degradation of a highly condensed aromatic structure formed at the previous degradation stages.Downloads
References
Back, M.H. 1989. Comment on the thermal decomposition of anisole and the heat of formation of the phenoxy radical. Journal of Physical Chemistry 93:6880-6881.
Bährle, C.; Custodis, V.; Jeschke, G.; van Bokhoven, J.; Vogel, F. 2014. In situ observation of radicals and molecular products during lignin pyrolysis. ChemSusChem 7:2022-2029.
Bianchi, O.; Martins, J. De N.; Fiorio, R.; Oliveira, R.V.B.; Canto, L.B. 2011. Changes in activation energy and kinetic mechanism during EVA crosslinking. Polymer Testing 30:616-624.
Brosse, N.; El Hage, R.; Chaouch, M.; Pétrissans, M.; Dumarçay, S. 2010. Investigation of the chemical modifications of beech wood lignin during heat treatment. Polymer Degradation and Stability 95:1721-1726.
Buranov, A.U.; Ross, K.A.; Mazza, G. 2010. Isolation and characterization of lignins extracted from flax shives using pressurized aqueous ethanol. Bioresource Technology 101:7446-7455.
Criado, J.M.; Málek, J.; Ortega, A. 1989. Applicability of the master plots in kinetic analysis of non-isothermal data. Thermochimica Acta 147:377-385.
Faravelli, T.; Frassoldati, A.; Migliavacca, G.; Ranzi, E. 2010. Detailed kinetic modeling of the thermal degradation of lignins. Biomass and Bioenergy 34:290-301.
Feldman, D.; Banu, D.; Campanelli, J.; Zhu, H. 2001. Blends of vinylic copolymer with plasticized lignin: thermal and mechanical properties. Journal of Applied Polymer Science 81:861-874.
Ferdous, D.; Dalai, A.K.; Bej, S.K.; Thring, R.W. 2002. Pyrolysis of lignins: experimental and kinetics studies. Energy & Fuels 16:1405-1412.
Flynn, J.H.; Wall, L.A. 1966. General treatment of the thermogravimetry of polymers. Journal of Research of the National Bureau of Standards 70A:487-523.
Frankenstein, C.; Schmitt, U. 2006. Microscopic studies on modified wall structure and lignin topochemistry in xylem fibres of poplar after wounding. Maderas-Cienc Tecnol 8(2):93-106.
Godoy, E.A.; Rodrigues, J.C.C.; Alves, A.M.M.; Lazo, D.A. 2007. Content and quality study of the lignin by analytical pyrolysis in Pinus caribaea. Maderas-Cienc Tecnol 9(2):179-188.
Jiang, G.; Nowakowski, D. J.; Bridgwater, A.V. 2010. A systematic study of the kinetics of lignin pyrolysis. Thermochimica Acta 498:61-66.
Kiaei, M.; Kord, B.; Vaysi, R. 2014. Influence of residual lignin content on physical and mechanical properties of kraft pulp/PP composites. Maderas-Cienc Tecnol 16(4):495-503.
Klein, M.T.; Virk, P.S. 2008. Modeling of lignin thermolysis. Energy & Fuels 22:2175-2182.
Kubo, S.; Kadla, J. 2005. Hydrogen bonding in lignin: a Fourier transform infrared model compound study. Biomacromolecules 6:2815-2821.
Ornaghi Jr., Poletto, M.; Zattera, A.J., Amico, S.C. 2014. Correlation of the thermal stability and the decomposition kinetics of six different vegetal fibers. Cellulose 21: 177-188.
Ozawa T. 1965. A new method of analyzing thermogravimetric data. Bulletin of the Chemical Society of Japan 38:1881-1886.
Pérez-Maqueda, L.A.; Criado, J.M. 2000. The accuracy of Senum and Yang’s approximations to the Arrhenius integral. Journal of Thermal Analytical and Calorimetry 60:909-915.
Poletto, M.; Dettenborn, J.; Pistor, V.; Zeni, M.; Zattera, A.J. 2010. Materials Produced from Plant Biomass. Part I: Evaluation of Thermal Stability and Pyrolysis of Wood. Materials Research 13:375-379.
Poletto, M.; Zattera, A.J. 2013. Materials Produced from Plant Biomass. Part III: degradation kinetics and hydrogen bonding in lignin. Materials Research 16:1065-1070.
Sanchez-Silva, L.; López-González, D.; Villaseñor, J.; Sánchez, P.; Valverde, J.L. 2012. Thermogravimetric-mass spectrometric analysis of lignocellulosic and marine biomass pyrolysis. Bioresource Technology 109:163-172.
Tejado, A.; Peña, C.; Labidi, J.; Echeverria, J.M.; Mondragon, I. 2007. Physico-chemical characterization of lignins from different sources for use in phenol-formaldehyde resin synthesis. Bioresource Technology 98:1655-1663.
Yao, F.; Wu, Q.; Lei, Y.; Guo, W.; Xu, Y. 2008. Thermal decomposition kinetics of natural fibers: activation energy with dynamic thermogravimetric analysis. Polymer Degradation and Stability 93:90-98.
Yasuda, S.; Fukushima, K.; Kakehi, A. 2001. Formation and chemical structures of acid-soluble lignin I: sulfuric acid treatment time and acid-soluble lignin content in hardwood. Journal of Wood Science 47:69-72.
Wang, S.; Wang, K.; Liu, Q.; Gu, Y.; Luo, Z.; Cen, K.; Fransson, T. 2009. Comparison of the pyrolysis behavior of lignins from different tree species. Biotechnology Advances 27:562-567.
Wang, S.; Ru, B.; Lin, H.; Sun, W.; Luo, Z. 2015. Pyrolysis behaviors of four lignin polymers isolated from the same pine wood. Bioresource Technology 182:120-127.
Zhao, X.; Liu, D. 2010. Chemical and thermal characteristics of lignins isolated from Siam weed stem by acetic acid and formic acid delignification. Industrial Crops and Products 32:284-291.
