Pyrolysis characteristics of different kinds of lignins

The present chapter deals with pyrolysis characteristics of different kinds of lignins, focusing on an industrial raw lignin arising from the Kraft pulping process, a commercial alkali lignin, and Klason lignins lab-isolated from two lignocellulosic biomasses with different lignin contents (27 and 5...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Bonelli, P.R., Cukierman, A.L.
Formato: CHAP
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_97816112_v_n_p355_Bonelli
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_97816112_v_n_p355_Bonelli
record_format dspace
spelling todo:paper_97816112_v_n_p355_Bonelli2023-10-03T16:44:12Z Pyrolysis characteristics of different kinds of lignins Bonelli, P.R. Cukierman, A.L. The present chapter deals with pyrolysis characteristics of different kinds of lignins, focusing on an industrial raw lignin arising from the Kraft pulping process, a commercial alkali lignin, and Klason lignins lab-isolated from two lignocellulosic biomasses with different lignin contents (27 and 57 wt%), emerging from the processing of agro-industrial products. Characterization of the lignins includes determination of ash content, elemental composition, Fourier-transform infrared (FT-IR) spectra, and surface morphological features by scanning electronic microscopy (SEM). Pyrolysis characteristics of the different lignin samples as well as of the whole biomasses from which they are obtained, in the case of Klason lignins, are comparatively examined by non-isothermal thermogravimetric analysis from room temperature up to 1000 °C. In order to investigate possible effects of mineral matter inherently present in the industrial Kraft lignin on its pyrolytic behaviour, pyrolysis characteristics are also determined using samples prior subjected to demineralization by a mild acid treatment. The industrial Kraft lignin possesses the highest contents of ash (16 wt%) and elemental carbon (62.2 wt%) among all the investigated raw lignins. A similar pyrolytic behavior is found for the industrial raw Kraft lignin and the commercial alkali one. It is characterized by differentiated thermal degradation domains, as evidenced by three peaks in reaction rate profiles, successively attributable to moisture evolution, primary and secondary pyrolysis, with progressive increase in temperature. Mineral matter reduction of the industrial Kraft lignin induces some structural changes, as suggested by SEM images and FT-IR spectra, and noticeable modifications in its pyrolytic behavior, leading to shift primary pyrolysis to higher temperatures, to increase the maximum primary pyrolysis rate, and to inhibit secondary pyrolysis. Pyrolysis characteristics for binary mixtures composed of equal proportions of the commercial alkali lignin and polyethylene in powder form, as a representative major polymeric waste of massive post-consumed plastics, are also examined following some current research trends towards alternative energy generation based on the advantageously favourable environmental nature of bio-resources and the higher energy content of synthetic polymers. No interactions between the lignin and polyethylene are found, the pyrolytic behaviour of the mixtures arising from independent thermal degradation of the individual constituents. On the other hand, the two Klason lignins separated from sawdust of Aspidosperma australe wood and nutshells from Bertholletia excelsa, exhibit different ash contents and elemental compositions as well as noticeable differences in their pyrolysis characteristics depending on the biomass source and with respect to the pyrolytic behaviour of the untreated parent biomasses. Compared to the raw alkali lignins, the Klason lignins do not seem to undergo secondary pyrolysis and are more resistant to thermal degradation, likely due to more condensed chemical structures related to the method applied for isolation. Overall, the results highlight the marked influence of both the botanical origin of the bio-resource and extraction method used to obtain the lignins on their physicochemical characteristics and pyrolytic behaviour.© 2012 Nova Science Publishers, Inc. All rights reserved. Fil:Bonelli, P.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cukierman, A.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. CHAP info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_97816112_v_n_p355_Bonelli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The present chapter deals with pyrolysis characteristics of different kinds of lignins, focusing on an industrial raw lignin arising from the Kraft pulping process, a commercial alkali lignin, and Klason lignins lab-isolated from two lignocellulosic biomasses with different lignin contents (27 and 57 wt%), emerging from the processing of agro-industrial products. Characterization of the lignins includes determination of ash content, elemental composition, Fourier-transform infrared (FT-IR) spectra, and surface morphological features by scanning electronic microscopy (SEM). Pyrolysis characteristics of the different lignin samples as well as of the whole biomasses from which they are obtained, in the case of Klason lignins, are comparatively examined by non-isothermal thermogravimetric analysis from room temperature up to 1000 °C. In order to investigate possible effects of mineral matter inherently present in the industrial Kraft lignin on its pyrolytic behaviour, pyrolysis characteristics are also determined using samples prior subjected to demineralization by a mild acid treatment. The industrial Kraft lignin possesses the highest contents of ash (16 wt%) and elemental carbon (62.2 wt%) among all the investigated raw lignins. A similar pyrolytic behavior is found for the industrial raw Kraft lignin and the commercial alkali one. It is characterized by differentiated thermal degradation domains, as evidenced by three peaks in reaction rate profiles, successively attributable to moisture evolution, primary and secondary pyrolysis, with progressive increase in temperature. Mineral matter reduction of the industrial Kraft lignin induces some structural changes, as suggested by SEM images and FT-IR spectra, and noticeable modifications in its pyrolytic behavior, leading to shift primary pyrolysis to higher temperatures, to increase the maximum primary pyrolysis rate, and to inhibit secondary pyrolysis. Pyrolysis characteristics for binary mixtures composed of equal proportions of the commercial alkali lignin and polyethylene in powder form, as a representative major polymeric waste of massive post-consumed plastics, are also examined following some current research trends towards alternative energy generation based on the advantageously favourable environmental nature of bio-resources and the higher energy content of synthetic polymers. No interactions between the lignin and polyethylene are found, the pyrolytic behaviour of the mixtures arising from independent thermal degradation of the individual constituents. On the other hand, the two Klason lignins separated from sawdust of Aspidosperma australe wood and nutshells from Bertholletia excelsa, exhibit different ash contents and elemental compositions as well as noticeable differences in their pyrolysis characteristics depending on the biomass source and with respect to the pyrolytic behaviour of the untreated parent biomasses. Compared to the raw alkali lignins, the Klason lignins do not seem to undergo secondary pyrolysis and are more resistant to thermal degradation, likely due to more condensed chemical structures related to the method applied for isolation. Overall, the results highlight the marked influence of both the botanical origin of the bio-resource and extraction method used to obtain the lignins on their physicochemical characteristics and pyrolytic behaviour.© 2012 Nova Science Publishers, Inc. All rights reserved.
format CHAP
author Bonelli, P.R.
Cukierman, A.L.
spellingShingle Bonelli, P.R.
Cukierman, A.L.
Pyrolysis characteristics of different kinds of lignins
author_facet Bonelli, P.R.
Cukierman, A.L.
author_sort Bonelli, P.R.
title Pyrolysis characteristics of different kinds of lignins
title_short Pyrolysis characteristics of different kinds of lignins
title_full Pyrolysis characteristics of different kinds of lignins
title_fullStr Pyrolysis characteristics of different kinds of lignins
title_full_unstemmed Pyrolysis characteristics of different kinds of lignins
title_sort pyrolysis characteristics of different kinds of lignins
url http://hdl.handle.net/20.500.12110/paper_97816112_v_n_p355_Bonelli
work_keys_str_mv AT bonellipr pyrolysischaracteristicsofdifferentkindsoflignins
AT cukiermanal pyrolysischaracteristicsofdifferentkindsoflignins
_version_ 1782029859193618432

Ejemplares similares