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Analytical Pyrolysis

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Helena Pereira – One of the best experts on this subject based on the ideXlab platform.

  • Influence of tree eccentric growth on syringyl/guaiacyl ratio in Eucalyptus globulus wood lignin assessed by Analytical Pyrolysis
    Journal of Analytical and Applied Pyrolysis, 2001
    Co-Authors: Jose Carlos Rodrigues, José Graça, Helena Pereira

    Abstract:

    Abstract Wood disks from 9-year-old Eucalyptus globulus trees that showed eccentric growth were analysed by Analytical Pyrolysis to determine lignin syringyl/guaiacyl (s/g) ratio, lignin content and polysaccharide composition (hexosans/hexosans+pentosans). Three cross-sectional fractions were analysed: the long radius, the short radius and the intermediate sections. Between-tree variation was observed for the s/g ratio from 2.0 to 2.8, the lignin content from 26.5 to 28.0% and the hesosans/hexosans+pentosans ratio from 0.76 to 0.83. The reliability of the Pyrolysis analysis assessed by the pooled standard deviation was very high for the three determinations (2–3% coefficients of variation). Eccentric tree growth in E. globulus has no impact in the s/g ratio and does not necessarily imply differences in lignin content or in polysaccharide composition. When differences occur, lower lignin and higher cellulose are found in the cross section part with the highest radial growth. Sampling for wood chemical analysis in eccentric cross sections should avoid the stem parts with high radial differences between opposite sides. Analytical Pyrolysis can be used to prospect for the presence of tension wood.

  • influence of tree eccentric growth on syringyl guaiacyl ratio in eucalyptus globulus wood lignin assessed by Analytical Pyrolysis
    Journal of Analytical and Applied Pyrolysis, 2001
    Co-Authors: Jose Carlos Rodrigues, José Graça, Helena Pereira

    Abstract:

    Abstract Wood disks from 9-year-old Eucalyptus globulus trees that showed eccentric growth were analysed by Analytical Pyrolysis to determine lignin syringyl/guaiacyl (s/g) ratio, lignin content and polysaccharide composition (hexosans/hexosans+pentosans). Three cross-sectional fractions were analysed: the long radius, the short radius and the intermediate sections. Between-tree variation was observed for the s/g ratio from 2.0 to 2.8, the lignin content from 26.5 to 28.0% and the hesosans/hexosans+pentosans ratio from 0.76 to 0.83. The reliability of the Pyrolysis analysis assessed by the pooled standard deviation was very high for the three determinations (2–3% coefficients of variation). Eccentric tree growth in E. globulus has no impact in the s/g ratio and does not necessarily imply differences in lignin content or in polysaccharide composition. When differences occur, lower lignin and higher cellulose are found in the cross section part with the highest radial growth. Sampling for wood chemical analysis in eccentric cross sections should avoid the stem parts with high radial differences between opposite sides. Analytical Pyrolysis can be used to prospect for the presence of tension wood.

  • Determination of tree to tree variation in syringyl/guaiacyl ratio of Eucalyptus globulus wood lignin by Analytical Pyrolysis
    Journal of Analytical and Applied Pyrolysis, 1999
    Co-Authors: Jose Carlos Rodrigues, Dietrich Meier, Oskar Faix, Helena Pereira

    Abstract:

    Abstract High syringyl/guaiacyl ratios (S/G ratios) are advantageous for pulping. Analytical Pyrolysis was applied to Eucalyptus globulus wood to measure S/G ratios and assess its potential in forest breeding programmes. Samples were collected from five trees of two provenances grown in three sites. After peak assignment, relative peak areas were calculated for carbohydrate, guaiacyl and syringyl type degradation products. Lignin derived products account on average for 21% of the total identified area. The average S/G ratio of trees was 2.0, ranging from 1.5 to 2.6. The analysis of variance for the S/G ratios showed that provenance and tree were highly significant sources of variation accounting for 48 and 27% of the variation, respectively. Site had no influence but ‘site×provenance’ interaction was significant and accounted for 16% of the variation. The error associated with the method represented only 6% of the variation. Analytical Pyrolysis proved reproducible and sensitive for the measurement of the natural variability of E. globulus with regard to lignin composition. The pyrolytic determination of the S/G ratios is recommended as an evaluation trait in breeding programmes for pulpwood production.

Jose Carlos Rodrigues – One of the best experts on this subject based on the ideXlab platform.

  • Characterization of residual lignin in cellulose isolated by the diglyme method from three Pinus species by IR spectroscopy and Analytical Pyrolysis
    Holzforschung, 2018
    Co-Authors: Ana Alves, Sara Santos, Rita Simões, Jose Carlos Rodrigues

    Abstract:

    AbstractQuantitative determination of cellulose content by means of diglyme [bis(2-methoxyethyl) ether] isolation is useful for rapid screening experiments. However, diglyme isolation from softwoods results in a certain amount of residual lignin in the cellulose. In this paper, the lignin content (L) in diglyme cellulose of three pine species (Pinus halepensisMiller,Pinus sylvestrisL. andPinus pinasterAiton) was analysed by ATR-FTIR spectroscopy and Analytical Pyrolysis (Py). Py allowed lignin quantification. The influence of wood milling on cellulose yield was also analyzed and it was shown that a particle size between 10 and 60 mesh did not noticeably influence the cellulose yield or L; however, ball-milling to powder did cause a cellulose loss of around 37%. The diglyme method is only reproducible if the experimental parameters are standardized and meticulously followed.

  • Analytical Pyrolysis as a direct method to determine the lignin content in wood: Part 3. Evaluation of species-specific and tissue-specific differences in softwood lignin composition using principal component analysis
    Journal of Analytical and Applied Pyrolysis, 2008
    Co-Authors: Ana Alves, Notburga Gierlinger, Manfred Schwanninger, Jose Carlos Rodrigues

    Abstract:

    Both the genetics and the environment determine the chemical composition of wood. To assess the chemical composition Analytical Pyrolysis is being increasingly used. Each single pyrogram is a fingerprint of the chemical composition that should reflect tissue, species, and site related information although hidden in an amount of data. Principal component analysis was applied to evaluate the Pyrolysis results with respect to differences in lignin composition using G- and H-lignin-derived peaks from the pyrograms. The three species: pine, spruce and larch were separated in the first principal scores plot and the corresponding loadings plot revealed that it is vanillin (G 9) and G–C C C (G 11) on one hand and isoeugenol (G 8) and dihydroconiferyl alcohol (G 19) on the other hand that separate spruce and larch from pine. Beside others G 9 plus G 11 and G 8 plus G 19 separate spruce form larch as well as Vaquey pine from Blagon pine. In addition an investigation of the different tissues – normal wood and reaction wood – and the discussion of these results together with the loadings helped to reveal the differences in lignin composition between the species, tissues, and two sites. It was shown that Analytical Pyrolysis combined with principal component analysis could be useful for the identification of species and their origin.

  • Influence of tree eccentric growth on syringyl/guaiacyl ratio in Eucalyptus globulus wood lignin assessed by Analytical Pyrolysis
    Journal of Analytical and Applied Pyrolysis, 2001
    Co-Authors: Jose Carlos Rodrigues, José Graça, Helena Pereira

    Abstract:

    Abstract Wood disks from 9-year-old Eucalyptus globulus trees that showed eccentric growth were analysed by Analytical Pyrolysis to determine lignin syringyl/guaiacyl (s/g) ratio, lignin content and polysaccharide composition (hexosans/hexosans+pentosans). Three cross-sectional fractions were analysed: the long radius, the short radius and the intermediate sections. Between-tree variation was observed for the s/g ratio from 2.0 to 2.8, the lignin content from 26.5 to 28.0% and the hesosans/hexosans+pentosans ratio from 0.76 to 0.83. The reliability of the Pyrolysis analysis assessed by the pooled standard deviation was very high for the three determinations (2–3% coefficients of variation). Eccentric tree growth in E. globulus has no impact in the s/g ratio and does not necessarily imply differences in lignin content or in polysaccharide composition. When differences occur, lower lignin and higher cellulose are found in the cross section part with the highest radial growth. Sampling for wood chemical analysis in eccentric cross sections should avoid the stem parts with high radial differences between opposite sides. Analytical Pyrolysis can be used to prospect for the presence of tension wood.

Carlos Henrique Ataide – One of the best experts on this subject based on the ideXlab platform.

  • Thermal Analysis and Analytical Pyrolysis of Three Types of Lignin
    Materials Science Forum, 2017
    Co-Authors: José Alair Santana, Wender Santana Carvalho, Tiago José Pires De Oliveira, Carlos Henrique Ataide

    Abstract:

    There is a growing interest in new technologies for power generation, making use of renewable natural resources. Fast Pyrolysis is an effective and promising process of thermal decomposition of organic materials. This study evaluated the thermal decomposition of three different types of lignin and investigated the composition of the volatiles formed during the Analytical Pyrolysis. The thermogravimetric analysis, which is a widely used Analytical technique to observe the thermal behavior of materials, was used to investigate the decomposition of the samples at different heating rates. The microPyrolysis is a fast and reliable Analytical technique that provides useful background information for development of the complex process production of bio-oil. This study evaluated the composition of the vapor formed during Analytical Pyrolysis at 450, 550 and 650°C. The curves obtained by thermogravimetric analysis indicate the degradation of all lignin samples takes place in a wide temperature range. Analytical Pyrolysis tests for three types of lignin showed formation of phenolic compounds as most significant components.

  • Fast Pyrolysis of sweet sorghum bagasse in a fluidized bed reactor: Product characterization and comparison with vapors generated in Analytical Pyrolysis
    Energy, 2017
    Co-Authors: Wender Santana Carvalho, Tiago José Pires De Oliveira, José Alair Santana Júnior, Carlos Henrique Ataide

    Abstract:

    Lignocellulosic biomass can be used as an alternative for the production of fuels and chemical feedstocks using thermochemical conversion processes, such as Pyrolysis. This study aims to perform the fast Pyrolysis of sweet sorghum bagasse in a fluidized bed unit, comparing the results obtained with the products from Analytical Pyrolysis. Furthermore, the apparent activation energy of thermal decomposition of biomass was determined using two global reaction models. The estimated values of apparent activation energy ranged from 106.2 to 203.3 kJ/mol. The main compounds identified in the vapors generated in the Analytical Pyrolysis were acetic acid, isoprene, methyl pyruvate, furfural, 2,3-dihydrobenzofuran, 4-hydroxy-3-methylacetophenone and 5-hydroxymethylfurfural. In the bio-oil produced in the fluidized bed unit, the main compounds identified were benzene, acetic acid, isoprene, 3-methoxypropanal, toluene, furfural, 1,1-dimethoxycyclohexane and phenol. The difference between the identified compounds could be attributed to the solvent used, the efficiency of the condensation system, the occurrence of secondary reactions during the fast Pyrolysis process in the fluidized bed reactor and the polymerization after the condensation of the vapors produced.

  • thermal decomposition profile and product selectivity of Analytical Pyrolysis of sweet sorghum bagasse effect of addition of inorganic salts
    Industrial Crops and Products, 2015
    Co-Authors: Wender Santana Carvalho, Izabel F Cunha, Marina Seixas Pereira, Carlos Henrique Ataide

    Abstract:

    Sweet sorghum is an important biomass in biofuels and value-added chemicals production. This work studied the effects of inorganic chlorides in the Analytical Pyrolysis of sweet sorghum bagasse. Two inorganic chlorides were used: ZnCl2 and MgCl2·6H2O. The thermal decomposition kinetics of this biomass was investigated by thermogravimetric analysis. The results indicated that the addition of inorganic salts modified the degradation profile of sweet sorghum bagasse. A decrease in the maximum degradation rate was observed for both hemicellulose and cellulose fractions in the assays with addition of ZnCl2. Tests with MgCl2 showed a significant decrease in the peak corresponding to hemicellulose. In the presence of both salts, a solid residues increase was observed. The large amount of non-oxygenated compounds (isoprene and limonene), which are obtained from the Analytical Pyrolysis of pure sweet sorghum bagasse, may indicate the formation of a bio-oil chemically more stable than the bio-oil produced from another biomass. On the other hand, the addition of salts led to an increase in the content of furfural, especially in the test with ZnCl2.