Chemometric appraisal of lignin pyrolytic assemblages from Eucalyptus woods relevant for pulping in Uruguay

Abstract

Analytical pyrolysis (Py-GC/MS) at 500 ºC was applied to study wood composition of Eucalyptus species (E. grandis, E. dunnii and E. benthamii) which are relevant for pulping in Uruguay. Multivariate data treatments mainly principal component analysis and discriminant analysis with automatic backwards variable selection were used to explore differences between the original wood cultivars. Multivariate analyses with automatic backwards variable selection indicated that simplified methoxyphenol patterns (up to 10 compounds) are sufficient for wood discrimination in terms of species and geographical origin but also with purposes of forecasting the ease of delignification of the resulting pulps measured as active alkali. No additional chemotaxonomical accuracy was achieved when the data sets were enlarged with carbohydrate-derived products. On the other side, discriminant or forecasting models were much less significant when based on individual diagnostic compounds, groups of compounds, or the classical syringyl-to-guaiacyl (SG) ratio. Principal component analysis indicated that the variability in lignin composition due to bioclimatic variations (spatial replications) was more significant than that due to phylogenetic differences (species and cultivars).

Compound‐specific stable carbon isotopic signature of carbohydrate pyrolysis products from C3 and C4 plants

“…The marker compounds F, HMF and LV are structures commonly found not only in pyrolysates of sucrose but also in a wide range of more complex organic materials that have a variable carbohydrate proportion, i.e. natural fibres, woods, soils, peat and other organic deposits, compost, etc . This technique could also be used in tetramethylammonium hydroxide (TMAH) thermochemolysis where a Py‐GC/MS system is being employed to carry out thermally assisted hydrolysis (THM) in the presence of TMAH provided that the isotopic composition of the added methyl groups have been measured, e.g.…”

Environmental changes recorded in the Holocene sedimentary infill of a tropical estuary

“…Other relevant biomarkers for vegetation are the methoxyphenols, released from lignins during pyrolysis and widely used for the direct study this biopolymer (Meier & Faix, 1992;Galetta et al, 2014;Blánquez et al, 2017). Lignin is mainly composed by three precursors: pcoumaryl (H), coniferyl (G), and sinapyl (S) alcohols and their proportion differ between groups of plants; whereas the softwood lignin from gymnosperms is made up by G units, that in hardwood from angiosperms contains G and S, and grass lignin G, S and H units.…”

Pyrolysis-GC/MS Analysis of Fast Growing Wood Macaranga Species

“…Previous studies of Py-GC/MS of closely related species had different aims. Galetta et al (2014) pyrolysed samples of three Eucalyptus species from various locations at one temperature and looked at the yields of of a few compounds to calculate the guaiacyl/syringyl ratio in the lignin and assess the pulping potential of the samples. Gerber et al (2016) analysed a large number of genotypes of Arabidopsis in order to study how closely the different types were related DOI: http://dx.doi.org/10.17509/ijost.v6i1 p-ISSN 2528-1410 e-ISSN 2527-8045…”

“…Therefore, it is worthwhile to study the characteristics of the products obtained from pyrolysis of Macaranga species, differing in characteristics such as lignin and cellulose content, using Py-GC/MS, to provide information on the potential values of the pyrolysis products as liquid fuel. (Galetta et al, 2014) In this paper, we report the results obtained from Py-GC/MS of six different species of Indonesian Macaranga. The pyrolysis yield and relative abundance of different classes of identified compounds at different temperatures were determined.…”