Molecular aspects of the peatification and early coalification of angiosperm and gymnosperm woods

Stout, Scott A.; Boon, Jaap J.; Spackman, W.

doi:10.1016/0016-7037(88)90096-8

Cited by 165 publications

(86 citation statements)

References 32 publications

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“…In particular, aromatic compounds and phenol have multiple origins. Lignin-and protein-derived products could contribute to the peaks of benzene, C2-benzene, toluene, styrene, and phenol (Chiavari et al, 1994;Li et al, 2004;Nierop et al, 2001;Stankiewicz et al, 1997a, b;1997b;Stout et al, 1988), but, including C3-benzene, most of these compounds may as well originate from carbohydrates (Faure et al, 2004;Park et al, 2002). The source of benzofuran and o-xylene is not clear.…”

Section: Pyrolysis Productsmentioning

confidence: 99%

Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis

Flessa

Amelung

Helfrich

et al. 2008

Z. Pflanzenernähr. Bodenk.

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Quantitative information about the amount and stability of organic carbon (OC) in different soil organic-matter (OM) fractions and in specific organic compounds and compound-classes is needed to improve our understanding of organic-matter sequestration in soils. In the present paper, we summarize and integrate results performed on two different arable soils with continuous maize cropping (a) Stagnic Luvisol with maize cropping for 24 y, b) Luvic Phaeozem with maize cropping for 39 y) to identify (1) the storage of OC in different soil organic-matter fractions, (2) the function of these fractions with respect to soil-OC stabilization, (3) the importance and partitioning of fossil-C deposits, and (4) the rates of soil-OC stabilization as assessed by compound-specific isotope analyses. The fractionation procedures included particle-size fractionation, density fractionation, aggregate fractionation, acid hydrolysis, different oxidation procedures, isolation of extractable lipids and phospholipid fatty acids, pyrolysis, and the determination of black C. Stability of OC was determined by 13 C and 14 C analyses. The main inputs of OC were plant litter (both sites) and deposition of fossil C likely from coal combustion and lignite dust (only Phaeozem). Total soil OC stocks down to a depth of 65 cm (7.83 kg m -2 in the Luvisol and 9.66 kg m -2 in the Phaeozem) consisted mainly of mineral-bound OC (87% of total SOC in the Luvisol and 69% in the Phaeozem). In the Luvisol, free light particulate OM, OM associated with sand and coarse silt, and particulate OM occluded in macro-aggregates represented SOM fractions with mean turnover times shorter than that of the bulk soil OC (54 y). Additionally, the turnover of all individual compounds or compound classes (except for black carbon) was faster than that of bulk soil OC. These OM fractions that were less stable than the bulk soil OM made up 13% to 20% of the total OC. Organic matter in fine and medium silt and clay fractions, particulate OM occluded in micro-aggregates (53-250 lm) and OM resistant to acid hydrolysis had intermediate turnover times of about 50-100 y. These fractions with intermediate turnover times contributed 70%-80% to total soil OC. Passive OM with turnover times >200 y was isolated from the mineral-bound OM by different oxidation procedures (H 2 O 2 , Na 2 S 2 O 8 ) and made up ≤10% of the total OC. The isotopic signature of PLFAs suggests an efficient recycling of OC derived from C3 substrate. In the Phaeozem, partitioning of maize-derived C exhibited a pattern similar to the Luvisol, but turnover rates of vegetation-derived soil OC were lower, probably because of the considerably smaller input of plant residues. Fossil C contributed approx. 50% to the total OC and accumulated preferentially in the particulate OM occluded in aggregates and in the fine-sand and

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Section: Pyrolysis Productsmentioning

confidence: 99%

Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis

Flessa

Amelung

Helfrich

et al. 2008

Z. Pflanzenernähr. Bodenk.

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“…Use of the butylating reagent avoids one of the main limitations of pyrolytic methylation -its inability to distinguish between the methoxyl groups originally present in the macromolecule and the free hydroxyl groups that become methylated after the pyrolysis. This differentiation can be of key importance in studying chemical structure of lignins and in monitoring lignin signature in the geological record, since lignins are cIassed by the relation of contents in phenolic units with more or fewer hydroxyl and methoxyl groups, and the changes that lignin moieties undergo during organic matter diagenesis affect mainly their methoxyl contents [7,8]. Pyrolysis in the presence of TBAH introduces a butyl moiety in the originally free hydroxyl group (forrning an O-butyl ether) that can thus be distinguished from the original methoxyl group.…”

Section: Inlroductionmentioning

confidence: 99%

Pyrolytic alkylation-gas chromatography-mass spectrometry of model polymers Further insights into the mechanism and scope of the technique

González-Vila

Rı́o

Martı́n

et al. 1996

Journal of Chromatography A

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AbstraetThe mechanism of the high-temperature hydrolysis and alkylation with tetraalkylammonium hydroxides of bio-and geopolymers has been approached mainly by studying the behaviour of single standard compounds. In the present work, we have applied this technique to three polymers of known structure, i.e. suberin, polycitraconic acid (peA) and a lignin dehydrogenase polymer (DHP), related respectively to natural polyesters, fulvic acids and lignins, in order to get new insight into the reaction mechanism. As further application of the technique, the case study of the lignin signature during the coalification process has been analyzed by pyrolysis-butylation of humic acids extracted from two peat and lignite samples.

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“…This, in turn, leads to alkylation of aromatic rings (Botto, 1987). Another important early coalification process is the cleavage of aryl-O bonds in lignin, specifically methoxyl groups attached to the aromatic rings through a demethylation process (Hatcher et al, 1981;Stout et al, 1988). Consequently, the chemical structural composition of subbituminous coal is that of the lignin precursor after losing its methoxyl groups through demethylation and dehydroxylation and after the loss of its side chain hydroxyls.…”

Section: Organic Geochemical Changes With Rankmentioning

confidence: 99%

On the fundamental difference between coal rank and coal type

O’Keefe

Bechtel

Christanis

et al. 2013

International Journal of Coal Geology

298

104

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Molecular aspects of the peatification and early coalification of angiosperm and gymnosperm woods

Cited by 165 publications

References 32 publications

Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis

Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis

Pyrolytic alkylation-gas chromatography-mass spectrometry of model polymers Further insights into the mechanism and scope of the technique

On the fundamental difference between coal rank and coal type

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