Pyrolysis residual analysis

Wilson, M.A., Young, B.C., and Scott, K.M. Coal pyrolysis residue analysis by Al and Si nuclear magnetic resonance spectrometry. 1986 65 1584-1587. 

Helsen L Bulck E.V.D. (1998) The microdistribotion of copper, chromium and arsenic in CCA treated wood and its pyrolysis residue using energy dispersive X-ray analysis in scanning electron microscopy Noiz/orschung S2 607-614. 

Helsen L. and Van den Buick E. (1998) The Microdistribution of Copper, Chromium and Arsenic in CCA Treated Wood and Its Pyrolysis Residue Using Energy Dispersive X-Ray Analysis in Scanning Electron Microscopy. Hoizforschung, 52 (6), 607-614. 

The electrolytic conductivity detector for gas chromatography was developed by Coulson (15, 16, 17), who described modes of operation for the detection of chlorine, sulfur, or nitrogen, but did not establish the reliability of the detector for pesticide residue analysis or the minimum detectability for each molecular species. Cassil et al. (11) described the use of the detector for determining residues of carbamate pesticides and compared its response with that of the microcoulometric detector, as mentioned earlier, finding them equal in response and selectivity and usable over a range of 3 to 200 ng of nitrogen. An improved pyrolysis tube was described, and nickel wire or turnings was used as the catalyst... 

The effect of additives on the asphaltene from the Catalytic Incorporated (Cat. Inc.) coal liquid product was studied. Asphaltene is defined as the pentane insoluble but benzene soluble part of the coal liquid. The fractionation procedure has been described in detail elsewhere(l) and is shown schematically in Figure 1. Some work was also done with A240 petroleum pitch. Elemental analysis for the Wyoming sub-bituminous coal. Cat. Inc. coal liquid product, and Cat. Inc. asphaltene and A240 petroleum pitch are shown in Table I. Measured amounts of the additive compounds to be studied were added to the Cat. Inc. asphaltene and petroleum pitch. The samples were pyrolyzed and the pyrolysis residues examined by cross polarized light microscopy. Elemental analyses of the residues were done. 

Furthermore, the analysis of the pyrolysis residue of PC obtained at 400°C, after 1 hour of isothermal heating, showed the presence of several consecutive xanthone units indicating that at this temperature the isomerization and condensation processes are quite extensive. ... 

In another study, ammonolysis of the main-chain carbonate groups (Scheme 7.6), followed by FAB-MS analysis, was performed to characterize the pyrolysis residue of poly(bisphenol-A carbonate) (PC). °... 

The branched chain poly tertiary-butyl acrylate has been considered by several workers [36] at low temperatures. Schaefgen and Sarasohn [37] have studied this degradation at several low temperatures. At 160 °C isobutylene was lost quantitatively while above 180 °C approximately half of the weight of the polymer was lost after 12 hours of heating with the gaseous products being 36% isobutylene, 11% water, and 3% carbon dioxide. Elemental analysis of the pyrolysis residue corresponded approximately to polyacrylic anhydride (C H Oj). 

Poly(bisphenol-A carbonate) (PC) is an important engineering thermoplastic material, which is subjected to injection moulding operations at temperature above 300 °C. At this temperature, degradation reactions are likely to occur 732351, and therefore the understanding of its thermal behaviour is of crucial importance in the end-use applications 895472 891434 888765 882593 856011 [a.71]. The thermal decomposition of PC 882592 855971 (Scheme 29) has been investigated by heating isothermally at 300, 350,400 and 450 °C and subsequent analysis of the pyrolysis residue by means of MALDI mass spectrometry 870570 766615. ... 

Chemical Analysis. The presence of siUcones in a sample can be ascertained quaUtatively by burning a small amount of the sample on the tip of a spatula. SiUcones bum with a characteristic sparkly flame and emit a white sooty smoke on combustion. A white ashen residue is often deposited as well. If this residue dissolves and becomes volatile when heated with hydrofluoric acid, it is most likely a siUceous residue (437). Quantitative measurement of total sihcon in a sample is often accompHshed indirectly, by converting the species to siUca or siUcate, followed by deterrnination of the heteropoly blue sihcomolybdate, which absorbs at 800 nm, using atomic spectroscopy or uv spectroscopy (438—443). Pyrolysis gc followed by mass spectroscopic detection of the pyrolysate is a particularly sensitive tool for identifying siUcones (442,443). This technique rehes on the pyrolytic conversion of siUcones to cycHcs, predominantly to [541-05-9] which is readily detected and quantified (eq. 37). 

Thermolysis-mass spectrometry is ideal for examining the amount of residual monomer and processing solvents present in polymers. In thermolysis, the polymer is heated from room temperature to 200-300 °C, and is then often held isothermally in order to drive off volatile components. Low-temperature pyrolysis (350-400 °C) of PP compounds in direct mass-spectral analysis has shown volatiles from PP at every carbon number to masses well above 1000 Da [37]. 

The material balance is consistent with the results obtained by OSA (S2+S4 in g/100 g). For oil A, the coke zone is very narrow and the coke content is very low (Table III). On the contrary, for all the other oils, the coke content reaches higher values such as 4.3 g/ 100 g (oil B), 2.3 g/ioo g (oil C), 2.5 g/ioo g (oil D), 2.4/100 g (oil E). These organic residues have been studied by infrared spectroscopy and elemental analysis to compare their compositions. The areas of the bands characteristic of C-H bands (3000-2720 cm-1), C=C bands (1820-1500 cm j have been measured. Examples of results are given in Fig. 4 and 5 for oils A and B. An increase of the temperature in the porous medium induces a decrease in the atomic H/C ratio, which is always lower than 1.1, whatever the oil (Table III). Similar values have been obtained in pyrolysis studies (4) Simultaneously to the H/C ratio decrease, the bands characteristics of CH and CH- groups progressively disappear. The absorbance of the aromatic C-n bands also decreases. This reflects the transformation by pyrolysis of the heavy residue into an aromatic product which becomes more and more condensed. Depending on the oxygen consumption at the combustion front, the atomic 0/C ratio may be comprised between 0.1 and 0.3 ... 

GC cannot be applied to the analysis of bromocriptine mesilate due to its low volatility and its thermal instability. A procedure according to 29 or 30, which claims excellent identification and quantitation on the basis of well-defined peptide section pyrolysis products, has not yet been attempted. However, GC is very useful determining the residual recrystallization solvent butanone-2. 

Mos of the solid carbonaceous material available to industry is derived from the pyrolysis of petroleum residues, coal, and coal tar residues. Understanding the reactions occurring during pyrolysis would be beneficial in conducting materials research on the manufacture of carbonaceous products. The pyrolysis of aromatic hydrocarbons has been reported to involve condensation and polymerization reactions that produce complex carbonaceous materials (I). Interest in the mechanism of pyrolysis of aromatic compounds is evidenced in a recent study by Edstrom and Lewis (2) on the differential thermal analysis of 84 model aromatic hydrocarbons. The study demonstrated that carbon formation was related to the molecular size of the compound and to energetic factors that could be estimated from ionization potentials. 

Gonzalez-Vila,F. J.,Tinoco, P., Almendros, G., and Martin,F. (2001). Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass. I. Agric. Food Chem. 49,1128-1131. 

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