Pyrolysis of organic substances

There has long been an interest in eliminating sulfur during pyrolysis of organic substances (3) however, little fundamental data pertinent to formation of carbonaceous residues are available on the pyrolysis of sulfur corn-... 

Pyrimidines la 266,438,439 lb 32,430 Pyrimidine nucleoside derivatives lb 290 Pyrocatechol lb 170,172,185 -, 4-rerr-butyl- lb 201 Pyrocatechol derivatives lb 119 Pyrocatechol violet reagent la 398 Pyrogallol lb 383,399,400 Pyrogallol derivatives lb 312 Pyrolysis of organic substances la 92,96 a-Pyrone derivatives la 288 lb 387,388 Pyrrole lb 268,270 Pyrrole alkaloids la 66 lb 279 Pyrrole derivatives la 266.269,270 lb 63 Pyrrolidine derivatives lb 290 Pynolizidine alkaloids lb 243,246,291... 

The pyrolysis of organic substances in the gaseous state is often catalyzed by iodine vapour. The chain mechanism of homogeneous decomposition is then replaced by a series of simple bimolecular reactions between the iodine molecule and the organic substance having much lower activation energies. 

PAH have very low vapor pressure at room temperature. These substances, however, may deposit on the dusts in the air. PAH may be produced during pyrolysis of organic materials. These compounds can contaminate the air near coke ovens, as well as during loading and unloading of pencil pitch. 

Schulten, H.-R., Leinweber, R, and Jandl, G. (2002). Analytical pyrolysis of humic substances and dissolved organic matter in water. In Refractory Organic Substances (ROS) in the Environment, Frimmel, F. H., Abbt-Braun, G., Heumann, K. G., Hock, B., Ludemann, H.-D., and Spiteller, M., eds., Wiley-VCH, Weinheim, pp. 163-187. 

Application. Delplots are of greatest utility in the early stages of exploration of complex reactions that yield large numbers of products. To date they have mostly been applied to oxidation and pyrolysis reactions of organic substances, reactions in which most or all steps are irreversible. An example is shown for illustration. 

Schulten H.-R. and Gleixner G. (1999) Analytical pyrolysis of humic substances and dissolved organic matter in aquatic systems structure and origin. Water Res. 33, 2489-2498. 

Biacetyl has often been used for sensitizing the pyrolysis of organic compounds" . Radicals, resulting from the thermal decomposition of biacetyl, initiate the chain decomposition of such substances. However, NO causes no inhibition of notable significance in such systems . Nevertheless, this cannot be considered as an evidence against the occurrence of chains, since the sensitized decompositions are definitely inhibited by, for instance, propene . 

A particle sample collected from the flue gases of the No. 12+13 pine pyrolysis oil was studied by light and electron microscopy. Single particles contained a lot of inorganic substances, mainly calcium, other substances being iron, silicon, magnesium, aluminium, potassium, chrome and vanadium. The amount of organic substances (e.g. tars) or carbon is likely small. 

Chiavari, G., Ferretti, S., GaUetti, G.C., Mazzeo, R. (1991) Analytical pyrolysis as a tool for the characterization of organic substances in artistic and archaeological objects. Journal of Analytical and Applied Pyrolysis, 20, 253-261. 

Analytical pyrolysis has been used successfiilly in many disciplines such as polymer chemistry, organic geochemistry, soil chemistry, forensic sciences, food science, environmental studies, microbiology, and extraterrestrial studies involving meteorites and lunar samples. A large number of organic substances found in nature are unsuitable for direct analysis by modern techniques such as column chromatography and mass spectrometry. This may be due to their complex structure and polar and nonvolatile character. 

A reevaluation of molecular structure of humic substances based on data obtained primarily from nuclear magnetic resonance spectroscopy, X-ray absorption near-edge structure spectroscopy, electrospray ionization-mass spectrometry, and pyrolysis studies was presented by Sutton and Sposito (2005). The authors consider that humic substances are collections of diverse, relatively low molecular mass components forming dynamic associations stabilized by hydrophobic interactions and hydrogen bonds. These associations are capable of organizing into micellar structures in suitable aqueous environments. Humic components display contrasting molecular motional behavior and may be spatially segregated on a scale of nanometers. Within this new structural context, these components comprise any molecules... 

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