Thermal decomposition of organic matter

Diminished alkalinity, attributable to thermal decomposition of organic matter to acidic compounds... 

Impairment of steam purity, attributable to thermal decomposition of organic matter to volatile compounds this is especially important where steam is used directly in processing food, pharmaceuticals, or beverages... 

Tammann and Oelsen, Z. anorg. Chem., 1927, 172, 407 many metals (copper, iron, tin, aluminium) have characteristic smells, at least when handled (when the perspiration of the skin may have some action). The smell of stones on attrition, noticed by Boyle (see Partington, Nature, 1921, 106, 631), is probably due to thermal decomposition of organic matter. 

All those results are concordant with other found in literature [6, 7] where the CO is the majority product fi-om the carbonate decon osition in presence of C. Up to 650 C CO and C02 come from thermal decomposition of organic matter and from this temperature the inorganic decomposition starts mainly carbonate decomposition. As these reactions are endothermic they are tfacrmodynamically favoured a higher temperatures. So, as ten erature increases both peaks, CO and CO2, are greater, mainly the CO ones. 

Pyrolysis (or devolatilisation) is a thermal decomposition of organic matter in an inert atmosphere. In the gasification or partial gasification oxidation medium is added to the process. This oxidation medium usually is air or oxygen. Pyrolysis is also the first step in combustion and gasification. 

Lewan MD, Winters JC (1991) Retardation of the thermal decomposition of organic matter in shales under hydrous conditions. Geol Soc Am Abstr Programs 23 24 Lewan MD, Winters JC, McDonald JH (1979) Generation of oil-like pyrolyzates from organic-rich shales. Science 203 897-899... 

Pyrolysis refers to the decomposition of organic matter by heat in the absence of air. A common synonym for pyrolysis is devolatilization. Thermal decomposition and destructive distillation are frequently used to mean the same. 

Acem Hiiyiik. The data in Table III for these, the oldest artifacts examined, reveal a consistent loss of organic matter with no detectable nitrogen. This would indicate a complete loss of proteinaceous matter with some residual free carbon. As previously reported (6), the presence of blue, black, or grey coloration in ivory has been attributed to the thermal decomposition of the collagen with a consequent deposition of free carbon. Some loosely held water was occasionally present. Leaching experiments (samples marked Acem Hiiyiik IV) demonstrate the possible presence of only a small amount of carbonate. 

Examination of the data on C02 and pyrolytic water evolution may provide some insight into the thermal decomposition behavior of specific organic and inorganic structures in the parent coals. Some C02 may arise from the decomposition of inorganic matter within the coal. It also has been suggested (16) that decomposition of carboxyl groups in the... 

Both profiles, CO and COj arc very similar up to 650°C. In the case of CO two peaks appear, one about 250 C and the other one about 500 C. For CO2 a peak also appears at about 250°C and reaches its maximum value at 400 °C. A second CO2 peak appears at the same time that the second CO peak. These CO and CO2 peaks are due to the thermal decomposition of the organic matter contained in the black liquor as it has been explained before. 

This sequence of reactions indicates that conversion of I to I03 in seawater is not likely or is certainly not a significant chemical process, particularly in the presence of organic matter, which converts the intermediates (I2 and HOI) into organic iodine or I. Thermal or dark chemical reactions are not likely in deep waters indicating that any I detected in deep waters occurs primarily from mixing processes and/or the decomposition of particulate organic matter sinking to the sediments. 

The overall thermal decomposition of the organic matter (kerogen) in an oil shale can be expressed as a general process described by equation (6),... 

RockEval (also Rock-Eval, RockEval analysis) A rapid analytical method that utilizes pyrolysis to provide a semi-quantitative measure of the relative proportions of hydrogen, carbon and oxygen in bulk sedimentary organic matter. The instrument heats sediment samples to measure the amounts of hydrocarbons and hydrocarbon-like substances that escape at different temperatures from the organic matter contained in the sediment. The unit also calculates the amount of CO2 created during thermal decomposition of the organic matter. The results of Rock-Eval pyrolysis can help to identify the biotic sources of sediment organic matter. 

The process may also be referred to as destructive distillation and has been applied to a range of organic materials, but more particularly to naturally occurring materials such as wood, sugar, and vegetable matter. The carbonaceous residue from the thermal decomposition of coal is usually referred to as coke (Chapters 13 and 16) (which is physically dissimilar from charcoal) and has the more familiar honeycomb-type structure. 

According to the data obtained from the TGA, the thermal decomposition of rice husks in air medium occurred in three main stages of mass loss, namely removal of moisture (drying), release of organic volatile matters (devolatilization), and oxidation of fixed carbon (slow combustion) [7, 65, 103]. The TG and DTG curves of studied samples are presented in Fig. 13.10 [70]. 

---