Proximate analysis reactivity

Tests for coke characteristics can be divided into two major classes chemical and physical. Considering chemical tests first, there are ultimate analysis and proximate analysis for the coke. Another chemical property, reactivity, which refers to the ability of coke to react with carbon dioxide, has also been proposed (Schapiro and Gray, 1963 Miller et al., 1965 Rao and Jalon, 1972 Daly and Budge, 1974) the ASTM does not provide a standard reactivity test procedure. 

From the burner design perspective, this fuel reactivity is typically expressed as the fixed carbon/volatile matter (FCA M) ratio derived from the proximate analysis. The influence of aromaticity on that ratio can be observed from equation 1-3 ... 

The general position taken by researchers in the field is that the kinetics will mirror the parent coal—with some initial reaction suppression being caused by the water and ash content of the CWS [27]. At the same time reactivity measures can be calculated from the data presented previously in Tables 3.6 and 3.7. Such reactivity measures include volatile matter/fixed carbon (VM/FC) ratios from the proximate analysis, and atomic hydrogen/carbon (H/C) ratios and atomic oxygen/carbon (O/C) ratios from the ultimate analysis. Further, pollution measures can be calculated including kg S/GJ, kg SO2/GJ, kg N/GJ, and kg ash/GJ. 

Chemical Composition. Chemical compositional data iaclude proximate and ultimate analyses, measures of aromaticity and reactivity, elemental composition of ash, and trace metal compositions of fuel and ash. All of these characteristics impact the combustion processes associated with wastes as fuels. Table 4 presents an analysis of a variety of wood-waste fuels these energy sources have modest energy contents. 

Carbohydrates, whose continental and marine productions have been estimated at nearly 1011 and 10 t/year respectively (42), have qualified for recognition as a possible carbon source. Indeed, the treatment of carbohydrate with hydrogen sulfide at a temperature as low as 100 °C is reported to result in S-heterocycle formation (43). Recently, glucose has been treated with hydrogen sulfide at 40 °C then pyrolyzed in the course of product analysis. Although S-heterocycles were found in the pyrolysate (44), the conditions to which the carbohydrates were subjected may result in their conversion to the proximate carbon source, which only then is sufficiently reactive enough to combine with hydrogen sulfide. Thus, the role assumed of carbohydrates as proximate carbon source molecules in low-temperature reactions is presently not readily appraised. 

Whereas selective diffusion can be better investigated using classical dynamic or Monte Carlo simulations, or experimental techniques, quantum chemical calculations are required to analyze molecular reactivity. Quantum chemical dynamic simulations provide with information with a too limited time scale range (of the order of several himdreds of ps) to be of use in diffusion studies which require time scale of the order of ns to s. However, they constitute good tools to study the behavior of reactants and products adsorbed in the proximity of the active site, prior to the reaction. Concerning reaction pathways analysis, static quantum chemistry calculations with molecular cluster models, allowing estimates of transition states geometries and properties, have been used for years. The application to solids is more recent. 

Given the many clinicopathologic similarities between EPS (especially its proximal variant) and the very rare purely epithelioid synovial sarcoma, it would follow that they are difficult to separate by immunophenotypic analysis. A helpful discriminant between these neoplasms is CD34, which is present in EPS but not in epithelioid synovial sarcoma. Moreover, as cited above, Kato and associates found that nearly all EPS cases were immunoreactive for CA125, whereas synovial sarcomas lacked that marker. As mentioned earlier in this discussion, monophasic spindle-cell synovial sarcoma is consistently reactive for nuclear TLEl protein however, that moiety has not been studied specifically in the monophasic epithelioid variant. 

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