Direct thermal generation

This paper touches on the chemistry of coal gasification and liquefaction comments on the current status of conversion processes and the influence of coal properties on coal performance in such processes and examines the contributions which coal conversion could make towards attainment of Canadian energy self-sufficiency. Particular attention is directed to a possible role for the medium-btu gas in long-term supply of fuel gas to residential and industrial consumers to linkages between partial conversion and thermal generation of electric energy and to coproduction of certain petrochemicals, fuel gas and liquid hydrocarbons by carbon monoxide hydrogenation. 

The first example of the direct observation of a thermally generated nitrile ylide has been reported (3). This was achieved by studying the thermal flash vacuum pyrolysis (FVP) decomposition of the oxazaphospholes 3 (R = t-Bu, Ph) via the... 

A well-known reaction of tetrazoles is the thermolysis of 2,5-disubstituted tetrazoles to give nitrilimines by loss of N2 an example is shown in Scheme 4. The reaction is used not only for its synthetic potential but also as a source of nitrilimines for direct observation and exploration of their behavior. The first direct detection of a thermally generated nitrilimine was the species (31) produced by flash vacuum pyrolysis of 5-phenyl-2-trimethylsilyltetrazole (85AG(E)56). The parent nitrilimine, HCNNH, has been generated by file photolysis of tetrazole (96LA1041). 

An integrated GC/IR/MS instrument is a powerful tool for rapid identification of thermally generated aroma compounds. Fourier transform infrared spectroscopy (GC/IR) provides a complementary technique to mass spectrometry (MS) for the characterization of volatile flavor components in complex mixtures. Recent improvements in GC/IR instruments have made it possible to construct an integrated GC/IR/HS system in which the sensitivity of the two spectroscopic detectors is roughly equal. The combined system offers direct correlation of IR and MS chromatograms, functional group analysis, substantial time savings, and the potential for an expert systems approach to identification of flavor components. Performance of the technique is illustrated with applications to the analysis of volatile flavor components in charbroiled chicken. 

Scheme 18). The 1,3-pentadiene derivatives may be formed by an initial [2 + 2]-cycloaddition reaction, while the formation of the l-oxa-6-silacy-clohexene derivative can be explained by a direct [2 + 4]-cycloaddition reaction (98). It has been reported that the reaction of thermally generated silaethene derivatives with acrolein affords products that can be accounted for in terms of initial competing [2 + 2]- and [2 + 4]-cycloaddition reaction between the intermediates and acrolein (99). 

Certain functional groups can direct through hydrogen-bonding the outcome of the intermolecular Diels-Alder cycloaddition. This was the case in the key Diels-Alder cycloaddition step during the total synthesis of ( )-rishirilide B in the laboratory of S.J. Danishefsky. The diene was thermally generated in situ. 

The thermoelectric semiconductor converts directly thermal energy into electric one. It can generate electric power even when the temperature difference between the heat source and atmosphere is much smaller compared with the one needed in conventional thermal power generation. 

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