enthalpy of combustion

The temperature dependence of the saturated vapor pressure and the combustion energy of 2-methyl-5-phenylfuran-3-carboxylic acid were determined by experimental methods. Based on the obtained data, the values of the enthalpies of combustion and formation in the condensed state were calculated. The enthalpy of sublimation was recalculated to 298K. The additive Benson scheme is supplemented with new fragments for calculating the enthalpies of formation in the gaseous state.

Combustion energies of esters (ethyl 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate; ethyl 6-methyl-4-(4-methylphenyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate; ethyl 4-(4-methoxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate and ethyl 4-(6-methoxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate) were experimentally obtained using a bomb calorimetry. According to the experimental data, the enthalpies of combustion and the enthalpies of formation in a solid state were calculated.

Using the precision bomb combustion calorimeter B-08-MA, the combustion energies of 5- (2-nitrophenyl) -furan-2-carbaldehyde, 5- (2-nitro-4-methylphenyl) -furan-2-carbaldehyde and 5- ( 2-nitro-4-oxymethylphenyl) -furan-2-carbaldehyde. Based on the obtained data, the values of enthalpies of combustion and formation of substances in the condensed state are calculated. A comparative analysis of experimentally determined values with theoretically calculated values by additive calculation methods is given.

Six species of wood were studied by combined thermogravimetric and differential thermal analysis (TG/DTA) so as to evaluate their combustion properties in terms of the amount of energy released, the initial temperature of ignition, and the cleanness of burning. Pinus monticola, Acer saccharum, Quercus rubra, Diospyrus spp., Tabebuia spp. and Guaiacum spp. were chosen to provide a wide range of hardness values and densities. Quercus rubra burned to the hottest temperature of the samples, and also left the least amount of ash behind. For Guaiacum spp.