Oxygen to carbon ratio

The thermoneutral point (of oxygen-to-carbon ratio) is where the enthalpy of the reaction is zero, (AHf 298 = 0). 

Okada (Ref 15) states that the oxygen to carbon ratio for LOX of maximum brisance is 2.6. This is essentially the theoretical ratio to convert all the carbon to C02. This writer believes that Okada really meant maximum strength rather than maximum brisance, as the latter depends not only on compn but also on pack-... 

Thomas and co-workers found ion scattering data to be somewhat non individualistic, but they determined that it was very useful for determining segregation at the surface of a polymer. Table VI from Thomas, et al (15) shows the variation in the oxygen to carbon ratio at the surface compared to the bulk values. 

Abstract In this paper, we discuss the results of a preliminary systematic process simulation study the effect of operating parameters on the product distribution and conversion efficiency of hydrocarbon fuels in a reforming reactor. The ASPEN One HYSYS-2004 simulation software has been utilized for the simulations and calculations of the fuel-processing reactions. It is desired to produce hydrogen rich reformed gas with as low as possible carbon monoxide (CO) formation, which requires different combinations of reformer, steam to carbon and oxygen to carbon ratios. Fuel properties only slightly affect the general trends. 

The mole fractions of air have been simulated as 0.21 and 0.79 for 02 and N2 respectively. The two parameters, S/C, O/C (oxygen to carbon) ratios have been used to analyze the reforming reactors effectively. These two relationships can be written as follows ... 

The experiments were carried out at ambient pressure. All hydrocarbons were tested at a S/C ratio of three and all alcohols at a corresponding oxygen to carbon ratio. Decreasing conversion was found for the various fuels with increasing feed rates except for methanol owing to the very high reaction temperature of 725 °C. Table 2.9 summarizes some of the results presented for the various fuels. The proprietary catalyst showed only minor deactivation after 70 h TOS. It was deactivated reversibly by sulfur. Load changes of the liquid input from 100 to 10% resulted in a system response after 5-10 s. 

The total volatile matter yield, and hence the yield of tar plus light oils, is proportional to the hydrogen-to-carbon ratio in the raw material. On the other hand, the chemically formed water vapor that distills off during pyrolysis in an inert atmosphere is proportional to the oxygen-to-carbon ratio. The yields and product distributions also depend on the rate of pyrolysis. 

The overall partial oxidation catalytic reforming can be exothermic or endothermic. The main factor determining the heat balance for the reaction is the oxygen-to-carbon ratio. The thermal neutral point (where enthalpy of the reaction is zero) varies from an x/n ratio of 0.23 for methanol to 0.37 for iso-octane. It is advantageous to run in the exothermic region, and at a low x/n ratio to maximize the yield of H2. The experiments reported here were performed with an x/n ratio of 0.5, except for methanol and ethanol experiments, which were performed at a lower x/n (0.32 and 0.25, respectively) to compensate for the oxygen already present in the alcohol. 

Oxygen Depth Profile. When coal samples of different particle size (400 mesh to 35 mesh) which had not been exposed to air after grinding were analyzed for the oxygen to carbon ratio, it was essentially the same for all sizes. This implies that the oxygen to carbon ratio is constant throughout the particle. When the same analysis was carried out for coal exposed to air for two months, there was a definite increase in the oxygen to carbon... 

Theoretically, cellulose has the gross formula QHioCfe, and thus the oxygen-to-carbon ratio should be 0.83. The ESCA experimental data obtained in this study gave an oxygen-to-carbon ratio of 0.78. This result can be due to the deposition of impurities of hydrocarbon nature at the cellulosic surface. 

The films deposited in various substrates after plasma treatment in the presence of perfluorinated olefins were subject to partial removal with extraction. Generally, after extraction, the fluorine to carbon ratio, determined through XPS analysis, decreased to 0.2 1 to 0.3 1 regardless of the applied power and residence time used during the fonnation of the film. In all cases a moderate but consistent amount of oxygen was detected in the fluorocarbon film. The oxygen to carbon ratio 0.12 1 to O.l t before extraction and 0.08 1 to 0.1 1 after extraction. 

Fig. 5.6 Calculated energy gaps with respect to the overall oxygen-to-carbon ratio for different phases of GO (Adapted from Ref. [43]. Copyright (2009) by the American Physical Society)...

An alternative route to produce synthesis gas starting from hydrocarbon feedstock is the partial oxidation reaction (POX) [16]. This reaction utilizes the oxygen in the air as oxidant and results moderately exothermic. The oxygen to carbon ratio is lower than that required by stoichiometric complete combustion. 

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