Hydrogen-carbon ratio

Other hydrocarbons can be used. Stoichiometricahy, ethane [74-84-0] is preferable to methane since its lower hydrogen/carbon ratio results in a smaller yield of coproduct hydrogen sulfide ... 

Fig. 3. Theoretical mole percent of the principal combustion products of hydrocarbon fuels for fuel hydrogen carbon ratios from 1, eg, to 4, eg, CH, ...

The high hydrogen/carbon ratio of gas means that the quantity of water vapor in the products of combustion is greater than most other fossil fuels. The latent heat of this cannot be released in conventional appliances leading to a low net/gross ratio of calorific value of 90 per cent. (It is normal practice to quote gross CV in Europe net CV is often used. If net CV is quoted, efficiencies of over 190 per cent are possible.)... 

Elemental analysis of fuel oil often plays a more major role that it may appear to do in lower-boiling products. Aromaticity (through the atomic hydrogen/carbon ratio), sulfur content, nitrogen content, oxygen content, and metals content are all important features that can influence the use of residual fuel oil. 

To calculate how many electrons have to be transferred to 02 or NOj respectively, when oxidizing 1 mole of toluene (C7H8) to C02, determine first the average oxidation state of the carbon atoms present in toluene (see also examples discussed in Illustrative Example 2.1). Since this compound is made up only of carbon and hydrogen atoms (the oxidation state of H is +1), you can just consider the hydrogen/ carbon ratio, which yields an average carbon oxidation state of -8/7. Considering that the oxidation state of carbon in C02 is +IV, it is easy to see that a total of (4 - (-8/7)) x 7 = 36 moles of electrons have to be transferred. The overall reactions are, therefore ... 

These results are supported by volumetric studies [52,54]. With both nickel and palladium there is a slow self-hydrogenation at —78°C. This becomes increasingly important as the temperature is increased at 0°C the overall hydrogen/carbon ratio in the surface species is 1.5, falling to 1.0 at room temperature. Field emission microscopic (FEM) studies of ethylene adsorption on iridium [56] and tungsten [57] are also satisfactorily... 

As regards actual combustion of jet fuels, the two critical combustion factors are fuel volatility and hydrogen/carbon ratio. As might be expected, fuels that are too heavy for the spray system and for the combustor design do not burn as well as more volatile fuels. Low hydrogen/carbon ratios also interfere with combustion efficiency, even though straight aromatics have been handled in specially adapted burners (5). 

FUEL PROPERTIES. Hydrogen-carbon ratio, aromatic content, American Society for Testing Materials (ASTM) distillation temperatures, gravity, and aniline point are the properties that have been used alone or in combinations to indicate the coke-forming tendency of a fuel. Two of these relations are discussed below. 

Hydrogen-carbon ratio and volatility were related (177) to deposits as follows ... 

Fig. 3. Theoretical mole percent of the principal combustion products of hydrocarbon fuels for fuel hydrogen carbon ratios from 1, eg, C6H6, to 4, eg, CH4, wet basis, where (-----------------------------) represents H20 (----) C02 ) CO 02 and (.) H2 (8,10,11).

Mechanism of Hydropyrolysis of -Paraffins. The hydrogen carbon ratio in the total hydropyrolysis product from 1 is higher (H C > 2.2) than that in 1 itself (H C = 2.12) in all experiments performed (Tables II and III). This clearly indicates participation of hydrogen in the process. To account for the observed differences between hydropyrolysis and conventional thermal cracking (Table I), and to rationalize the variations in product composition as a function of reaction conditions,... 

Table 7.3 Hydrogen/Carbon Ratios in Plasma Polymers and Corresponding Monomers...

Given that the Orsat analysis from a turbojet shows 12.2% CO2, 0.4% CO, and 6.2% O2, compute the net hydrogen/carbon ratio in the fuel (the fuel contains negligible sulfur and nitrogen). Also compute the cubic meters of air used at 27"C and 101.4 kPa/kg of fuel burned. 

The yield of coke in a given coking process tends to be proportional to the earbon residue eontent of the feed (measured as the Conradson earbon residue), which is, in turn, related to the atomie hydrogen/ carbon ratio. 

The pour point is the lowest temperature at which the bitumen will flow. The pour point for tar sand bitumen can exceed the natural temperature of tar sand deposits. It is important to consider because for efficient production a thermal extraction process to increase the reservoir temperature to beyond the pour point temperature must supply supplementary heat energy. Elements related to pour point are depth, bitumen viscosity, original reservoir temperature, and atomic hydrogen/carbon ratio. 

There will be a drive toward fuels with higher hydrogen/carbon ratio, but balanced against the need to utilize the extensive low hydrogen/carbon coal resource base in the United States. (Venki Raman, Nathan Lewis)... 

Natural gas has tremendous potential for meeting the energy needs of the future because it has a high hydrogen/carbon ratio and can be converted to H2 and environmentally clean liquid fuels.4... 

In contrast to methane, acetylene (C2H2) is anisotropic, highly unsaturated, and has a much lower 1 1 hydrogen carbon ratio. The it bonding system allows for the possibility of facile addition polymerization reactions, and therefore acetylene is predicted to be much more reactive than methane upon shock compression. This is reflected in a significantly lower flyer plate velocity threshold for the onset of chemical reactions. Polymerization of acetylene is also exothermic a simple bond energy calculation shows that the reaction... 

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