Paraffinic carbons

Cp = weight per cent of paraffinic carbon % = weight per cent of cyclic carbon... 

Correlations have been found between certain absorption patterns in the infrared and the concentrations of aromatic and paraffinic carbons given by the ndA/method (see article 3.1.3.). The absorptions at 1600 cm due to vibrations of valence electrons in carbon-carbon bonds in aromatic rings and at 720 cm (see the spectrum in Figure 3.8) due to paraffinic chain deformations are directly related to the aromatic and paraffinic carbon concentrations, respectively. )... 

Paraffin carbon chain length Nominal chlorine contents, %w / w Color hazen (APHA) Viscosity, mPa-s (=cP) Density, g/mL Thermal stability, %w/wHCl Volatihty, %w/w Refractive index... 

In general, FCC feeds are predominately paraffinic. The paraffinic carbon content is typically between 50 wt% and 65 wt% of the total feed. Paraffinic stocks are easy to crack and normally yield the greatest amount of total liquid products. They make the most gasoline and the lea.st fuel gas, but also the lowest octane number. 

LAB is derived exclusively from petroleum- or natural gas-based feedstocks. Thus, it is referred to as a petrochemical (or synthetic) surfactant intermediate. Feedstocks for LAB production are generally paraffins (carbon chain length in the range of C8-C14) derived from kerosene and benzene. Internal olefins derived from ethylene are sometimes used in place of paraffins. 

Paraffinic carbon (0-50 ppm, %) content of natural organic matter... 

Fig. 4. Positive correlation between phenanthrene log Koc values and paraffinic carbon content (0-50 ppm) of the natural organic materials calculated from CP/MAS 13C NMR. Adopted from Salloum et al. (2002).

Fig. 9. Relationship between polarity index ((O + N)/C) and percentage of paraffinic carbon in organic sorbents from the literature. The percentage of paraffinic carbon was calculated as the product of paraffinic carbon content (0-50 ppm) from NMR distribution and percentage of carbon, nitrogen, and oxygen contents from elemental analysis.

A negative correlation was observed between PI and percentage of paraffinic carbon in organic sorbents (Fig. 9). This relationship is similar to the relationship between PI and aromaticity. Thus, polarity and paraffinic carbons, like polarity and aromaticity, could also be interactive... 

The information addressed here emphasized that the HOC sorption capacity in context relates to the chemical structures of SOM. Aromatic structures of SOM were reported to be the domains primarily responsible for HOC sorption, supported by positive correlations between aromaticity and Koc. Recently, aliphatic components, particularly paraffinic carbons, of SOM are reported to sorb significant amounts of HOCs, similarly supported by positive correlations between aliphaticity and Koc values. From a series of sorption experiments and literature review, we concluded... 

For straight paraffinic hydrocarbons (i.e., methane, ethane, propane, etc.) the commonly accepted autoignition temperatures decrease as the paraffinic carbon atoms increase (e g., methane 540 °C (1004 °F) and octane 220 °C (428 °F)). 

If the only constituents of petroleum were the hydrocarbons, the complexity is further illustrated by the number of potential isomers (i.e., molecules having the same atomic formula) that can exist for a given number of paraffinic carbon atoms and that increases rapidly as molecular weight increases ... 

Distribution of Aromatic Carbon (Ca), Naphthenic Carbon (Cn), and Paraffinic Carbon (Cp)... 

The pour point of residual fuel is not the best measure of the low-temperature handling properties of the fuel. Viscosity measurements are considered more reliable. Nevertheless, residual fuels are classed as high pour and low pour fuels. Low-pour-point fuels have a maximum pour point of 60°F (15.5°C). There is no maximum pour point specified for high-pour-point residual fuels. A residual oil paraffin carbon number analysis is provided in FIGURE 3-1. 

FIGURE 3-1. Paraffin Carbon Number Analysis of a Typical Atmospheric... 

Fuel Paraffin Carbon Number Range Paraffin Boiling Temperatures, °F (°C)... 

Paraffin combustion, however, can proceed more completely to HzO and C02 because each carbon atom carries with it at least two hydrogen atoms. By burning only one paraffin carbon atom, enough hydrogen is released to react with oxygen to produce a molecule of water. The paraffin carbon can further react to form CO or C02. 

The n-paraffin carbon number distribution for a fuel is narrow. 

Paraffin carbon bond (C-C) PAR Xylene-hydroxyl radical adduct XINT... 

Fig. 11. Diffusion of n-paraffins in a cis-polyisoprene as function of concentration at 51 °C. Lines are two-parameter fits of Eq. (17) to data. Paraffin carbon numbers are indicated. (Ref.70), with permission).

Niobium pentafluoride forms colourless, highly refractive prisms density 8 2932 at 18° C. It melts at 75 5° C.f and boils at 217° to 220° C. under a pressure of 760 mm. of mercury. It is extremely hygroscopic and deliquesces rapidly in air. It is reduced by hydrogen at 286° C. in contact with platinum to an unstable lower blue fluoride. Excess of concentrated alkali hydroxide or alkali carbonate solutions attack it with formation of the alkali niobate. It dissolves in toluene, paraffin, carbon bisulphide, and other organic solvents. 

Mibashan s (61, 138) relationship was entirely arbitrary. For paraffins, carbon atoms in the longest chain were numbered from the end to the center. A centralization index was developed by adding these position numbers. Corrections were made for various functional groups. Centralization index and octane number were then related by an empirical equation which could be used as a rough prediction guide. 

Table VI shows the detailed gasoline composition (as a per cent of fresh feed), particularly the breakdown of the straight chain and branched paraffins. The results show an increase in the ratio of the branched to straight chain paraffins for each carbon number when ZSM-5 is used. This is particularly striking in that the total paraffin yield is unchanged when ZSM-5 is added. Thus, although the total paraffin yield remains essentially unchanged, the iso/normal paraffin ratio increases for all carbon numbers. There is also a change in the paraffin carbon number distribution in that the Cq and Cg paraffin yields decrease and the C5 and Cg paraffin yield increases. The normal paraffins are decreasing at a faster rate than the isoparaffins despite the fact that their initial concentration is 5 to 10 times lower. In the C7 carbon number, catalyst A shows an increase in the isoparaffins while catalyst B shows a decrease. The normal C7 decreases for both catalysts.

Number of Naphthenic Carbons Number of Paraffinic Carbons... 

Paraffins.—Carbon and hydrogen do not unite directly under ordinary laboratory conditions but in certain natural substances compounds of the two elements are present. Similar compounds of the two elements may also be formed by the decomposition of complex substances containing other elements than carbon and hydrogen. The hydrocarbons so found or formed are usually very stable compounds and... 

The relative yields of various carbon species in these chars are shown in Table VI. These data indicate that the glycosylic carbon disappears on heating up to 400 °C. At this temperature the char contains 69% aromatic and 27% paraffinic carbons which change to 88% and 12%, respectively, at 500 °C. 

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