Aromatic ring percent

The values of these parameters can be described as functions of the feed. In order to collapse the data from the cumene-decane mixtures and the cumene-naphthalene mixtures into a single curve, a single variable has been defined to describe the nature of the two different types of feeds. Note that decane, cumene and naphthalene contain respectively 0, 1 and 2 aromatic rings per molecule, and the different aromatic rings appear to be related to the differences between the coking abilities of these three species. Hence, we suggest that the aromatic ring percent in the feed, A, may be a possible independent variable, defined by ... 

Figure 4. Effect of aromatic ring percent of feed, A, on maximum deposition level of coke, M,...

Figure 5. Effect of aromatic ring percent, on the initiation (non-catalytic) rate constant for coking, ki- (Reproduced with permission from Ref. 1. Copyright 1994 Elsevier.)...

A, aromatic ring percent of feed a, initial conversion b, sensitivity to coke... 

Percent Sulfur Percent Aromatic Rings Percent Naphthene Rings Percent Paraffin Side Chains ... 

The n-d-M correlation is an ASTM (D-3238) method that uses refractive index (n), density (d), average molecular weight (MW), and sulfur (S) to estimate the percentage of total carbon distribution in the aromatic ring structure (% C ), naphthenic ring structure (Cj,), and paraffin chains (% Cp). Both refractive index and density are either measured or estimated at 20°C (68°F). Appendix 4 shows formulas used to calculate carbon distribution. Note that the n-d-M method calculates, for example, the percent of carbon in the aromatic ring... 

The percent conversion of the monomer to the polypeptide can be estimated by the quantity 100 (Aq - At) / Aq, where Aq and At are the integrated intensities of the ester band at the start and time t, respectively. At 40 °C, it tended to saturate at about 30 % for the Y-type films of L-NaphAla-C-i s, and L-PyrAla-G 8, although the conversion for the LB film of long-chain ester of alanine (L-Ala- Ci s) reached to 90 % [52]. This difference is considered to be due to a larger steric hindrance of the aromatic rings. 

The bottom of the barrel contains heavy, smelly compounds that have polyaromatic rings and that contain up to several percent of S and N in aromatic rings and in side chains sulfides and amines. This fi action will not boil below temperatures where the molecules begin to crack, and it is called residual oil or vacuum resid if it boils at reduced pressure. This fraction also contains perhaps 0.1% of heavy metals tied up as porphyrin rings in the polyaromatics. All these species are severe poisons to either FCC or catalytic reforming... 

The authors also considered the relative influence of para substitution in the phenylethynyl compared to simply phenyl (i.e., compared to the analogous styrenes). They found that over the four substituents noted above, the stabilization energy from Eq. (6.14) varied by 5.2 kJ mol for phenylethynyl and 7.0 kJ mol for phenyl. Thus, insertion of the acetylene unit between the radical center and the aromatic ring is predicted to decrease the influence of the aryl substituent by only about 25 percent. 

For the light cycle oil from the base FCC operation, a correlation predicts the component mol fractions based on various properties computed by the FCC simulator. These properties include density, molecular weight, and percent carbon as aromatic ring and cycloparaffin ring. The correlation is based on mass spectrometer data on FCC cycle oils. 

The solid support is a special polystyrene bead in which some of the aromatic rings have chloromethyl groups. This polymer, often called the Merrifield resin, is made by copolymerizing styrene with a few percent of p-(chloromethyl)styrene. 

In 1973, the Federal Trade Commission recognized aramid as a distinctly different generic material and defined it as a long-chain synthetic polyamide in which at least 85 percent of the amide linkages are attached directly to two aromatic rings. This distinguishes aramids... 

---