Conversion results

Many odorous compounds may be converted to compounds with higher odor thresholds or to nonodorous substances. An example of conversion to another compound is the oxidation of H2S, odor threshold 0.5 ppb, to SO2, odor threshold 0.5 ppm. The conversion results in another compound with an odor threshold three orders of magnitude greater than that of the original compound. 

Polk et al. reported27 that PET fibers could be hydrolyzed with 5% aqueous sodium hydroxide at 80°C in the presence of trioctylmethylammonium bromide in 60 min to obtain terephthalic acid in 93% yield. The results of catalytic depolymerization of PET without agitation are listed in Table 10.1. The results of catalytic depolymerization of PET with agitation are listed in Table 10.2. As expected, agitation shortened the time required for 100% conversion. Results (Table 10.1) for the quaternary salts with a halide counterion were promising. Phenyltrimethylammonium chloride (PTMAC) was chosen to ascertain whether steric effects would hinder catalytic activity. Bulky alkyl groups of the quaternary ammonium compounds were expected to hinder close approach of the catalyst to the somewhat hidden carbonyl groups of the fiber structure. The results indicate that steric hindrance is not a problem for PET hydrolysis under this set of conditions since the depolymerization results were substantially lower for PTMAC than for die more sterically hindered quaternary salts. 

GL 1[ [R 1[ [R 3[[P la-d[ The fluorine content in the gas phase of a falling film micro reactor was varied at 10, 25 and 50% [38]. A nearly linear increase in conversion results at constant selectivity. The substitution pattern, i.e. the ratio of ortho-to para-isomers, is strongly affected by this. 

Sn-S-4, Sn-ST-4 (Si/Sn = 106) showed better conversion results (38-42% 64-41%) with 100% selectivity to corresponding lactone with respect to 2-methyl and 4-methyl cyclohexanones compared with high conversions in case of bulkier bicyclic ketones. Even the hydrothermal catalysts gave lower than that in case of Sn-ST-4 which was also supported by the UV and XPS studies which showed that the incorporation of Sn in tetrahedral site is more and thus leading to the more catalytic activity. 

Data on the reaction, 2A B, were taken with a CSTR with the tabulated time-conversion results in the table. Feed concentrations were Ca0 = 1.5 and Cb0 = 0.5 Ibmol/cuft. Find the rate equation. 

Owing to this large concentration of OH relative to O and H in the early part of the reaction zone, OH attack on the fuel is the primary reason for the fuel decay. Since the OH rate constant for abstraction from the fuel is of the same order as those for H and O, its abstraction reaction must dominate. The latter part of the reaction zone forms the region where the intermediate fuel molecules are consumed and where the CO is converted to C02. As discussed in Chapter 3, the CO conversion results in the major heat release in the system and is the reason the rate of heat release curve peaks near the maximum temperature. This curve falls off quickly because of the rapid disappearance of CO and the remaining fuel intermediates. The temperature follows a smoother, exponential-like rise because of the diffusion of heat back to the cooler gases. 

Table 6.10 Hydrogenation of benzophenone Initial reaction rate (r,) selectivity to products at 100% conversion. Results for the chemical reduction with NaBH4 are included for comparison. DPM diphenylmethanol, CHPK cyclohexyl phenyl ketone, CHPM cyclohexylphenylmethanol, DCHK dicyclohexyl ketone and DCHM dicyclohexylmethanol. (Reproduced from Reference [34].)...

Dong and co-workers studied the effect of adding a transition metal (Cu, Co and Fe) to Ni/Ceo.2Zro.iAlo.650s catalyst on the activity in the ATR of methane [49, 50]. It was observed that the presence of Cu and Co allows a significant improvement of the catalytic activity at lower temperature, whereas the addition of Fe leads to a remarkable decrease in CH4 conversion. Results of catalyst characterization showed that the improvement in the catalytic activity when Cu is added as a promoter is due to the improvement of NiO dispersion, vdth inhibition of NiAl204 formation. 

The initial process to achieve success was developed by Miyata of Kyowa in the mid 1970s [101].This process is based on the hydrothermal conversion in an autoclave of the fine agglomerated particles formed by addition of ammonia or lime to a magnesium salt solution. This hydrothermal conversion results in the formation of particles of about 1 micron in size and with a fairly low aspect ratio. This original process appears to be expensive to operate because of the low value of the ammonium or calcium chloride co-product which has to be disposed of and because the reported reaction conditions give a low yield and a relatively slow reaction. 

Molsidomine is a prodrug that is converted in the liver to metabolites which have a vasodilatory action similar to the organic nitrates. The hepatic conversion results in the release of NO. 

As could be expected, the conversion resulting in the reaction inhibition depends on the reagent ratio in that a higher A10/E0 ratio results in an increase in the limiting conversion (Fig. 5, Curve 1). 

The reduction of azepinone 484 leads to 1,2,3,4-tetrahydroderivative 485, whereas dehydrogenation of 484 by chloroanil results in 1H-naphtho[Mazepine-2-one 486 (76JHC371). The interesting conversion resulting in l//-l-methyl-3-formyl-7-methoxynaphtho[bc]azepine-2-one 490 occurs on interaction of 4-methoxy-8-(N-methyl-N-acetyl)aminonaphthal-dehyde 487 with the Vilsmeier reagent (86ZOR2394). It was assumed that compounds 488 and 489 are intermediates in this reaction. 

The molecular weights increase with conversion and the increase is much more pronounced for the VA runs. The strong increase of molecular weight with conversion results from the transfer of reaction loci from the solution to the polymer particles. At low conversion the polymers are mostly formed in the continuous phase in which the termination rate is high. In polymer particles the local concentration of monomer is much higher than that in the continuous phase and, therefore, the growth events are favored in the polymer particles. 

The dispersion copolymerization of PEO-MA macromonomer and styrene is presented in Figs. 1 and 2 [70]. The rate-conversion plot is curved with a maximum at very low conversion. In all runs, neither the gel effect nor the stationary interval were observed. The strong decrease of the rate of polymerization with increasing conversion results from a decrease in the monomer concentration at the reaction loci (mainly in the polymer particles). The low monomer concentration in particles is a reason why the gel effect may be operative only at very low conversion. 

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