Effect on product yields

The product distributions shown in Figures 9.7 and 9.8 are obviously quite different, so we again see that the manner of contacting can have significant effects on product yields. We... 

In CRE textbooks (Hill 1977 Levenspiel 1998 Fogler 1999), the types of reactors considered in this book are referred to as non-ideal. The flow models must take into account fluid-mixing effects on product yields. 

The reaction of dicyclohexylborane and trifluoromethanesulfonic acid is highly exothermic. On one occasion, the checkers cooled the reaction in an ice bath during the addition period, with no effect on product yield. The submitter reports that he once experienced a sudden vigorous reaction under cooling conditions, probably due to accumulation of unreacted triflic acid. It thus appears safer to add the acid at room temperature, slowly, so that it reacts immediately. 

The results clearly show that temperature and time at 95% and 99% confidence level respectively have a significant effect on production yield. It is also clear that there is no interaction between temperature and time factors. Experimental error is small with respect to interaction so that the used measurement equipment can be considered satisfactory. 

After realizing each trial, it is possible to determine factor effects on product yields ... 

Pepper and Supathna (1978) studies the effect on product yields of Rh-C applications ranging in amount from 1 to 30% of the original wood in the hydrogenolysis of spruce wood meal The yield of dihydroconiferyl alcohol, (9), was found to increase while the yield of 4-n-propylguaiacol, (8), decreased When the catalyst application exceeded 10%, traces of cyclohexyl derivatives were detected The maximum total yield of (8) and (9) was obtained with a 10-20% catalyst application... 

The three feedstocks were processed by hydropyrolysis at selected process conditions. Previous results (1,7) have shown that gas to liquid ratios increase sensitively with increasing temperature. This effect can be offset somewhat by decreasing the residence time. A variation in pressure does not have a major effect on product yields or gross properties, but pressures above about 1200 psig are required to inhibit coke formation. 

Effects of Added Scavengers. Several additives were used to obtain more information about the reaction mechanism. Adding 5% nitrous oxide had no measurable effect on product yields. However, with 5% added oxygen or ethylene, all products listed in Table II except CoF4 were eliminated, and new but unidentified products were formed. These results strongly suggest that the final products from pure F-cyclobutane arise from a free radical sequence. 

That water has a profound effect on product yield and selectivity was demonstrated by a series of reactions that contained varying amounts of protic material. Thus, as the amount of water was increased in the reaction, the conversion of nitrobenzene decreased dramatically. However, increasing the amount of water also resulted in reactions which displayed a higher degree of selectivity to the desired... 

Modeling the soaker with VLE has a strong effect on product yields and conversion. In this reactor, the feed (partially converted vacuum residue plus visbroken products) coming from the coil reactor has certain amount of vapor, which is increased due to the long residence time in the soaker. 

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