Effect of catalyst amount

The effects of catalyst amount and reaction time were investigated as shown in Fig 2. While other conditions were kept constant, 2.5 wt% HPA (1 g in 40 g reaction mixture) showed fairly good activity. Further increase of the catalyst amount does not have serious effect on the activity. One hour was enough for the reaction to complete as illustrated in Fig. 2 (b). 

Effect of Catalyst Amount on Hydrotreating of Kentucky 9/14 Coal Liquid... 

Figure 20.9. Effects of catalyst amount on the conjugated linoleic acids of soybean oil with selective type nickel catalyst, hydrogen pressure 0.5kg/cm2, and agitation rate 500rpm. Source Jung et al., 2002.

The effect of catalyst amount on photoadsorption capacity is shown in Figure 9. This figure reports the benzyl alcohol moles photoadsorbed per unit mass of catalyst vs. the catalyst amount the reported data refer to runs carried out at equal initial benzyl alcohol concentration and lamp power. From the observation of data of Figure 9, a decrease of specific photoadsorption capacity by increasing the catalyst amount, differently from that expected on thermodynamic basis for which an increase of catalyst amount determines a corresponding increase of adsorbed substrate, may be noted. 

Table I. Effect of Catalyst Amount on the Molecular Weight of PSBO...

Trianto A. and T. Kokugan, Effects of catalyst amount, membrane tube diameter and permeation rate on the performance of porous membrane reactors. Journal of Chemical Engineering of Japan, 2001.34(11) 1332-1340. 

Conflicting results have been reported for the effects of catalyst concentration in the cobalt-catalyzed reaction. In early work, Hughes and Kirshenbaum (31) reported that these parameters were very influential in determining product composition high temperatures and high catalyst concentrations resulted in products containing decreased amounts of the... 

Study of the effect of small amounts of water in the liquid, organic phase on the polymerization of bisphenol-A and HFB in several solvents.[14] Solvents were rigorously dried and assayed for water content by potentiometric Karl Fischer titration. A series of polymerizations catalyzed and uncatalyzed in each solvent were carried out in which the water content was increased incrementally. Polymer yields and inherent viscosities were determined as a function of water content in each solvent. The optimal water content expressed as the mole ratio of water to catalyst shows that the necessary water level varies substantially with solvent (see Table V and Figure 1-3). 

Cho, Y. H., Park, H. S., Cho, Y. H., Jung, D. S., Park, H. Y, and Sung, Y. E. Effect of platinum amount in carbon supported platinum catalyst on performance of polymer electrolyte membrane fuel cell. Journal of Power Sources 2007 172 89-93. 

Effects of the Amount of Catalyst, Solvent, Temperature and Pressure... 

Table 3 Isomerization of ds-4-aminocyclohexane carboxylic acid on Raney nickel catalyst (Metalyst). Effect of the amount of catalyst, temperature and H2 pressure...

A maximum phenol conversion of 65% was reached, due to the fact that the consumption of benzoic acid was higher than that of phenol. Indeed, despite the 1/1 load ratio, the selectivity to those products the formation of which required two moles of benzoic acid per mole of phenol, made the conversion of benzoic acid approach the total one more quickly than phenol. A non-negligible effect of catalyst deactivation was present in fact, when the catalyst was separated from the reaction mixture by filtration, and was then re-loaded without any regeneration treatment, together with fresh reactants, a conversion of 52% was obtained after 2.5 h reaction time, lower than that one obtained with the fresh catalyst, i.e., 59% (Figure 1). The extraction, by means of CH2CI2, of those compounds that remained trapped inside the zeolite pores, evidenced that the latter were mainly constituted of phenol, benzoic acid and of reaction products, with very low amount of heavier compounds, possible precursors of coke formation. 

Figure 11 The effect of cerium amount on the isopropylation of naphthalene over ceria modified H-mordenite. Reaction conditions catalyst, 1 g naphthalene, 200 mmol propylene pressure, 0.8 MPa temperature, 300 °C period, 4 h.

This paper reports the effect of various amounts of selenium dioxide under different operating conditions on the conversion of 2-methylpropene to methacrolein and proposes a hypothesis for the hydrocarbon oxidation, which explains particularly the reactivity and selectivity of selenium-copper oxide catalysts in oxidizing 2-methylpropene. 

To understand the significant effect of catalyst nature, a better understanding of the main reactions, peracetic acid decomposition, and its reaction with acetaldehyde was needed. A literature -survey showed that the kinetics were not well studied, most of the work being done at very low catalyst concentration 1 p.p.m.), and there is disagreement with respect to the kinetic expressions reported by different authors. The emphasis has always been on the kinetics but not on the products obtained, which are frequently assumed to be only acetic acid and oxygen. Consequently, the effectiveness of a catalyst was measured only by the rates and not by the significant amount of by-products that can be produced. We have studied the kinetics of these reactions, supplemented by by-product studies and experiments with 14C-tagged acetaldehyde and acetic acid to arrive at a reaction scheme which allows us to explain the difference in behavior of the different metal ions. 

The effect of the amount of catalyst (which is high, approximately 30 mol%) on this model reaction was also studied. Conducting the reaction with 10 mol% L-proline resulted in the same yield and enantioselectivity (quantitative yield for (R)-13a, and 98% ee reaction time 24 h). A further decrease to 5 mol% led, however, to a slightly lower yield of 81%, although enantioselectivity was not affected (98% ee) [12a]. 

Effect of Catalyst Loading. The effect of the amount of Co-Mo-Al catalyst present in the hydrotreating reaction is tabulated in Table II. It was observed that increasing... 

Figure 3 shows the effect of the amount of a promoter (M0O3) in a commercial Ni/a-AJ203 catalyst (series C) on the length of the induction period and the coking rate... 

Effect of Catalyst Concentration. Since the effectiveness of AFR polymerization should depend on the number of active ends of the anionic polymer chain, it is of interest to study the effect of the change of anionic catalyst concentration on AFR polymer formation. At high catalyst levels the effect of catalyst concentration is difficult to demonstrate, but at low catalyst levels monomer conversion is directly related to the amount of TiCl3 used (Table XII). 

Figure 20.12. Effects of alcohol amounts on the quantity of total CLA formed in soybean oil during hydrogenation process. The hydrogenation was performed with 0.1% catalyst and different amount (0-15%) of ethanol under 210°C of reactor temperature and 500rpm of agitation rate. Source Ju et al., 2003.

The effect of the amount of the catalyst on the yield is shown in Table 1. 

The results show that small amounts of both C2 and C3 olefins were formed at 723 K. This observation could provide an important clue to the deactivation mechanism. It is likely that the olefins can polymerize to give carbon structures on the catalyst surface and thus cover and block the catalytically active reforming sites. The effect of small amounts of olefins added to the feed on the carbon formation rates and carbon thresholds has also been investigated. Fig. 19 indicates that olefins, and in particular propene, increase the rate of carbon formation. Flowever, care... 

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