Conversion curve, optimum

Wlien the O2 concentration was increased to 8% the separation of the conversion curves for propylene and NO occured at a lower temperature (210°C), and the maximum NO conversion attained was only of the order of 40%. Also under these conditions the optimum operating temperature range was found to be narrower. 

ATP formation on creatine and MgCl2 concentrations was also examined and the results are summarized in Fig. 6 and Fig. 7. Without creatine, ATP formation occurred later and more slowly but at the same high conversion level. The addition of excess creatine caused acceleration of ATP formation. Without creatine, the induction period took two times longer. As shown in the time conversion curve with heptakis-(2,6-dimethyl)-g-CD (DM-g-CD) without creatine, ATP formation occurred later and more slowly at the same conversion level. Besides these examinations, the effect of O2, buffer solution and temperature were observed. Without O2, the reaction did not proceed. Ionic strength and pH of the phosphate buffer and reaction temperature were optimum under the present conditions. The results obtained here showed the same kind of catalytic activity of the CD in the equilibrium between ADP and ATP in this scheme 1. This new type of transphosphorylation seems to be a... 

Dioxane is preferable to ethanol for the confirmation of the rate enhancement effect caused by the presence of polymer matrix, because the polycondensation of DEC with HMD in dioxane proceeds more slowly than that in ethanol. Therefore, dioxane was used as a solvent in this work. Figure 16 shows time-conversion curves for the polycondensation of DEC with HMD in dioxane at a monomer concentration of 0.1 mole/dm in the presence or the absence of EK or PVK at 30°C. As shown in Figure 16, the polycondensation of DEC with HMD was enhanced by the presence of PVK, while the presence of monomeric EK slightly retarded the polycondensation. Figure 17 indicates the polycondensation of DEC with HMD in the presence of various concentrations of PVK at a monomer concentration of 0.1 mole/dm in dioxane at 30 C. Rate enhancement caused by the PVK matrix increased in proportion to the increase in the molar ratio of PVK matrix to DEC monomer. The optimum molar ratio of monomer to the PVK matrix in the polycondensation of DEC with HMD could not be determined, because of the limited solubility of PVK( 0.15 mole/dm in dioxane). 

Figure 5. Molecular weight-conversion contour map for various concentrations of a free-radical initiator operating in a tubular-addition polymerization reactor of fixed size. Curves were constructed using varying jacket temperatures (kinetic parameters for the initiator Ea = 32.921 Kcal/mol In k/ = 26.494 In sec f = 0.5 (------------------------) optimum operating line)...

Figure 7. Tubular plug-flow addition polymer reactor effect of the frequency factor (ka) of the initiator on the molecular weight-conversion relationship at constant activation energy (Ea). Each point along the curves represents an optimum initiator feed concentration-reactor jacket temperature combination and their values are all different, (Ea = 32.921 Kcal/mol In ka = 35,000 In sec ...

The optimum size ratio of the two reactors is achieved where the slope of the rate curve at M equals the diagonal NL. The best value of M is shown in Fig. 6.11, and this determines the intermediate conversion as well as the size of units needed. 

The three contributions to dispersion are also shown as separate curves in figure 1. It is seen that the major contribution to dispersion at the optimum velocity, where the value of (H) is a minimum, is the multipath effect. Only at much lower velocities does the longitudinal diffusion effect become significant. Conversely, the mobile phase velocity must be increased to about 0.2 cm/sec before the resistance to mass transfer begins to become relatively significant compared to that of the multipath effect. 

A question arises frequently whether it may be more efficient to use multiple fermenters connected in series instead of one large fermenter. Choosing the optimum fermenter system for maximum productivity depends on the shape of the l/rx versus Cx curve and the process requirement, such as the final conversion. 

Polymerization Results. A batch polymerization of MMA-MAA comonomer was analyzed for the determination of the reactivity ratios of the two monomers. The change in the ratio of the copolymer composition determined by GC was plotted against conversion as shown in Figure 1. Similarly, the calculated curves for some assumed reactivity ratios are also shown in the same Figure. The optimum values of the reactivity ratio for the emulsion poly-... 

Influence of Salt Concentration. A series of experiments were performed to determine the influence of the salt concentration on the S02 reaction rate. The salts used were NaCl and NaN03 in concentrations ranging from 1 to 15 mole%. The experiments were carried out at a relative humidity of 54%, and a reactor temperature of 66°C. As can be seen from Figure 9, the conversion increases with increasing concentration of additive until about 10 mole%. After this the curve levels off. The optimum concentration of additive is then about 10 mole% for 1 1 electrolytes like NaCl and NaN03. 

When the conditions are such that a lowering of the approach (or Tctws) would require a large increase in fan operating costs (Ml"), the minimum point on the total cost curve (A"). will be above the minimum attainable approach (A ). Conversely, if the approach can be reduced with a small increase in fan operating costs (MT) the optimum operating point for the total system will correspond to the minimum Tctws temperature and therefore would be at the minimum attainable approach (A t). Whichever total... 

Figure 14. Equilibrium limitation of exothermic reactions. A) Equilibrium conversion as a function of temperature B) Optimum reaction rate curve C) Improvement of conversion by multiple beds with interstage cooling.

The desirable pH increment, ApH, can be decided on the basis of a function similar to that shown in Figure 5.5, which establishes for each soil how high the pH must be to eliminate A1 toxicity for a crop. Of course, the optimum pH varies for different crops because of plant-specific A1 tolerances and Ca requirements. The hme requirement of any soil can be calculated from the slope of the titration curve of that soil, as diagrammed in Figure 5.10. Conversely, the buffer capacity of the soil is the reciprocal of this slope that is, buffer capacity is the quantity of lime (alkali) added to the soil that achieves a unit change in pH. 

From the above discussion it can be concluded that the close approach to the maximum rate point on the rate dependence curve at the entrance of the reformer tube gives higher initial rate of reaction but at the same time gives faster approach to the positive order region where the order of reaction drops sharply. This means that there is always an optimum steam feed partial pressure that gives maximum reactor performance (expressed in terms of methane conversion) and this optimization problem is a result of the non-monotonic dependence of the rate of reaction upon steam partial pressure. 

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