Reactants kinetics

The rate of a chemical reaction is influenced by pressure, temperature, concentration of reactants, kinetic factors such as agitation, and the presence of a catalyst. Since the viability of a plant depends not only on reaction efficiencies but also on the capital cost factor and the cost of maintenance, it may be more economic to alter a process variable in order that a less expensive material of construction can be used. The flexibility which the process designer has in this respect depends on how sensitive the reaction efficiency is to a change in the variable of concern to the materials engineer. 

Reactant Kinetic characteristics Temperature range (K) E (kj mole-1 Ref. l)... 

The viability of one particular use of a membrane reactor for partial oxidation reactions has been studied through mathematical modeling. The partial oxidation of methane has been used as a model selective oxidation reaction, where the intermediate product is much more reactive than the reactant. Kinetic data for V205/Si02 catalysts for methane partial oxidation are available in the literature and have been used in the modeling. Values have been selected for the other key parameters which appear in the dimensionless form of the reactor design equations based upon the physical properties of commercially available membrane materials. This parametric study has identified which parameters are most important, and what the values of these parameters must be to realize a performance enhancement over a plug-flow reactor. 

Figure 24. Apparent cross sections for collisional dissociation reaction, N2+(N2 N2,N)N+, as function of reactant kinetic energy. Both laboratory (lab) and center-of-mass (CM) energy scales are shown. Energies of ionizing electrons producing N2+ in each case are indicated. Arrows indicate upper limits on cross section for reaction when is produced by 19.2-eV electrons.36 ...

Pressure can affect the operation of a fuel cell in several ways, such as in its thermodynamic performance, transport of reactants, kinetics of reactants, etc. Here, only the more prominent pressure benefit to the fuel cell resulting from the Nemst potential will be considered. The Nemst potential is given by ... 

The absence of a reactant kinetic isotope effect indicates that C-H bond breaking is not part of the rate determining event. 

The derivation of the Michaelis-Menten equation in the previous section differs from the standard treatment of the subject found in most textbooks in that the quasi-steady approximation is justified based on the argument that the catalytic cycle kinetics is rapid compared to the overall biochemical reactant kinetics. In... 

The reaction of borane with keten forms a single addition product BC2H5O (bimolecular rate constant of formation =4 x 10 1 mol s at low partial pressures of reactants). Kinetic and mass-spectrometric data are consistent with the formulation (64). 

Bukhavtsova, N.M. and Ostrovskii, NAi., Kinetics of catalyst poisoning during capillary condensation of reactants, Kinet. Catal., 43, 81—88, 2002. 

B. A reaction sequence such as (N) is occurring, but /c2 first increases and then decreases with increasing reactant kinetic energy, k is not expected to be affected by increasing the kinetic energy of 4. ) Alternatively, the first step in the reaction sequence could be slightly endothermic, but proceeds because some of the A ions are internally excited. As the kinetic... 

Again, the same explanations as used for curve 5 hold here, but the rate constant increases first and then decreases with increasing reactant kinetic energy. It is also possible that ions are being lost to the cell walls in the source at the highest kinetic energy, accounting for the decrease as the resonant frequency is approached. 

Fig. 2.21 Derivation of the equation for the source reactant kinetic curve...

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