Category: COMPUTATIONS IN KINETICS

Determination of intrinsic kinetics forms an essential and important component of chemical engineering kinetics. Typically, such determinations are carried out by bench-scale batch experiments wherein the concentrations of species are monitored as a function of time and the concentration-time data are subjected to analysis. Example 9.2.1 illustrates such analysis conducted for the determination of rate expression. EXAMPLE…

The reactor analysis and design acquires another level of complexity when the reactor is operated under nonisothermal conditions; that is, the temperature of the reactor varies with time or position in the reactor, mostly due to the substantial heat effects associated with most reactions. As the temperature varies, the rate constant also changes according to…

The discussion in section 9.1.3 assumes that the rate expression is dependent only on the concentration of one reactant, reactant A. However, in general, the rate depends on the concentrations of several other species as well. The component balance in equation 9.1 (and its simplifications discussed earlier) can be written for each species involved in the reaction, yielding as…

A typical reactor design problem for batch reactors involves determination of the batch time needed for producing the specified quantity of the product. This batch time is obtained by separating the variables and integrating equation 9.4 as follows: Here, Ni0 are the initial moles of i. Many of the batch reactors operate under constant volume conditions; that is, the volume…

Some chemical reactions are conducted in a batchwise mode [6]: raw material is charged initially into the reactor and the reaction allowed to proceed until such a time that the desired quantity of product is obtained. This is an unsteady state process wherein the conditions within the reactor with respect to the number of moles…

The reaction rate for any species i is generally defined as the rate of change of quantity of i (commonly moles of i) per unit time per unit volume of the reactor. Typically, the reaction rate is a function of the concentration of the reacting species and temperature [2]. The mechanism of the reaction, or the exact pathway by which…

The essence of reactor design is obtaining economically optimum specifications for a reactor for a specified duty. For example, let us assume that the market demand for a certain chemical product (let us denote it by R) is 3000 tons per year. The specified duty then might be defined as a production rate of 10…