Kinetic Computer Programs

Ampaya, J.P. and Rinker, R.G. (1974) Kinetics Computer Programs for Chemical Engineeering Education, Ed. M.Reilly, Aztec Publ.Co. C.A.Ch.E. Comm. AIChE. 

BITTKER D.A., SCULLIN V.J., General chemical kinetics computer program for static and flow reactions, with application to combustion and shock-tube Idnetics, Lewis Research Center, NASA, Cleveland, Ohio (USA). 

Snow, R.M. A chemical kinetics computer program for homogeneous and free-radical systems of reactions. J. Phys. Chem. 70, 2780-2786 (1966)... 

Bittker, D. A. Scullin, V. J. (1972). General Chemical Kinetics Computer Program for Static and Flow Reactions with Application to Combustion and Shock Tube Kinetics, NASA TN-D 6586. Revised (1984) NASA TP-2320. 

Work continues on improving the efficiency of this process, such as for freeing the alkan olamine from heat-stable salts that can form (125). Formulations have been developed which inhibit degradation of mono- and diethanolamine in processing (126). Models (127), computer programs (128), and kinetics and enthalpies (129—136) have been developed to help determine equiUbria of the acid gas—alkanolamine—water system. Additional references relate to the use of tertiary alkan olamines, such as triethanolamine, for gas conditioning (137—139). 

When the kinetics are unknown, still-useful information can be obtained by finding equilibrium compositions at fixed temperature or adiabatically, or at some specified approach to the adiabatic temperature, say within 25°C (45°F) of it. Such calculations require only an input of the components of the feed and produc ts and their thermodynamic properties, not their stoichiometric relations, and are based on Gibbs energy minimization. Computer programs appear, for instance, in Smith and Missen Chemical Reaction Equilibrium Analysis Theory and Algorithms, Wiley, 1982), but the problem often is laborious enough to warrant use of one of the several available commercial services and their data banks. Several simpler cases with specified stoichiometries are solved by Walas Phase Equilibiia in Chemical Engineering, Butterworths, 1985). 

Using the same values of the kinetic parameters as in Type 1, and given C o = 0-1 mo 1/1, it is possible to solve Equation 6-155 with Equations 6-127 and 6-128 simultaneously to determine the fractional conversion X. A computer program was developed to determine the fractional conversion for different values of (-iz) and a temperature range of 260-500 K. Eigure 6-30 shows the reaction profile from the computer results. 

Nowadays one very often fits data by means of a least-squares computer program. (Indeed, in Chapter 2 some data-fitting applications will be considered.) It is important to examine the residuals from the fits, to confirm that, with time, they lie randomly about the zero line. Examining them makes it is much easier to spot discrepancies. If the kinetic data are acquired with a computer-controlled instrument, then the data are already contained in a file that can be read by the fitting program. 

A new chapter (5) on reaction intermediates develops a number of methods for trapping them and characterizing their reactivity. The use of kinetic probes is also presented. The same chapter presents the Runge-Kutta and Gear methods for simulating concentration-time profiles for complex reaction schemes. Numerical methods now assume greater importance, since useful computer programs are available. The treatment of pH profiles in Chapter 6 is much more detailed. 

Exercise 3.2. Write a computer program that solves Exercise 3.1 for any given time and evaluate the kinetic energy and potential energy as a function of time. 

Assume that this is the controlling resistance so that U=h. A kinetic model is needed for Rp and for the instantaneous values of and Iw The computer program in Appendix 13 includes values for physical properties and an expression for the polymerization kinetics. Cumulative values for the chain lengths are calculated as a function of position down the tube using... 

Perona, J. (1972) Computer Programs for Chemical Engineering Education Kinetics, Ed. M. Reilly, AIChE. 

On some occasions, the body does not behave as a single homogeneous compartment, and multicompartment pharmacokinetics are required to describe the time course of drug concentrations. In other instances certain pharmacokinetic processes may not obey first-order kinetics and saturable or nonlinear models may be required. Additionally, advanced pharmacokinetic analyses require the use of various computer programs, such as those listed on the website http //www.boomer.org/pkin/soft.html. 

A chemical reaction is a complex process. Besides thermodynamic factors, the process has two other distinct aspects kinetic and molecular mechanistic ones. With the development of modem technology, more and more complex kinetic schemes can be determined by using sufficient experimental information and fairly general computer programs [155]. In order to proceed, it is useful to define what we mean by a theoiy of chemical reactions in the first place. 

Kinetic simulation methods are used as advisory controls in potentially thermally hazardous batch amination reactions of nitroaromatic compounds. Time-temperature process data are fed as input to a kinetic simulation computer program which calculates conversions, heat release and pressure profiles. Results... 

Carlos and Latif both fluidised glass particles in dimethyl phthalate. Data on the movement of the tracer particle, in the form of spatial co-ordinates as a function of time, were used as direct input to a computer programmed to calculate vertical, radial, tangential and radial velocities of the particle as a function of location. When plotted as a histogram, the total velocity distribution was found to be of the same form as that predicted by the kinetic theory for the molecules in a gas. A typical result is shown in Figure 6.11(41 Effective diffusion or mixing coefficients for the particles were then calculated from the product of the mean velocity and mean free path of the particles, using the simple kinetic theory. 

Some of these programs, as well as many others, may be found and retrieved from the Internet by performing a search using keywords such as chemical kinetics computer codes or by visiting the homepage of various laboratories and universities, for example, the homepage of the National Institute of Standards and Technology (NIST). 

THERM Thermodynamic Property Estimation for Radicals and Molecules, Edward R. Ritter and Joseph Bozzelli, Int. J. Chem. Kinet. 23, 767-778, (1991). A computer program for IBM PC and compatibles for estimating, editing, and entering thermodynamic property data for gas-phase radicals and molecules using Benson s group additivity method. 

NIST Chemical Kinetics Database, Mallard, N. G Westley, F Herron, J. T Hampson, R. F. and Frizzell, D. H. NIST, NIST Standard Reference Data, Gaithersburg, MD, 1993. A computer program for IBM PC and compatibles for reviewing kinetic data by reactant, product, author, and citation searches and for comparing existing data with newly evaluated data. 

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