Mihaela-Ligia Unguresan

Pre-equilibrium kinetics. Modeling and simulation

AbstractMathematical modeling of pre-equilibrium reactions of the type:

Modeling and Simulation of the Gas Absorption Process in the Liquid Phase

A + B\underset{{k_{ - 1} }}{\overset{{k_1 }}{\longleftrightarrow}}X;X + X\xrightarrow{{k_2 }}P

Application of linear regression analysis for iron and copper removal process using natural zeolites

proceeds with the use differential rate laws for the forward and backward reactions of: intermediate formation, as well as for the decay of the intermediate, in which the differentials d, are approximated by finite differences Δ. Numerical simulation with several values of the forward and backward rate constants, k1 and k−1, respectively, the decay rate constant k2 of the intermediate, and initial concentrations of A (a0) and B (b0), shows the superposition domain of the kinetic curves resulting from simulation and pre-equilibrium kinetics with constant K of intermediate formation, i.e., the time lapse from which the pre-equilibrium supposition holds.

Modelling and numerical simulation examples of distributed parameters processes

In this paper, a variant for the pH control of the residual water from a foundry is presented. The blunting process of the residual water, being a distributed parameters one, is modeled using equations with partial derivatives. For the numerical simulation is used a method based on the matrix of the partial derivatives of the state vector (Mpdx) associated with Taylor series.

Cascade PID control of some processes with distributed parameters through the (Mpdx) method with approximating solutions

In this paper, a solution for the modeling and simulation of the gas absorption process in a liquid is presented. In the modeling procedure, the technological process is decomposed in two sub-processes connected in series, the first sub-process being considered a lumped parameter one, respectively the second sub-process being considered a distributed parameter one. In order to simulate, with a high accuracy, a process that includes in its structure a distributed parameter sub-process, an original method based on the matrix of partial derivatives of the state vector, associated with Taylor series, is used. The modeling-simulation procedure introduces the premise to approximate the concentration value of the gas absorbed in liquid, in relation to the initial pressure from the reactor, respectively the premise of including the technological process in a concentration control structure.

The Taylor series — Local iterative linearization method for numerical modeling and simulation of linear processes

In this paper, a solution for the automatic control of a residual water blunting system is proposed. The blunting technological process, being a distributed parameter one, is modeled us ...

Modeling and composition estimation of an isotopic distillation column

Natural zeolites (zeolitic volcanic tuffs) cropped out from three regions of Transilvania, Vultureni (V), Pâglişa (P) and Măcicaş (M), were evaluated in the process of iron (V, P, M) and copper (M) removal from wastewaters. Iron and copper removal process was studied using a fixed bed column, when equilibrium and kinetic data were acquired. Four isotherms, Langmuir, Freundlich, Langmuir–Freundlich and Redlich–Peterson, were used to fit the experimental data obtained for each natural zeolite sample. Parameters of the adsorption isotherms were estimated from the experimental equilibrium data using MATLAB. Using these data the best fit with one of the chosen isotherm can be found. Isotherm constants were determined by linear regression analysis of the experimental data. We concluded that the mathematical model based on Freundlich isotherm is the most appropriate to describe the iron and copper exchange on our natural zeolite samples.

Investigation of Copper(II) – Thiosulfate Reaction Kinetics

Abstract Continuing the papers (Abrudean et al ., 2007), (Colosi et al ., 2006), where the theoretical preliminaries of the definition and use of the M pdx matrix are presented, associated to the Taylor series, for the modelling and numerical simulation of some categories of processes with distributed parameters from power systems, thermoenergetic, electro-energetic, chemical and electromechanical processes, etc, this paper presents a number of four examples. The advantages, the limits and the disadvantages of the method applied to these examples are being underlined.