scholarly journals DYNAMICS OF COOPERATIVE REACTIONS BASED ON CHEMICAL KINETICS WITH REACTION SPEED: A COMPARATIVE ANALYSIS WITH SINGULAR AND NONSINGULAR KERNELS

Fractals ◽  
2021 ◽  
Author(s):  
ZUBAIR AHMAD ◽  
FARHAD ALI ◽  
AISHA M. ALQAHTANI ◽  
NAVEED KHAN ◽  
ILYAS KHAN
Keyword(s):  
Chemical Kinetics ◽  
Reaction Rate ◽  
Opposite Effect ◽  
Classical Model ◽  
Chemical Processes ◽  
Systems Dynamics ◽  
Fractional Operators ◽  
Nonlinear Odes ◽  
Fractional Models ◽  
Reaction Speed

Chemical processes are constantly occurring in all existing creatures, and most of them contain proteins that are enzymes and perform as catalysts. To understand the dynamics of such phenomena, mathematical modeling is a powerful tool of study. This study is carried out for the dynamics of cooperative phenomenon based on chemical kinetics. Observations indicate that fractional models are more practical to describe complex systems’ dynamics, such as recording the memory in partial and full domains of particular operations. Therefore, this model is modeled in terms of classical-order-coupled nonlinear ODEs. Then the classical model is generalized with two different fractional operators of Caputo and Atangana–Baleanu in a Caputo sense. Some fundamental theoretical analysis for both the fractional models is also made. Reaction speeds for the extreme cases of positive/negative and no cooperation are also calculated. The graphical solutions are achieved via numerical schemes, and the simulations for both the models are carried out through the computational software MATLAB. It is observed that both the fractional models of Caputo and Atangana–Baleanu give identical results for integer order, i.e. [Formula: see text]. By decreasing the fractional parameters, the concentration profile of the substrate [Formula: see text] takes more time to vanish. Moreover, binding of first substrate increases the reaction rate at another binding site in the case of extreme positive cooperation, while the opposite effect is noticed for the case of negative cooperativity. Furthermore, the effects of other parameters on concentration profiles of different species are shown graphically and discussed physically.

Chemical kinetics: The effect of surface area on reaction rate

1978 ◽  
Vol 55 (1) ◽  
pp. 34
Author(s):  
Mark S. Felice ◽  
Mark B. Freilich
Keyword(s):  
Surface Area ◽  
Chemical Kinetics ◽  
Reaction Rate ◽  
Effect Of Surface

scholarly journals Electrical Model for Analyzing Chemical Kinetics, Lasing and Bio-Chemical Processes

Processes ◽  
2013 ◽  
Vol 1 (1) ◽  
pp. 12-29 ◽  
Author(s):  
Asaf Shahmoon ◽  
Zeev Zalevsky
Keyword(s):  
Chemical Kinetics ◽  
Chemical Processes ◽  
Electrical Model

scholarly journals Fast pyrolysis of biomass: A review of relevant aspects. Part I: Parametric study

DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 239-248 ◽  
Author(s):  
Jorge Ivan Montoya Arbeláez ◽  
Farid Chejne Janna ◽  
Manuel Garcia-Pérez
Keyword(s):  
Reaction Rate ◽  
Fast Pyrolysis ◽  
Chemical Processes ◽  
Biomass Pyrolysis ◽  
Promising Alternative ◽  
Strongly Coupled ◽  
Thermochemical Processes ◽  
Energy And Momentum ◽  
Pyrolysis Of Biomass ◽  
Physical And Chemical

Recent years have witnessed a growing interest in developing biofuels from biomass by thermochemical processes like fast pyrolysis as a promising alternative to supply ever-growing energy consumption. However, the fast pyrolysis process is complex, involving changes in phase, mass, energy, and momentum transport phenomena which are all strongly coupled with the reaction rate. Despite many studies in the area, there is no agreement in the literature regarding the reaction mechanisms. Furthermore, no detailed universally applicable phenomenological models have been proposed to describe the main physical and chemical processes occurring within a particle of biomass. This has led to difficulties in reactor design and pilot industrial scale operation, stunting the popularization of the technology. This paper reviews relevant topics to help researchers gain a better understanding of how to address the modeling of biomass pyrolysis.

scholarly journals The specifics of mathematical modeling complex multicomponent chemical processes

2021 ◽  
Vol 1 (1) ◽  
pp. 37-52
Author(s):  
Naum Samoilov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Rate Constant ◽  
Diesel Fuel ◽  
Reaction Rate ◽  
Kinetic Coefficient ◽  
Raw Materials ◽  
Reaction Rate Constant ◽  
Chemical Processes ◽  
Raw Material ◽  
Reaction Unit

A critical analysis of the problem of identifying raw materials for hydrotreating diesel fuel by organosulphuric components and quantifying the value of the rate constant of the hydrodesulphurization reaction is presented. It is proposed to describe the raw material as a set of narrow fractions, in each of which the content of various organosulphuric components is considered as a single pseudo-component. The prospects of separate hydrotreatment of diesel fuel pre - fractionated into wide easily and hardly hydrogenated fractions are confirmed, which allows reducing the loading of the catalyst into the reaction unit of the plant by 1.4-1.7 times compared to the traditional process scheme.. It is proposed to use the concept of kinetic coefficient for mathematical modeling of the hydrotreating process instead of the incorrect reaction rate constant in this case. The dependence of the gross conversion rate constant of the raw material on the time of fixing the depth of its hydrodesulfurization is proved by the example of modeling the hydrotreatment of diesel fuel for a number of raw material variants.

scholarly journals Conformable Laplace Transform of Fractional Differential Equations

Axioms ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 55 ◽  
Author(s):  
Fernando Silva ◽  
Davidson Moreira ◽  
Marcelo Moret
Keyword(s):  
Differential Equations ◽  
Laplace Transform ◽  
Fractional Differential Equations ◽  
Classical Model ◽  
Transform Method ◽  
Fractional Models ◽  
Constant Coefficients ◽  
Fractional Differential ◽  
Linear Differential ◽  
Fractional Orders

In this paper, we use the conformable fractional derivative to discuss some fractional linear differential equations with constant coefficients. By applying some similar arguments to the theory of ordinary differential equations, we establish a sufficient condition to guarantee the reliability of solving constant coefficient fractional differential equations by the conformable Laplace transform method. Finally, the analytical solution for a class of fractional models associated with the logistic model, the von Foerster model and the Bertalanffy model is presented graphically for various fractional orders. The solution of the corresponding classical model is recovered as a particular case.

Thermodynamics and foundations of mass-action kinetics

2005 ◽  
Vol 30 (1-2) ◽  
pp. 3-113 ◽  
Author(s):  
Miloslav Pekař
Keyword(s):  
Chemical Kinetics ◽  
Reaction Rate ◽  
Chemical Potential ◽  
Kinetic Equations ◽  
Reaction Rates ◽  
Equilibrium States ◽  
Mass Action ◽  
Rate Equations ◽  
Mass Action Kinetics ◽  
Non Equilibrium

A critical overview is given of phenomenological thermodynamic approaches to reaction rate equations of the type based on the law of mass-action. The review covers treatments based on classical equilibrium and irreversible (linear) thermodynamics, extended irreversible, rational and continuum thermodynamics. Special attention is devoted to affinity, the applications of activities in chemical kinetics and the importance of chemical potential. The review shows that chemical kinetics survives as the touchstone of these various thermody-namic theories. The traditional mass-action law is neither demonstrated nor proved and very often is only introduced post hoc into the framework of a particular thermodynamic theory, except for the case of rational thermodynamics. Most published “thermodynamic'’ kinetic equations are too complicated to find application in practical kinetics and have merely theoretical value. Solely rational thermodynamics can provide, in the specific case of a fluid reacting mixture, tractable rate equations which directly propose a possible reaction mechanism consistent with mass conservation and thermodynamics. It further shows that affinity alone cannot determine the reaction rate and should be supplemented by a quantity provisionally called constitutive affinity. Future research should focus on reaction rates in non-isotropic or non-homogeneous mixtures, the applicability of traditional (equilibrium) expressions relating chemical potential to activity in non-equilibrium states, and on using activities and activity coefficients determined under equilibrium in non-equilibrium states.

A Study Numerical Simulation of Post Combustion CO2 Capture Process

2009 ◽  
Author(s):  
Rosa-Hilda Chavez ◽  
Javier de J. Guadarrama ◽  
Abel Hernandez-Guerrero
Keyword(s):  
Co2 Capture ◽  
Flue Gas ◽  
Reaction Rate ◽  
Operating Cost ◽  
Chemical Processes ◽  
Operating Conditions ◽  
Fast Reaction ◽  
Capture Process ◽  
Amine Absorption ◽  
Fast Reaction Rate

Amine absorption technology, in particular that based on the Monoethanolamine (MEA) process, is considered to be viable for low pressure flue gas CO2 capture because of the MEA-CO2 fast reaction rate. MEA absorption processes are associated with high capital and operating cost because a significant amount of energy is required for solvent regeneration and severe operating problems are present such as corrosion and solvent loss and degradation. The overall objective of this study is to evaluate the feasibility of obtaining the heat required for amine absorption for a particular recovery of carbon dioxide. Comparisons among cases were performed to determine the best operating conditions for CO2 capture. An analysis of the lean loading and recovery percent were carried out as well as the different absorber and stripper combinations by using the chemical processes simulator.

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