Study of Distributed Activation Energy Model Using Various Probability Distribution Functions for the Isothermal Pyrolysis Problem

Dhaundiyal, Alok; Singh, Sukhwinder

doi:10.17794/rgn.2017.4.1

Cited by 7 publications

(6 citation statements)

References 10 publications

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“…Kinetic models presume a series of decompositions, for n th order reactions. By contrast, the distributed activation energy model (DAEM) describes the pyrolysis reaction itself, and postulates that many decomposition, n th order reactions occur simultaneously, with distributed activation energies [148]. There are also double exponential terms which can be used to describe the distributed activation energy model for isothermal pyrolysis.…”

Section: Adsorption and Kinetics Mechanismmentioning

confidence: 99%

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

et al. 2019

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The choice of activating agent for the thermochemical production of high-grade activated carbon (AC) from agricultural residues and wastes, such as feedstock, requires innovative methods. Overcoming energy losses, and using the best techniques to minimise secondary contamination and improve adsorptivity, are critical. Here, we review the importance and influence of activating agents on agricultural waste: how they react and compare conventional and microwave processes. In particular, adsorbent pore characteristics, surface chemistry interactions and production modes were compared with traditional methods. It was concluded that there are no best activating agents; rather, each agent reacts uniquely with a precursor, and the optimum choice depends on the target adsorbent. Natural chemicals can also be as effective as inorganic activating agents, and offer the advantages that they are usually safe, and readily available. The use of a microwave, as an innovative pyrolysis approach, can enhance the activation process within a duration of 1–4 h and temperature of 500–1200 °C, after which the yield and efficiency decline rapidly due to molecular breakdown. This study also examines the biomass milling process requirements; the influence of the dielectric properties, along with the effect of washing; and experimental setup challenges. The microwave setup system, biomass feed rate, product delivery, inert gas flow rate, reactor design and recovery lines are all important factors in the microwave activation process, and contribute to the overall efficiency of AC preparation. However, a major issue is a lack of large-scale industrial demonstration units for microwave technology.

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Section: Adsorption and Kinetics Mechanismmentioning

confidence: 99%

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

et al. 2019

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“…Thus, the model must be robust enough to explain the transition states that depend on the residence time of volatile. Although the release of volatile content changes if heating rate varies from ramping to constant temperature cases, so there is no appreciable variation encountered in the amount of released volatile until the two parts of the DAEM integral overlap completely [3]. DExp as well as distribution together must be varied with time and temperature.…”

Section: Characteristic Of Distribution Functionmentioning

confidence: 99%

“…The problem arises when the dynamical behavior of inflexion point of thermogravimetric (TG) variation of mass curve impedes the predicted stochastic modeling of activation energies to converge around the neighboring point of it. Many methodologies [1][2][3][4][5][6][7] have been adopted to fetch the best suitable prediction that can converge up to 90% of the measurand value.…”

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confidence: 99%

“…The purpose of study is solely based on the application perspective of transmuted function, reducing the variation gap between Arrhenius parameters, and proposing the new concept for modeling activation energies, not to over-fitting of curves. Therefore, a new scheme has been proposed where the kinetic parameters are not influenced by the inflexion point of two different reaction phases, which is overlooked in the previous studies [1,3,14].…”

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5 Distributed Activation Energy Modeling by the transmutation of different density functions

Dhaundiyal¹,

Singh²

2020

Soft Computing

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This chapter incorporates the different perspective of modeling of activation energies through ingression of an additional parameter of distribution function to increase the flexibility and controlling ability of modeling by the linear mixing. The transmuted functions are adopted to bring flexibility in the numerical solution of multireaction models. A stochastic model is used to represent the activation energy function. Thus, the different activation energies can be represented by a density function to describe the pyrolysis process. The qualitative, as well as quantitative effects of the transmuted family of distribution on biomass pyrolysis, are carefully examined by the proposed mathematical solution. The nonlinear thermal history is implemented to demonstrate the approach.

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“…The Weibull distribution has some interesting properties and generates a variety of distributions [11]. For λ =1, the Weibull distribution coincides with the exponential distribution.…”

Section: Model-based Approachmentioning

confidence: 99%

Fuzzification of the Distributed Activation Energy Model Using the Fuzzy Weibull Distribution

Dhaundiyal

Suraj²

2018

J. nat. resourc. dev.

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This study focuses on the influence of some of the relevant parameters of biomass pyrolysis on a fuzzified solution of the Distributed Activation Energy Model (DAEM) due to randomness and inaccuracy of data. The study investigates the fuzzified Distributed Activation Energy Model using the fuzzy Weibull distribution. The activation energy, frequency factor, and distribution variables of the 3-parameter Weibull analysis are converted into a non-crisp set. The expression for the fuzzy sets, and their α-cut are discussed with an initial distribution for the activation energies following the Weibull distribution function. The thermo-analytical data for pine needles is used to illustrate the methodology to exhibit the fuzziness of some of the parameters relevant to biomass pyrolysis. Research article Many engineering systems that need to be controlled or simply are analyzed by the introduction of an indefinite value for parameters in a prototype. For a concrete mathematical problem, it is necessary to tackle any anomaly in the given data. The basis of incompatibility reveals that our faculty for envisaging some precise and relevant axioms becomes misleading while the critical level of the compounded complexity of the system is not reached, and, proceeding further, the precision and significance do not co-exist [1]. The ramifications of fallacy in a deterministic model is of the least importance. The conundrum of this state is whether substituting the rigid imprecise

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Study of Distributed Activation Energy Model Using Various Probability Distribution Functions for the Isothermal Pyrolysis Problem

Cited by 7 publications

References 10 publications

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

5 Distributed Activation Energy Modeling by the transmutation of different density functions

Fuzzification of the Distributed Activation Energy Model Using the Fuzzy Weibull Distribution

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