Behaviors and non-isothermal kinetics of Chlorella pyrenoidosa fodder pyrolysis by a modified kinetic compensation effects and a parallel two-step reaction model

Wang, Xiaoxuan; Wang, Yanxue; Guo, Jiaru; Zhao, Yuchao; Wang, Xun; Zhang, Xin; Chen, Zhihua

doi:10.1007/s13399-022-02723-7

Cited by 3 publications

(3 citation statements)

References 52 publications

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“…The software allows the kinetic study to be performed by using thermal analysis techniques, such as TG, DTG, and/or DSC. For established isoconversional methods, in order to estimate the pre-exponential factors as logA values (software has the ability to transform “ ln ” data into “ log ” scale data, where it normally operates), the actual software uses the kinetic compensation effect (KCE) model [ 31 ]. The reliability of the modeling using Kinetics Neo software relies on accurate and reproducible thermal analysis data, which enables the numerical optimization of the investigated process and represents the model-free method (being used FR results) using the non-linear least squares optimization.…”

Section: Methodsmentioning

confidence: 99%

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Janković,

Kojić,

Milošević

et al. 2023

Polymers

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Thermo-chemical conversion via the pyrolysis of cigarette butt (CB) filters was successfully valorized and upcycled in the pre-carbonization and carbonization stages. The pre-carbonization stage (devolatilization) of the precursor material (cellulose acetate filter, r-CAcF) was analyzed by micro-scale experiments under non-isothermal conditions using TG-DTG-DTA and DSC techniques. The results of a detailed kinetic study showed that the decomposition of r-CAcF takes place via complex mechanisms, including consecutive reaction steps and two single-step reactions. Consecutive stages include the α-transition referred to as a cellulose polymorphic transformation (cellulose I → II) through crystallization mechanism changes, where a more thermodynamically ordered system was obtained. It was found that the transformation rate of cellulose I → II (‘cellulose regeneration’) is strongly affected by the presence of alkali metals and the deacetylation process. Two single-step reactions showed significant overlapping behavior, which involves a nucleation-controlled scission mechanism (producing levoglucosan, gaseous products, and abundant radicals) and hydrolytic decomposition of cellulose by catalytic cleavage of glycosidic bonds with the presence of an acidic catalyst. A macro-scale experiment showed that the operating temperature and heating rate had the most notable effects on the total surface area of the manufactured carbon. A substantial degree of mesoporosity with a median pore radius of 3.1695 nm was identified. The presence of macroporosity on the carbon surface and acidic surface functional groups was observed.

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Section: Methodsmentioning

confidence: 99%

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Janković,

Kojić,

Milošević

et al. 2023

Polymers

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“…Así, Hotta & Koga (2024) lo aplican al estudio de la descomposición térmica reversible de CaCO3 en estado sólido, lo que les permite verificar que se cumple la compensación cinética y obtener los puntos isocinéticos. La pirolisis es una tecnología ampliamente utilizada para convertir la biomasa en biocombustibles en estado líquido o gaseoso (Jankovic et al, 2023;Wang et al, 2024), aunque en estos procesos se utilizan temperaturas sumamente superiores a las utilizadas en los procesos alimentarios convencionales. En el primero de estos dos últimos trabajos se examina la descomposición pirolítica de compuestos lignocelulósicos (Miscanthus gigantescus y Arundo donax L.), obteniendo que se cumple tanto la compensación cinética como termodinámica y pueden determinar que el alcance del efecto de la compensación depende de la composición de cada muestra; además, se pone de manifiesto que existe al menos tres tipos de mecanismos cinéticos.…”

Section: Compensación Cinética Y Termodinámicaunclassified

“…En el primero de estos dos últimos trabajos se examina la descomposición pirolítica de compuestos lignocelulósicos (Miscanthus gigantescus y Arundo donax L.), obteniendo que se cumple tanto la compensación cinética como termodinámica y pueden determinar que el alcance del efecto de la compensación depende de la composición de cada muestra; además, se pone de manifiesto que existe al menos tres tipos de mecanismos cinéticos. En el trabajo de Wang et al (2024) se estudia la pirólisis de la microalga Chlorella pyrenoidosa utilizando la compensación cinética para poder caracterizar de forma adecuada la cinética tan compleja de este proceso térmico. En el trabajo de Lyon (2023) se muestra que la compensación cinética se cumple para la descomposición térmica de poli (metil metacrilato), de peróxidos orgánicos de masa molecular elevada y carbonato cálcico.…”

Section: Compensación Cinética Y Termodinámicaunclassified

Compensación cinética y termodinámica del pardeamiento no enzimático de zumos clarificados de limón

Ibarz,

Garvín,

Tomasa

et al. 2024

Sci. agropecu.

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This paper presents a study on kinetic and thermodynamic compensation to evaluate the kinetics of non-enzymatic browning of clarified lemon juices. In a previous work, the kinetic constants of browning were presented using the evolution of the absorbance at 420 nm (A420) and luminosity (L*) for different soluble solids contents (64.6; 50; 35; 20 and 10 ºBrix) and different working temperatures (70, 80, 90 and 95 ºC). The parameters of the Arrhenius equation were obtained by fitting the kinetic constants and temperatures. The variation of lnK0 with Ea follows a linear trend, so there is kinetic compensation, with isokinetic temperature values being 126.6 ºC and 149.7 ºC for A420 and L*, respectively. The transition state equilibrium constants were determined using the Eyring equation for each soluble solids content and each temperature. The equilibrium constants were adjusted to the Van't Hoff equation and the set of pairs of estimated values for the activation enthalpy and the activation entropy also followed a straight line, which causes thermodynamic compensation, with isoequilibrium temperatures of 112.8 ºC and 136.3 ºC for A420 and L*, respectively. It was concluded that the browning mechanism is the same for the ranges of soluble solids content and temperature studied. Since all isokinetic and isoequilibrium temperatures were higher than the working temperature values, it was also concluded that the control was enthalpic for all cases. To avoid the deterioration of these juices, it is advisable to intervene in the working temperature, trying to ensure that the heat treatment is carried out at the lowest possible temperature.

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Kinetic compensation effects of non-isothermal gasification in the diffusion control region

Zhang,

Cui,

Sun

et al. 2023

Thermal Science and Engineering Progress

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Behaviors and non-isothermal kinetics of Chlorella pyrenoidosa fodder pyrolysis by a modified kinetic compensation effects and a parallel two-step reaction model

Cited by 3 publications

References 52 publications

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Compensación cinética y termodinámica del pardeamiento no enzimático de zumos clarificados de limón

Kinetic compensation effects of non-isothermal gasification in the diffusion control region

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