Kinetic and thermodynamic compensation phenomena in C3 and C4 energy crops pyrolysis: Implications on reaction mechanisms and product distributions

Janković, Bojan; Manić, Nebojša; Popović, Mina; Cvetković, Slobodan; Dželetović, Željko; Stojiljković, Dragoslava

doi:10.1016/j.indcrop.2023.116275

Cited by 6 publications

(3 citation statements)

References 108 publications

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“…On the other hand, the existence of weak compensation does not mean that there is no KCE; rather, it means that there is a variation in molecular ordering. This is related to a similar observation called enthalpy–entropy compensation [ 75 ], which associates the decrease in enthalpy (exothermic changes) with tauter bonding and consequently with less entropy (freedom of movement). In this context, the values of thermodynamic parameters (change of standard activation enthalpy, ΔH°, change of standard activation entropy, ΔS°, and change of standard Gibbs free energy, ΔG°) were calculated using Eyring equations [ 76 ] as follows:

where T max is the maximum decomposition temperature (K), k B is the Boltzmann constant (1.381 × 10 −23 J·K −1 ), and h is the Planck constant (6.626 × 10 −34 J·s −1 ).…”

Section: Resultsmentioning

confidence: 72%

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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where T max is the maximum decomposition temperature (K), k B is the Boltzmann constant (1.381 × 10 −23 J·K −1 ), and h is the Planck constant (6.626 × 10 −34 J·s −1 ).…”

Section: Resultsmentioning

confidence: 72%

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

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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“…Fertilizing with higher amounts of nitrogen fertilizers results in stronger and bigger plants. Like other non-food plants, A. dubia can produce a considerable amount of biomass without fertilizing, so fertilizing is only recommended, but not necessary [29].…”

Section: Biomass Yieldmentioning

confidence: 99%

Potential of Artemisia dubia Wall Biomass for Natural Crop Protection

Bakšinskaitė,

Tilvikiene,

Barčauskaitė

et al. 2023

Plants

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The Green Deal strategy has the very ambitious goal of transforming the European Union into the first climate-neutral continent by 2050. For the agricultural sector, one of the main challenges is to reduce the use of synthetic fertilizers and pesticides. Crop protection measures aim to maintain and ensure certain standards of yield and quality, which are generally achieved by the control of pests, diseases, and weeds. One of the possibilities to reduce the use of pesticides could be allelopathic plants, which are not only potential sources of allelochemicals but also renewable biomass sources. The aim of this study was to analyze the productivity of Artemisia dubia Wall and evaluate the allelopathic effects of biomass on crops and weeds. It was determined that the biomass productivity of A. dubia varied from 2 to 18 t ha−1, depending on how many times it is cut during the growing season and the fertilizer rate. A. dubia has allelopathic properties, which were verified using an aqueous extract and can completely suppress the germination of Taraxacum officinale seeds. Young plants harvested in the middle of summer were characterized by the highest number of phenolic compounds. This shows the strong allelopathic effect of A. dubia biomass on other plants.

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Kinetic and thermodynamic compensation phenomena in C3 and C4 energy crops pyrolysis: Implications on reaction mechanisms and product distributions

Cited by 6 publications

References 108 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

Potential of Artemisia dubia Wall Biomass for Natural Crop Protection

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