A semi-detailed kinetic model of char combustion with consideration of thermal annealing

Senneca, Osvalda; Salatino, Piero

doi:10.1016/j.proci.2010.08.011

Cited by 29 publications

(14 citation statements)

References 40 publications

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“…It is however worth noting that the structural modifications are not solely responsible for the reac tivity change throughout the gasification. Other factors intervene, such as the char inner mineral species concentration and types [28 30,25,31], the thermal annealing phenomena occurring in par allel with the gasification reaction [32], and also the type of gasify ing media, as it has been demonstrated that the char contact with the steam drastically changes its structure into a more ordered one [33 35]. Owing to these observations and to the difficulties in determining the individual contribution of each of these parame ters on the gasification reactivity, we opted for a determination of an empirical formulation for the structural term FðXÞ which is assumed to encompass all the influencing parameters that cause the reactivity change along the gasification reaction.…”

Section: Methods Of Data Analysismentioning

confidence: 99%

The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2

Guizani

Sanz

Salvador

2013

Fuel

144

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. The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2. Fuel, Elsevier, 2013, 108, pp.812-823. 10.1016/j.fuel.2013 The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H 2 O and CO 2 C. Guizani ⇑ , F.J. Escudero Sanz, S. Salvador t r a c tGasification reactivity of high heating rate chars (HHR chars) in steam, carbon dioxide and their mix tures was investigated in a new macro TG experimental device. The higher reactivity of the HHR chars was highlighted by a comparison with reference chars prepared at a low heating rate (LHR chars). It was found that the char reactivity in a mixed atmosphere of steam and carbon dioxide can be expressed as the sum of the individual reactivities obtained in single atmosphere gasification experiments. This result was not dependent on the pyrolysis heating rate. In addition, gas alternation gasification experi ments for both HHR chars and LHR chars showed that gasifying the char with CO 2 up to 30% of con version does not affect its reactivity to H 2 O. Altogether, the results tend to indicate that the two reactant gases H 2 O and CO 2 react on separate active sites when mixed atmospheres are used, and that CO 2 does not affect the char structure to favor or inhibit the char H 2 O gasification reaction.

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Section: Methods Of Data Analysismentioning

confidence: 99%

The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2

Guizani

Sanz

Salvador

2013

Fuel

144

View full text Add to dashboard Cite

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“…It has been recently observed that the microstructural transformations associated with thermal annealing affect most severely the propensity of carbon to uptake oxygen and form oxygen complexes [16]. On this basis, in a recent kinetic model of char combustion and annealing, the hypothesis was made that the overall loss of reactivity associated with thermal annealing is primarily due to the decreased rate of oxygen chemisorption [17].…”

Section: The Conceptual Frame For Ashes Beneficiationmentioning

confidence: 99%

Beneficiation of coal fly ashes by oxygen chemisorption

Senneca

Salatino

Sorrenti³

2012

Experimental Thermal and Fluid Science

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“…Senneca and Salatino [8] also noted a similar effect based on calculations performed with the use of bituminous coal sample; in this case, as the diameter of particles was increased, thermal deactivation came into play at a lower temperature and at a smaller degree of conversion of the sample.…”

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confidence: 56%

Effect of the rate of pulverized coal preheating on char reactivity

et al. 2017

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Abstract-The effect of the preheating rate of the char particles from Kuznetsk bituminous coal on their specific reaction rate was determined. The experiments were carried out with char samples with mean diameters of 0.15 and 0.35 mm heated to temperatures of 900-1000°C. It was found that the specific surface area of the initial coal, measured by CO 2 adsorption at 273 K, for rapid and slow heat treatments increased more that two times. According to the results of thermogravimetric analysis, it was established that rapid pyrolysis in a muffle furnace led to the production of char whose maximum specific reaction rate was higher than that of the samples after slow pyrolysis. DOI: 10.3103/S0361521917010037The efficient and environmentally appropriate use of coals for the generation of thermal and electrical power and the production of metallurgical coke is a problem of considerable current interest. A possible solution of this problem is the development of scientific fundamentals for a solid fuel preparation technology, which will make it possible to considerably increase the quality of fuel due to its partial gasification. The preliminary thermal preparation of fuel is one of such technologies [1]. On the thermal preparation of fuel, its partial gasification occurs in the burner volume, and a highly reactive mixture, which consists of combustible gases and coal char as the products of gasification, is formed at the inlet of the combustion chamber. As found experimentally [2][3][4][5][6][7], the pyrolysis temperature, the heating rate, and the pressure at the zone where volatile matter release and burning have an effect on the char reactivity and lead to changes in its structure. High-rank coals remain less sensitive to such a thermal activation/deactivation.A pyrolysis temperature increase and a decrease of the coal heating rate led to a decrease in the chemical reaction activity of char with reactant gases [2][3][4][5]. Senneca and Salatino [8] also noted a similar effect based on calculations performed with the use of bituminous coal sample; in this case, as the diameter of particles was increased, thermal deactivation came into play at a lower temperature and at a smaller degree of conversion of the sample.Data on changes in the properties of coals upon heating [9], on the dynamics of volatile matter release upon thermal destruction [10], and on changes in the porous structure of char during combustion [11] are widely available in the publications of Russian researchers; however, it is difficult to combine them for an integrated consideration of the effects on reactivity. As a successful example, Maistrenko et al. [12] reported in 1990 the results of an integrated study for anthracite concerning the effect of pyrolysis temperature on the subsequent rate of conversion in an atmosphere of CO 2 and O 2 .From a practical point of view, coal from the Kuznetsk Basin is of considerable current interest for the development of promising technologies with an integrated gasification combined cycle [13]. The conditions o...

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A semi-detailed kinetic model of char combustion with consideration of thermal annealing

Cited by 29 publications

References 40 publications

The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2

The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2

Beneficiation of coal fly ashes by oxygen chemisorption

Effect of the rate of pulverized coal preheating on char reactivity

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