New approximate formula for the generalized temperature integral

Chen, Haixiang; Liu, Naian

doi:10.1002/aic.11775

Cited by 10 publications

(12 citation statements)

References 17 publications

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“…Modern TGA and DTG methods coupled with the application of infrared spectroscopy and differential calorimetry are widely used in almost all physical and technical branches of science [1][2][3][10][11][12][13][14], the substances ranged from food products, polymers and solid household wastes, biofuels and fossil fuels were analyzed with these methods. Such diversity caused the need for the development of perfect methods of processing and generalization of experimental data [3,5,11,[13][14][15]. Following [11,14], it is possible to provide the following classification of analysis methods (see Table 2).…”

Section: Data Analysis and Processingmentioning

confidence: 99%

Thermal destruction kinetics of coal and solid biomass mixtures

Dunayevska¹,

Zasiadko²,

Shchudlo³

2018

Ukr

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Introduction. The work deals with the research on the kinetics of constituent stages of the combustion process of biomass as an individual fuel and as blends with low reactive anthracite coal from the Donetsk Coal Basin. Materials and methods. The samples of biomass (including the wastes of agricultural and food industries) and Ukrainian from the coal Donetsk Basin were studied by means of nonisothermal TGA. Kinetic studies of the samples was carried out on the Paulik-Paulik-Erdei Q-1000 system derivatograph with the integrated complex of the synchronous data analysis of the STZ 449 Jupiter NETZSCH in the air atmosphere with the heating rate of 20 °C/min within the temperature interval 25-1000 °С. Results and discussion. Raw data were processed and generalized within differential and integral approaches. It has been shown that the differential method of data processing has to be used coupled with the determination of current normalized values of mass change rate derivative, which presents a serious difficulty. In this respect the integral approach looks more acceptable. Comparison of approximations has been presented. It has been shown that the Coats-Redfern approximation in a form of a series does not increase the approximation accuracy if an increased number of the series members is taken into account. The appropriate range of correlations has been determined by means of the parameter E/RT>4 which is valid for the dehumidification and devolatilization regions. For the processes of the coke burnout the correlation of Senum-Yang looks more appropriate. The obtained set of kinetic constants were used with the appropriate form of the Arrhenius type differential equation and the sample mass loss thermal histories were calculated. The deviation between calculated and experimental values of the sample mass loss does not exceed 10% within a whole temperature range 0-700 K. Conclusions. The methodology of the constituent stages distinguishing and obtained kinetic constants can be used in engineering calculations of the combustion constituent stages duration and fuel components balance as well as development of process sub models for 3-d simulations.

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Section: Data Analysis and Processingmentioning

confidence: 99%

Thermal destruction kinetics of coal and solid biomass mixtures

Dunayevska¹,

Zasiadko²,

Shchudlo³

2018

Ukr

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“…(2) leads to where “ x ” denotes E/RT , and p ( x ) is the famous temperature integral which has no analytical solution but has many approximations. [5–9] For brevity, all equations in this study are derived with a linear heating rate because it is a most commonly used approach, but an arbitrary heating program can be derived by replacing $\left( {1/\beta } \right)d\alpha /dt$ with $d\alpha /dT$ .…”

Section: Introductionmentioning

confidence: 99%

Comprehensive method based on model free method and IKP method for evaluating kinetic parameters of solid state reactions

Han

Saito

2012

J Comput Chem

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This article presents, firstly, a short review of methods for evaluating kinetic parameters of solid state reactions and a critical analysis of the isoconversional principle of model free methods. It shows theoretically that the activation energy for complex reactions is not only a function of the reaction degree but also of heating programs, and points out that any method that attempts to extract the dependences of activation energy on conversion degree without considering the dependences of heating programs is problematic. Then an analysis is given of the invariant kinetic parameters (IKP) method and recommends an incremental version of it. Based on the incremental IKP method and model free method, a comprehensive method is proposed that predicts the degree of the dependences of activation energy on heating programs, selects reliable values of activation energy and extracts the values of variable pre-exponential factor. This comprehensive method is tested using both simulation data and experimental data, the results of which show it can not only give reliable values of kinetic parameters but also be helpful in explaining inconsistencies of kinetic results in solid state reactions.

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“…Ìåòîäèêà îáðîáêè òà óçàãàëüíåííÿ äàíèõ. Ñó÷àñí³ òåðìîãðàâ³ìåò-ðè÷í³ (TGA) òà äåðèâàòîãðàìåòðè÷í³ ìåòîäè àíàë³çó ³ç çàñòîñóâàííÿì ³íôðà÷åðâîíî¿ ñïåêòðîñêîï³¿, äèôåðåíö³àëüíî¿ êàëîðèìåòð³¿ øèðîêî çàñòîñîâóþòüñÿ ïðàêòè÷íî â óñ³õ ô³çèêî-òåõí³÷íèõ ãàëóçÿõ íàóêè [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Çà äîïîìîãîþ öèõ ìåòîä³â àíàë³çóâàëèñÿ ðå÷îâèíè â³ä õàð÷îâèõ ïðîäóêò³â, ïîë³ìåð³â òà òâåðäèõ ïîáóòîâèõ â³äõîä³â, á³îïàëèâ ³ äî âèêîïíèõ ïàëèâ.…”

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“…Çà äîïîìîãîþ öèõ ìåòîä³â àíàë³çóâàëèñÿ ðå÷îâèíè â³ä õàð÷îâèõ ïðîäóêò³â, ïîë³ìåð³â òà òâåðäèõ ïîáóòîâèõ â³äõîä³â, á³îïàëèâ ³ äî âèêîïíèõ ïàëèâ. Òàêå ð³çíîìàí³òòÿ îáóìîâèëî íåîáõ³äí³ñòü ðîçðîáêè äîñêîíàëèõ ìåòîä³â îáðîáêè òà óçàãàëüíåííÿ åêñïåðèìåíòàëüíèõ äàíèõ [3,5,9,[11][12][13]. Çà ðåçóëüòàòàìè ðîá³ò [9,12] Äî ïåðåâàã íå³çîòåðì³÷íîãî ìåòîäó ñë³ä â³äíåñòè òå, ùî âèêîðèñòàííÿ äàíèõ îäíîãî íå³çîòåðì³÷íîãî ÒGA åêñïåðèìåíòó äëÿ ðîçðàõóíêó ê³íåòè÷íèõ êîíñòàíò ïðîöåñó, ÿêèé ñóïðîâîäaeóºòüñÿ çì³íîþ ìàñè, çàì³íþº îòðèìàííÿ òà îáðîáêó ñåð³¿ ³çîòåðì³÷íèõ êðèâèõ.…”

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“…Ð³âíÿííÿ (8) ³ (9) äàþòü çìîãó âèçíà÷àòè ê³íåòè÷í³ õàðàêòåðèñòèêè çà ðåçóëüòàòàìè ÒGA åêñïåðèìåíò³â, âèêîðèñòîâóþ÷è âèêëþ÷íî ïîòî÷í³ äà-í³ ç ãðàâ³òîãðàì ³ íå çâåðòàþ÷èñü äî óñêëàäíåíîãî âèçíà÷åííÿ ïîõ³äíèõ çì³íè ìàñè ó ÷àñ³. Îñòàíí³ì ÷àñîì ç'ÿâèëèñÿ ñï³ââ³äíîøåííÿ, ÿê³ àïðîêñèìóþòü òåìïåðàòóðíèé ³íòåãðàë Àððåí³óñà çà äîïîìîãîþ äð³áíî-ðàö³îíàëüíèõ âèðàç³â òà ïîë³íîì³â [6,11,13]. Ó [13] áóëî çàïðîïîíîâàíî íîâó àïðîêñèìàö³þ äëÿ òåìïåðàòóðíîãî ³íòåãðàëó ó ð³âíÿíí³ (6), ÿêà âèäàºòüñÿ á³ëüø âäàëîþ, îñê³ëüêè çàáåçïå÷óº íàéêðàùó àïðîêñèìàö³þ íèçêè äîñë³äíèõ äàíèõ ïîïðè á³ëüøó ñêëàäí³ñòü: àáî ³íøèõ àïðîêñèìàö³éíèõ çàëåaeíîñòåé â³ä1/ T ÿê³ ÿâëÿþòü ñîáîþ ïðÿìó ç êóòîì íàõèëó E R / , òà äîäàíêîì, ÿêèé ó ò³é ÷è ³íø³é ôîðì³ â³äòâîðþº ïåðåäåêñïîíåíö³àëüíèé ìíîaeíèê A.…”

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