Dynamic evaluation of heat flow reaction calorimeters under reflux conditions

R. Nomen; J. Sempere; R. L. Cunha

doi:10.1016/S0040-6031(96)03050-X

Dynamic evaluation of heat flow reaction calorimeters under reflux conditions

R. Nomen, J. Sempere, R. L. Cunha

Chemical Engineering and Materials Science Department

Research output: Indexed journal article › Article › peer-review

2 Citations (Scopus)

Abstract

An alternative method to obtain the product of the overall heat transfer coefficient by the transfer area (U·A) in heat flow reaction calorimetry under reflux conditions is exposed. The new method uses the dynamics of the system during non-steady states to obtain U·A and the effective value of the heat capacity flow (ṁ_c·c_Pc) of the cooling fluid in the condenser. The validation of this method, its statistical evaluation and its limitations are extensively treated using pure solvents and water at their boiling point. The dynamic method gives excellent estimates of U·A, being less dependent on stirring speed and geometry of the reactor cover than the pseudo-dynamic method. The probability of obtaining an error smaller than 10% is higher than 95%, except for small volumes and very high stirring speeds.

Original language	English
Pages (from-to)	311-325
Number of pages	15
Journal	Thermochimica Acta
Volume	289
Issue number	2
DOIs	https://doi.org/10.1016/S0040-6031(96)03050-X
Publication status	Published - 1 Dec 1996

Keywords

Dynamics
Heat flow reaction calorimetry
Overall heat transfer coefficient
Reflux

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10.1016/S0040-6031(96)03050-X

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title = "Dynamic evaluation of heat flow reaction calorimeters under reflux conditions",

abstract = "An alternative method to obtain the product of the overall heat transfer coefficient by the transfer area (U·A) in heat flow reaction calorimetry under reflux conditions is exposed. The new method uses the dynamics of the system during non-steady states to obtain U·A and the effective value of the heat capacity flow (ṁc·cPc) of the cooling fluid in the condenser. The validation of this method, its statistical evaluation and its limitations are extensively treated using pure solvents and water at their boiling point. The dynamic method gives excellent estimates of U·A, being less dependent on stirring speed and geometry of the reactor cover than the pseudo-dynamic method. The probability of obtaining an error smaller than 10% is higher than 95%, except for small volumes and very high stirring speeds.",

keywords = "Dynamics, Heat flow reaction calorimetry, Overall heat transfer coefficient, Reflux",

author = "R. Nomen and J. Sempere and Cunha, {R. L.}",

note = "Funding Information: One of the authors (R.L.C.) is grateful to the Conselho Nacional de Pesquisa e Desenvolvimiento (CNPq-Brasilia-Brazil) for a fellowship.",

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AU - Nomen, R.

AU - Sempere, J.

AU - Cunha, R. L.

N1 - Funding Information: One of the authors (R.L.C.) is grateful to the Conselho Nacional de Pesquisa e Desenvolvimiento (CNPq-Brasilia-Brazil) for a fellowship.

PY - 1996/12/1

Y1 - 1996/12/1

N2 - An alternative method to obtain the product of the overall heat transfer coefficient by the transfer area (U·A) in heat flow reaction calorimetry under reflux conditions is exposed. The new method uses the dynamics of the system during non-steady states to obtain U·A and the effective value of the heat capacity flow (ṁc·cPc) of the cooling fluid in the condenser. The validation of this method, its statistical evaluation and its limitations are extensively treated using pure solvents and water at their boiling point. The dynamic method gives excellent estimates of U·A, being less dependent on stirring speed and geometry of the reactor cover than the pseudo-dynamic method. The probability of obtaining an error smaller than 10% is higher than 95%, except for small volumes and very high stirring speeds.

AB - An alternative method to obtain the product of the overall heat transfer coefficient by the transfer area (U·A) in heat flow reaction calorimetry under reflux conditions is exposed. The new method uses the dynamics of the system during non-steady states to obtain U·A and the effective value of the heat capacity flow (ṁc·cPc) of the cooling fluid in the condenser. The validation of this method, its statistical evaluation and its limitations are extensively treated using pure solvents and water at their boiling point. The dynamic method gives excellent estimates of U·A, being less dependent on stirring speed and geometry of the reactor cover than the pseudo-dynamic method. The probability of obtaining an error smaller than 10% is higher than 95%, except for small volumes and very high stirring speeds.

KW - Dynamics

KW - Heat flow reaction calorimetry

KW - Overall heat transfer coefficient

KW - Reflux

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JO - Thermochimica Acta

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ER -

Dynamic evaluation of heat flow reaction calorimeters under reflux conditions

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Keywords

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